The cerebellum is no longer considered a purely motor control device, and convincing evidence has demonstrated its relationship to cognitive and emotional neural circuits. The aims of the present study were to establish the core cognitive features in our patient population and to determine the presence of Cerebellar Cognitive Affective Syndrome (CCAS) in this group. We recruited 38 patients with spinocerebellar ataxia type 3 (SCA3) or Machado–Joseph disease (MJD)-SCA3/MJD and 31 controls. Data on disease status were recorded (disease duration, age, age at onset, ataxia severity, and CAG repeat length). The severity of cerebellar symptoms was measured using the International Cooperative Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia. The neuropsychological assessment consisted of the Mini-Mental State Examination, Clock Drawing Test, Wechsler Adult Intelligence Scale, Rey–Osterrieth Complex Figure, Wisconsin Card Sorting Test, Stroop Color–Word Test, Trail-Making Test, Verbal Paired Associates, and verbal fluency tests. All subjects were also submitted to the Hamilton Anxiety Scale and Beck Depression Inventory. After controlling for multiple comparisons, spatial span, picture completion, symbol search, Stroop Color–Word Test, phonemic verbal fluency, and Trail-Making Tests A and B were significantly more impaired in patients with SCA3/MJD than in controls. Executive and visuospatial functions are impaired in patients with SCA3/MJD, consistent with the symptoms reported in the CCAS. We speculate on a possible role in visual cortical processing degeneration and executive dysfunction in our patients as a model to explain their main cognitive deficit.

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Cerebellar ataxias comprise a wide range of etiologies leading to central nervous system-related motor and non-motor symptoms. Recently, a large body of evidence has demonstrated a high frequency of non-motor manifestations in cerebellar ataxias, specially in autosomal dominant spinocerebellar ataxias (SCA). Among these nonmotor dysfunctions, sleep disorders have been recognized, although still under or even misdiagnosed. In this review, we highlight the main sleep disorders related to cerebellar ataxias focusing on REM sleep behavior disorder (RBD), restless legs syndrome (RLS), periodic limb movement in sleep (PLMS), excessive daytime sleepiness (EDS), insomnia and sleep apnea. Key words: sleep disorders, ataxias, diagnosis.Distúrbios do sono nas ataxias cerebelares RESUMO As ataxias cerebelares se caracterizam por uma enorme variedade de etiologias, cursando tanto com sintomas motores como também com sintomas não motores. Recentemente, várias evidências têm demonstrado uma frequência elevada de sintomas não motores nas ataxias cerebelares, especialmente nas ataxias espinocerebelares autossômicas dominantes (SCA). Dentre os sintomas não motores, estão os distúrbios do sono, que muitas vezes são sub-diagnosticados ou pouco valorizados. Nessa revisão, enfatizamos os principais distúrbios do sono relatados nas ataxias cerebelares, como transtorno comportamental do sono REM, síndrome das pernas inquietas, movimentos periódicos das pernas no sono, sonolência diurna excessiva, insônia e apnéia do sono. Palavras-chave: distúrbios do sono, ataxias, diagnóstico.