Ataxia

Ataxia : is Greek word mean disorder Symptoms and signs of ataxia consist of : Gait impairment Unclear ("scanning") speech Visual blurring due to nystagmus Hand incoordination Tremor with movement. These result from the involvement of the cerebellum and its afferent and efferent pathways.

True cerebellar ataxia must be distinguished from ataxia associated with vestibular nerve or labyrinthine disease, as the latter results in a disorder of gait associated with a significant degree of dizziness, light-headedness. True cerebellar ataxia is devoid of these vertiginous(dizziness and light-headedness) complaints and is clearly an unsteady gait due to imbalance.

Ataxia is classified into: Sensory disturbances can also on occasion simulate the imbalance of cerebellar disease; with sensory ataxia (due to involvment of joint position) , imbalance dramatically worsens when visual input is removed (Romberg sign). Ataxia is classified into: Acute ,sub acute and chronic Hereditary and acquired

Acute (Hours to Days) Vascular: cerebellar infarction, hemorrhage, Intoxication: alcohol, lithium, phenytoin barbiturates Acute cerebellitis eg: (varcilla ,polio ,caosaki) virus cerebellar abscess. Post infection syndrome especially after varcilla

Subacute (Days to Weeks) Intoxication: mercury, solvents, gasoline, glue; cytotoxic chemotherapy, degeneration of the cerebellar vermis: may be due to the combined effects of alcoholism and malnutrition, particularly with deficiencies of vitamins B1 and B12. Tumour: cerebellar glioma or metastatic tumor Demyelinating: multiple sclerosis

Chronic (Months to Years) Paraneoplastic cerebellar ataxia is associated with a number of different tumors (and autoantibodies) such as : breast and ovarian cancers (anti-Yo), small-cell lung cancer (anti-PQ type voltage-gated calcium channel), Inherited diseases Amiodarone, phenytoin

The Inherited Ataxias These may show autosomal dominant, autosomal recessive, or maternal (mitochondrial) modes of inheritance:

Autosomal Dominant Ataxias The autosomal dominant spinocerebellar ataxias (SCAs) include SCA types 1 through SCA 30,

Autosomal Recessive Ataxias Friedreich's Ataxia This is the most common form of inherited ataxia, comprising one-half of all hereditary ataxias. It can occur in a classic form or in association with a genetically determined vitamin E deficiency syndrome; the two forms are clinically indistinguishable. Symptoms and Signs Friedreich's ataxia presents before 25 years of age with: progressive ataxia . the lower extremities are more severely involved than the upper ones

Musculoskeletal deformities :progressive scoliosis, foot deformity pes cavus, pes equinovarus extensor plantar responses, absence of deep tendon reflexes, and weakness (greater distally than proximally) are usually found. Loss of vibratory and proprioceptive sensation occurs. ,

Cardiac involvement occurs in 90% of patients Cardiac involvement occurs in 90% of patients. Cardiomegaly, symmetric hypertrophy, murmurs, and conduction defects are reported. Moderate mental retardation or psychiatric syndromes are present in a small percentage of patients. A high incidence of diabetes mellitus (20%) is found and is associated with insulin resistance and pancreatic B-cell dysfunction.

The median age of death is 35 years The median age of death is 35 years. Women have a significantly better prognosis than men, MRI of the spinal cord shows atrophy  also slight atrophy of the cerebellum may occur.

investigation for ataxia Blood Studies: CBP ,Alcohol level,,Anticonvulsant drug levels,Vitamin E levels, paraneoplastic antibody panel Neuroimaging:Brain imaging is useful for demonstrating posterior fossa tumors or malformations, cerebellar infarction or hemorrhage, and cerebellar atrophy associated with degenerative disorders and Brain (MRI) provides better visualization of posterior fossa lesions, including tumors, and is superior to CT scanning for detecting the lesions of multiple sclerosis.

CSF : in case of infection eg. Cerebellitis. Genetic studies: in case of hereditary ataxia

Treatment of Ataxic Disorders The most important goal in management of patients with ataxia is to identify treatable disease entities. Mass lesions must be recognized promptly and treated appropriately. Paraneoplastic disorders treated by removal the primary cancer or by immunotherapy.

Malabsorption syndromes leading to vitamin E deficiency may lead to ataxia. The vitamin E deficiency form of Friedreich's ataxia must be considered, and serum vitamin E levels measured. Vitamin E therapy is indicated for these rare patients. Vitamin B1 and B12 levels in serum should be measured, and the vitamins administered to patients having deficient levels.

Wernicke’s encephalopathy Wernicke–Korsakoff syndrome The presentation of Wernicke’s encephalopathy (ophthalmoplegia, ataxia and confusion) can progress to the irreversible deficits of Korsakoff’s syndrome (severe short-term memory impairment ) resulting from an acquired nutritional deficiency of thiamine (vitamin B1). Thiamine (and other B vitamins) is a co-enzyme in glucose and lipid metabolism, amino acid production and neurotransmitter synthesis. Because thiamine stores are relatively small and there is a large daily turnover, deficiency may occur within 2–3 weeks of low intake

Causes Treatment Alcohol hyperemesis of pregnancy systemic malignancy haemo- or peritoneal dialysis Gastrointestinal surgery prolonged intravenous feeding anorexia AIDS Treatment is by thiamine given immediately commencing at 50–100 mg parenterally in the acute stage may continue for several days..