A computational neurodegenerative disease progression score: method and results with the Alzheimer's disease Neuroimaging Initiative cohort.

While neurodegenerative diseases are characterized by steady degeneration over relatively long timelines, it is widely believed that the early stages are the most promising for therapeutic intervention, before irreversible neuronal loss occurs. Developing a therapeutic response requires a precise measure of disease progression. However, since the early stages are for the most part asymptomatic, obtaining accurate measures of disease progression is difficult.

PRRT2 mutations: a major cause of paroxysmal kinesigenic dyskinesia in the European population.

Objective: Paroxysmal kinesigenic dyskinesia (PKD) is a rare disorder characterized by recurrent attacks of hyperkinetic movements. PKD can be isolated or associated with benign infantile seizures as part of the infantile convulsions with choreoathetosis (ICCA) syndrome. Mutations in the PRRT2 gene were recently identified in patients with PKD and ICCA.

[Tremor in the elderly].

The various causes of tremor are considered by order of prevalence in the elderly. 1) Essential tremor occurs in 5% of the population beyond 65 years of age. It is characterized by a tremor accompanying muscle activity, and interesting, when complete, the two upper limbs, the head and the voice, with variable degree of severity.

Myoclonus-dystonia: clinical and electrophysiologic pattern related to SGCE mutations.

Objective: To clarify the clinical and neurophysiologic spectrum of myoclonus-dystonia patients with mutations of the SGCE gene.

Methods: We prospectively studied 41 consecutive patients from 22 families with documented mutations of the SGCE gene. The patients had a standardized interview, neurologic examination, and detailed neurophysiologic examination, including surface polymyography, long-loop C-reflex studies, and EEG jerk-locked back averaging.

[Dystonia, tremor and repetitive instrumental use].

Three characteristic observations are presented along with three tables presenting 24 patients with the following elements in common: excessively repeated use of an instrument such as a pen, a musical instrument or a tool. The appearance after that use of a central pathological phenomenon that includes a local dystonia of a hand or the mouth, a tremor, or the association of a tremor and a dystonia, all within the muscular domain corresponding to that of the use. The discussion, which is based exclusively on the clinical findings, deals with the following elements: the role of the use of the instrument rather than task itself, the predominant pathogenic factor which is the repetitive action, to which is added a genetic component in one incompletely penetrant case of DYT 1, and a probable genetic susceptibility in the others.