Transient hypoxemia induced by cortical electrical stimulation: A mapping study in 75 patients.

OBJECTIVE: To identify which cortical regions are associated with direct electrical stimulation (DES)-induced alteration of breathing significant enough to impair pulse oximetry (SpO2). METHODS: Evolution of SpO2 after 1,352 DES was analyzed in 75 patients with refractory focal epilepsy who underwent stereo-EEG recordings. For each DES, we assessed the change in SpO2 from 30 seconds prior to DES onset to 120 seconds following the end of the DES. The primary outcome was occurrence of stimulation-induced transient hypoxemia as defined by decrease of SpO2 ≥5% within 60 seconds after stimulation onset as compared to pre-DES SpO2 or SpO2 nadir <90% during at least 5 seconds. Localization of the stimulated contacts was defined according to MarsAtlas brain parcellation and Freesurfer segmentation. RESULTS: A stimulation-induced transient hypoxemia was observed after 16 DES (1.2%) in 10 patients (13%), including 6 in whom SpO2 nadir was <90%. Among these 16 DES, 7 (44%) were localized within the perisylvian cortex. After correction for individual effects and the varying number of DES contributed by each person, significant decrease of SpO2 was significantly associated with the localization of DES (p = 0.019). CONCLUSION: Though rare, a significant decrease of SpO2 could be elicited by cortical direct electrical stimulation outside the temporo-limbic structures, most commonly after stimulation of the perisylvian cortex.

[Management of drug-resistant epilepsy]. / Prise en charge d'une épilepsie pharmacorésistante.

Epilepsy is considered as drug-resistant when seizures persist despite the administration of 2 antiepileptic drugs adapted to the patient's needs, with an effective dosage, well-tolerated, whether as a single agent or in combination. Any patient suffering from drug-resistant focal epilepsy should be evaluated at least once in a tertiary epilepsy centre to discuss the appropriateness of a pre-surgical work-up. In drug-resistant epilepsy, the determinants of quality of life are multifactorial and not exclusively linked to the seizure frequency. Anticipating the side effects of treatments is a key element during management of polytherapy. Screening for psychiatric and cognitive comorbidities must be systematic.

[Therapeutic arsenal in adult epilepsy]. / Arsenal thérapeutique dans l'épilepsie de l'adulte

Over the last 20 years, the number of drugs licensed for the treatment of seizure disorders has increased exponentially. Although the second-generation antiepileptic drugs have failed to significantly reduce the proportion of drug-resistant patients, their safety profile and the reduction of drug to drug interactions now allow to better tailor the treatment to each patient. The decision to initiate an antiepileptic drug in newly diagnosed epilepsy relies on a careful assessment of the expected benefit according both to the risk of seizure recurrence and to the risk of drug-related adverse events. In patients in whom a treatment is initiated, the final choice of the drug must then take into account both the expected efficacy of the drug and its relevance to the specific characteristics of the patient, including his/her gender, age or comorbidities. This approach is essential in all patients, with a special attention to the issues raised in women of childbearing age.

Au cours des 20 dernières années, l'arsenal thérapeutique disponible pour le traitement de l'épilepsie de l'adulte s'est très largement développé. Si les molécules de seconde génération n'ont pas permis de diminuer significativement la proportion de patients pharmacorésistants, leurs profils de tolérance et d'interaction permettent actuellement de mieux adapter le traitement à chaque patient. La décision d'introduire un traitement antiépileptique après une première crise repose sur une évaluation du bénéfice attendu en fonction du risque de récidive et des risques d'effets indésirables du traitement. Le choix final du médicament doit ensuite prendre en compte tant l'efficacité attendue de la molécule que son adéquation avec les caractéristiques spécifiques du patient, qu'il s'agisse de son sexe, de son âge ou des comorbidités dont il souffre. Cette approche est primordiale chez tous les patients, avec une attention toute particulière à la jeune femme en âge de procréer.

High incidence of carpal tunnel syndrome after deep brain stimulation in Parkinson's disease.

We observed several cases of carpal tunnel syndrome (CTS) revealed after subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD). 115 consecutive PD patients who underwent STN-DBS between 2010 and 2014 at the Neurological Hospital in Lyon were retrospectively included. CTS was accepted as the diagnosis only if clinical examination and ENMG both confirmed it. Nine patients (7.8 %) developed CTS in the 2 years following surgery, which is far beyond the 2.7/1000 incidence in the general population. The present study shows an overrepresentation of CTS occurrence after STN-DBS in PD.