MEETING REPORT

Among all the forms of vasculitis neuropathy, cases in which vasculitis is confined to the peripheral nervous system usually respond well t o treatment with steroids and immunosuppressive agents and have a better prognosis (J.G. Mac Leod). Cerebral venous thrombosis in connective tissue diseases was reported by Vidailhet. Behcet's disease is believed to be the leading cause. This hypothesis of a vasculo-Behcet subtype needs combined therapy wi th steroids and prolonged anticoagulants. Hypereosinophilic syndromes (presented by R.B. Layzer) fall into three broad categories: Churg-Strauss, fasciitis and perimyositis, and eosinophilic myositis wi th or without localized nodular myositis. Neuropathy in polyarteritis nodosa is of axonal type (G. Sa'id). Conversely necrotizing vasculitis is observed in HIV with demyelination. Some cases of inflammatory infiltrates have been observed in diabetic neuropathy. In systemic lupus erythematous focal CNS symptoms may result from vasculitis, cardiogenic embolism of thrombotic ischemia, but diffuse CNS symptoms (i.e., epilepsy, psychosis) are more frequent and are related to neuron reactive auto-antibodies but may also be related to vascular lesions (P. Berlit). PNS symptoms of demyelinating type (D. Cros) may be due to both vasculitis or auto-antibodies. Most patients are women and the onset ranges from 21 to 76 years. All types of manifestations can be seen in Gougerot Sjogren syndrome: psychiatric (M.F. Khan) with depression, peripheral neuropathy (J.M. Leger and Pou Serradel) wi th three rare forms: mononeuropathy multiplex. recurrent cranial polyneuropathy and chronic inflammatory demyelinating polyradiculoneuropathy or CNS involvement (clinical or T2 weighted hypersignal on MRI or PEM abnormalities). Sometimes the onset of neuropathy precedes the Sicca syndrome. With a series of 14 cases of neurosarcoidosis, 0. Lyon-Caen showed that a diagnosis is ofteil difficult (pseudomultiple sclerosis, encephalitis, meningitis...). The CNS involvement may precede the systemic lesions. The diagnosis is supported by the biochemical study of C.S.F. All monoclonal dysglobulinemia associated with plasma cell dyscrasia may induce a peripheral neuropathy (J.M. Vallat). The mechanism of !g G or lg A neuropathy is often unknown but the identification of a specific antibody activity against a myelin antigen, in conjunction with elevated serum lg M levels, is often assessed by imrriunologic techniques. A significant number of monoclonal dysglobulinemias r iay be associated with secondary or essential cryoglobulinemia and vasculitis may be involved. Several treatments are available in neuropathies associated with monoclonal proteins, plasma exchange seem effective when the neuropathy is associated with lg G or lg A (P.J. Dyck). Antiphospholipid (APS) are sometimes associated with a determined disease, lupus in most cases, but it can also be primary. A high frequency of strokes is noted in APS. Thrombosis is the basic mechanism. A new approach of the pathogenesis of non-dystrophic myotonias, which is based on muscular sodium channel dysfunction, was presented by LehmannHorn. A. Engel has explained the development of the pathologic mechanisms in congenital myasthenic syndromes. A reduced safety margin of neuromuscular transmission could explain the disease by a defect in the quantal release mechanism, a decrease in quantal size (familial infantile myasthenia) or a reduction in quantal efficiency affected by five different factors: the geometry of neuromuscular junction (NMJ), the density and functional state of acetylcholinesterase, the packing density of the acetylcholine receptor (Ach R) on the post synaptic membrane, the affinity of Ach R for Ach and the kinetic properties of the Ach R ion channel. Although quantal release mechanisms may be affected in congenital PJMJ Ach E deficiency and in a disorder associated with a paucity of the synaptic vesicles, quantal efficiency is abnormal in a syndrome with abnorinal interact.ion of Ach and Ach R, a syndrome with abnormally high conductance and fast closure of the Ach R ion channel, the slow-channel myasthenic syndrome and a syndrome wi th a mutation affecting the epsilon subunit of Ach R Ach R is kinetically abnormal but is not reduced in amount in the first t w o syndromes and also reduced in amount in the two last entities. Crespi et a!. have studied 18 cases of peripheral neuropathy associated wi th essential mixed cryoglobulinemia. Neuropathy was detected in 50% of the cases. Generally, neuropathy seemed to be less severe than previously and sometimes may be subclinical. Brinkmeier et ai. have proposed CSF filtration as a new treatment of GuillainBarre Syndrome (GBS) to remove the blocking sodium channel factors that they have detected. lmmcinoglobulins and other immunosuppressive drugs seem to be effective in most cases of CIDP, which is one of the most easily treatable neuropathy (Azulay). At the end of a large multicentric study, the whole peripheral nervous system may be involved during HIV infection: CIDP a t the beginning and axonal neuropathy a t a further stage of the disease. In many cases neuropathy is detected only by VCN study, myositis and myopathy related to Zidovudine. Azouni et al.. demonstrated that Lyme disease is not a frequent agent of facial palsy. Several authors have reported their experiences of motor syndromes associated with anti GM 1 antibodies (Latov, Pouget and de Jaeger) sometimes improved by intravenous immunoglobulins. Other antibodies are found in other Vpes of neuropathy (Younes, Chenoufi, Steck): anti Hu and Denny-Brown paraneoplasic neuropathy, anti-MAG and subgroups in neuropathies associated with an lg M component and anti-sulfatide antibodies that are frequent but not specific of any etio-