a. Spastic (Reflex or Automatic) bladder - due to upper motor neuron lesion, loss of conscious sensations and cerebral motor control, reduced bladder capacity and marked hypertrophy of bladder wall.
b. Flaccid (Atonic, Non-reflex, Autonomous) bladder - due to lower motor neuron lesion. Bladder continues to fill until it becomes greatly distended, bladder musculature does not contract forcefully at any time, when pressure reaches breakthrough point small amounts of urine dribble from urethra as bladder continues to fill resulting in overflow incontinence.
4. Sensory loss may accompany flaccid bladder; patient is not aware of discomfort.