A decrease in the level of erythritol in the urine.

An increase in the level of D-threitol in the urine.

An increase in the level of ribitol in the urine. Ribotol is a crystalline pentose alcohol (C5H12O5) and is a metabolic end product formed by the reduction of ribose.

An increase in the level of ribose in the urine.

An increase in the level of xylitol in the urine.

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).

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.

A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes.

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

A generalized disorder of peripheral nerves.

This term describes abnormality of the white matter of the cerebrum resulting from damage to the myelin sheaths of nerve cells.

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

Concentration of erythritol in the cerebrospinal fluid below the lower limit of normal.

The concentration of D-threitol in the cerebrospinal fluid is above the upper limit of normal.

The concentration of ribitol in the cerebrospinal fluid is above the upper limit of normal.

The concentration of ribose in the cerebrospinal fluid is above the upper limit of normal.

The concentration of xylitol in the cerebrospinal fluid is above the upper limit of normal.

An increase in the level of polyol compounds in the brain identified by magnetic resonance spectroscopy (MRS).

The concentration of ribitol in the blood circulation is above the upper limit of normal.

An increase in the level of D-threitol in the plasma.

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

Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.