A decreased magnitude of the sensory perception of sound.

A defect in the understanding of complex motor commands and in the execution of certain learned movements, i.e., deficits in the cognitive components of learned movements.

Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).

Chorea (Greek for 'dance') refers to widespread arrhythmic involuntary movements of a forcible, jerky and restless fashion. It is a random-appearing sequence of one or more discrete involuntary movements or movement fragments. Movements appear random because of variability in timing, duration or location. Each movement may have a distinct start and end. However, movements may be strung together and thus may appear to flow randomly from one muscle group to another. Chorea can involve the trunk, neck, face, tongue, and extremities.

Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements.

An impairment of memory as manifested by a reduced ability to remember things such as dates and names, and increased forgetfulness.

A tremor present when the limbs are active, either when outstretched in a certain position or throughout a voluntary movement.

A type of tremors that is triggered by holding a limb in a fixed position.

An unintentional, oscillating to-and-fro muscle movement affecting head movement.

Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.

Wasting (atrophy) of the vermis of cerebellum.

An abnormal result of a physical examination of the the hand that tests for palsy of the ulnar nerve. This nerve innervates the adductor pollicis and interossei muscles and thereby enables adduction of the thumb and extension of the interphalangeal joint. An abnormal result consists in reduced functionality and muscular weakness in the pinch grip between the thumb and index finger of the affected hand as the patient attempts to pinch a piece of paper that the examiner tries to pull away. The flexor pollicis longus muscle tries to compensate for the weakness by flexing the tip of the thumb at the interphalangeal joint.

A disturbance of executive functioning, which is broadly defined as the set of abilities that allow for the planning, executing, monitoring, and self-correcting of goal-directed behavior while inhibiting task-irrelevant behavior. At least some degree of executive skill is needed to complete most cognitive tasks, and deficits in executive abilities are central to many clinical conditions, including fronto-temporal dementia.

The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective).

Diplopia is a condition in which a single object is perceived as two images, it is also known as double vision.

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.