The paired-pulse TMS paradigm of short intracortical inhibition is mediated by a reduction of repetitive motor neuron discharges.

Transcranial magnetic stimulation (TMS) causes repetitive spinal motoneuron discharges (repMNDs), but the effects of short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) on repMNDs remain unknown. Triple stimulation technique (TST) and the extended TST-protocols that include a fourth and fifth stimulation, the Quadruple (QuadS) and Quintuple (QuintS) stimulation, respectively, offer a precise estimate of cortical and spinal motor neuron discharges, including repMNDs. The objective of our study was to explore the effects of SICI and ICF on repMNDs. We explored conventional paired-pulse TMS protocols of SICI and ICF with the TMS, TST, the QuadS, and the QuintS protocols, in a randomized study design in 20 healthy volunteers. We found significantly less repMNDs in the SICI paradigm compared with a single-pulse TMS (SP-TMS). No significant difference was observed in the ICF paradigm. There was a significant inter- and intrasubject variability in both SICI and ICF. We demonstrate a significant reduction of repMNDs in SICI, which may result from the suppression of later I-waves and mediate the inhibition of motor-evoked potential (MEP). There is no increase in repMNDs in ICF suggesting another mechanism underlying facilitation. This study provides the proof that a reduction of repMNDs mediates the inhibition seen in SICI.NEW & NOTEWORTHY Significant reduction of repetitive motor neuron discharges (repMNDs) in short-interval intracortical inhibition (SICI) may result from the suppression of later I-waves and mediate the inhibition of motor-evoked potential (MEP). There is no change in the number of repMNDs in intracortical facilitation (ICF). There was a significant variability in SICI and ICF in healthy subjects.

[Cerebral small vessel disease]. / Microangiopathie cérébrale.

Cerebral microangiopathy is the second leading cause of dementia after Alzheimer's disease and is a co-factor in the majority of dementias. Its clinical manifestations are multiple and include in addition to cognitive and neuropsychiatric manifestations, also problems of gait, urinary continence, and lacunar-ischaemic and haemorrhagic strokes. Patients with similar radiologic images can present very variable clinical pictures, partially resulting from damage to the neurovascular unit, not visible on conventional MRI, and affecting different neural networks. Management and prevention are possible and effective with well-known, readily available and affordable treatments, through aggressive management of cerebrovascular risk factors.

La microangiopathie cérébrale est la deuxième cause de démence après la maladie d'Alzheimer et est un cofacteur dans la majorité des démences. Ses manifestations cliniques sont multiples et incluent, en plus des troubles cognitifs, des troubles de la marche, de la continence urinaire, neuropsychiatriques, et des AVC lacunaires-ischémiques et hémorragiques. Des patients avec des images radiologiques similaires peuvent présenter des tableaux cliniques très variables, en partie découlant d'atteintes de l'unité neurovasculaire, non visibles en IRM conventionnelle, et altérant des réseaux neuronaux différents. Une prise en charge et une prévention sont possibles et efficaces avec des traitements bien connus, disponibles à un prix abordable, par un traitement agressif des facteurs de risque cérébrovasculaire.

[Neurology: what's new in 2022]. / Neurologie : ce qui a changé en 2022.

The year 2022 was marked by the development of numerous new treatments for refractory myasthenia gravis. The link between epilepsy and cerebrovascular disorder was studied and lamotrigine discovered to be the optimal treatment choice for epilepsy secondary to stroke to prevent mortality on patient of 45 years and older. New randomized study finally demonstrated the utility of thrombectomy in selected patients with basilar artery occlusion. The causal relationship between Epstein-Barr infection and multiple sclerosis has been proved thanks to a large cohort study. A new possibility of subcutaneous continuous levodopa administration gave promising result. Finally, numerous studies confirmed the efficacy and excellent tolerability of anti-CGRP antibodies.

L'année 2022 a été marquée par l'arrivée de nombreux traitements pour la myasthénie réfractaire. Le lien entre l'épilepsie et le risque cérébro-vasculaire a été bien étudié, démontrant que la lamotrigine semble être le meilleur traitement pour prévenir la mortalité chez les patients de 45 ans et plus. De nouvelles études ont enfin pu établir l'utilité de la thrombectomie dans les occlusions basilaires. Le lien entre le virus d'Epstein-Barr et la sclérose en plaques a pu être prouvé à la suite d'une importante étude de cohorte. Une nouvelle technique d'administration sous-cutanée de la lévodopa semble prometteuse. Enfin, de nombreuses études confirment l'efficacité et l'excellente tolérance des anticorps anti-CGRP (Calcitonine Gene Related Protein).

Ketamine in adult super-refractory status epilepticus: Efficacy analysis on a prospective registry.

BACKGROUND: Status epilepticus (SE) persisting despite two anti-seizures medications (ASM) and anesthetics is labeled super refractory (SRSE), correlating with important morbidity and mortality. Its treatment relies on expert opinions. Due to its pharmacological properties, ketamine (KET) has received increasing attention, but data are essentially retrospective. AIMS: To describe an unselected cohort of adults receiving KET for SRSE. METHODS: Analysis of a prospective registry of consecutive SE episodes, identifying SRSE patients receiving ketamine (KET). Comparison with recent adult series including more than 10 patients. RESULTS: Eleven patients received KET after a median of 4 days (range: 2-20); median dose was 5 mg/kg/h (range: 2.5-15). KET provided permanent SE control in three (27%). Previous series, using KET administration delays and doses similar to our cohort, report KET efficacy in 28-96% of cases. CONCLUSIONS: We found a lower SE control rate than existing literature, whose data are, however, often retrospective, potentially selecting patients with less severe SE forms or responding to KET. This might explain outcome differences, as KET administration modalities were comparable with our cohort. Since randomized controlled studies are lacking on this subject, the analysis of this prospective, unselected cohort, if confirmed, suggests a current overestimation of KET efficacy in SRSE.

Pearls and Oy-sters: Post-dural Puncture Headache, Cerebral Sinus Venous Thrombosis, and Reversible Cerebral Vasoconstriction Syndrome in the Peripartum.

We report the case of a 34-year-old female patient complaining of headaches one day after childbirth, initially interpreted as post-dural puncture headache (PDPH) and treated successfully with an epidural blood patch. Five days later, she presented an acute proportional right sensorimotor hemisyndrome and a new onset left-sided headache, attributed to a venous stroke from left-sided cerebral sinus venous thrombosis (CSVT). Simultaneously, we found radiological signs of reversible cerebral vasoconstriction syndrome (RCVS), considered as asymptomatic. We started the patient on anticoagulant therapy and she showed full motor recovery at the 3-month clinical follow-up.PDPH, CSVT and RCVS are well-known neurological complications of the peripartum period. All three conditions present with headaches and headache features may overlap, masking co-occurrence and making accurate diagnosis (differentiation) of these diseases difficult. Each disease can potentially lead to disabling deficits, but all respond to specific treatment.Knowledge of the causes of headaches in the peripartum period, their specific clinical characteristics and potential complications helps to prioritize and interpret diagnostic tests to offer appropriate therapy.

Encephalopathies Associated With Severe COVID-19 Present Neurovascular Unit Alterations Without Evidence for Strong Neuroinflammation.

OBJECTIVE: Coronavirus disease (COVID-19) has been associated with a large variety of neurologic disorders. However, the mechanisms underlying these neurologic complications remain elusive. In this study, we aimed at determining whether neurologic symptoms were caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) direct infection or by either systemic or local proinflammatory mediators. METHODS: In this cross-sectional study, we checked for SARS-CoV-2 RNA by quantitative reverse transcription PCR, SARS-CoV-2-specific antibodies, and 49 cytokines/chemokines/growth factors (by Luminex) in the CSF +/- sera of a cohort of 22 COVID-19 patients with neurologic presentation and 55 neurologic control patients (inflammatory neurologic disorder [IND], noninflammatory neurologic disorder, and MS). RESULTS: We detected anti-SARS-CoV-2 immunoglobulin G in patients with severe COVID-19 with signs of intrathecal synthesis for some of them. Of the 4 categories of tested patients, the CSF of IND exhibited the highest level of cytokines, chemokines, and growth factors. By contrast, patients with COVID-19 did not present overall upregulation of inflammatory mediators in the CSF. However, patients with severe COVID-19 (intensive care unit patients) exhibited higher concentrations of CCL2, CXCL8, and vascular endothelium growth factor A (VEGF-A) in the CSF than patients with a milder form of COVID-19. In addition, we could show that intrathecal CXCL8 synthesis was linked to an elevated albumin ratio and correlated with the increase of peripheral inflammation (serum hepatocyte growth factor [HGF] and CXCL10). CONCLUSIONS: Our results do not indicate active replication of SARS-CoV-2 in the CSF or signs of massive inflammation in the CSF compartment but highlight a specific impairment of the neurovascular unit linked to intrathecal production of CXCL8.