Ataxia is a term to describe loss of balance and coordination.

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.

Causes of Ataxia include a huge number of conditions:

Many conditions can cause the cerebellum to stop working normally.

Congenital (present at birth) – a variety of structural brain defects can present with ataxia including: Agenesis of the vermis, Dysplasia of the cerebellum, Arnold-Chiari malformation, Dandy-Walker malformation, Encephalocele, Platybasia and Hydrocephalus

Drugs and toxins – these include drugs such as clonazepam, carbamazepine (Tegretol), phenobarbital, primidone, phenytoin (Dilantin), and toxins including alcohol intoxication, solvent abuse, lead and mercury poisoning

Trauma – to the cerebellum from head injury

Neoplastic (tumor) – primary or metastatic

Paraneoplastic antibodies – disease causing immune particles associated with a distant tumor

Vascular causes (strokes) – these include vasculitis (inflammation of blood vessels, 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)

Endocrine disorders (diseases of the glands that release hormones – e.g. Hypothyroidism

Nutritional deficiencies – e.g. vitamin E deficiency, vitamin B12 deficiency, thiamine deficiency (Wernicke encephalopathy_

Infections – 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 (ADEM), Lupus, Antiphospholipid antibody syndrome, Anti-GAD syndrome, Celiac disease

Sporadic degenerative neurological conditions – Primary Cerebellar Degeneration, Multiple System Atrophy – type C (previously referred to as Olivo-Ponto-Cerebellar Degeneration)

Genetically inherited degenerative neurological 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
  • Friedreich’s ataxia
  • Hereditary ataxia (with intellectual retardation, choreoathetosis, and  eunuchoidism)
  • Hereditary ataxia (with myotonia and cataracts)
  • Acute Intermittent Cerebellar Ataxia, Ataxia (with retinitis pigmentosa, deafness, vestibular abnormality, and intellectual dysfunction)
  • Hypertrophic interstitial neuritis
  • Marinesco-Sjogren Syndrome
  • Pelizaeus-Merzbacher disease
  • Episodic ataxia (with attacks of vertigo, diplopia, and ataxia)
  • Ataxia (with posterior, and lateral column difficulties, with nystagmus and muscle atrophy)
  • Ataxia with Optic Apraxia
  • Progressive cerebellar ataxia and epilepsy
  • Ramsy Hunt syndrome
  • Roussy-Levy syndrome

Inherited ataxias with metabolic defects – typical onset in childhood

  • Abetalipoproteinemia (Bassen-Kornzwieg Syndrome) – ataxia, retinitis, acanthocytosis, malabsorption, low cholesterol (low beta-lipoprotein, and absent LDL cholesterol)
  • Arginosuccinic aciduria – seizures, hypotonia, hepatomegaly, tufted friable hair, child onset, increased arginosuccinic acid in plasma
  • Ceroid lipofuscinosis (Kufs Disease) – seizures, ataxia, myoclonus, dementia, hypertension. Exam shows cerebellar, pyramidal, and extrapyramidal signs. Increased lipopigments Ceroid, and Lipofuscin on brain biopsy, along with peripheral leukocyte vacuoles, and Ceroid engorged vacuoles on conjunctival biopsy
  • GM2 gangliosidoses (Tay-Sachs and Sandhoffs disease) – 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
  • Hyperalaninemia – severe retardation, seizures, myoclonus in childhood. Ketoacidosis, and increased alanine in urine, and serum
  • Hyperammonemia I and II – increased ammonia and hypoglycemia
  • Galactocerebrosidase Lipidosis (Krabbe Disease) – early onset of retardation, spasticity, seizures 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. Buildup of unmetabolized lipids secondary to galactocerebrosidase deficiency.
  • Maple syrup urine disease – rarely to live to age 5. Patients acquire spasticity, seizures, intermittent ataxia, and present with sweet smelling urine secondary to increased amino (branched) acids in urine.
  • Metochromatic Leukodystrophy – patients acquire retardation, leukodystrophy, psychosis, and dementia. Have elevated CSF protein, peripheral neuropathy and Arylsulphatase deficiency.
  • Niemann-Pick disease – patients acquire retardation, seizures, ataxia and supranuclear  gaze palsy (upgaze). Have “sea blue” histiocytes in bone marrow, vacuolated lymphocytes and Sphingomyelinase deficiency.
  • Hereditary atactica polyneuritiformis (Refsum disease) – chronic neuropathy (motor and sensory, ataxia, retinitis. increased CSF protein and increased serum Phytanic acid.
  • Tryptophanuria – ataxia, photosensitivity, short stature, and mental retardation, along with increased serum tryptophan.

For more information, please visit the National Ataxia Foundation.