[Pathophysiological and diagnostic aspects of Guillain-Barré syndrome]. / Syndrome de Guillain-Barré : physiopathologie et aspects diagnostiques.

Guillain-Barré syndrome (GBS) is the most common cause of acute neuropathy. It usually onset with a rapidly progressive ascending bilateral weakness with sensory disturbances, and patients may require intensive treatment and close monitoring as about 30% have a respiratory muscle weakness and about 10% have autonomic dysfunction. The diagnosis of GBS is based on clinical history and examination. Complementary examinations are performed to rule out a differential diagnosis and to secondarily confirm the diagnosis. GBS is usually preceded by an infectious event in ≈ 2/3 of cases. Infection leads to an immune response directed against carbohydrate antigens located on the infectious agent and the formation of anti-ganglioside antibodies. By molecular mimicry, these antibodies can target structurally similar carbohydrates found on host's nerves. Their binding results in nerve conduction failure or/and demyelination which can lead to axonal loss. Some anti-ganglioside antibodies are associated with particular variants of GBS: the Miller-Fisher syndrome, facial diplegia and paresthesias, the pharyngo-cervico-brachial variant, the paraparetic variant, and the Bickerstaff brainstem encephalitis. Their semiological differences might be explained by a distinct expression of gangliosides among nerves. The aim of this review is to present pathophysiological aspects and the diagnostic approach of GBS and its variants.

Toxic-metabolic encephalopathy in adults: Critical discussion and pragmatical diagnostic approach.

Toxic-metabolic encephalopathy (TME) results from an acute cerebral dysfunction due to different metabolic disturbances including medications or illicit-drugs. It can lead to altered consciousness, going from delirium to coma, which may require intensive care and invasive mechanical ventilation. Even if it is a life-threatening condition, TME might have an excellent prognosis if its etiology is rapidly identified and treated adequately. This review summarizes the main etiologies, their differential diagnosis, and diagnostic strategy and management of TME with a critical discussion on the definition of TME.

COVID-19-related encephalopathy: a case series with brain FDG-positron-emission tomography/computed tomography findings.

AIM: The aim of this paper is to describe the clinical features of COVID-19-related encephalopathy and their metabolic correlates using brain 2-desoxy-2-fluoro-D-glucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) imaging. BACKGROUND AND PURPOSE: A variety of neurological manifestations have been reported in association with COVID-19. COVID-19-related encephalopathy has seldom been reported and studied. METHODS: We report four cases of COVID-19-related encephalopathy. The diagnosis was made in patients with confirmed COVID-19 who presented with new-onset cognitive disturbances, central focal neurological signs, or seizures. All patients underwent cognitive screening, brain magnetic resonance imaging (MRI), lumbar puncture, and brain 2-desoxy-2-fluoro-D-glucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) (FDG-PET/CT). RESULTS: The four patients were aged 60 years or older, and presented with various degrees of cognitive impairment, with predominant frontal lobe impairment. Two patients presented with cerebellar syndrome, one patient had myoclonus, one had psychiatric manifestations, and one had status epilepticus. The delay between first COVID-19 symptoms and onset of neurological symptoms was between 0 and 12 days. None of the patients had MRI features of encephalitis nor significant cerebrospinal fluid (CSF) abnormalities. SARS-CoV-2 RT-PCR in the CSF was negative for all patients. All patients presented with a consistent brain FDG-PET/CT pattern of abnormalities, namely frontal hypometabolism and cerebellar hypermetabolism. All patients improved after immunotherapy. CONCLUSIONS: Despite varied clinical presentations, all patients presented with a consistent FDG-PET pattern, which may reflect an immune mechanism.

Are the French neurology residents satisfied with their training?

BACKGROUND: There have been dramatic changes in neurology over the past decade; these advances require a constant adaptation of residents' theoretical and practical training. The French Association of Neurology Residents and the College of Neurology Teachers conducted a national survey to assess the French neurology residents' satisfaction about their training. METHODS: A 16-item questionnaire was sent via e-mail to French neurology residents completing training in 2014. Data were collected and processed anonymously. RESULTS: Of eligible respondents, 126 returned the survey, representing approximately 40% of all the French neurology residents. Most residents (78%) rated their clinical training favorably. Seventy-two percent reported good to excellent quality teaching of neurology courses from their faculty. However, many residents (40%) felt insufficient their doctoral thesis supervision. All residents intended to enter fellowship training after their residency, and most of them (68%) planned to practice in a medical center. CONCLUSION: French neurology residents seemed satisfied with the structure and quality of their training program. However, efforts are required to improve management of the doctoral thesis and make private practice more attractive and accessible during the residency. In the future, similar surveys should be scheduled to regularly assess neurology residents' satisfaction and the impact of the forthcoming national and European reforms.

Daily FOUR score assessment provides accurate prognosis of long-term outcome in out-of-hospital cardiac arrest.

BACKGROUND: The accurate prediction of outcome after out-of-hospital cardiac arrest (OHCA) is of major importance. The recently described Full Outline of UnResponsiveness (FOUR) is well adapted to mechanically ventilated patients and does not depend on verbal response. OBJECTIVE: To evaluate the ability of FOUR assessed by intensivists to accurately predict outcome in OHCA. METHODS: We prospectively identified patients admitted for OHCA with a Glasgow Coma Scale below 8. Neurological assessment was performed daily. Outcome was evaluated at 6 months using Glasgow-Pittsburgh Cerebral Performance Categories (GP-CPC). RESULTS: Eighty-five patients were included. At 6 months, 19 patients (22%) had a favorable outcome, GP-CPC 1-2, and 66 (78%) had an unfavorable outcome, GP-CPC 3-5. Compared to both brainstem responses at day 3 and evolution of Glasgow Coma Scale, evolution of FOUR score over the three first days was able to predict unfavorable outcome more precisely. Thus, absence of improvement or worsening from day 1 to day 3 of FOUR had 0.88 (0.79-0.97) specificity, 0.71 (0.66-0.76) sensitivity, 0.94 (0.84-1.00) PPV and 0.54 (0.49-0.59) NPV to predict unfavorable outcome. Similarly, the brainstem response of FOUR score at 0 evaluated at day 3 had 0.94 (0.89-0.99) specificity, 0.60 (0.50-0.70) sensitivity, 0.96 (0.92-1.00) PPV and 0.47 (0.37-0.57) NPV to predict unfavorable outcome. CONCLUSION: The absence of improvement or worsening from day 1 to day 3 of FOUR evaluated by intensivists provides an accurate prognosis of poor neurological outcome in OHCA.

[Chronic obstructive pulmonary disease: an autoimmune disease?]. / La bronchopneumopathie chronique obstructive: une maladie auto-immune ?

Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and mortality characterized by irreversible airflow limitation involving a reduced caliber of distal airways (less than 2mm) and alveolar destruction. Exposure to tobacco is a major risk factor for COPD, but all smokers do not develop the disease. In addition, there is continued progression of the disease several years after cessation of the exposure. To explain these phenomena, factors involving innate immunity including the release of neutrophil elastase, macrophage metalloproteases, in combination with pro-apoptotic factors, involved in the worsening of the lesions of emphysema and fibrosis of small airways have been described for many years. More recently, it has been proposed at an advanced stage of the disease that an autoimmune reaction directed mainly at elastin could participate to the pathogenesis of the disease. We here review the immunological processes and currently available data on autoimmunity in COPD.

Prevalence of MRI-defined recent silent ischemia and associated bleeding risk with thrombolysis.

BACKGROUND: Uncertainties about the frequency and the associated bleeding risk of recent silent ischemia (RSI), incidentally found on pretreatment MRI, in candidates for thrombolysis require clarification because exclusion from therapy is a serious consequence for patients with such MRI findings. METHODS: We retrospectively analyzed the fluid-attenuated inversion recovery (FLAIR)/diffusion-weighted imaging (DWI) obtained before IV thrombolysis in 115 patients to search for MRI-defined RSI; these corresponded to well-developed FLAIR/DWI brain hyperintensities (RSI+), as distinct from the acute index ischemia, which typically lacked FLAIR changes. Patients without such findings were assigned to the RSI- group. Groups were compared for baseline characteristics and for rates of symptomatic and asymptomatic hemorrhagic transformation (HT) using odds ratios (OR) and their 95%confidence intervals (CI). RESULTS: We observed RSI in 21 patients (18.3%). The mean (SD) volume of RSI was 6.5 (12) mL (interquartile range 0.6-9). None of the baseline parameters differed between groups. There was no significant difference in rates of any type of HT between groups. Parenchymal hemorrhage type 1 or type 2 according to European Cooperative Acute Stroke Study criteria occurred in 2 (10%) RSI+ patients and in 10 (11%) RSI- patients (OR 0.88; 95% CI 0.18-4.37). Symptomatic HT, defined according to National Institute of Neurological Disorders and Stroke criteria, occurred in 1 (5%) RSI+ patient and in 10 (11%) RSI- patients (OR 0.42; 95% CI 0.05-3.47). CONCLUSIONS: We found that 18.3% of patients with acute stroke treated by IV thrombolysis in a stroke unit had RSI on pretreatment MRI. However, the presence of RSI was not associated with an increased risk of asymptomatic or symptomatic HT.