Early features

Difficulty with concentration and memory

“Slowness” of thinking, losing track of conversation

Tasks take longer to complete

Cannot follow written material or television

Motor movement slowed and clumsy

Handwriting changes

Gait incoordination with tripping and ataxia

Apathy and indifference

Social withdrawal

Reduced spontaneity

Rarely dysphoric, but may be anxious or irritable

Neurologic signs

Slowing of rapid movements of extremities and

eyes

Pathological (“frontal release”) signs (e.g.,

snout)

Late features

Bowel and bladder incontinence

Myoclonus

Vegetative state