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).

A group of abnormalities characterized by hyperglycemia and glucose intolerance.

A type of diabetic metabolic abnormality with an accumulation of ketone bodies.

Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.

The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction.

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

Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.

Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract.

The presence of an abnormal lateral curvature of the spine.

Absence of neurologic reflexes such as the knee-jerk reaction.

Hypertrophic cardiomyopathy with an symmetrical and concentric pattern of hypertrophy.

Any abnormality of the cardiovascular system.

An abnormal gait pattern that arises from weakness of the pretibial and peroneal muscles due to a lower motor neuron lesion. Affected patients have footdrop and are unable to dorsiflex and evert the foot. The leg is lifted high on walking so that the toes clear the ground, and there may be a slapping noise when the foot strikes the ground again.

Abnormal rhythm of the heart.

The presence of an unusually high plantar arch. Also called high instep, pes cavus refers to a distinctly hollow form of the sole of the foot when it is bearing weight.

Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint.

A decrease in the ability to perceive vibration. Clinically, this is usually tested with a tuning fork which vibrates at 128 Hz and is applied to bony prominences such as the malleoli at the ankles or the metacarpal-phalangeal joints. There is a slow decay of vibration from the tuning fork. The degree of vibratory sense loss can be crudely estimated by counting the number of seconds that the examiner can perceive the vibration longer than the patient.

An abnormal reduction in sensation in the distal portions of the extremities.

A loss or impairment of the sensation of the relative position of parts of the body and joint position.

Atrophy of the intrinsic muscle groups of the hand, comprising the thenar and hypothenar muscles; the interossei muscles; and the lumbrical muscles.

Weakness of the muscles responsible for dorsiflexion of the foot, that is, of the movement of the toes towards the shin. The foot dorsiflexors include the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus, and the peroneus tertius muscles.

Diminution of tendon reflexes, which is an invariable sign of peripheral nerve disease.

A type of subvalvular aortic stenosis resulting from thickening of the musculature of the interventricular septum, which results in obstruction to blood flow through the left-ventricular outflow tract.

An abnormality of the conduction of electrical impulses by peripheral (motor or sensory) nerves. This finding is elicited by a nerve conduction study (NCS).

An abnormality of the medulla oblongata, the lower half of the brainstem.

Any structural abnormality of the pyramidal tract, whose chief element, the corticospinal tract, is the only direct connection between the brain and the spinal cord. In addition to the corticospinal tract, the pyramidal system includes the corticobulbar, corticomesencephalic, and corticopontine tracts.

Wasting of the tibialis anterior muscle.

An abnormality of the dorsal columns, i.e., of the dorsal portion of the gray substance of the spinal cord. The dorsal column consists of the fasciculus gracilis and fasciculus cuneatus and itself is part of the dorsal funiculus.

Muscle weakness affecting the tibialis anterior muscle.

A decreased rate of pyruvate carboxylase activity.

An abnormality of the spinocerebellar tracts, a set of axonal fibers originating in the spinal cord and terminating in the ipsilateral cerebellum. The spinocerebellar tract convey information to the cerebellum about limb and joint position (proprioception). They comprise the ventral spinocerebellar tract, the anterior spinocerebellar tract, and the posterior spinocerebellar tract.