Anatomy Cerebrospinal Fluid



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Sarcoidosis


  • General

    • Disease of granulomatous tubercles most frequently in mediastinal and peripheral lymph nodes, lungs, liver, skin, phalangeal bones, eyes, muscle, and parotid glands

    • 5% of cases have neurosarcoidosis

    • In 50% of neurosarcoidosis cases, presentation with neurologic symptoms precedes systemic symptoms

  • Presentation

    • Granulomas of peripheral/cranial nerves lead to mononeuropathies (mutiple= mononeuropathy multiplex. Can be distinguished from other forms of MM by large, irregular zones of sensory loss over the trunk). The facial nerve is the most frequently involved cranial nerve (see facial nerve anatomy to localize lesion along the course of the nerve. Hyperacusis indicates that a lesion is proximal to the stylomastoid foramen).

    • CNS sarcoidosis is rare and consists of granulomatous infiltration of the meninges and underlying parenchyma, mostly at the base of the brain. These can affect cranial nerves (including the optic nerve) and the hypothalamus/pituitary system (causing endocrine dysfunction). Other complications include seizure, hydrocephalus, corticospinal tract dysfunction, or cerebellar involvement. In the spine, involvement of the meninges and spinal cord can mimic arachnoiditis or inflammatory myelopathy

  • Differential Diagnosis

    • Entities causing subacute/chronic deficits that may be multifocal

    • SLE, MS, lymphoma, fungal infections (can cause basilar meningitis), Sjogren syndrome, toxoplasmosis, TB, syphilis, metastatic disease

  • Diagnosis

    • Systemic involvement such as lymph nodes (especially bilateral hilar lymphadenopathy), skin, liver, ling lesions.

    • Mantoux test (skin injection for tuberculosis) causes non-caseating granuloma in 2/3 of patients

    • Serum and CSF ACE elevations

    • Biopsy

  • Imaging

    • MRI may demonstrate a thickened infundibular stalk, focal hypothalamic mass, or diffuse basilar leptomeningeal thickning. These findings are non-specific (other entities in differential diagnosis may have similar findings)

  • Pathology

    • Grossly, thickened and yellowed leptomeninges are seen over the base of the brain, particularly around the infundibular stalk and optic chiasm, or spinal cord. Grey, gelatinous deposits maybe present in the walls of the ventricles and the choroids plexus (may be associated with obstructive hydrocephalus)

    • Microscopically consist of non-caseating granulomas that may have fibrotic or (rarely) necrotic centers. These may be associated with an inflammatory infiltrate. Small veins and arteries may be incorporated into the granulomas. Other granulomatous diseases include TB, fungal infection (Coccidiomycosis (Southwest U.S. and Latin America), Histoplasmosis, Cryptococcosis). These are best diagnosed by the identification of the specific organism within the lesion. Non-infectious granulomas may be caused by Wegner’s disease (has prominent necrotizing vasculitis), idiopathic hypertrophic pachymeningitis (causes extensive fibrosis with less prominent granulomatous infiltration, no deep parenchymal or systemic involvement), or isolated CNS angiitis (different clinical presentation, granulomatous infiltration restricted to blood vessels)

  • Treatment/Prognosis

    • Corticosteroids, especially for recent onset of symptoms (indicates active disease) or disabling syndrome such as myelopathy

    • Cyclosporine for patients who cannot tolerate steroids (other immunosuppressants do not work)

    • 50% of cases remit spontaneously


TORCH organisms

  • maternal infection leads to congenital malformations

  • may be acquired transplacental, partruitionally, or by ascending infection (bacteria)

  • manifest as 1) Malformations (from abnormal neuronal migration); 2) Destruction (so-called encephaloclastic); 3) Calcifications

  • Mneumonic

    • To – Toxoplasma

    • R – Rubella

    • C – CMV

    • H – Herpes, HIV

    • E – Enteroviruses

    • S – Syphilis

  • Toxoplasma gondii – an INTRAcellular protozoan acquired via cat feces or infected meat

    • TRANSPLACENTAL infection

    • has a high rate of conversion from fetal infx to symptomatic disease

    • causes CNS necrosis

    • Brain atrophy, microcephaly, hydranencephaly, calcifications in basal ganglia, and periventricular

    • Path show granulomas, eosinophils (think parasites), sometimes organisms.

    • Early (< 26 week) fetal period = highest risk of developing problems

    • Babies present w/ seizures, small heads, and chorioretinitis (eye infections)

    • Calcifications may occur anywhere but mostly in basal ganglia and cortex

    • Hydrocephalus results from aqueductal scarring and subsequent stenosis -> non communicating hydrocephalus

    • TRIAD = calcifications + bilateral chorioretinitis + hydrocephalus

  • Rubella – togavirus, ss RNA virus, causes “German measles” acquired via inhalation

    • baby gets infected via TRANSPLACENTAL route

    • most severe during first 8-12 weeks’ of gestation. Few effects seen if infected in 3rd trimester

    • affects dividing cells in the GERMINAL MATRIX (periventricular region)

    • loss of dividing neurons leads to small brain, and oligodendroglia loss leads to less myelination, copious calcifications seen

    • causes meningitis, vasculitis, lack of myelination and encephalitis

    • path shows inflammatory cells in meninges, and perivascular spaces w/ necrosis

    • clinically manifests as abortive fetus, still birth, and the following findings if the baby lives:

      • cataracts and other eye abnormalities

      • deafness

      • bone marrow suppression

      • heart malformations

    • US shows subependymal cysts (not specific)

    • CT shows widespread calcifications

    • MRI show perivascular lesions and brain loss

  • CMV – cytomegalovirus, member of herpes family, DNA genome, human reservoir

    • TRANSPLACENTAL infection

    • Affects during 1st and 2nd trimesters

    • Causes porencephaly, microcephaly

    • Path shows NUCLEAR + CYTOPLASMIC inclusions, microglial nodules

    • 40% of babies of those who are seropositive are also infected

    • most common cause of TORCH infections (toxo is #2)

    • most common clinical manifestation is neurological

    • neuronal migration abnormalities, necrosis and calcification

    • Diagnosed by a positive culture, seropositivity for IgM, and path showing inclusions

    • CT shows atrophy, ventriculomegaly, and periventricular calcification

    • MRI shows heterotopias, prominent sulci, delayed myelination and cysts

    • Clinically babies are premature w/ hepatosplenomegaly, jaundice, chorioretinitis…later babies have seizures, retardation, hearing loss and hydrocephalus

    • ?active infection?? Treat w/ ganciclovir – but does not reverse abnormalities

  • HERPES – usually HSV-2 (sexually-transmitted), rarely HSV-1 (cold sores), see also Herpes Zoster

    • diffusely affects brain but infection usually occurs during PARTRUITION (down birth canal)

    • intrauterine infection occurs but clinically rarely seen b/c spontaneous abortion usually happens

    • Clinically see hydrocephalus, small heads, chorioretinitis

    • Virus has predilection for endothelial tissue

    • Pathologically see INTRANUCLEAR inclusions, and perivascular anoxic injury (strokes)

    • 3 types of lesions: 1) mucosal – skin lesions (drop on rosepetal lesions), eye, mouth; 2) CNS – fever, lethargy, seizures; 3) Disseminated – full-on sepsis if untreated

    • CT shows hypodense white matter, “falsely dense” cortical matter

    • MRI shows meningeal and cortical enhancement

    • Treat w/ acyclovir

    • **Varicella Zoster – can infect during and trimester, see worse lesions if infected LATER in pregnancy, may see necrotizing encephalitis if infected early.

  • HIVretrovirus (RNA), sexually transmitted

    • usually perinatal (down birth canal), also sometimes transplacental

    • 1/3 mothers pass onto their babies, 80% of childhood infections are from mothers

    • diffuse brain atrophy, basal ganglia calcifications

    • clinically see encephalitis, rarely see opportunistic, wt loss, failure to thrive, may rarely see thrush, may progress to spastic quadriparesis, rarely seizures

    • path shows glial nodules, giant cells, perivascular calcification, also in caudate and putamen, or demyelination

  • Enteroviruses – include coxsackie A + B, Echo, Polioviruses

    • infection is POSTNATAL and seasonal (not true TORCH)

    • may affect anterior horn cells, cranial nerve nuclei

    • Polio – ssRNA, spreads via cell lysis once consumed, may cause bulbar or myelo symptoms, has affinity for anterior horn cells in spinal cord gray

    • MRI suggest encephalitis

  • Syphilis – treponema pallidum (spirochete), sexually transmitted

    • infection occurs transplacentally, usually from 4-7 months

    • HUTCHINSON’s triad = dental disorders (notched teeth) + bilateral deafness + interstitial keratitis

    • See hydrocephalus, strokes

    • Dx w/ VDRL, FTA-Abs

    • Tx w/ penicillin until CSF has no WBCs, and normal protein


Spinal Infectious/Inflammatory Lesions

  • Ankylosing Spondylitis – 10-30 years old, 1% of population, affects site of ligament attachment to bone

  • Rheumatoid arthritis – 80% of cases involve the spine

    • causes pannus (can compress cord), atlantooccipital instability, necrotizing parenchymal vasculitis, cranial settling, leptomeningeal rheumatoid nodules

  • Acute Transverse Myelitis – acute inflammation and softening of spinal cord throughout its cross section

    • all ages, M=F, usually thoracic spine

    • MRI normal

    • Caused by infection, vasculitis, multiple sclerosis, malignancy, lupus

  • Radiation necrosis – usually chronic progressive

    • starts about 18 months after exposure

    • painless paresthesias (sensory > motor, white > gray)

    • hyaline intimal thickening of blood vessels causes fibrinoid necrosis and thrombosis

  • Necrotizing Myelopathy – Devic’s disease (form of MS), lupus, paraneoplastic

  • Nonnecrotizing Myelopathy – radiation, AIDS (vacuolar), viral, compression, AVM, ethanol, B12 deficiency

  • Infection

    • Osteomyelitis – usually caused by staphylococcus (60%) or enterococcus (30%)

      • Originates in subchondral body in adult, vascular disc space in children

      • Associated with end plate erosion and marrow changes (hypo T1, hyper T2)

    • Tuberculosis – 6% of TB cases involve spine (usually lower thoracic/upper lumbar)

      • 90% involve at least 2 bodies (50% at least 3)

      • usually associated with paraspinal abscess

      • also known as Pott’s disease

    • Epidural Abscess – usually staph aureus; 80% have associated discitis


Spinal Degenerative Disease

  • Disc bulge – affects 35% by age 30, 100% by age 60 (30% will have asymptomatic herniation by age 60)

  • Schmorl’s Nodule – herniation of disc through endplate into spongiosa of vertebra

  • Osteophytes – at insertion of Sharpey’s fibers

  • Spinal stenosis – hypertrophy of superior articular facet

    • Cervical spine normally 18 mm; symptomatic at 10 mm

    • Congenital stenosis caused by achondroplasia, Moquio’s syndrome (also hypoplastic dens)

  • Spondylolysis – congential absence of pars interarticularis

  • Spondylolisthesis – more than half at L45, most of the rest at L5S1

  • Ossification of the Posterior Longitudinal Ligament (OPLL) – more common in Japan; usually at C3-5 or T4-7

  • Ossification of the Ligamentum Flavum – more common in Japan


Spinal Trauma

  • Anterior Cord Syndrome – flexion injury

    • Loss of sensation and pain (anterior and lateral spinothalamic) with spastic paralysis (corticospinal)

  • Central Cord Syndrome – extension injury in previously stenotic spine

    • Loss of sensation/joint position (posterior columns), loss of sensation in arms and shoulders, weakness of upper extremities (medial corticospinal tract)

  • Brown-Sequard Sydrome

  • Atlantooccipital dislocation – distance between dens and basion greater than 12.5 mm

  • Jefferson Burst – bilateral burst fracture of C1 anterior and posterior neural arch; stable unless transverse ligament disrupted

    • Rule of Spence – 7 mm overlap of both lateral masses; indicates disruption of transverse ligament, need for halo fixation

  • Rotatory Atlanto-axial Subulxation – C1 rotates on C2 with locked facet; associated with flexion injury; more common with rheumatoid arthritis or pharyngitis

  • Odontoid fracture – three types

    • Type 1 – tip of dens

    • Type 2 – neck of dens – most unstable; 30% nonunion rate (70% if greater than 6 mm; 10% if less than 6 mm)

    • Type 3 – body of C2

  • Hangman’s fracture – C2 traumatic spondylolisthesis with bilateral pedicle fracture; due to hyperextension and axial loading, often due to diving


Cranial Trauma

  • Elevated ICP present in:

    • 3% of patients with GCS greater than 13

    • 10% of patients with GCS 8-12

    • 50% of paitents with GCS less than 8

  • Monitor ICP if:

    • GCS less than 8 and abnormal CT

    • GCS less than 8, normal CT, and two of following:

      • Age greater than 40

      • Decerebrate

      • Blood pressure less than 90

    • GCS greater than 8 with mass lesion that cannot follow clinically


Peripheral Nerve, Muscle
Peripheral Nerve Diseases

  • Wallerian degeneration – loss of axis cylinder and myelin distal to site of axonal interruption

  • Segmental demyelination – axon is spared; no muscle atrophy

  • Axonal degeneration – distal degeneration of myelin and axis cylinder due to neuronal disease

  • Recurrent demyelination and remyelination leads to “onion bulb” formations and enlargement of nerves

  • Toxic – vincristine, mercery, actinomycin D

    • Thallium Salt Toxicity (resembles GBS)

      • Abdominal pain, vomiting, diarrhea, then weakness progressing distal to proximal

      • Decreased DTR’s

      • Decreased pain sensation; acral pain with allodynia

      • Cranial nerve palsies

      • Rapid loss of hair, painful paresthesias, sensory loss, pain in joints/back/chest

    • Drug Induced Neuropathy – usually sensory

      • Isoniazid – sensory loss progressing to distal weakness and loss of DTR’s

        • Due to interference with pyridoxine metabolism

        • Prevent with pyridoxine

      • Disulfuram

      • Vincristine

      • Toxol/Cisplatin – sensory, acrochymia, color changes of fingers and toes, sensory ataxia and athetosis

      • Nitrofurantoin

      • Amiodarone

      • Dilantin – distal sensory loss, loss of DTR’s

      • Neuronal Dysfunction produced by drugs:

        • Transcription – actinomycin D

        • Translation – methylmercury

        • Microtubule – vincristine, vinblastine

        • Oxidative phosphorylation – dinitrophenol

        • Turnaround – acrylamide, diabetes

    • Diphtheric polyneuropathy

      • 5-8 weeks after infection, there is acute limb weakness with paresthesias and distal loss of vibratory and position sense

      • demyelination seen without inflammatory reaction of spinal roots, ganglia, and nerves

  • Metabolic

    • Diabetes – ischemia of vaso nervorum; painful pupil-sparing CNIII palsy (center of nerve); ischemic femoral neuropathy; distal symmetric sensory loss

      • Acute Diabetic Mononeuropathy – due to nerve infarction

        • Diabetic ophthalmoplegia – isolated CN III palsy (rarely CN IV)

        • Femoral and sciatic neuropathy

      • Multiple Mononeuropathy and Radiculopathy – painful, asymmetric

        • pain in low hip radiating to thigh

        • weakness, atrophy, loss of DTR’s on affected side

        • recovery over months to years

      • Distal Polyneurophaty – distal, symmetric, primarily sensory form; absent DTR’s

      • Autonomic Neuropathy – papillary and lacrimation dysfunction, impaired sweating and vascular reflex, nocturnal diarrhea, atonicity of GI and bladder, impotence, postural hypotension

    • Amyloid – immunoglobulin light chain forms extracellular beta-sheets; congo red dye green with polarized light

    • Porphyria – rapid symmetric

      • Motor > sensory

      • Abdominal pain, psychiatric changes, seizures

      • Axon and myelin degeneration without inflammation

    • Uremia – painless, symmetric, worse in lower extremities

    • Leukodystrophy – central and peripheral

    • Fabry’s disease

    • Viramin deficiency

    • Hypothyroid

  • Autoimmune

    • Guilliane-Barre – cell mediated reaction to myelin basic protein 2

      • 1.7 cases per 100,000

      • weakness, lower > upper, distal then proximal, progresses over days to respiratory paralysis

      • paresthesias progress to numbness over 1-2 weeks

      • greatly decreased or absent DTR’s

      • facial diplegia, cranial nerve palsies late

      • Autonomic dysfunction common, including urinary retention

      • CSF demonstrates increase in protein (mostly acellular)

      • Nerve conduction studies are consistent with peripheral demyelination, prolonged F response, and prolonged latencies

      • Pathology – perivascular lymphocyte infiltrate (usually perivenous), widespread demyelination, Wallerian degeneration

      • Treatment – immune globulin or plasmapheresis; steroids have no role

      • 10-14 days to peak; usually monophasic

      • caused by trauma, surgery, infection, neoplasm

      • CSF acellular with increased protein

      • Steroids do not work

      • NCV show decreased velocity and amplitude

    • Chronic Inflammatory Demyelating Polyneuropathy (CIDP)

      • Characteristics different from GBS:

        • Chronic relapsing

        • Nerves enlarged

        • Responds to steroids

      • Characteristics similar to GBS:

        • CSF cytoalbuminologic dissociation

        • Decreased conduction velocity, partial conduction block consistent with demyelination

        • Inflammatory changes

        • Mixed sensorimotor involvement

      • CSF protein elevated in 80%; some have papilledema and pseudotumor when protein > 1000; protein increase due to CSF gamma globulin and mild lymphocyte pleocytosis

      • Can treat with plasmapheresis and IVIG; steroids work but are used as a last resort (require chronic treatment)

  • Ischemic

    • Polyarteritis nodosa – most common vasculitis affecting central nervous system

      • Mononeuritis multiplex from obstruction of vaso nervorum

      • Axonal degeneration

      • Vessel walls show intimal proliferation with infiltration of polys, lymph, eosinophils

      • Skin purpura, renal problems

      • Diffuse, asymmetric, due to multiple nerve infarctions (like a polyneuritis)

      • Can also look like a mononeuritis multiples (random infarction of two or more individual nerves) – produces abrupt onset of pain or numbness in distribution of affected nerve

  • Infectious – nerves usually protected by perineurium

    • Zoster – hemorrhagic ganglioradiculitis/myelopathy

    • Leprosy

    • HSV

  • Hereditary (onion bulb) – demyelination and remyelination with decreased nerve conduction velocities

    • Peroneal muscular atrophy (Charcot-Marie-Tooth disease or hereditary motor sensory neuropathy (HMSN type I or II))

      • Autosomal dominant, usually on chromosome 17

      • Type I – slow conduction velocity in median and ulnar nerve (<38 m/sec)

      • Type II – normal conduction velocity

      • Symptoms:

        • Chronic degeneration of peripheral nerves and roots resulting in distal muscle atrophy

        • Feet and legs involved before hands

        • Equinovarous deformity (pied en griffe) – “stork” legs

        • Eventual inability to plantarflex

        • Claw hands (main en griffe)

      • Rarely extends above elbows or midthighs

      • Sensory loss distally

      • Affects anterior horn, posterior column, dorsal root ganglion

      • Both axon and myelin affected

      • Atrophy of feet and hands (pes cavus, clawhand)

      • No autonomic changes, CSF normal

      • Sensory changes and weakness

      • Ataxia

      • Pathology – degeneration of nerves (axons and myelin), especially motor nerves and dorsal root ganglion

        • Type I – onion bulbs

    • Hypertrophic Neuropathy of Infancy (Dejerine-Sottas Disease, HMSN type III)

      • Usually autosomal recessive

      • 1st decade of life

      • Pain and paresthesias of feet, progressive symmetric weakness and distal wasting

      • DTR absent

      • Ataxia, nystagmus

      • Enlarged nerves (feel like ropelike tendons)

      • Greatly increased CSF protein because of involvement of roots

      • Disabling – usually wheelchair bound

      • Clawfoot/hand, weakness,wasting, foot parasthesia

      • Enlarged nontender ulnar/median/radial/peroneal nerves

    • Hereditary Areflexic Dystonia (Ramsey-Levy Syndrome)

      • Sensory ataxia with pes cavus and areflexia, atrophy

      • Distinct from Friedrich’s ataxia, which has faster course, cerebellar/brainstem/corticospinal signs, and NO atrophy

      • Distinct from peroneal muscular atrophy, which has later onset, lacks sensory ataxia, and lacks kyphoscoliosis

    • Refsum’s disease (HMSN type IV)

      • Autosomal recessive

      • due to phytanic acid oxidase deficiency, accumulate phytanic acid

      • Distal symmetric sensorimotor

      • Retinitis pigmentosa, cerebellar ataxia of gait (prominent finding), chronic polyneuropathy

      • Increased levels of phytanic acid in blood

      • Cardiomyopathy and neurogenic deafness (congenital)

      • Anosmia and night blindness

      • Decreased sensation, distal weakness, onion bulbs, absent DTR’s

    • Amyloid Neuropathies

      • Autosomal dominant

      • Amyloid infiltration and deposition in small diameter sensory and autonomic nerves

  • Trauma

    • Neuropraxia – motor > sensory, recover in 6-8 weeks

    • Axontmesis – sheath intact

    • Neornotmesis

    • Morton neuroma – traumatic neuroma (digital neuroma between toes)

  • Paraneoplastic polyneuropathy

    • Distal, symmetric, sensorimotor, weakness, atrophy, ataxia, sensory loss of limbs

    • Associated with Anti-Hu antibody in serum and CSF; typically small cell of lung

    • Seen in 2-5% of patients with cancer

    • Treatment – gamma globulin

    • Seen frequently in multiple myeloma and other paraproteinemias due to antimylein antibodies (IgM against myelin associated glycoprotein); see deep sensory loss with imbalance, Romberg sign

  • Compressive Syndromes

    • Median

      • Carpal Tunnel Syndrome

        • Associated with multiple myeloma, rheumatoid arthritis, amyoidosis, acromegaly, mucopolysaccharidosis, hypothyroidism, pregnancy

        • Compression of motor branches deep to transverse carpal ligament

        • LOAF muscles (lumbricals 1-2, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis)

        • Phalan’s test – wrist flexion for 30-60 sec (80% positive)

        • Tinel’s test – percussion over nerve (60% positive)

        • Nerve conduction velocities normal in 25% of patients (sensory latency more sensitive than motor)

      • Pronator syndrome – median nerve between heads of pronator teres

        • Generally no nocturl symptoms (as with carpal tunnel)

        • Ache, fatigue of grip (especially thumb to index finger)

        • Numb palm (palmar cutaneous branch travels over transverse carpal ligament and is spared with carpal tunnel)

      • Struther’s ligament – median nerve compression at elbow

        • medial epicondyle to supracondylar process; median nerve/brachial artery passes underneath

      • Anterior interosseous nerve – median – weakness without sensory loss – affects pronator quadratus, flexor pollicis longus, flexor digitorum profundus 1-2, pinch sign

    • Ulnar nerve compression – claw hand (ulnar supplies lumbricals 4-5 – flex PIP, extend MCP), Wartenburg’s sign (cannot adduct 5th finger due to weak third palmar interosseous muscle)

      • Arcade of Struthers – ulner nerve compression at medial head of triceps

      • Cubital tunnel – ulnar nerve compression by heads of flexor carpi ulnaris

      • Guyon’s Canal – ulnar nerve compression between transverse carpal ligament and palmaris fascia at wrist

    • Radial – can be at

      • Spiral groove/intramuscular septum – of upper arm; causes wrist drop without triceps weakness

      • Posterior interosseous nerve – radial – affects supinator, extensor digitorum, extensor carpi ulnaris, abductor pollicis longus, sensation over dorsolateral forearm and hand; finger extension weakness without wrist drop or sensory loss

      • Radial tunnel – elbow pain without weakness

    • Meralgia paresthetica – lateral femoral cutaneous (L2-3) beneath inguinal ligament – anterolateral thigh numbness/dysesthesia, caused by obesity/pregnancy/diabetes

    • Tarsal tunnel – posterior tibial nerve, paresthesias on sole of foot, no motor abnormality

  • Reflex Sympathetic Dystrophy – incomplete PNS injury hyperresponsive to sympathetics; diffuse persistent pain usually in an extremity; often associated with vasomotor disturbances, trophic changes, and limitation or immobility of joints; frequently follows local injury; causalgia (burning sensation), Sudek atrophy of bone/joint/muscle/skin (not nerve); can treat with sympathectomy or antisympathetic medication

  • Sarcoidosis

    • Facial palsy or multiple cranial nerve palsies

    • Involvement of muscles (polymyositis) or CNS (stalk of pituitary, cerebellum)

    • Non-caseating granulomas in lymph nodes, lung, skin, eyes, salivary gland, liver

    • 5% have CNS involvement (esp CN VII)

    • can get meningitis, pituitary dysfunction, hydrocephalus, hypothalamic granuloma, myelopathy, neuropathy, myopathy

    • ACE levels increased

  • Lyme Disease

    • Cranial nerves sometimes involved

    • Painful radiculitis or dermatome of insect bite (Bannworth syndrome, cauda equina syndrome)

    • Usually presents with fever, erythema chronicum migrans, lymphadenopathy, and joint symptoms

    • Facial palsy, sensory neuropathy

  • Polyradiculopathy

    • More patchy than polyneuropathy; proximal = distal, muscles of a common root innervation (e.g., hamstring/gastrocnemius, or iliopsoas/quadriceps/obturator)


Brachial plexus



  • Upper plexus injury (Erb-Duchenne palsy, often occurs at birth)

    • C5-6 – deltoid, biceps, brachioradialis, supinator, supra/infraspinatous, rhomboids

    • Arm hangs at side, internally rotated and extended at elbow

    • Movements of hand and forearm unaffected

  • Lower plexus injury (Degerine-Klumpke’s palsy)

    • Traction on abducted arm, operation on axilla, tumor of lung apex, compression by cervical ribs or bands

    • Birth injury (breech)

    • Claw hand deformity

    • May have partial Horner’s syndrome

  • Infraclavicular lesions of cords

    • Lateral cord – musculocutaneous nerve, lateral root of median nerve; causes weakness of flexors and pronators of forearm, intrinsic hand muscles spared

    • Medial cord – medial root of median nerve, ulnar nerve

    • Posterior cord – weak deltoid, extensors of wrist, elbows, fingers

  • Brachial plexus neuropathy (Parsonage-Turner Syndrome)

    • Severe pain and weakness, sensory and reflex impairment

    • Progresses over 3-10 days, eventual recovery over 6-12 weeks

    • Mostly shoulder and upper arm

    • Loss of DTR’s

    • May be bilateral

    • Possibly associated with CMV or AIDS

    • No leukocytosis or increased ESR

  • Suprascapular nerve

    • Supplies supraspinatous/infraspinatous

    • Weakness of first 15 degrees of shoulder abduction and external rotation

  • Axillary nerve

    • C5-6

    • supplies teres major and deltoid

    • Weakness of shoulder abduction from 15 to 90 degrees

  • Radial nerve

    • C6,7,8 (mostly C7)

    • supplies triceps, brachioradialis, supinator, extensors of wrist and fingers, abductors of thumb

    • Lesion causes brachioradialis weakness with inability to flex forearm midway between pronation and supination

  • Median nerve

    • C5,6,7,T1 (mostly C6)

    • Supplies pronators of forearm, long finger flexors, abductor brevis and opponens of thumb, 1st and 2nd lumbricals

    • Lesion causes

      • inability to pronate forearm or flex hand

      • paralysis of flexion of index finger and terminal phalanx of thumb

      • weakness of opposition and abduction of thumb (abductor and flexor pollicis brevis)

  • Ulnar nerve

    • C8,T1

    • Supplies ulnar flexors of wrist, ulnar flexor profundii digitorum, adductors and abductors of fingers, adductor of thumb, 3rd and 4th lumbricals, muscles of hypothenar eminence

    • Complete paralysis (elbow fracture) produces claw hand deformity

    • May see compression distal to medial epicondyle of elbow beneath aponeurosis of flexor carpi ulnaris (cubital tunnel)


Motor Neuron Disease

  • Spinal Muscular Atrophy (SMA) – degeneration of anterior horn and hypoglossal nuclei, sparing of corticospinal tracts and other bulbar nuclei

    • Type 1 (infantile, Werdnig-Hoffman syndrome) – most common; onset before 6 months, death by 18 months (pneumonia), autosomal recessive (chromosome 5), worst in proximal trunk and extremities, extraocular muscles spared, no mental retardation

    • Type 2 (Wohlfart-Kugelberg-Welander) – onset childhood, death 5-10 years, M>F, autosomal recessive chromosome 5 (can also be X linked)

    • Type 3 – adult onset, usually autosomal dominant

  • Amyotrophic lateral sclerosis – 35 years, death 3-6 years, upper and lower motor neurons

    • Fasciculations in all extremities, diffuse hyperreflexia, sensation preserved

    • M>F, sporadic (10% autosomal dominant chromosome 21)

    • Degeneration of motor neurons and corticospinal tract

    • Bladder not affected

    • Starts with hands, involves face and tongue

    • Antibodies to glycosides

    • Bunina bodies – intracytoplasmic, in anterior horns

    • Usually male, over 50 years old

    • Symptoms

      • Starts with awkwardness in finger movements and finger stiffness

      • Progresses to atrophic weakness of hand and forearms, slight spasticity of arms and legs, and generalized hyperreflexia, all in the absence of sensory changes

      • Complete lack of sensory changes help to differentiate from other diseases (cervical spondylosis/disc, peripheral diseases such as peroneal muscular atrophy/Charcot-Marie-Tooth)

      • Eventually the legs and thigh are affected, but often after spread to shoulder, upper arm, tongue, neck, pharynx/larynx, etc.

    • Signs

      • Course fasciculations are usually evident in weakened muscles

      • EMG shows widespread fibrillations and fasciculations

      • Motor nerve conduction only slightly slowed

    • Primary Lateral Sclerosis

      • Mostly rigidity and spasticity

      • Almost no LMN involvement (unlike ALS)

    • Wohlfart-Kugelberg-Welander Syndrome

      • Proximal limb involvement in children

      • Slowly progressive



Neuromuscular Junction


  • Myasthenia gravis – antibodies to acetylcholine receptors (but IgG cannot be isolated in 10% of patients)

    • F>M; 30-40 years old; 10% of patients have thymoma – these are M>F, 50-60 years old

    • 50% have thymic hyperplasia, and 30% improve with thymectomy even if no thymoma is identified

    • symptoms start with EOM, progresses proximal to distal

      • pupils unaffected (unlike with botulism)

    • EMG is decremental (tensilon improves, aminoglycosides worsen due to effect on calcium channels)

    • Associated with hypothyroidism, rheumatoid arthritis, lupus, polymyositis

    • Treatment is AchE inhibitors followed by thymectomy, steroids, immunosuppression (azathioprine), then plasmapheresis

      • AchE inhibitors can cause cholinergic crisis (weakness, salivation, diarrhea, bradycardia, miosis, nausea, etc.) – diagnosed by giving edraphonium (if symptoms worsen, lower dose of AchE inhibitors)

  • Eaton-Lambert myasthenic syndrome – antibodies to presynaptic calcium channels so less calcium enters with action potential and fewer quanta are released

    • M>F; more than half have oat cell cancer of lung

    • No ocular or bulbar findings

    • Weakness progresses proximal to distal; reflexes decreased; no fasciculations; autonomic system affected

    • Treat with plasmapharesis, steroids, immunosuppression

    • Worsened by aminoglycosides, high magnesium, low calcium (decreases acetylcholine release)

    • Incremental response to repetitive stimuli on EMG (as does botulism)


Muscle Diseases

  • Types of Muscle Fibers

    • Type 1 – red – involved with myotonic dystrophy, most congenital myopathies, central core disease

    • Type 2 – white – involved with myasthenia gravis, denervation, disuse, steroids, and peripheral neuropathy

  • Muscular dystrophy – differentiate from polymyositis, which has more rapid course with higher CK levels, more fibrillation, and responsiveness to steroids

    • Congenital muscular dystrophy – more common in Japan, autosomal recessive

    • Duchenne’s disease – most common muscular dystrophy

      • X-linked recessive (but 1/3 are spontaneous), M>F

      • Affects 1/3500 births; become symptomatic at 2-5 yrs, 75% dead by 25 years

      • Decreased dystophin in muscle fibers (stabilizes membranes) – see muscle fiber necrosis/regeneration

      • Atrophy worse in shoulder and pelvic girdle; calf seems to hypertrophy

      • Spares hands/face/eyes

      • Associated with mental retardation, CHF, and respiratory problems

    • Becker’s disease – milder form of Duchenne’s

      • X-linked recessive, M>F

      • Affects 1/30,000 births; becomes symptomatic at 11 years, nonambulatory by 30 years, most dead by 50 years

      • Dystrophin abnormal – no necrosis/regeneration

    • Fascioscapularhumoral dystrophy

      • Autosomal dominant on chromosome 4

      • Symptomatic 10-20 years

      • Face affected first, then shoulders and upper arm

      • Associated with sensorineural hearing loss

      • Chronic inflammatory cells seen in muscle (only MD to do this)

      • CK normal; no associated CHF or mental retardation

      • Sometimes associated with absence of a muscle

    • Limb-Girdle Syndrome

      • Autosomal recessive

      • Axial weakness

      • Sometimes associated with CHF, no mental retardation

      • 1/3 have pseudohypertrophy

    • Oculopharyngeal muscular dystrophy

      • Autosomal dominant

      • Becomes symptomatic 40-50 years

      • Weakness of eye muscles and pharynx

    • Myotonic Dystrophy – most common muscular dystrophy in adults

      • Autosomal dominant on chromosome 19

      • Affects 1/20,000 births; generally nonambulatory 20 years after first symptoms

      • Face affected first, then distal extremities

      • Weakness and myotonus (cannot relax muscle after contraction)

      • Dysrhythmia (especially with quinine, procainamide, and phenytoin which increase AV block), decreased intelligence, cataracts, endocrine dysfunction, testicular atrophy, frontal balding

  • Metabolic Myopathies – usually affect proximal lower extremities; face and eye are rarely involved; CK invariably elevated

    • Glycogen storage diseases (glycogen in vacuoles)

      • Acid Maltase deficiency

        • Autosomal recessive

        • Infantile form (Pompe’s disease) symptomatic by 1 month with hepatomegaly, cardiac problems, death by 2 years

        • Glycogen accumulates in liver, heart, and muscle

      • Myophosphorylase deficiency (McArdle’s disease, type V glycogen storage disease)

        • Painful muscle cramps and decreased ability to exercise

        • Symptomatic by 15 years

        • Associated with myoglobinuria

      • Phosphofructokinase deficiency (Tarui’s disease, type VII glycogen storage disease) – similar to McArdles

        • Autosomal recessive

        • Unable to mobilize glycogen

    • Lafora’s diease – myoclonus epilepsy, autosomal recessive

      • Symptomatic age 6 to 19

      • characterized by generalized tonic-clonic seizures, resting and action myoclonus, ataxia, dementia, and classic EEG findings, including polyspike and wave discharges

      • Lafora bodies – basophilic cytoplasmic inclusion bodies present in portions of the brain, the liver, and skin, as well as the duct cells of the sweat glands

      • Death usually occurs within 10 years of onset

    • Lipid Storage Diseases

      • Carnitine deficiency – cannot use long chain fatty acids

      • Fabry’s disease – alpha-galactosidase deficiency, x-linked recessive

        • Accumulate ceramides

        • Peripheral neuropathy, anhydrosis, corneal opacities, renal insufficiency

        • Skin angiokeratomas

    • Mitochondrial disorders – often associated with ragged red fibers

    • Malignant Hyperthermia – defect in ryanodine calcium release channels – too much calcium released from SR

      • rapid onset of extremely high fever with muscle rigidity precipitated by exogenous agents (especially halothane or succinylcholine)

      • Autosomal dominant, 1/15,000 affected

      • Tachycardia, dysrhythmia, labile blood pressure, hyperkalemia, increased CK, myoglobinuria, renal failure

      • Dantroline (decreases calcium release from SR) – decreases mortality from 70% to 5%; also cool patient, hydrate, 100% oxygen, bicarb, stop anesthetics

      • Caffeine or halothane will cause muscle fibers of affected individuals to contract in vitro

    • Thyroid myopathy – with hyperthyroidism

      • Exophthalmos/ophthalmoplegia (esp IR/MR, so downgaze palsy); painful with monocyte/lipocyte infiltration

      • Thyrotoxic periodic paralysis – responds to beta-blocker

  • Inflammatory myopathy

    • Bacterial myositis – staph aureus, causes fever, high white count, muscle tenderness

    • Trichinosis – affects eye, face, proximal limbs; eosinophilia present; affects both fiber types; can also happen with toxo or cysticercosis

    • Viral myopathy – 1-2 weeks after infection

      • influenza, coxsackie; causes rhabdomyolysis with ATN

      • HIV, HTLV

    • Polymyositis – most common inflammatory myopathy in adults

      • Subacute, painless, symmetric, proximal to distal, fever

      • Increased CK/myoglobinuria

      • T-cells and macrophages in muscle fibers

      • 10% associated with cancer

      • steroids help

      • most improve with time

      • Black > white, female > male, associated with cancer, responds to steroids/immunosuppressants

      • Involves proximal muscles; face spared

      • Fever, malaise, dysphagia

      • Increased ESR and CK levels

      • EMG shows small short-duration polyphasic motor units with fibrillations

      • Interstitial lung disease found in 70% of patients

      • Pathology: Cell mediated tissue destruction with T cells around muscle, also see necrosis and phagocytosis of individual muscle fibers

      • Endomysia inflammatory exudate with large number of T and B cells

    • Dermatositis

      • Maculopapular butterfly rash, heliotrope, periorbital edema

      • Angiopathy affecting skin, muscle (especially extensors/neck/shoulders), peripheral nerves, intestines

      • 10% associated with cancer

      • B-cells seen perivascularly NOT in muscle

      • Female > male, associated with cancer, responds to steroids/immunosuppressants

      • 90-95% of patients get cutaneous rash on extensor surfaces

      • systemic angiopathy and vasculitis with mucosal ulceration (sometimes GI bleeding), subcutaneous calcifications and nodules

      • interstitial lung disease in only 30%

      • Pathology: lymphocytic inflammation ; mostly B cells around blood vessels; also see perifascicular muscle atrophy

      • Incidence of malignancy 25% in patients over 55 years old

      • Etiology is immune complexes deposited in walls of arterioles and veins

      • IgG, IgM, complement, MAC deposition in small vessels

    • Inclusion body myositis – like polymyositis with inclusion bodies

      • CK normal, steroids don’t work

      • Possibly caused by virus

    • Drug induced – penicillin or tryptophan

  • Familial periodic paralysis – genetic defect of Na, Cl, Ca channels

    • Recurrent episodes of remarkable generalized weakness

    • Autosomal dominant, M>F, improves with age

    • Brought on by cold, hyotension

    • Potassium very low

    • See vacuoles in sarcoplasm

  • Neurogenic atrophy – consists of grouped atrophy, then large group similar reinnervation (instead of normal checkerboard pattern); may also see target fibers


Diagnostic Studies

  • EMG

    • Motor unit potential – myopathy polyphasic – small amplitude, short duration

    • Neuropathy – large amplitude, long duration

    • Conduction velocity = distance / (distal latency - proximal latency)

    • Internodal demyelination – conduction delay

    • Segmental demyelination – loss of conduction proximally

    • Cut axon

      • loss of conduction proximally, unaffected distally immediately after injury

      • 7-10 days later – see loss of conduction distally as well due to distal Wallerian degeneration (motor 5-6 days, sensory 10-11 days)

      • proximal signal will be dispersed due to different speeds of various sized axon

      • 3 weeks – fibrillation potentials indicating denervation of muscle; but it does not give location (radicular vs. peripheral nerve injury)

      • best determination of nerve injury – EMG immediately afterwards, then in 7-10 days to determine if there is still an action potential

    • Insertional activity

      • Electrical response to mechanical damage to the muscle

      • Prolonged in acute neuropathies and active myopathies

      • Decreased with advanced myelopathy with fibrous or fatty tissue replacement

    • Spontaneous activity

      • Resting muscle has little or no activity

      • Some spontaneous mEPSP from released quanta

      • Fibrillation potential – triphasic potential 1-5 msec

        • Not visible through the skin

        • Caused by deinnervation with increased muscle sensitivity

        • Starts 3 weeks after injury

        • May display positive sharp wavs

      • Fasciculation ptential – 3-5 phases lasting 5-15 msec

        • Caused by activity in a motor unit

        • Visible through the skin

        • Associated with nerve irritability, not destruction

    • Recruitment

      • Initiation of firing of additional motor units from increase in firing rate of active units

      • Rapid in myopathy – all units recuited at low levels of force

      • Decreased in neuropathy – Total number of motor units is reduced

    • Myopathy EMGs

      • Active – fibrillations, positive waves

        • From deinnervation, inflammation (polymyositis, Duschenne MD)

      • Chronic – small EP, rapid recruitment

        • Other MDs, congenital and metabolic myopathies

    • Neuropathy EMGs

      • Active – Fasciculations

      • Chronic (reinnervation) – large EP, slow recuitment

  • Nerve Conduction Velocities

    • Axonal disease – decreases wave amplitude

    • Myelin disease – increases latency (decreased velocity), signal degredation

    • M wave – direct motor response to stimulation of a motor nerve

    • F wave – caused by supramaximal stimulation of a mixed motor-sensory nerve

      • Antidromic impulse to the anterior horn followed by orthodromic impulse back

      • Forms a second, smaller action potential with greater latency than direct stimulation

      • Can be used to measure conduction in the proximal protion of the nerve

    • H reflex – elicited by submaximal stimulation of a sensory fiber

      • Sends impulse to the spinal cord that elicits a monosynaptic reflex

      • Only works in the calf (Achilles reflex)

Neurology
Cerebellum


  • Horizontal segments

    • Flocculonodular lobe (arch/vestibulocerbellum) input from vestibular nuclei, function equilibrium. Lesion causes positional nystagmus and impaired equilibrium

    • Anterior lobe (Paleocerebellum) input from spinocerebellar tracts from muscle tendons, function posture and muscle tone. Lesion: hyperreflexia

    • Posterior lobe (neocerebellum) input corticopontine fibers, function: coordination. Lesion causes decreased tone, clumsiness and intention tremor (if dentate involved).

  • Longitudinal segments

    • Vermis (fastigial nucleus) input vestibular nuclei, function: coordination of eyes, head, and body to account for gravity, axial posture and tone, locomotion.

    • Intermediate zone (interposed nuclei) input area 4 and spinocerebellar tract, function: posture tone and ipsilat. Limb movements. Lesion causes intention tremor.

  • Lesions

    • Flocculonodular lobe- nystagmus

    • Vermis- truncal ataxia, scanning speech, and hypotonia

    • Intermediate hemisphere- appendicular ataxia and hypotonia

    • Lateral hemisphere- terminal tremor, decomposition of multijoint movements, delay in initiating movements, mild ipsilateral weakness

    • Anterior nucleus- slight hyperreflexia


Tremor


  • Def: rhythmic, regular, oscillating action of agonists/antagonists.

  • Physiologic tremor- awake and asleep (8-13Hz)

  • Pathological tremor- only awake (except palatal and ocular myoclonus) 4-7Hz

  • Parkinsons- at rest, inc with stress, persistent when walking (unlike essential tremor), treated with anticholinergic or contralateral VL thalamic lesion.

  • Intention- 2-3Hz, end of movement, absent at rest, assoc with titubation (rhythmic ossic of head on the trunk). Treatment VL thalamic lesion

  • Postural/action tremor:

  • Physiologic- normal, inc. with fear, hyperthyroid, hypoglycemia, ETOH w/d, caffeine, steroids, pheo.

  • Essential- 4-8 Hz, familial, AD inheritance, adulthood onset. Suppression with ETOH, B blocker, primidone, and VL lesion.

  • Kinetic predom. Action tremor- worse with activity, slower, disabling. Treat w/ clonazepam or botox.

  • Hysterical tremor- single limb w/ gross movements and persists in repose.


Myoclonus

Aphasia
Broca’s- nonfluent, effortful, poor repetition, poor naming, good comprehension. Lesion: frontal operulum (area 44,45)

Wernickes- fluent, nl sentence length, good articulation, impaired repetition, poor comprehension. Lesion: posterior-superior temporal region.

Conduction- fluent, good comprehension, paraphasic errors (assoc., with agraphia and limited reading comprehension. Lesion: left inferior parietal lobule, anterior supramarginal gyrus.

Global aphasia- poor fluency, poor comprehension, poor repetition. Lesions: both Broca’s and Wernicke’s area.




EEG

  • Alpha – 8-13 Hz, symmetric, present posteriorly (occipital) with eyes closed, disappear (are blocked) with eye opening

    • Resting with eyes closed

  • Beta – above 13 Hz; symmetric, present frontally; no effect with eye opening

    • Awake, eyes open

  • Gamma (4-8 Hz) and Delta (less than 4 Hz) – seen in children and young adults with frontal and temporal predominance

  • Theta waves – 4-7 Hz

    • Parietal and temporal areas in children

  • Delta waves – 1-3 Hz

    • Deep sleep

  • EEG in Sleep

    • Stage I – loss of alpha waves

    • Stage II – sleep spindles, K-complexes

    • Stage III – delta waves, some spindles

    • Stage IV – Delta waves only.

      • Sleepwalking, night terrors

    • REM – beta waves


Headache

  • Nonthrobbing

    • Dissection of ICA

      • Nonthrobbing pain centered in/around eye, then ischemic symptoms, unilateral Horner’s sign; may have CN X, XI, or XII involvement

      • More common in women than men

    • Cluster headache

      • Young men, constant unilateral orbital pain, burning excruciating pain above and behind eye; deep, nonthrobbing; may have rhinorrhea, flush and edema of cheek, miosis, lacrimation, injected conjuntivum; may also have ptosis, partial Horner’s syndrome

      • Paryoxysmal, short duration (20-30 minutes), occur at same time of day (usu 1-2 hrs after dark) for weeks

      • NO ischemic signs associated with it

  • Throbbing – usually associated with vascular etiology

    • Migraine – usually unilateral; may be classic 10% (aura) or common (no aura), familial, pulsatile, femal predominance

    • Glossopharyngeal Neuralgia

      • intense paroxysmal pain originates in throat, provoked by swallowing or talking, chewing, yawning, laughing

      • pain may be localized in ear

      • may be accompanied by bradycardia or syncope


Abnormal Eye Movements

  • Optokinetic Nystagmus

    • Toward involved (lesioned) hemisphere is lost

    • Right parietal lesion causes impared smooth tracking to right

  • Vertical eye movements

    • Under bilateral control of cortex and upper brainstem

    • Pretectal fibers of midbrain tegmentum, involve fibers of posterior commissure near superior colliculus

      • Rostral MLF at junction of midbrain and thalamus

      • Medial cells serve upgaze; lateral cells serve downgaze (initially are medial and commingle with upgaze fibers)

    • Lesion of both medial RiMLF causes complete vertical gaze palsy

    • Lateral lesion causes isolated downgaze palsy (rare)

  • Saccades – fast conjugate eye movements, voluntary

    • Generalized in contralateral frontal lobe (area 8)

  • Smooth Pursuit – slow involuntary movement generated in ipsilateral occipital lobe (area 18 and 19)

  • Hypermetria (overshooting) – midline cerebellar lesion

  • Inability to initiate voluntary movements (vertically or horizontally)

    • May be congenital (Cogan syndrome, ataxia-telangiectasia)

  • Impaired Smooth Pursuit with slow, hypotonic saccades – caused by Parkinson’s, Huntington’s, Progressive Supranuclear Palsy

  • Midbrain lesion or in region of posterior commissure – interfere with conjugate movements in vertical plane (seen in Nieman-Pick)

    • Parinaud’s syndrome – vertical gaze palsy (usually upgaze)

      • Mydriasis; loss of convergence and papillary light reflexes

      • Refractory nystagmus or lid retraction (Collier’s sign)

  • Congenital Ocular Motor Apraxia (Cogan’s Syndrome)

    • Abnormal eye and head movements during attempts to change position of eyes

  • Effects of Lesions

    • Right cerebral lesion produces right eye deviation, left hemiparesis

    • Right PPRF lesion produces left eye deviation, left hemiparesis, left CN VI/VII palsies

    • CN III lesion produces ipsilateral CN III palsy (down and out)

    • CN III + Red nucleus lesion also produces contralateral tremor (Benedikt’s syndrome)

    • CN III + pyramid lesion produces contralateral hemiparesis (Weber’s syndrome)

    • CN VI+VII + pyramid lesion produces cranial nerve deficits and contralateral hemiparesis (Millard-Gubler syndrome)

    • Cavernous lesions

      • Retrocaverous compressive lesions(infraclinoid extradural aneurysms/tumor) – involve V1, V2, V3, III, IV, VI

      • Posterior cavernous sinus – V1, V2, III, IV, VI

      • Anterior cavernous sinus – VI, III, VI, VI

    • CN IV lesion – difficulty with downward gaze, especially with adduction

      • Paralyzed eye tends to look up and in (opposite of CN III lesion)

      • Bielchowski’s sign – head tilt to opposite shoulder because of paralyzed intortion

      • Inferior oblique intorts abducted eye, depresses adducted eye

  • Spasmus Mutans – pendular nysyagmus of infancy

    • Any direction, one eye predominates, worse when head immobilized

  • Vertical Nystagmus

    • Upbeat – can be demyelinating; caused by vascular, tumors

    • Downbeat – always central; caused by Wenickes, syringobulbia, Chiari, basilar invagination

  • Course Horizontal Nystagmus – can be caused by CP angle tumors

  • Convergence Nystagmus – after accompanied by nystagmus retractorius in Parinaud syndrome

    • Usually lesion of upper midbrain tegmentum or pinealoma

  • Seesaw Nystagmus – torsional-vertical oscillation; caused by sella or parasellar masses

  • Palatal Nystagmus – lesion of central tegmental tract

  • Oscillopsia – illusionary movement of environment

    • Associated with lesion of labyrinth (such as aminoglycoside toxicity)

  • Opsoclonus – rapid, conjugate oscillations of eyes in all positions

    • Childhood form associated with ataxia, myoclonus; responds to ACTH


Autonomic Disorders

  • Anhidrosis, orthostatic hypotension, increased or decreased blood pressure, cardiovascular changes, adynamic ileus and atonic bladder

  • Seen in amyloid, small fiber polyneuropathy, diabetes, pure autonomic polyneuropathy and Shy-Drager syndrome, GBS

  • Primary Autonomic Failure (Idiopathic Orthostatic Hypotension)

    • Presents as anhydrosis, impotence, bladder atonicity

    • Two possible etiologies:

      • (1) Lesion of postganglionic sympathetic neurons (spinal parasympathetic and CNS); associated with denervation sensitivity to plasma infusion of norepinephrine

      • (2) Lesion of preganglionic lateral horn neurons of thoracic spinal cord; produces later cerebellar or basal ganglia signs (Shy-Drager)

  • Diabetic Neuropathy – impotence, constipation, or diarrhea; hypotonia of bladder, gastroparesis, orthostasis, sensory polyneuropathy, small pupils

  • Autonomic Dysreflexia – occurs in quadriplegics with high cervical lesions (central control of sympathetics is abolished)

    • flexors spasms of legs, involuntary emptying of bladder associated with increased blood pressure, bradycardia, sweating and pilomotor reactions, dilated pupils

  • Sjogren’s syndrome – Autoantibodies Ro and La; associated with peripheral neuropathy

  • Myasthenic syndrome – Treat with guanidine (blocks reuptake of calcium into mitochondria) or diaminopyradine (increases acetylcholine by blocking potassium channels)

  • Hypothalamic lesion – anterior produces hyperthermia, posterior produces hypothermia (poikilothermia), suprachiasmatic produces alteration of circadium rhythm of temperature

  • Wernicke’s encephalopathy – hypothermia

  • Shapiro’s syndrome (agenesis of corpus callosum) – episodic hypothermia and hyperhidrosis

  • Riley-Day syndrome (hereditary sensory-autonomic neuropathy type II) – defective synthesis of norepinephrine; autosomal recessive, orthostasis, faulty regulation of temperature, decreased hearing, hyperhidrosis, denervation sensitivity

    • Autosomal recessive, decreased lacrimation, hyperhidrosis, labile blood pressure, GI dysfunction with vomiting, decreased pain and temperature with Charcot joints and acral mutilation, areflexia, poor feeding and aspiration, scoliosis, corneal abrasions

  • Fabry’s disease – alpha-galactosidase deficiency with buildup of ceremide trihexosidase in dorsal root and peripheral autonomic ganglia

  • MEN 2b – mucosal neuromas, medullary thyroid cancer, pheochromocytoma, ganglioneuromatosis, bony deformities, hypotonia, marfanoid appearance

  • Porphyria – persistent tachycardia, labile hypertension due to vagus denervation, catecholamine release

  • Multiple System Atrophy (Shy-Drager Disease) – autonomic dysfunction, orthostatic hypotension, Parkinson’s symptoms (akinesia/rigidity) due to cell loss in substantia nigra and putamen (no Lewy bodies), anhidrosis, urinary incontinence, extrapyramidal symptoms

    • Shy Drager – parkinsonism + dysautonomia

    • Olivopontocerebellar Atrophy – parkinsonism + cerebellar signs

    • Striatonigral degeneration – parkinsonism + pyramidal signs and laryngeal stridor

  • Acromegaly

    • Diagnosis

      • Clinical features (acral growth, prognathism, visceromegaly, headache, diabetes, hypermetabolism)

      • Elevated growth hormone (above 10 ng/ml)

      • Failure of growth hormone levels to rise in response to TRH or glucose

    • Late complications:

      • Carpal tunnel syndrome

      • Myopathy (proximal muscle weakness and atrophy)

      • Polyneuropathy (paresthesia, decreased DTRs, distal muscle atrophy, sometimes enlargement of nerves)


Metabolism

  • Osm = 2 (Na + K) + BUN/28 + glucose/18

  • Oxygen-Hemoglobin Dissociation Curve

    • Shifted to the right (higher PO2 required) by:

      • Increased temperature

      • Low pH

      • Increased PCO2

      • Increased DPG

    • Shifted to the left (lower PO2 required)

      • CO poisoning

Anesthetic agents


  • Increase CBF

    • All inhaled agents and ketamine

    • Enflurane – lowers seizure threshold)

    • Nitrous oxide – Least increase in CBF, no vasodilation

    • Isoflurane – small increase in CBF

  • Decrease CBF

    • All IV agents except ketamine

    • Thiopental – cardiodepressant

    • Etomidate – suppresses adrenal response to stress

  • Cerebral metabolism changes with CBF



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