Christophe Marcel

Lyme optic neuritis

Lyme optic neuritis (ON) is a rare disease and only a few cases have been reported. We describe two cases of isolated Lyme ON, one with recurrence 9 months after the appearance of initial symptoms. Diagnosis criteria for multiple sclerosis and neuromyelitis optica were not met. The etiological diagnosis was based on European case definition criteria for neuroborreliosis. Both patients had positive serum and cerebrospinal fluid serology, a positive intrathecal anti-Borrelia antibody index, and a good outcome on ceftriaxone. Specific diagnosis of Lyme ON is important since improvement of visual acuity is possible with specific antibiotherapy, even after many months.

Electrophysiological studies in a mouse model of Schwartz–Jampel syndrome demonstrate muscle fiber hyperactivity of peripheral nerve origin

Schwartz–Jampel syndrome (SJS) is an autosomal‐recessive condition characterized by muscle stiffness and chondrodysplasia. It is due to loss‐of‐function hypomorphic mutations in the HSPG2 gene that encodes for perlecan, a proteoglycan secreted into the basement membrane. The origin of muscle stiffness in SJS is debated. To resolve this issue, we performed an electrophysiological investigation of an SJS mouse model with a missense mutation in the HSPG2 gene. Compound muscle action potential amplitudes, distal motor latencies, repetitive nerve stimulation tests, and sensory nerve conduction velocities of SJS mice were normal. On electromyography (EMG), neuromyotonic discharges, that is, bursts of motor unit action potentials firing at high rates (120–300 HZ), were constantly observed in SJS mice in all muscles, except in the diaphragm. Neuromyotonic discharges were not influenced by general anesthesia and disappeared with curare administration. They persisted after complete motor nerve section, terminating only with Wallerian degeneration. These results demonstrate that perlecan deficiency in SJS provokes a neuromyotonic syndrome. The findings further suggest a distal axonal localization of the generator of neuromyotonic discharges. SJS should now be considered as an inherited disorder with peripheral nerve hyperexcitability. Muscle Nerve, 2009

Moindre réactivité émotionnelle aux stimuli négatifs dans la sclérose en plaques, résultats préliminaires

BACKGROUND Charcot first described emotional deficits in multiple sclerosis (MS) in the XIXth century. Despite this early description, there are very few studies about emotions and MS. OBJECTIVES This study aimed at better understanding the emotional process in MS and more specifically recognition of facial emotions and emotional experience. METHODS Thirteen women with remittent MS (R-MS), with a mean EDSS score of 2, were compared with thirteen healthy control subjects, matched for age (mean age of 42±2), sex and educational level. The Beck Depression Inventory (BDI), the Hamilton Anxiety Scale and the brief repeatable battery of neuropsychological tests for MS (BCcogSEP) were administered. Recognition of faces and facial expression of emotion were assessed by the Benton facial recognition test and recognition of facial emotions was assessed by Ekmans facial expression test. We have also presented 12 different sounds and pictures from the International Affective Digitized Sounds and Picture System (IADS and IAPS) in order to study the emotional experience by using criteria of valence and arousal. RESULTS No deficit of facial emotion recognition was found in MS in this small population. Nevertheless, patients who had difficulty recognizing faces were the least able to recognize facial expressions. No significant difference was observed between the patient and control group for the experience of emotional valence. However, independently of their mood and cognitive status, the self-assessment of the MS patient population suggested that the patients were less reactive to negative sounds (P=0.005) and negative pictures (P=0.002) as compared with the control group, pointing to lesser sensitivity towards aversive stimuli. CONCLUSION These data suggest disorders in emotional processes in R-MS, mainly a poor reactivity to negative stimuli which may have an impact on everyday life. A larger population should be studied to confirm these modifications of emotion.

L-2-hydroxyglutaric aciduria diagnosed in a young adult with progressive cerebellar ataxia and facial dyskinesia.

INTRODUCTION L-2-hydroxyglutaric aciduria is a rare metabolic disorder with quite typical radiological abnormalities and various clinical symptoms. OBSERVATION A 19-year-old girl presented with ataxia, facial dyskinesia, and mild cognitive impairment. Cerebral magnetic resonance imaging demonstrated subcortical white matter T2 abnormalities and a suggestive rim hyperintensity around the caudate nuclei and the putamen. Diagnosis was confirmed by increased 2-hydroxyglutaric acid in urine and a genetic study (Gly260Ala mutation in the L-2-hydroxyglutarate dehydrogenase (L2HGDH) gene). DISCUSSION This case highlights the movement disorder onset and radiological aspects that should indicate the L-2-hydroxyglutaric aciduria diagnosis.

MémoireMoindre réactivité émotionnelle aux stimuli négatifs dans la sclérose en plaques, résultats préliminairesReduced emotional reactivity to negative stimuli in multiple sclerosis, preliminary results

BACKGROUND Charcot first described emotional deficits in multiple sclerosis (MS) in the XIXth century. Despite this early description, there are very few studies about emotions and MS. OBJECTIVES This study aimed at better understanding the emotional process in MS and more specifically recognition of facial emotions and emotional experience. METHODS Thirteen women with remittent MS (R-MS), with a mean EDSS score of 2, were compared with thirteen healthy control subjects, matched for age (mean age of 42±2), sex and educational level. The Beck Depression Inventory (BDI), the Hamilton Anxiety Scale and the brief repeatable battery of neuropsychological tests for MS (BCcogSEP) were administered. Recognition of faces and facial expression of emotion were assessed by the Benton facial recognition test and recognition of facial emotions was assessed by Ekmans facial expression test. We have also presented 12 different sounds and pictures from the International Affective Digitized Sounds and Picture System (IADS and IAPS) in order to study the emotional experience by using criteria of valence and arousal. RESULTS No deficit of facial emotion recognition was found in MS in this small population. Nevertheless, patients who had difficulty recognizing faces were the least able to recognize facial expressions. No significant difference was observed between the patient and control group for the experience of emotional valence. However, independently of their mood and cognitive status, the self-assessment of the MS patient population suggested that the patients were less reactive to negative sounds (P=0.005) and negative pictures (P=0.002) as compared with the control group, pointing to lesser sensitivity towards aversive stimuli. CONCLUSION These data suggest disorders in emotional processes in R-MS, mainly a poor reactivity to negative stimuli which may have an impact on everyday life. A larger population should be studied to confirm these modifications of emotion.

Prospective study of relevance of 123 I-MIBG myocardial scintigraphy and clonidine GH test to distinguish Parkinson’s disease and multiple system atrophy

Background123I-MIBG myocardial scintigraphy and clonidine growth hormone test (CGH test) may help to distinguish multiple system atrophy (MSA) from Parkinson’s disease (PD). Their relevance in the first-stage parkinsonism of uncertain etiology is unknown.MethodsPatients experiencing parkinsonism of ambiguous etiology were clinically classified into the PD group or the MSA group as initial clinical diagnosis (ICD). Then, CGH test and myocardial scintigraphy were performed. Clinical assessment was repeated throughout the disease course until the final clinical diagnosis (FCD) could be established according to the criteria of PD and MSA, respectively.ResultsTwenty-five patients with uncertain diagnosis were included (15 MSA and 10 PD as ICD). At the end of a 6-year follow-up, FCD was MSA in 11/25 patients and PD in 14/25. The CGH test and the scintigraphy showed a sensitivity of 82%, and a specificity of 71 and 93%, respectively, for the diagnosis of MSA. The combination of a normal scintigraphy (i.e., with myocardial MIBG uptake) with genitourinary dysfunction was the most relevant test to diagnose MSA, whereas an abnormal scintigraphy with a levodopa response of > 30% or an abnormal scintigraphy with the absence of OH was the most relevant combinations to diagnose PD. All these combinations had an accuracy superior than 90% and a specificity of 100%.ConclusionCombinations of myocardial scintigraphy with genitourinary dysfunction, levodopa response of > 30%, or orthostatic hypotension could be of interest for the distinction between PD and MSA when the clinical diagnosis remains ambiguous at the first stage of the disease.

IRM de diffusion dans les myelopathies non compressives : a propos de 32 patients

Objectifs Notre travail etait d’evaluer l’apport de la sequence de diffusion en IRM et du calcul du coefficient apparent de diffusion (ADC) dans le diagnostic etiologique des myelopathies non compressives. Materiels et methodes Trente-deux patients souffrant de myelopathies non compressives ont beneficie entre septembre 2005 et novembre 2007 d’une IRM medullaire avec sequence de diffusion. Pour chaque patient, l’ADC a ete calcule dans la moelle pathologique. Des calculs en moelle saine ont ete realises chez dix patients temoins. Les resultats des differents sous-groupes ont ete compares selon un test de Student. Resultats Quinze patients presentaient une myelopathie d’origine inflammatoire dont neuf sclerose en plaques. Six patients presentaient une myelopathie para-infectieuse, cinq patients une ischemie medullaire et six patients des etiologies autres. L’ADC etait significativement plus eleve dans la moelle pathologique des patients presentant une atteinte inflammatoire ou para-infectieuse que dans la moelle saine ou dans la moelle ischemique. Il n’existait pas de difference significative entre les valeurs d’ADC des patients presentant une pathologie inflammatoire et celles des patients presentant une atteinte para-infectieuse. Conclusion Ces resultats sont importants pour differencier les myelopathies ischemiques des myelopathies inflammatoires ou para-infectieuses. Les calculs restent parfois limites par les qualites techniques de la sequence.

U - 11 IRM de diffusion dans la pathologie médullaire : étude prospective de 34 patients

Introduction La sequence de diffusion avec mesure du coefficient apparent de diffusion (ADC) est frequemment pratiquee lors des IRM cerebrales. Par contre, elle reste peu utilisee dans la pathologie medullaire. Objectifs L’objectif de ce travail a ete d’evaluer l’apport de cette technique dans le diagnostic etiologique des pathologies medullaires. Methodes Trente quatre patients souffrant de pathologies medullaires ont beneficie entre septembre 2005 et decembre 2006 d’une IRM medullaire avec sequence de diffusion. Pour chaque patient, l’ADC a ete mesure dans la moelle, en zone pathologique et si possible en zone saine. Des mesures en moelle saine ont ete realisees chez 8 temoins ne souffrant pas d’atteinte medullaire. Nous avons ensuite compare les resultats des differents sous-groupes selon un test de Student. Resultats Onze patients presentaient une compression medullaire extrinseque (notamment 5 d’origine tumorale, 3 hematomes et 1 abces). Vingt trois patients presentaient une atteinte medullaire sans compression (dont 9 d’origine inflammatoire, 6 infectieuse et 2 ischemique). L’ADC etait significativement plus eleve dans la moelle pathologique des atteintes inflammatoires et infectieuses que dans la moelle saine, et significativement abaisse dans la moelle ischemique. L’ADC etait diminue au sein des hematomes et de l’abces peri medullaire. Discussion Les differences de valeurs d’ADC entre les atteintes ischemiques d’une part et infectieuses et inflammatoires d’autre part sont importantes pour le diagnostic etiologique des myelites a la phase aigue. Elles peuvent orienter la prise en charge de ces tableaux cliniques souvent peu specifiques. Ces resultats semblent proches de ceux obtenus a l’etage cerebral. Conclusion La mesure de l’ADC au niveau medullaire precise les diagnostics suggeres par les sequences habituelles des IRM. Ce calcul reste parfois limite par les qualites techniques de la sequence.