Diagnostic approach is determined by the nature of the ataxia (Table 184-1). For symmetric ataxias, drug and toxicology screens; vitamin B1, B12, and E levels; thyroid function tests; antibody tests for syphilis and Lyme infection; antigliadin and anti-GAD antibodies; paraneoplastic antibodies (Chap. 77. Neurologic Paraneoplastic Syndromes); and CSF studies often indicated. Genetic testing is available for many inherited ataxias. For unilateral or asymmetric ataxias, brain MRI or CT scan is the initial test of choice; CT is insensitive for nonhemorrhagic lesions of the cerebellum.
Treatment: Ataxia - The most important goal is to identify treatable entities including hypothyroidism, vitamin deficiency, and infectious causes.
- Ataxia with antigliadin antibodies and gluten enteropathy may improve with a gluten-free diet.
- Paraneoplastic disorders are often refractory to therapy, but some pts improve following removal of the tumor or immunotherapy (Chap. 77. Neurologic Paraneoplastic Syndromes).
- Vitamins B1, B12, and E should be administered to pts with deficient levels.
- The deleterious effects of phenytoin and alcohol on the cerebellum are well known, and these exposures should be avoided in pts with ataxia of any cause.
- There is no proven therapy for any of the autosomal dominant ataxias; family and genetic counseling are important.
- There is preliminary evidence that idebenone, a free-radical scavenger, can improve myocardial hypertrophy in Friedreich's ataxia; there is no evidence that it improves neurologic function.
- Cerebellar hemorrhage and other mass lesions of the posterior fossa may require emergent surgical treatment to prevent fatal brainstem compression.
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For a more detailed discussion, see Rosenberg RN: Ataxic Disorders, Chap. 450, p. 2626, in HPIM-19. |