The Canadian Movement Disorder Group

Definition: Ataxia is a term to describe loss of balance.

The part of the brain that is involved in balance is at the back of the brain, attached to the brainstem, and is called the "Cerebellum". Damage to the cerebellum or its connections may result in dizziness, unsteadiness of walking, and clumsiness of hand and foot coordination. a very good descriptive example video can be seen on youtube at

Many conditions can cause the cerebellum to stop working normally.

Causes of Ataxia include a huge number of conditions:

    Drug / Toxin induced cerebellar dysfunction:

      These include drugs; Clonazepam, Tegretol, Phenobarb, Primidone, Dilantin and toxins including; alcohol intoxication, alcoholism, solvent abuse , lead / mercury

    Trauma to the cerebellum

      Head Injury

    Endocrine Disorders (diseases of the glands that release hormones)


      Vitamin E deficiency

      Nutritional Deficiencies

      Vitamin B12 deficiency

    Neoplastic (Tumor) - Primary or Metastatic

    Paraneoplastic (Associated with a distant tumor)

    Vascular Causes (Stroke)

      These include; vasculitis (inflamation of blood vessels eg. Lupus), angioblastoma (a tumor of the blood vessels), embolism (a blood clot plugging a blood vessel), hemorrhage (a blood vessel rupturing and  bleeding into the cerebellum), and Von-Hippel-Lindau Syndrome (a disorder of blood vessel formation),

     Infectious Conditions Affecting the Cerebellum:

      These include; syphilis, A.I.D.S., cerebellar abscess, Coxsackie virus,  Diptheria, Mumps, Polio, Typhus, Echovirus, Pertusis, Rubeola, Varicella, Infectious Mononucleosis, Mycoplasma, Infectious polyneuropathy, and Japenese B encephalopathy.

    Inflammatory / Autoimmune conditions:

      Multiple Sclerosis, Acute Disseminated Encephalomyelitis, Lupus, Antiphospholipid antibody syndrome, Anti GAD syndrome, Celiac disease

    Sporadic Degenerative Neurologic Conditions:

      Primary cerebellar degeneration, Multiple system Atrophy - type C (previously referred to as Olivo-ponto-cerebellar Degeneration (O.P.C.A.),

    Inherited Degenerative Neurologic Conditions:

    • Spinocerebellar Ataxias (S.C.A.1,2,3,4,5,6,7 etc), Ataxia Telangiectasia, Fragile X premutation syndrome, Cerebellar Ataxia (with deafness, anosmia, absent corneals, nonreactive pupils, and hyporeflexia), Huntington's disease, Dentate cerebellar ataxia, Familial Ataxia with macular degeneration, Familial intention tremor, ataxia, lipofuscinosis, Friedreichs ataxia, Hereditary ataxia (with intellectual retardation, choreoathetosis, and  eunuchoidism), Hereditary ataxia (with myotonia and cataracts), Acute Intermittent Cerebellar Ataxia, Ataxia (with Retinitis Pigmentosa, deafness, vestibullar abnormality, and intellectual dysfunction), Hypertrophic interstitial neuritis, Marinesco-Sjogren Syndrome, Pelizaeus-Merzbacher disease, Periodic ataxia (with attacks of vertigo, diplopia, and ataxia), Ataxia (with posterior, and lateral column difficulties, with nystagmus and muscle atrophy), Progressive cerebellar ataxia and epilepsy, Ramsy Hunt syndrome, and Roussy-Levy syndrome  

    Inherited Ataxias with known metabolic defects (with lists of main features:

      Abetalipoprotienemia( Bassen-Kornzwieg Syndrome)

        Ataxia, retinitis, acanthocytosis, malabsorption, acanthocytes, low cholesterol, low Beta-Lipoprotein, and absent LDL's

      Arginosuccinic aciduria

        Siezures, hypotonia, hepatomegally, tufted friable hair, child onset, increasd Arginosuccinic acid in plasma

      Ceroid lipofuscinosis  (Kufs Disease)

        Seizures, ataxia, myoclonus, dementia, Hypertension. Exam shows cerebellar, pyramidal, and extrapyramidal siggns. Increased Lipopigments Ceroid, and Lipofuscin on brain biopsy, Peripheral leukocyte vacoules, and ceroid engorged vacuoles on conjunctival biopsy

      Gm2 gangliosidoses (Tay-Sachs)( Sandhoffs)

        Hyperacusis,myoclonus, seizures, developemental delay. Onset in first months of life. Very low levels of beta-hexosaminidase in serum, Leukocytes, and cultured fibroblasts

      Neutral amminoaciduria (Hartnup disease)

        Pellagra type rash, and intermittent ataxia, triggered by sunlight or stress.


        Severe retardation, siezures, myoclonus, in childhood. Ketoacidosis, and increased alanine in urine, and serum

       Hyperammonemia I and II;

        Increased ammonia, Hypoglycemia

      Galactocerebrosidase Lipidosis (Krabbe Disease)

        Early oset of retardation, spasticity, siezures and optic atrophy (blindness). Unlikely to live past 2 years. Macrocephaly,peripheral  neuropathy,hyporeflexia. Adult syndrome consists of leukodysrophy, cortical blindness, and spasticity. Peripheral neuropathy is rare. Dx B-gaclactocerebrosidase measurement.

       Maple suryp urine disease

        Rarely to live to age 5. Patients aquire spasticity, seizures, intermintant ataxia. Dx sweet smelling urine, increased amino (branched) acids in urine.

      Metochromatic Leukodystrophy

        Patients aquire retardation, leukodystrophy, psychosis, and dementia. Dx increased csf protein, peripheral neuropathy: Arylsulphatase def.

      Niemann-Pick disease

        Patients aquire retardation, seizures,ataxia. Dx by finding "Sea Blue" histiocytes in bone marrow, supranuclear  gaze palsy (upgaze). Vacuolated Lymphocytes, Sphingomyelinase def.

      Hereditary atactica polyneuritiformis (Refsum disease)

        Chronic neuropathy(motor and sensory (HMSN type IV), ataxia, increase csf protien,retinitis. Dx increased serum Phytanic acid


        Ataxia, photosensitivity, short stature, and mental retardation. Dx increased serum tryptophan

    Wernike encephalopathy

      Thiamine deficiency due to malnutrition, or Alcoholism

    Congenital (I.E. present at Birth)

      A variety of structural brain deffects can present as Ataxia including: Agenesis of vermis, Dysplasia, of cerebellum, Arnold-Chiari Malformation, Dandy Walker Malformation, Encephalocele, Platybasia and Hydrocephalus

    Functional causes

    Ataxia Websites


    National Ataxia Foundation   USA



    MSA Type C (Olivopontocerebellar Atrophy

    OPCA awareness site.

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