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ACUTE ATAXIA

Myoclonic encephalopathy / Dancing eye Syndrome: It is an idiopathic encephalopathy. It has an acute onset of ataxia in children between 6 months to 6 years. The most predominant feature is chaotic eye movements (opsoclonus). The child cannot control the head, cannot maintain balance on sitting or standing and there is intention tremors in the limb. The symptoms evolve over a period of week or more. The symptoms may persist for months or years and may impair the child's mental development. The most common differential diagnosis would be an occult neuroblastoma and diagnosis is made by exclusion. Treatment consists of either ACTH or prednisolone. Marked improvement may occur within 1 to 4 weeks after starting treatment. ACTH is given as injection in the dose of 20 - 80 units/day either IV/IM for several weeks or months. Alternatively, oral prednisolone in the dose of 2 mg/kg/day can replace ACTH or may be given instead of ACTH. Partial or complete remission may occur in 80% of the patients.

Neuroblastoma Syndrome: The patient has same features as seen in myoclonic encephalopathy. The tumor may occur anywhere in the body - commonly in the abdomen. It is diagnosed by measuring urinary excretion of homovanillic acid (HVA) and vanillylmandelic acid (VMA). Radio-isotope studies using Metaiodobenzyl guanidine (MIBG) - a specific isotope is the investigation of choice. Treatment is surgical removal, chemotherapy and/or radiation.

Brain Tumors: Although brain tumors do present with insidious onset, sudden bleeding into the tumor or hydrocephalus may cause acute ataxia. Diagnosis is by brain imaging.

Multiple Sclerosis: It is usually seen in children above 12 years of age. It is an uncommon condition in India. It is commonly seen in females and may present as an attack of optic or retrobulbar neuritis, ataxia, regional paraesthesis, hemiparesis or seizures. It is due to non - contiguous demyelination in different areas of the CNS. The diagnosis of multiple sclerosis can be established only after the patient has had 2 separate attacks of symptoms with different localization with attacks being separated by months or years. CSF studies may show increased proteins, presence of oligoclonal bands and presence of plasma cells. MRI may detect demyelination. Treatment consists of Interferon - b and/or ACTH/Steroids. Long term outcome is unpredictable.

INVESTIGATIONS IN ACUTE CEREBELLAR ATAXIA

• CT/ MRI of the brain
  
  
• Lumbar Puncture
  
  
• Drug screen

Other investigations:

• MIBG/VMA
  
  
• METABOLIC SCREENING (UAA / PAA / LACTATE / PYRUVATE / CHOLESTEROL / LIPOPROTEINS)

Optional Investigations:

• ECG
  
  
• 2 D Echo, Friedreich's Ataxia and Refsum's disease
  
  
• Funduscopy
  
  
• Serum IgA Ataxia Telangiectasia