No abstract

Two thousand three hundred and eighty-nine patients with first-ever stroke were registered in the population-based Dijon Stroke Registry over an 11-year period. There was a history of migraine in 49 cases (2%), with a majority of women (2.8% versus 1.1% men) with the following distribution: 27 cases among 1,380 large-artery cerebral infarctions (1.9%), 6 cases among 358 small-artery cerebral infarctions (1.6%), 6 cases among 412 cerebral infarctions due to cardiac embolism (1.4%), 7 cases among 191 cerebral hemorrhages (3.6%) and 3 cases among 47 subarachnoid hemorrhages (6.3%). The male/female ratio was 0.58 for the 49 strokes with a history of migraine versus 1.27 for the 2,340 strokes with no history of migraine. Twelve migraine-induced ischemic strokes occurred with an infarction of the posterior area of the brain in young patients. The annual incidence was 0.80/100,000/year (confidence interval, CI = 0.37–1.57) with a predominance of women (1.02/100,000/year, CI = 0.52–1.25; men: 0.57/100,000/year; CI = 0.28–1.04). We conclude that a history of migraine is more frequent in women, in particular in those with hemorrhagic strokes, and that the incidence of migraine-induced stroke in our population-based study is higher in women, although it remains low.

To analyze the distribution of the cortical electrical activity related to self-paced voluntary movements, i.e. the movement-related readiness potentials (Bereitschaftspotential, BP) and the event-related desynchronization (ERD) and synchronization (ERS) of cortical rhythms using intracerebral recordings. EEG was recorded in 14 epilepsy surgery candidates during preoperative video-stereo-EEG monitoring. Subjects performed self-paced hand movements, with their right and left fingers in succession. EEG signals were obtained from a total of 501 contacts using depth electrodes located in primary and nonprimary cortical regions. In accordance with previous studies, BP was found consistently in the primary motor (M1) and somatosensory (S1) cortex, the supplementary motor area (SMA), and in a few recordings also in the cingulate cortex and in the dorsolateral prefrontal and premotor cortex. ERD and ERS of alpha and beta rhythms were also observed in these cortical regions. The distribution of contacts showing ERD or ERS was larger than the distribution of those showing BP. In contrast to BP, ERD and ERS frequently occurred in the lateral and mesial temporal cortex and the inferior parietal lobule. The number of contacts and cortical regions showing ERD and ERS and not BP suggests that the two electrophysiological phenomena are differently involved in the preparation and execution of simple voluntary movements. Substantial differences between BP and ERD in spatial distribution and the widespread topography of ERD/ERS in temporal and higher-order motor regions suggest that oscillatory cortical changes are coupled with cognitive processes supporting movement tasks, such as memory, time interval estimation, and attention.

Event-related desynchronization (ERD) and synchronization (ERS) were studied during the invasive exploration of an epileptic surgery candidate. An electrode that was targeted in the amygdalo-hippocampal complex passed through the putamen with several contacts. During a simple self-paced motor task, we observed in the putamen a power decline (ERD) in both the alpha and beta frequency bands, and a rebound phenomenon (ERS) in the beta frequency band, concurrent with the movement of each hand. This is the first report of ERD/ERS in the basal ganglia.

We studied cognitive functions related to processing sensory and motor activities in the basal ganglia (BG), specifically in the putamen and in cortical structures forming the BG-frontocortical circuits. Intracerebral recordings were made from 160 brain sites in 32 epilepsy surgery candidates. We studied P3-like potentials in five different tests evoked by auditory and visual stimuli, and two sustained potentials that are related to cognitive activities linked with movement preparation: BP (Bereitschaftspotential) and CNV (contingent negative variation). We compared the presence of a potential with a phase reversal or an amplitude gradient to the absence of a generator. All of the studied cognitive potentials were generated in the BG; the occurrence in frontal cortical areas was more selective. The frequency of all but one potential was significantly higher in the BG than in the prefrontal and in the cingulate cortices. The P3-like potentials elicited in the oddball paradigm were also more frequent in the BG than in the motor/premotor cortex, while the occurrence of potentials elicited in motor tasks (BP, CNV, and P3-like potentials in the CNV paradigm) in the motor cortex did not significantly differ from the occurrence in the BG. The processing of motor tasks fits with the model by Alexander et al. of segregated information processing in the motor loop. A variable and task-dependent internal organisation is more probable in cognitive sensory information processing. Cognitive potentials were recorded from all over the putamen. The BG may play an integrative role in cognitive information processing.