Abnormal eyeblink conditioning is an early marker of cerebellar dysfunction in preclinical SCA3 mutation carriers

BACKGROUND: Spinocerebellar ataxias (SCAs) are a group of autosomal dominantly inherited degenerative diseases. As the pathological process probably commences years before the first appearance of clinical symptoms, preclinical carriers of a SCA mutation offer the opportunity to study the earliest stages of cerebellar dysfunction and degeneration. Eyeblink classical conditioning (EBCC) is a motor learning paradigm, crucially dependent on the integrity of the olivocerebellar circuit, and has been shown to be able to detect subtle alterations of cerebellar function, which might already be present in preclinical carriers. METHODS: In order to acquire conditioned responses, we performed EBCC, delay paradigm, in 18 preclinical carriers of a SCA3 mutation and 16 healthy, age-matched controls by presenting repeated pairings of an auditory tone with a supraorbital nerve stimulus with a delay interval of 400 ms. RESULTS: Preclinical carriers acquired significantly less conditioned eyeblink responses than controls and learning rates were significantly reduced. This motor learning defect was, however, not associated with the predicted time to onset. CONCLUSIONS: EBCC is impaired in preclinical carriers of a SCA3 mutation, as a result of impaired motor learning capacities of the cerebellum and is thus suggestive of cerebellar dysfunction. EBCC can be used to detect but probably not monitor preclinical cerebellar dysfunction in genetic ataxias, such as SCA3.status: publishe

Follow-up care by a genetic counsellor for relatives at risk for cardiomyopathies is cost-saving and well-appreciated: A randomised comparison

Increasing numbers of patient relatives at risk of developing dilated or hypertrophic cardiomyopathy (DCM/HCM) are being identified and followed up by cardiologists according to the ACC/ESC guidelines. However, given limited healthcare resources, good-quality low-cost alternative approaches are needed. Therefore, we have compared conventional follow-up by a cardiologist with that provided at a cardiogenetic clinic (CGC) led by a genetic counsellor. Phenotype-negative first-degree relatives at risk for DCM/HCM were randomly assigned to see either a cardiologist or to attend a CGC. Uptake and resource use were recorded. For 189 participants, we evaluated quality of care experienced, patient satisfaction and perceived personal control (PPC) using validated questionnaires and estimated the average cost difference of these two modes of care. Maximum patient satisfaction scores were achieved more frequently at the CGC (86% vs 45%,