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Limb-girdle muscular dystrophies (LGMDs) are a group of neuromuscular diseases presenting great clinical heterogeneity. Mutations in CANP3, the gene encoding muscle-specific calpain, were used to identify this gene as the genetic site responsible for autosomal recessive LGMD type 2A (LGMD2A; MIM 253600). Analyses of the segregation of markers flanking the LGMD2A locus and a search for CANP3 mutations were performed for 21 LGMD2 pedigrees from various origins. In addition to the 16 mutations described previously, we report 19 novel mutations. These data indicate that muscular dystrophy caused by mutations in CANP3 are found in patients from all countries examined so far and further support the wide heterogeneity of molecular defects in this rare disease.

We report three cases presenting mainly with neck extensor weakness, or dropped head syndrome, revealing respectively myasthenia gravis, amyotrophic lateral sclerosis and non-inflammatory neck extensors myopathy. We discuss the different diagnosis of this rare syndrome and this late onset localized myopathy of unknown etiology.

Charcot-Marie-Tooth (CMT) type-1 (CMT1) neuropathy is characterized by peripheral nerve demyelination and has been divided into several subtypes. The most frequent among these, subtype 1A, is related to a microduplication of the region p11.2 of chromosome 17. This region contains the PMP-22 gene which is involved in peripheral nerve myelination. Since motor nerve conduction velocity (MNCV) is closely related to nerve myelination, we compared type-1A patient MNCVs versus non-A CMT1 patient MNCVs, in 57 CMT1A patients and 21 non-A type-1 patients. Patients with the 17p11.2 duplication have MNCVs that are significantly more reduced (about 20 m/s) compared to patients without the 17p11.2 duplication (about 30 m/s). This study also permits a model of the MNCV in the median nerve (MedMNCV) of CMT1 patients, with age, gender and molecular status as parameters. Furthermore, in order to help clinicians to diagnose subtypes of CMT1 patients, the probability for type 1A is modeled as a function of MedMNCV only.

Carpal tunnel syndrome is the most frequent entrapment neuropathy. Nerve conduction studies and electromyography are useful to appreciate the localization and the degree of nerve involvement, and help to the therapeutic management. Various electrophysiological procedures may be used and are reviewed. For each of them, positive (sensitivity and specificity) and negative points (technical difficulties, errors and false positive) are reported. A guideline is proposed.

We performed DNA analysis in four families with hereditary neuropathy with liability to pressure palsy (HNPP). An interstitial deletion of the 17 p11.2 region was found in typically affected patients as well as in as yet asymptomatic patients. The opportunity for an individual genotyping permitted to ascertain a de novo deletion in one clinically affected case with no relevant familial history. DNA analysis thus becomes the most sensitive tool in diagnosing HNPP, since potentially affected patients may lack either informative familial history, or clinical symptoms or even suggestive EMG or histopathological data (tomaculas).

Multiple deletions of mitochondrial DNA have been detected by Southern blotting in the skeletal muscle of a 42-year-old woman with chronic progressive external ophthalmoplegia. A PCR method, using several combinations of primers covering the whole mtDNA as well as sequence analysis, disclosed the wide spectrum of these multiple deletions differing in size, location and sequence at the breakpoint junction. Most involved the major region between the two replication origins. However, three deletions affected the minor region and lacked either the light strand origin of replication or the heavy strand promoter. These data suggest an impairment of mtDNA replication leading to illegitimate recombination and extensive damage of mtDNA.

Hypokalemic periodic paralysis (hypoPP) is an autosomal dominant disorder belonging to a group of muscle diseases involving the abnormal function of ion channels. This group of muscle diseases also comprises hyperkalemic periodic paralysis and paramyotonia congenita, both sodium-channel diseases, and myotonia congenita, a chloride-channel disorder. HypoPP is characterized by acute attacks of muscle weakness concomitant with a fall in blood potassium levels. We recently localized the hypoPP locus (hypoPP1) to chromosome 1q31-32, in an interval where the alpha 1 subunit of the dihydropyridine receptor calcium channel (CACNL1A3) also maps. Subsequently, deleterious mutations in the voltage-sensor segment S4 were found, establishing the dihydropyridine receptor CACNL1A3 as the causative gene for hypoPP. In this paper, we report the study of 16 hypoPP families of Caucasian origin. We found only two mutations--Arg528His and Arg1239His--that cosegregated with hypoPP, each in half of the families. Analysis of the clinical characteristics of both groups of families demonstrated that incomplete penetrance is a distinctive feature of the Arg528His mutation. Using dinucleotide repeats contained within or close to the dihydropyridine receptor gene, in conjunction with evidence of a de novo Arg1239His mutation, we show that a founder effect is unlikely to account for the two predominant mutations.

Carpal tunnel syndrome (CTS) is very uncommon in childhood. Sixty-five cases are reported in the literature, principally due to metabolic diseases. In Mucopolysaccharidoses, prospective studies (Wraith and Alani, 1990) found a bilateral CTS in about 90%. We report four cases of Mucopolysaccharidoses, diagnosed on clinical and biological data (two cases of Hurler disease, and two cases of Hunter disease), in children aged less than five years. Each child had claw hands, without thenar atrophy. Median nerve conduction studies and electromyography confirm the CTS. Motor and sensory nerve conductions are normal in other nerves. Concentric needle studies show in two cases, on abductor pollicis brevis, spontaneous activities as repetitive discharges, fasciculations and multiplets. Median nerve stimulations reveal responses with late potentials during 70 ms due to reinnervation. The physiopathology of those carpal tunnel syndromes is discussed.

A myasthenic syndrome was diagnosed in 3 female patients aged 37, 47 and 56 years. The symptoms were first noticed in childhood, and at 16 and 25 years. Respectively weakness and atrophy of finger extensor muscles were present in all patients. In 2 of them scapular and cervical muscles were involved. Weakness was markedly increased by cold in every patient. Similar symptoms were noted in first degree relatives in all cases. Single nerve stimulus elicited a repetitive compound muscle action potential in hand muscles. Repetitive nerve stimulation induced a myasthenic decrement in finger extensor muscles. SFEMG studies demonstrated increased jitter with frequent blockings. Genetic, clinical and electrodiagnostic data were consistent with the hypothesis of the so-called "Slow-Channel" myasthenic syndrome. As 2 of these patients were considered to have "unknown myopathy" the use of careful nerve stimulation tests is advocated in such cases.

The authors report two cases of Lambert-Eaton myasthenic syndrome associated with small cell lung carcinoma. Following the observations, the clinical diagnosis of this syndrome is considered. We discuss the autoimmune pathogenesis and the relation between paraneoplastic syndrome and small cell cancer. This syndrome is caused by autoantibodies that block the voltage-dependent calcium channels at motor nerve terminals. Small cell carcinoma cells appear to express calcium channels, suggesting that autoantibody production may be triggered by tumor calcium channels determinants. The autoimmune paraneoplastic syndrome theory refers to cross-antigenicity.

After a brief report of median nerve anatomy at wrist, authors describe terminal variations of its distribution. Classic description of five terminal sensitive and motor median nerve branches is not constant. Many anatomic variations have been reported and so many, classifications proposed. Lantz' classification is useful, it may be divided in four groups. Other anatomic variations concern cutaneous palmar nerve branch and different nervous anastomosis. Advantage of this anatomic study is incidence of variations on surgical access of carpal tunnel. Those nervous variations of median nerve at wrist are frequent, unknown and wrong indexed and may be so many "anatomic traps" for surgeon.

A 67-year old patient with meningoradiculitis due to Borrelia Burgdorferi presented with unilateral trunk dysesthesias and severe asymmetrical abdominal distension. The causes of abdominal wall paralysis are reviewed.

Gold therapy is responsible for many neurological complications. We report a case presenting with the clinical and electrophysiological characteristics of neuromyotonia, polyradiculoneuritis and Morvan's fibrillary chorea. The various neurological complications of gold therapy and the possible relationships between these different syndromes are discussed.

The various electrophysiological techniques which can be used in cervicobrachial neuralgia and their respective advantages and limitations are described. Beside the conventional electromyography and electrostimulation techniques, the indications for radicular motor and somesthetic evoked potentials are discussed.

The electrophysiological data of 23 adult patients with Lambert-Eaton myasthenic syndrome (LEMS) have been reviewed. Lung carcinoma was disclosed in 17. In six cases with an EMG follow-up ranging between one and 17 years no carcinoma was detected. The results of repetitive nerve stimulation test (RNS) were not statistically different between the 2 groups. Low CMAP ulnar amplitude was present in all patients (mean: 1.7 mV). Decremental response at low rate of stimulation (3 Hz) was present in 17/20 (means: 30%). An abnormal incremental response at high rate of stimulation was present in all cases (mean: 826%). The authors emphasize the interest of a 50 Hz stimulation for 4 s. Increase of the 'F-wave' amplitude was noticed in some cases. Electrophysiological changes suggestive of an associated mild neuropathy were noticed in eight patients but H-reflex was present in 3/3 cases. SFEMG abnormalities were found in 6/6 cases. In one case, stimulated SFEMG showed more blockings and an increased jitter with low rate of stimulation. In one case the electrical pattern of RNS could be misinterpreted as myasthenia gravis in one tested muscle only. The author's results suggest that CMAP amplitude and RNS test could be used to appreciate the short-term improvement of LEMS with treatment and in some cases for the long-term follow-up.

The Eaton-Lambert syndrome is a clinical and electrophysiological entity, which affects less than 3% of patients with a small cell cancer. In the majority of cases the syndrome is present before the discovery of cancer. The diagnosis is primarily suggested by proximal muscle fatiquibility in the lower limbs. The confirmation of the diagnosis is carried out by an electromyography. The occurrence of non-para neoplastic cases are frequently associated with disorders of immunity (Auto-immune Disease, and various auto-antibodies) in the groups HLA B8 and DR3. The efficacy of immunosuppressants has led to a search for an auto-immune mechanism as the basis for this myasthenic type syndrome. The demonstration in recent years of anti-calcium channel antibodies at the origin of the pre-synaptic junctional block has confirmed this hypothesis. The demonstration of the auto-immune character of this para-neoplastic syndrome has led to better understanding of the host tumour relationship from an immunopathological stand point.

The clinical and electrophysiological data of 18 consecutive adult patients with paraneoplastic Lambert-Eaton myasthenic syndrome (LMES) have been reviewed. The cancer associated with LEMS was small-cell lung carcinoma (SCLC) in 15 cases and epidermoid lung carcinoma in 3 cases. The main clinical neurological features were proximal lower limb weakness (100%), depressed tendon reflexes (94%) and dryness of the mouth (66%). The results of repetitive nerve stimulation (RNS) were not statistically different in the paraneoplastic LEMS group and in a group of 6 LMS patients in whom no carcinoma had been detected. Low-amplitude compound muscle action potential (CMAP) was present in all cases; decremental response at low stimulation rates was present in 13/15 cases. An abnormal incremental response at high stimulation rates was observed in all cases. A close correlation between CMAP amplitude and clinical condition was found in 4 cases during the long-term follow-up. In one patient the RNS electrical pattern could be misinterpreted as myasthenia gravis in only one muscle tested. We underline the usefulness of a 50 Hz stimulation during 4 seconds to establish the diagnosis unequivocally, and that of post-exercise facilitation in routine detection among an SCLC population. Our results suggest that CAMP amplitude and RNS test could be used to evaluate the short-term improvement of LMS under treatment and, in some cases, for the long-term follow-up. The infraclinical axonal neuropathy detected in 8 patients probably was another associated autoimmune paraneoplastic complication.

The suprascapular nerve passes through the spinoglenoid notch with a risk of entrapment. This results in distal nerve lesion characterized by isolated paralysis of the infraspinatus muscle and, most often, by shoulder pain. We report 7 clinical and electromyographical cases of pure infraspinatus muscle paralysis. The value of the electrodiagnosis, which demonstrated prolonged suprascapular distal nerve latencies (over 5 milliseconds) in the infraspinatus muscle affected while latencies were normal in the supraspinatus muscle, is emphasized. Mechanical factors were associated with paralysis in 5 cases. Compressive synovial cysts were found in 2 patients operated upon. Surgical enlargement of the spinoglenoid notch regularly and rapidly relieves pain and sometimes helps in recovery of the infraspinatus muscle.

The diagnostic yield of electrodiagnostic tests was evaluated in 21 children with myasthenia gravis (MG). Twelve children had juvenile autoimmune MG, four had neonatal MG, four had congenital MG, and one had MG with arthrogryposis. Repetitive stimulation (RS) of the ulnar nerve was performed in every patient, sometimes with sensitization by ischemia. When the RS test was negative, the spinal or facial nerve was tested. In the group with neonatal MG, the RS test disclosed a significant decrement in 75% of the patients. Among the 17 other children, the overall percentage of positive RS tests was 88%. An ulnar nerve RS test was positive in 41% of them. Sensitization of ulnar nerve RS by ischemia improved the diagnostic yield to 66%. A spinal or facial nerve RS test was positive in seven of 10 patients. These results confirmed the diagnostic value of RS, with sensitization by ischemia, when necessary, in childhood MG whenever a careful technique is provided.

To assess the long-term evolution of diabetic polyneuropathy after a combined kidney-pancreas transplant, an electrophysiological study was performed in 20 diabetic patients before transplant, and 1 (n = 18), 2 (n = 16), 3 (n = 10) and 4 years (n = 5) at a later date. Motor and sensory scores were calculated for conduction velocity and amplitude to determine the physiopathological process. During evolution the scores were not found to be decreasing. Motor and sensory velocity scores were significantly improved (p less than 0.05) 1 and 2 years after the graft, when score values tended to stabilize. Motor and sensory amplitude scores, which are more sensitive for axonal loss assessment were slightly but not significantly improved.

We report a 25-year-old patient with a progressive asymmetric peripheral neuropathy of the distal lower limbs. Imaging studies showed enlargement of lumbosacral roots, plexus, and proximal sciatic nerve. Sacral plexus biopsy revealed amyloidosis associated with endoneurial edema. Immunohistochemistry with anti-prealbumin, serum amyloid A, and immunoglobulin light chain antisera failed to label the amyloid.

Median and ulnar sensory distal latencies were measured antidromically on the fourth finger in 158 patients (224 hands) with suspected carpal tunnel syndrome (CTS), in 60 normal subjects (100 hands), and in 30 patients (30 hands) who suffered from paresthesiae due to a cervical spondylotic radiculopathy (CSR). The difference between these 2 latencies was less than 0.4 msec in all normals and patients with CSR, while in all of the patients with CTS it was more than 0.5 msec. Median sensory nerve conduction was significantly slower for the fourth than for the second finger in the CTS group, but not in controls. The difference between median and ulnar sensory distal latencies on the fourth finger proved to be the most sensitive of the tested parameters and was the only abnormal one in 20% of the clinically affected hands. The ring finger technique is a quick and easy procedure, which should be recommended in the early diagnosis of mild CTS.

A 26-year-old male with a history of pulmonary sarcoidosis showed clinical, myelographic and intra-operative evidence of a C5-C6 spinal cord tumour, which was diagnosed by biopsy as a pure intramedullary granuloma. Among the 29 published cases of histologically proven cord sarcoidosis, only five presented with pure parenchymatous infiltration without meningeal involvement. Corticosteroids are the most useful therapy, and surgery is indicated only for minimal biopsy when the parenchyma is invaded.

Two cases of mainly interstitial myositis with epitheloid and giant cells are reported. In the first case, the late amyotrophic-type paralysis of the two girdles, of the clinical myositis type, was associated with severe myocardial damage, the atrioventricular conduction disorder requiring a pace-maker. This observation would appear to be a true polymyositis of the collagen diseases, in view of the associated skin affection, death occurring within a year, a large increase in serum muscle enzymes and urine creatine, the existence of a rheumatoid factor and striated muscle antibodies, and a large increase in M and G immunoglobulins. In the 2nd case, the amyotrophic affection of the pelvic girdle was associated with progressive blindness, diabetes insipidus, and anterior pituitary insufficiency. Death occurred after two years and autopsy showed a suprasellar dysgerminoma (ectopic pinealoma) without any visceral localization of sarcoidosis. The authors discuss the concept of granulomatous polymyositis, autonomous with respect to the sarcoidosis, and sometimes symptomatic of an inflammatory connective tissue condition or a malignant tumor.

In a patient with chronic active hepatitis (CAH) due to B-virus, a polyneuropathy developed following a cure of vidarabine. The pathophysiology of this neuropathy remains unclear as it appears not to occur in patients with diseases other than CAH. Muscular pains and paresthesias reported in such patients treated with vidarabine could be the consequence of peripheral nerve involvement.

The authors tried to test the diagnostic yield of muscle and nerve biopsies in children and studied the relationships between clinical, electrophysiological and histopathological findings in 97 cases seen over a 3-year period. Specific histopathological lesions were described in 17.9% of muscle biopsies and 27.2% of nerve biopsies. In 65% of the cases, the biopsy revealed or confirmed the diagnosis, or specified the process (neurogenic or myogenic). Histopathology was concordant with clinical and electrophysiological findings in 83.5% of the cases.

A 4 year old girl had been hypotonic and areflexic since birth with delayed milestones in motor development. Repetitive stimulation at high rates performed at 3 years elicited an incremental response typical of the Lambert-Eaton Syndrome.

After voluntary inhalation of a domestic solvent containing N-Hexane and N-Heptane for three months, a 23-year-old woman developed motor deficit of the lower limbs, sensory symptoms and areflexia. Clinical disorders continued to progress after discontinuation of the intoxication, with a parallel aggravation of the E.M.G. disturbances. A nerve biopsy with ultrastructural study showed axon dilatation with accumulation of neurofilaments. The clinical, electrophysiological and pathological features of neuropathies induced by hexacarbon solvents are reviewed and their pathogenesis is discussed.

Twenty-five cases of amyotrophic lateral sclerosis occurring before the age of 40, collected between 1963 and 1973 in the Neurological Hospital, Lyons, have prompted the authors to make the following observations. -The incidence of disease seems to have been on the increase during this period both in absolute terms and relatively speaking (relative to the total number of patients hospitalized and to the total number of patients hospitalized for amyotrophic lateral sclerosis after the age of forty). -The 25 cases involved mostly women--the opposite of what was found in cases of amyotrophic lateral sclerosis occurring after forty. -Only one was possibly familial. -The onset is mostly with purely pyramidal features or of the topographically circumscribed peripheral type. Development appears to take longer than the average for amyotrophic lateral sclerosis. It would be worth while confirming these findings by analysis of other similar groups.

The authors report the case of a patient having suffered a section of the oculomotor nerve during the excision of a tumor located in the tentorium incisura. The nerve was immediately sutured (end to end anastomosis). After 18 months, a partial recovery of the function of the nerve was seen clinically and on EMG. Ptosis had disappeared and adduction of the eye reappeared. An analysis of available data on the suture of oculomotor nerves is then given: reparation of the third nerve in animals and man give variable and partial results. Partial recovery and aberrant regeneration are explained by the fact that this nerve innervates many muscles and by the absence of ultrastructural systematisation. On the contrary, some still rare studies have indicated that the suture of the fourth and sixth cranial nerves give better results probably because these nerves have a simple ultrastructural organization, are purely motor and innervate only one ocular muscle.

Conduction velocity of the fastest fibres in sensory nerves (SCV), amplitude and shape of the sensory evoked potentials (SEPs) were studied in 94 normal children aged 5 days up to 15 years. Surface electrodes were used both for nerve stimulation and sensory evoked potential recording. Normal minimal value in young adults is reached between 2 and 4 years of age, earlier in the proximal segment of the nerve (wrist-elbow) than in the distal segment (digit-wrist). Amplitude of the median SEP at the wrist increases about 155% during the first 2 years of life; this increase becomes more progressive and moderate from 2 to 15 years of age. At the elbow, the SEP has a smaller amplitude and is made of two separate peaks in 80-100% of the children between 6 months and 10 years of age. The presence of those two separate components lends substance to the view that there are two groups of fibres with different degrees of maturation. Methodology and results are discussed along with previous data from the literature.

EMG and nerve conduction studies have limitations and require particular consideration in children. The indications and the main results are considered from the study of 1624 EMGs in 1385 children under 15 years old seen over a period of 3 years. Classification of cases was based on clinical criteria. The diagnostic yield of EMG is emphasized in the evaluation of 122 children with hypotonia and weakness (all under 3 years old); abnormalities were demonstrated in 48% leading to the diagnosis of spinal muscular atrophy in 16%, of congenital myopathies in 11%, and of peripheral neuropathies in 8%. In 103 children with hypotonia associated with mental deficiency and/or seizures, evidence of a peripheral neuropathy was shown in 20%. EMG abnormalities allowing the diagnosis of hereditary motor and sensory neuropathies or myopathies were demonstrated in a wide range of clinical conditions. EMG appears to be useful for the early detection of hereditary myopathies or neuropathies in asymptomatic children. It may have also a prognostic value as in adults, especially in nerve traumas.

Two familial and sporadic cases of amyloid neuropathy are reported. Nerve biopsies ultrastructural studies permit to involve endothelial and Schwann cells basement membranes into formation of amyloid. This classical notion was worth being recalled and specified. The purpose of amyloid formation is searched in a toxico-metabolic processus possibly in relation with observed demyelinating mechanism. The Schwann cell is at the cross of the cause and of its effect.

Introduction: Brachial plexus involvement in symptoms of thoracic outlet syndrome (TOS) is often difficult to assess from clinical data. Conventional EMG and nerve conduction studies (NCS) do not seem reliable to all authors. For this reason, our investigations of this syndrome were complemented by study of somatosensory evoked potentials (SEP) in order to compare the results of these different techniques., Patients and Methods: Ten patients were studied, all of whom had prominent vascular symptoms which led to their consulting a vascular surgeon. Only one had hand wasting without hypoesthesia. None had cervical rib or cervical spine anomaly. In all cases, diagnosis was confirmed by arteriography or phlebography. Operations were decided on clinical data and results of vascular investigations. Patients were tested with conventional motor and sensitive NCS F-wave studies. Needle EMG was performed in abductor pollicis brevis, first dorsal interosseus or abductor digitiminimi. Their SEP were performed as for controls. Ten controls were studied whose SEP were obtained at Erb's point (N9) and C2 cervical spine level (N13) after percutaneous stimulation of median and ulnar nerves at the wrist on both sides. The criterion of abnormality was the mean of controls + 2.5 SD for latencies. Amplitude was considered as low when it was less than 50% of the contralateral one., Results: For 2 patients EMG, NCS and SEP were abnormal. One had hand wasting and denervation in hand muscles as well as slowed median and ulnar sensory conduction with low amplitude responses. SEP at Erb's point were slightly delayed after ulnar stimulation. No cervical response was obtained after ulnar stimulation. The second one had normal responses at Erb's point but delayed responses at the cervical level. In addition, N13 amplitude after ulnar stimulation was low. Four patients had normal EMG, NCS and SEP. Two patients had normal EMG and NCS, but their SEP was questionable since latencies were normal, even though amplitude was low after median and ulnar stimulation. This was not considered this to be abnormal since it was bilateral. For the remaining 2 patients (F.1), EMG and NCS and Erb's point SEP were normal, but C2 median and ulnar responses were delayed in one case and C2 ulnar response amplitude was very low on one side only in the other. In conclusion, SEP were abnormal for 4 patients out of 10 but gave more information than conventional EMG and NCS for only 2 patients. SEP abnormalities prevailed after ulnar stimulation.

Eleven patients with motor neuron disease associated with a monoclonal gammopathy were studied. One patient had a previously known multiple myeloma. In the other patients neurological symptoms preceded diagnosis of the gammopathy by one month to 8 years. They were 5 multiple myeloma, 1 macroglobulinemia, 1 chronic lymphatic leukemia, 1 lymphoma and 3 benign monoclonal gammopathies. EMG and motor conduction velocities results were consistent with anterior horn cell disease but sensory conduction studies were abnormal in seven cases out of eight. Superficial peroneal nerve biopsy performed in all patients confirmed peripheral nerve involvement. The relations between gammopathy, clinical symptoms and electrophysiological data are discussed. The interest of sensory conduction studies in every patient with motor neuron disease is emphasized.

Five cases of peripheral neuropathies occurring with monoclonal gammapathies are studied by means of nerve biopsies. Immunofluorescence and HRP-immunolabelling with the electron microscope are performed. The direct pathogenic role of a subperineurial immunoglobulin deposit is pointed out. The relationship of the heavy chain monoclonal immunoglobulin with amyloid fibrils is discussed.

A case of chronic disabling sensory-motor polyradiculitis occurring in a female patient and followed up for 18 months is reported. Clinical findings were papilledema, hypertrichosis, abnormal pigmentation of the skin, generalized edema, and spontaneous cutaneous necrosis. The diagnosis of a plasmocytic dyscrasia to IgA Lambda was made at a late stage of the disease. There were no signs of a solitary plasmocytoma or of diffuse myeloma. At autopsy, there were mild lesions in the peripheral nervous system, but no plasmocytic infiltration or amylosis was seen on optical or electron microscopy. This case is similar to other clinical cases reported mainly by Japanese authors.

Three children referred for electromyographic investigations presented difficulty in standing upright and in walking. They walked on the points of the feet. The disorder had appeared several years after the development of normal walking. Electrophysiological tests demonstrated a severe peripheral neuropathy with slowing of motor conduction in all four limbs and severe disturbances of sensory conduction. The purely peripheral nature of the lesion was confirmed by studying cortical somatesthetic potentials. E.M.G. and stimulus-detection examinations in family ascendants free from any clinical disorders revealed a similar neuropathy. Biopsy confirmed the presence of a demyelinating neuropathy with schwannian hyperplasia in adult subjects. Biological tests showed anomalies of blood saturated/unsaturated fatty acid ratios. This represents therefore a rather unusual initial clinical presentation of a hypertrophic form of Charcot-Marie's disease with dominant transmission, or form I in Dyck's classification of sensory-motor hereditary neuropathies. Families of children presenting this type of clinical or electrical picture should undergo routine electrophysiological tests. In this way, a whole series of peripheral neuropathies previously considered as sporadic or transmitted in a recessive mode will be found to form part of the group of dominant forms.

Analysis of 105 peripheral and central nervous system complications in 1062 monoclonal gammapathies draws attention to two types of phenomena. The possibility of pure neurological manifestations of IgM monoclonal gammapathies with macroglobulinorachia leads to discussion of their nosological position in relation to Waldenström's disease, Burkitt's lymphoma and Marek's disease. It is suggested that these cases should be reclassified under the heading "secreting neurolymphomatosis". Immunofluorescence and electron microscopy of 10 biopsies of the peripheral nerve showed deposits of monoclonal immunoglobulin whose function in determining peripheral neuropathies is discussed. The simultaneous presence of lymphoid infiltration, amyloid deposits and the monoclonal immunoglobulin (M component) suggests that this immunoglobulin could be the link between the cellular infiltrate secreting it and amyloid infiltration which would be the visible manifestation of it.

The electrophysiological findings in 18 patients with Arnold-Chiari malformation (ACM) revealed by spinal symptoms excluding syringomyelic syndrome (Brown-Sequard syndrome, paraparesis with or without posterior column involvement, motor neuron syndrome or more complex myelopathies) are reported. In 16 cases, EMG disclosed abnormalities consistent with lesion of anterior horn cells restricted to upper limb in 7 cases, and generalized in 9 cases. In 2 cases, motor and sensory conductions were abnormal. The occurrence of such abnormalities in patients with ACM is emphasized as they could lead to confusion with amyotrophic lateral sclerosis or spinal muscular atrophy. Neuroradiological studies are therefore necessary owing to possible surgical treatment. The hypothesis relating lower motor involvement and ACM are reviewed.