BackgroundHuntington's disease (HD) is a fatal inherited neurodegenerative disease, caused by a

The role of the cerebellum in cognition, both in healthy subjects and in patients with cerebellar diseases, is debated. Neuropsychological studies in spinocerebellar ataxia type 1 (SCA1) and type 2 (SCA2) demonstrated impairments in executive functions, verbal memory, and visuospatial performances, but prospective evaluations are not available. Our aims were to assess progression of cognitive and psychiatric functions in patients with SCA1 and SCA2 in a longitudinal study. We evaluated at baseline 20 patients with SCA1, 22 patients with SCA2 and 17 matched controls. Two subgroups of patients (9 SCA1, 11 SCA2) were re-evaluated after 2 years. We tested cognitive functions (Mini Mental State Examination, digit span, Corsi span, verbal memory, attentional matrices, modified Wisconsin Card Sorting Test, Raven Progressive Matrices, Benton test, phonemic and semantic fluency), psychiatric status (Scales for Assessment of Negative and Positive Symptoms, Hamilton Depression and Anxiety Scales), neurological conditions (Scale for Assessment and Rating of Ataxia), and functional abilities (Unified Huntington Disease Rating Scale–part IV). At baseline, SCA1 and SCA2 patients had significant deficits compared to controls, mainly in executive functions (phonemic and semantic fluencies, attentional matrices); SCA2 showed further impairment in visuospatial and visuoperceptive tests (Raven matrices, Benton test, Corsi span). Both SCA groups had higher depression and negative symptoms, particularly apathy, compared to controls. After 2 years, motor and functional disability worsened, while only attentive performances deteriorated in SCA2. This longitudinal study showed dissociation in progression of motor disability and cognitive impairment, suggesting that in SCA1 and SCA2 motor and cognitive functions might be involved with different progression rates.

Pipis et al . describe the characteristics and longitudinal follow-up of 225 patients with Charcot-Marie-Tooth disease type 2A, caused by mutations in MFN2 . They describe how different mutations affect disease onset and rate of progression and identify sensitive clinical assessments that can be used for disease monitoring.

The study was conducted on 120 patients (76 men and 44 women) affected by idiopathic Parkinson's disease (IPD) responsive to L-dopa and observed for many years. Sixty had clinical onset between the ages of 20-40, representing 10.2% of our PD population; in the others the symptoms began after the 40th birthday. The two groups were matched for sex and length of illness. In all patients a diagnosis of IPD depended on history and clinical and neuroradiological findings. Clinical, pharmacological, evolutive, and epidemiological data were collected on all patients. Thirty-six patients from each group performed motor dexterity tests (reaction time to expected and unexpected stimuli) and cognitive tests (Wechsler Adult Intelligence Scale. Benton, Short tale, and Zazzo's speed and accuracy test). To assess the prevalence of dementia and the severity of psychiatric side effects of L-dopa administration, the 60 patients with early-onset PD were compared with 134 consecutive unselected PD patients. Five percent of early-onset PD patients had a family history of the disorder. Our study showed that early-onset PD does not differ fundamentally from the late-onset form except that the former is characterized by a more rapid establishment of the full-blown parkinsonian clinical picture and deterioration of the therapeutic efficacy of L-dopa, with an earlier appearance of side effects. The results of our neuropsychological investigations suggest that early-onset PD may be a "pure" form of extrapyramidal compromise with exclusively motor manifestations.

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