Usefulness of combined nerve and muscle biopsy in the diagnosis of amyloid neuropathy--a study of 6 new cases.

OBJECTIVE: Most cases of familial amyloid polyneuropathy are identified by molecular genetic analysis of the transthyretin (TTR) gene. However, it is not uncommon to find unexpected amyloid deposits marked by the anti-TTR serum in the endoneurium of aged patients. Light chain amyloid deposits may also be found in the endoneurium. During these past 5 years, we studied the muscle and nerve biopsies from 6 patients which revealed amyloid deposits. There were 2 patients with an idiopathic polyneuropathy and 4 with monoclonal gammopathy (MG). METHODS: In each case, specimens from the superficial peroneal nerve and peroneus brevis muscle were taken by the same cutaneous incision. RESULTS: Amyloid deposits were visible in the endoneurium of 2 cases and only on muscle specimens in 3 other cases, 1 with a MG and 2 with an idiopathic polyneuropathy. Amyloid deposits were strongly stained with the anti-TTR serum in the muscle specimens of the 2 idiopathic cases, mainly located in vessel walls. In one patient with polyneuropathy and MG, a small endoneurial amyloid deposit surprisingly revealed to be immunostained by the anti-TTR serum. In another case, a small amyloid deposit in close relationship with a macrophage was only visible in the endoneurium by electron microscopy. COMMENTS: Amyloid deposits were only visible on muscle fragments in 3 cases and were strongly marked by the anti-TTR serum in 2 of them, indicating their familial origin. Combining muscle and nerve biopsy raises the number of cases with visible amyloid deposits.

Sarcoid neuropathy: clinico-pathological study of 4 new cases and review of the literature.

There are several reviews devoted to neurosarcoidosis and a few reports restricted to sarcoid neuropathy. Since 1989, we have investigated 4 new cases of sarcoid neuropathy, 1 with chronic sensory motor neuropathy (CSMN), another with painful neuropathy and 2 with atypical chronic inflammatory demyelinating polyneuropathy (CIDP). In each case, biopsy specimens from the superficial peroneal nerve and peroneus brevis muscle were taken by the same cutaneous incision and studied on paraffin sections, semi-thin sections and under electron microscope. We compared neuropathological findings from our 4 cases with those from 34 well-studied nerve biopsies previously reported in the literature, and which concerned 16 cases of CSMN, 13 cases ofmononeuropathy multiplex, 2 cases of painful neuropathy and three cases of CIDP. In all of these 38 cases of sarcoid neuropathy, the characteristic noncaseiting granulomas (NCG) were observed on the nerve in 11 cases, on the muscle alone in 5, on both muscle and nerve in 10, and in the nerve and another parenchyma in 4. In the 8 remaining cases, NCG were observed in another parenchyma, mainly lung or lymph nodes. Moreover, necrotizing vasculitis was present in nerve biopsies from 8 cases and microvasculitis without obvious necrosis in 2 others. Nerve fiber lesions, which are mainly axonal, are probably related to mechanical compression by NCG and/or to an ischemic process due to vasculitis. Cytokines and immune factors may also play a role, especially in certain cases with a clinical presentation of CIDP.

[Lambert-Eaton Myasthenic Syndrome associated with vocal cord carcinoma]. / Syndrome myasthénique de Lambert-Eaton associé à un carcinome épidermoïde de la corde vocale.

INTRODUCTION: Lambert-Eaton Myasthenic Syndrome (LEMS) is an autoimmune channelopathy in which patients produce autoantibodies directed against voltage-gated calcium channels. LEMS is paraneoplastic in 50% of patients, most frequently associated with small cell lung carcinoma. We describe a case of paraneoplastic LEMS associated with a vocal cord carcinoma. OBSERVATION: A 64-year-old man developed in five months muscle weakness affecting gait. Clinical examination showed proximal muscular deficiency, areflexia and dysphonia. Electrophysiologic study showed potentiation greater than 500% after post exercise facilitation and 76 percent increment response at high-rate repetitive nerve stimulation (20Hz). Diagnosis of LEMS was confirmed by electrophysiologic study and anti-voltage gated calcium channel antibodies (90pM, positive value greater or equal to 70pM). Left vocal cord lesion histology showed epidermoid carcinoma. A combination of vocal cord tumor removal by endoscopy and treatment by pyridostigmine, 3-4 diaminopyridine and intravenous human immunoglobulin improved neurological symptoms. CONCLUSION: Paraneoplastic syndromes in association with cancers of the larynx and hypopharynx are unusual. Only two cases are reported with LEMS associated with larynx carcinoma. We describe an unusual case of LEMS associated with a left vocal cord carcinoma.

Epsilon sarcoglycan mutations and phenotype in French patients with myoclonic syndromes.

BACKGROUND: Myoclonus dystonia syndrome (MDS) is an autosomal dominant movement disorder caused by mutations in the epsilon-sarcoglycan gene (SGCE) on chromosome 7q21. METHODS: We have screened for SGCE mutations in index cases from 76 French patients with myoclonic syndromes, including myoclonus dystonia (M-D), essential myoclonus (E-M), primary myoclonic dystonia, generalised dystonia, dystonia with tremor, and benign hereditary chorea. All coding exons of the SGCE gene were analysed. The DYT1 mutation was also tested. RESULTS: Sixteen index cases had SGCE mutations while one case with primary myoclonic dystonia carried the DYT1 mutation. Thirteen different mutations were found: three nonsense mutations, three missense mutations, three splice site mutations, three deletions, and one insertion. Eleven of the SGCE index cases had M-D and five E-M. No SGCE mutations were detected in patients with other phenotypes. The total number of mutation carriers in the families was 38, six of whom were asymptomatic. Penetrance was complete in paternal transmissions and null in maternal transmissions. MDS patients with SGCE mutation had a significantly earlier onset than the non-carriers. None of the patients had severe psychiatric disorders. CONCLUSION: This large cohort of index patients shows that SGCE mutations are primarily found in patients with M-D and to a lesser extent E-M, but are present in only 30% of these patients combined (M-D and E-M).

[Cramp-fasciculation syndrome]. / Le syndrome crampes-fasciculations.

The cramp-fasciculation syndrome is a rare clinical entity in comparison with the frequency of cramps and isolated fasciculations in the general population. It is recognized as a benign syndrome without weakness and atrophy, however a few reports suggest that it may precede the occurrence of a motor neuron disease. Most often, the cramp-fasciculation syndrome is idiopathic and may be a component of a hyperexcitable peripheral nerve syndrome including other activities such as myokymia and neuromyotonia where antibodies to voltage-gated potassium channels (VGKCs) appear to be one of the effector mechanisms. The most complete form of this hyperexcitable peripheral nerve syndrome is Isaacs' syndrome. The central nervous system is also concerned with anti-VGKC antibodies found in Morvan's disease and limbic encephalitis which is often a paraneoplastic condition. These findings extend the spectrum of the anti-VGKC syndrome that may be associated with other auto-immune diseases, chiefly myasthenia gravis with thymoma. Carbamazepine and phenytoin cause reduction of the clinical and electrophysiological signs of the nerve hyperexcitability, and plasmapheresis and (or) immunosuppressors are useful when an auto-immune origin is considered.

[Chronic inflammatory demyelinating polyradiculoneuropathy: diagnostic strategy. Guidelines of the French CIDP study group]. / Polyradiculonévrites inflammatoires démyélinisantes chroniques: stratégie diagnostique. Recommandations du groupe d'Etude français des PIDC.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) comprises a group of dysimmune neuropathies easily diagnosed in more than half of the patients. Diagnosis is based on clinical, electrophysiological and biological clues. In some patients, diagnosis is unclear because of the debated value of the available clues. In such circumstances, dysimmune neuropathies may not be diagnosed, leading to insufficient treatment. This is an important category of patients because immunomodulatory drugs have proven efficacy. The CIDP spectrum includes a relatively wide range of diseases. Besides the easily recognized classic forms, there are many clinical variants, sometimes with a paucisymptomatic presentation leading to uncertain diagnosis. The French CIDP study group has established guidelines for diagnostic strategy in CIDP patients. The first part of this paper is devoted to the clinical aspects of the disease, classical forms and variants. In the second part, the results of electrophysiological studies are reported. In a third chapter, complementary examinations useful for diagnosis are discussed. The fourth chapter deals with the diagnostic strategy, discussed in relation to the different situations which may be encountered in clinical practice. details the technical modalities of appropriate electrophysiological studies and presents normal results together with those indicating demyelinating neuropathy. Nerve biopsy technique and results are given in appendix II.

Polyneuropathy in Waldenström's macroglobulinemia. Deposition of M component on myelin sheaths.

A chronic sensory neuropathy was the initial symptom in a case of Waldenström's macroglobulinemia in a 53-year-old woman. Ultrastructural analysis of a biopsied peripheral nerve revealed a modification of the lamellar structure of the myelin sheath. Immunofluorescent microscopy showed IgM-positive deposits on the myelin sheath. The monoclonal globulin (M component) present in the myelin appears to be a causative factor in the neuropathy.

Waldenström's macroglobulinemia and peripheral neuropathy: deposition of M-component and kappa light chain in the endoneurium.

Some cases of peripheral neuropathy associated with benign IgM monoclonal gammopathy, or Waldenström's macroglobulinemia, are probably of autoimmune origin; in some cases, anti-IgM serum reacts with the myelin sheaths of peripheral nerves. However, mechanisms may differ in other cases. In one case of neuropathy with macroglobulinemia, we found deposits of IgM immunoglobulin in the endoneurium. On ultrastructural examination, the deposits had erased the basement membrane of some nerve fibers that showed damage of both myelin and axon.

Chronic demyelinating neuropathy with IgM-producing lymphocytes in peripheral nerve and delayed appearance of "benign" monoclonal gammopathy.

A chronic demyelinating neuropathy with "benign" IgM gammopathy was followed for 6 years in a 63-year-old man. The clinical, biologic, and EMG aspects were similar to those already reported, but a lymphoplasmocytic infiltrate in the nerve connective tissue of this patient has only rarely been observed in benign IgM gammopathy. The paraprotein was not evident in the serum until 5 years after symptoms of the neuropathy started.

Minimal tissue damage after stimulation of the motor thalamus in a case of chorea-acanthocytosis.

Autopsy findings are reported from a patient with chorea-acanthocytosis treated for 2 years by deep brain stimulation (DBS) of the motor thalamus. Postoperative testing showed a progressive improvement in axial truncal spasms. Although relatively high currents were used for 2 years in this patient, postmortem analysis showed minimal tissue damage in the vicinity of the electrode tip. It is concluded that DBS has little impact on the surrounding tissues.

Progressive bulbospinal amyotrophy in triple A syndrome with AAAS gene mutation.

Triple A (3A) syndrome, a rare autosomal recessive disorder, is characterized by adrenocorticotropic hormone-resistant adrenal insufficiency, achalasia of the cardia, alacrima, and variable autonomic and neurologic dysfunction. The gene responsible, AAAS, recently has been identified. We describe the neurologic phenotype of the first adult case of 3A syndrome presenting bulbospinal amyotrophy as the prominent sign in association with a homozygous nonsense mutation identified in the AAAS gene.

Novel muscle chloride channel (CLCN1) mutations in myotonia congenita with various modes of inheritance including incomplete dominance and penetrance.

Autosomal-dominant and -recessive myotonia congenita are caused by mutations in the skeletal muscle voltage-gated chloride channel gene (CLCN1). We searched for mutations in this gene in 20 unrelated families with myotonia congenita. We identified 11 different mutations in 10 families. Two of five new mutations (Ala313Thr and Ile556Asn) were both autosomal recessive and dominant with either reduced penetrance or incomplete dominance. Mutations in the CLCN1 gene do not therefore necessarily behave in a classic Mendelian manner.

Peripheral myelin modification in CMT1B correlates with MPZ gene mutations.

Morphological modifications were investigated in the peripheral nerve of three unrelated patients with CMT1B. In two patients, molecular genetic analysis showed an Arg98His mutation in the extracellular domain of MPZ, associated with irregularly uncompacted lamellae. This observation confirms previous studies of a well-defined correlation between mutations and morphological phenotypes. In the third patient, a de novo Asp109Asn mutation was associated with abnormally thick myelin sheaths. This adds to the known list of MPZ gene mutations associated with this morphological phenotype.

Movement disorders induced by gamma-aminobutyric agonist and antagonist injections into the internal globus pallidus and substantia nigra pars reticulata of the monkey.

Injections of bicuculline into the medial segment of the globus pallidus (GPi) of the monkey induced dose-dependent hypokinesia with dystonic attitudes in contralateral limbs whereas muscimol injections elicited choreiform movements. Injections of the same drugs in substantia nigra pars reticulata (SNr) provoked severe axial postural anomalies with rotational behavior. Conversely, contralateral hypertonia after bicuculline and contralateral hypotonia after muscimol injections were observed. These data suggest that GABA inputs into GPi and SNr play different roles in terms of motor and postural control and add new insights into the pathophysiology of dystonias.

Sporadic late onset paroxysmal cerebellar ataxia in four unrelated patients: a new disease?

We describe a peculiar form of late onset paroxysmal cerebellar ataxia including clinical features similar to episodic ataxia type 2 (EA2) but unresponsive to acetazolamide. Four unrelated patients were clinically investigated. Neuropathological examination was performed in one patient and molecular analysis in all four. All 47 exons of CACNA1A were screened by a combination of single-strand conformer polymorphism and sequencing analysis in three patients. In addition, the length of the CAG repeat was determined in all four patients. The four patients were in their 60s at the onset of the disease, which was characterized by cerebellar ataxia attacks lasting from a few minutes to 1-2 h and occurring mainly in the morning. In the interictal period a nystagmus was present together with a slowly progressive cerebellar ataxia over the years. The neuropathological examination disclosed a dramatic loss of Purkinje cells mainly in the vermis. Moreover, certain cerebellar granular neurons had a strong cytoplasmic staining at immunopathological examination with an anti-tau protein serum. Search for truncating mutations or CAG repeat expansion in CACNA1A was negative. This late-onset paroxysmal cerebellar ataxia with neuropathological lesions restricted to Purkinje cells and with negative results both for truncating mutations and CAG expansion in the CACNA1A gene represents a new entity. Further studies are needed to delineate the underlying process.

Isolated peripheral nerve relapse masquerading as Guillain-Barré syndrome in a patient with acute lymphoblastic leukemia.

We report a 30 year old patient with acute lymphoblastic leukemia (ALL) whose leukemic relapse presented as an isolated symmetrical peripheral neuropathy with facial diplegia. Initially, this was consistent with a Guillain-Barré syndrome but the peripheral nerve biopsy revealed leukaemic infiltration. This was followed by a systemic relapse. Reports of peripheral nerve infiltration are scarce and to the best of our knowledge this is the first documented case of peripheral polyneuropathy as a presenting manifestation of ALL relapse.

Inclusion body myositis. Clinical, biological and ultrastructural study.

A 48-year-old patient presented for the past 4 years an amyotrophy of the quadriceps and moderate involvement of the truncal and pelvic girdle muscles. The CK level was elevated (10 times the normal rate) and the EMG revealed a fibrillation pattern on relaxation, myotonic bursts on needle insertion and reduced activity during contraction. The histological study of the muscle biopsy showed nuclear cytoplasmic inclusion bodies and pseudo-myelinic membranes. The case was classified in the inclusion body myositis group. Analysis of the other published cases underlines the variety of the clinical, biological and electromyographical aspects and abnormalities.

Guillain-Barré syndrome and Hodgkin's disease--ultrastructural study of a peripheral nerve.

A 46-year-old male patient developed the Guillain-Barre syndrome and recovered completely within 3 months. He had been treated 5 years previously for Hodgkin's disease, and during the neurological syndrome, relapse of the malignant lymphoma was discovered. On neuro-muscular biopsy, lymphocytes were observed penetrating Schwann cells. These neuropathological aspects confirm the auto-immune character of the nervous involvement.