Recessive ataxia with ocular apraxia - Review of 22 Portuguese patients

Background: The recessive ataxias are a heterogeneous group of neurodegener ative disorders characterized by cerebellar ataxia associated with a number of different neurologic, ophthalmologic, or general signs. They are often difficult to classify in clinical terms, except for Friedreich ataxia, atax ia-telangiectasia, and a relatively small group of rare conditions for whic h the molecular basis has already been defined. Objectives: To study the clinical presentation and to define diagnostic cri teria in a group of Portuguese patients with ataxia and ocular apraxia, an autosomal recessive form without the essential clinical and laboratory feat ures of ataxia-telangiectasia. Patients and Methods: We reviewed 22 patients in 11 kindreds, identified th rough a systematic survey of hereditary ataxias being conducted in Portugal . Results: Age at onset ranged from 1 to 15 years, with mean of 4.7 years. Th e duration of symptoms at the time of last examination varied from 5 to 58 years. All patients presented with progressive cerebellar ataxia, the chara cteristic ocular apraxia, and a peripheral neuropathy. Associated neurologi c signs included dystonia, scoliosis, and pes cavus. Magnetic, resonance im aging was performed in 16 patients, all of whom showed cerebellar atrophy. Conclusions: Ataxia with ocular apraxia may be more frequent than postulate d before, and may be identified clinically using the following criteria: (1 ) autosomal recessive transmission; (2) early onset (for most patients in e arly childhood); (3) combination of cerebellar ataxia, ocular apraxia, and early areflexia, with later appearance of the full picture of peripheral ne uropathy; (4) absence of mental retardation, telangiectasia, and immunodefi ciency; and (5) the possibility of a long survival, although with severe mo tor handicap.