Relapsing demyelinating disease affecting both the central and peripheral nervous systems.

BACKGROUND: Clinical and electromyographic findings of chronic inflammatory demyelinating polyradiculopathy (CIDP) are occasionally observed in patients with multiple sclerosis (MS). OBJECTIVE: To define a new inflammatory demyelinating disease unlike MS or CIDP. RESULTS: This study reports on five patients with a demyelinating disease affecting the central nervous system (CNS) and peripheral nervous system (PNS). Each case presented a relapsing-remitting course in which CNS involvement preceded PNS involvement. All patients fulfilled Barkhof's criteria on MRI and the McDonald criteria for MS. Two patients had grey matter lesions with typical white matter changes. No systemic inflammatory disease and no metabolic or inflammatory factor for peripheral neuropathy were found. In all cases electromyography showed a demyelinating peripheral neuropathy without conduction block. Four patients fulfilled the European Federation of Neurological Societies/PNS guideline for CIDP and Nicolas et al's criteria for CIDP, one of whom also fulfilled the Ad Hoc Subcommittee criteria for CIDP. Nerve biopsy, performed in two patients, showed histological evidence of CIDP. An improvement in clinical status and neurophysiological parameters was observed in three patients after treatment with either intravenous immunoglobulin (n = 1) or cyclophosphamide (n = 2). CONCLUSION: The CNS and PNS demyelination, the absence of oligoclonal bands and the peripheral demyelination without conduction block indicate pathogenic mechanisms different from MS and CIDP. The chronology of events suggests an entity unlike that involved in acute demyelinating encephalomyelitis. Immunological reactivity against antigens common to peripheral and central myelin may explain why the demyelinating disease affected both the CNS and PNS.

[Unconjugated pteridines and neuromeningeal infections]. / Ptéridines non conjuguées et infections neuro-méningées.

Concentrations of unconjugated pteridines (neopterin, monapterin, biopterin, pterin) were measured in the cerebrospinal fluid (CSF) of 310 patients, using a high performance liquid chromatography (HPCL) method. Our cohort included 209 controls (C), 15 patients with meningism (M), 22 with viral meningitis (VM), 17 with bacterial meningitis (BM), 9 with herpetic meningoencephalitis (HME), 2 with tuberculous meningoencephalitis (TME) and 36 with peripheral systemic infections (PI). These measurements, expressed as nmol/litre, showed a gradation of neopterin concentrations according to the type of infection: 20.1 + 6.5 in group C; 46.9 +/- 29.9 in group PI; 274.3 +/- 231.7 in group VM; 699.2 +/- 711.2 in group BM, 1,101.9 +/- 1,107.9 in group HME and 1,169 +/- 1,171.9 in group TME. There was no such gradation with biopterin. Comparisons of means showed that total concentrations in the pathology groups were very different from those observed in controls and in the neuromeningeal infections of the PI group. There was no correlation between the number of lymphocytes and the concentrations of neopterin or biopterin in the CSF. It is concluded that the concentration of neopterin in the CSF is a sensitive but little specific marker of infection, independent of CSF cellular reaction. Measuring this concentration makes it possible: 1) to evaluate the status of immune defences; 2) to predict that a meningitis will become chronic, and 3) to detect a possible parenchymal participation in a meningeal infection.

[Late auditory evoked potentials in subcortical cognitive deterioration]. / Potentiels évoqués auditifs tardifs dans les détériorations cognitives sous-corticales.

Late auditory evoked potentials (AEPs) were recorded by the odd-ball method in 55 non-deteriorated parkinsonians (NP) and in 27 parkinsonians with cognitive deterioration (CDP), compared with 20 controls (C) and 24 patients with Alzheimer-type senile dementia (ATSD). The latency of P 300 was prolonged in the CDP and ATSD groups (410.72 +/- 24.45 and 433.62 +/- 38.30 respectively; P less than 0.001. The latency of N 100 was prolonged only in the CDP group (106.6 +/- 4.82; P less than 0.001). Late AEPs were also studied in 63 subjects with possible or confirmed disseminated sclerosis (DS) compared with 33 controls of similar mean age. The ERFC test divided these patients into 38 with non-deteriorated DS (NDS) and 25 with deteriorated DS (DDS). The latency of P 300 was prolonged in both groups: NDS 331.14 +/- 25.89; DDS 376.64 +/- 29.51 (P less than 0.001). The latency of N 100 was prolonged in the NDS group (100.25 +/- 9.20) and the DDS group (104.43 +/- 9.01). Following a study of correlations between the degree of mental deterioration and the electrophysiological parameters in these populations, the significance of the N 100 latency as electrophysiological marker of subcortical dementia is discussed.

[Cortical and subcortical dementia. The value of long auditory evoked potentials]. / Démences corticales et sous-corticales. Intérêt des potentiels évoqués auditifs tardifs.

Long latency auditory evoked potentials were studied in 27 normal subjects, 19 patients with Alzheimer's Disease (A.D.) and 70 patients with Parkinson's Disease (P.D.). 17 patients with P.D. showed cognitive impairment measured by the "test rapide d'évaluation des fonctions cognitives - E.R.F.C.". The N2 and P3 peak latencies were prolonged in the demented group of P.D. compared to the non demented group P.D.. Between the electrophysiological parameters only the N1 latency prolongation distinguished the demented parkinsonian patients from the patients with A.D..

[Motor impersistance of the eyelids. Study of 93 cases and a discussion of pathogenic mechanisms]. / L'impersistance motrice palpébrale. Etude de 93 cas et discussion des mécanismes pathogéniques.

In a prospective study, 252 subjects were investigated for motor impersistence of the eyelids (MIE) by means of a protocol that evaluated its intensity and detected associated signs, notably other phenomena of motor impersistence. MIE was frequent, being found in 93 subjects. It was usually observed in diffuse brain lesions, then in lesions of the right hemisphere, particularly in the posterior and deep cortex. In right hemisphere lesions, MIE was significantly associated with constructional apraxia, visual neglect and Anton-Babinski syndrome. In diffuse cerebral lesions, MIE was accompanied by other phenomena of motor impersistence on a background of dementia. In these cases the P 300 wave latency was significantly prolonged. Three main mechanisms may be regarded as responsible for the occurrence of MIE: apraxia, disturbance of the interhemispheric balance (notably in lesions of the right hemisphere) and disorders of attention (predominant in diffuse lesions). Actually, in every case MIE should be inserted in a continuum the extremities of which are represented by the above mentioned mechanisms.