What is the place of electroneuromyographic studies in the diagnosis and management of pudendal neuralgia related to entrapment syndrome?

Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring.

Severe cardiac arrhythmias in young patients with myotonic dystrophy type 1.

Cardiac tachyarrhythmias have rarely been studied in young patients with myotonic dystrophy type 1 (DM1). The authors observed major cardiac rhythm disturbances in 11 patients aged 10 to 18 years. Tachyarrhythmic events were more frequent than impulse conduction disorders. Wide variations in CTG expansion were observed among the population. Since physical exercise was a prominent arrhythmogenic factor, systematic exercise tests with EKG monitoring may be indicated in young patients with DM1.

[Neurotoxic effects of medications: an update]. / Neuropathies médicamenteuses: mise a jour récente des données (1996 a 2003).

Peripheral neuropathy is a common neurotoxic effect of medications. Antineoplastic agents and antiretroviral medications are most often involved: platinum compounds, vinca alkaloids, taxols and nucleoside reverse transcriptase inhibitors. These agents cause a dose-related axonal polyneuropathy. Symptoms are indicative of a predominantly sensory or sensory-motor neuropathy which in some cases is accompanied by dysfunction of autonomic nervous system. Depending on dosage and agent used symptoms resolve completely or not. Neurotoxic effect can appear immediately during or shortly after administration of the drug but sometimes after cessation of chemotherapy. In all cases the neuropathy alters the quality of life. A general predisposition for developing a neuropathy has been observed in nerves previously damaged by diabetes mellitus, alcohol or in inherited neuropathy. Within the past five years, some cases of neuropathy caused by alpha-interferon, statins or tacrolimus have been reported. Although rare, these aetiologies should be considered by physicians and the drugs removed when others causes of neuropathy have been excluded. Few cases of peripheral neuropathy have been recently reported with metronidazole, dapsone, nitrofurantoin or colchicin. Thalidomide induces a dose-dependant sensori-motor length-dependent axonal neuropathy. It should be judiciously used with close neurologic monitorin. Little is known about the mechanisms responsible for the development of neuropathy. Up to now, no drug is available to prevent or cure drug-induced neuropathies.

[Muscle diseases in an internal medicine department]. / Diagnostic des maladies musculaires dans un service de médecine interne.

PURPOSE: (1) To describe the causes of muscular symptoms in patients undergoing a muscle biopsy in an internal medicine department; (2) to evaluate the diagnostic value of electromyography (EMG), CPK level and muscle biopsy. METHODS: A retrospective study including 90 patients from June 1995 to March 2001. RESULTS: The diagnosis were: inflammatory diseases (n = 35), non-organic (n = 24), peripheral neuropathy (n = 8), undetermined organic diseases (n = 7), metabolic diseases (n = 5), toxic diseases (n = 4), infectious diseases (n = 4), amyloidosis (n = 3). Diagnosis value of EMG, CPK and biopsy for organicity were: sensibility: 82%, 47% and 29%; specificity: 46%, 91%, 100%; positive predictive value: 78%, 94% and 100%; negative predictive value: 50%, 40% and 36%. Muscle biopsy is always normal when CPK and EMG are normal. It allows a diagnosis in one out of three cases if EMG and CPK are differing. It is also indicated when CPK are normal and EMG is myogenic. CONCLUSION: Numerous diseases account for muscular symptoms. The low rate of diagnostic muscle biopsy imposes a comprehensive clinical approach of the patient and justify the implication of internal medicine physicians in his care. Early intervention of a psychosomatic medicine practitioner in the diagnostic procedure should be evaluated to diminish the number of non-contributory biopsies.

Autonomic and respiratory dysfunction in Charcot-Marie-Tooth disease due to Thr124Met mutation in the myelin protein zero gene.

OBJECTIVE: To report the clinical and electrophysiological characteristics of a family presenting Charcot-Marie-Tooth disease (CMT) associated with autonomic nervous system disturbances. METHODS: We studied nerve conduction values, postural adaptation, sympathetic skin reflex, the variation in heart rate by the Valsalva ratio and pupillometry in 7 members of a French family in which CMT due to a Thr124Met mutation in the myelin protein zero (MPZ) gene was diagnosed. RESULTS: Clinical and laboratory evidence of autonomic nervous system disturbances were found in the affected individuals. The clinical phenotype was characterized by sensorimotor peripheral neuropathy, defined as axonal type by electrophysiological studies, and was associated with severe pain, bladder dysfunction, sudorimotor disturbances and abolished pupillary reflex to light. Moreover, two patients had severe restrictive respiratory insufficiency requiring noninvasive mechanical ventilation. CONCLUSIONS: Our study demonstrates that autonomic disturbances may be one of the major clinical signs associated with CMT secondary to MPZ gene mutation in codon 124. Testing of pupillary reflex allows the discrimination of affected and unaffected subjects in our family. However, involvement of the autonomic nervous system in this type of neuropathy is unclear and further studies are required to elucidate the role of the MPZ gene in the autonomic nervous system.

[Multiple mononeuritis and cerebral meningo-arteritis. Wegener disease or Lyme disease?]. / Mononévrite multiple et méningo-artérite cérébrale. Maladie de Wegener ou maladie de Lyme?

The pathogenic mechanisms underlying Lyme disease remain uncertain but an increasing number of reports suggest a vascular inflammatory process. On the other hand, the so-called systemic vasculitides, even though they remain of pathological definition, have recently been characterized by the presence, in the serum, of anti-neutrophil cytoplasmic antibodies (ANCA). We report on a patient, finally diagnosed as having neuroborreliosis, who presented initially with multiple mononeuropathy, ANCA, vascular lesions at muscle biopsy and lymphocytic meningitis. Despite antibiotherapy, he presented with two recurrent strokes, from which he completely recovered. He also developed oto-sinusitis. The disease was finally clinically and biologically controlled by immunosuppressive therapy. The relationship between angiitis and Lyme disease are discussed. It is hypothesized that Borrelia burgdorferi infection may cause a systemic vasculitis following its own course and requiring its own treatment.

A randomised double-blind placebo-controlled crossover add-on trial of lamotrigine in patients with treatment-resistant partial seizures.

Efficacy and safety of lamotrigine (LTG) as add-on therapy was assessed in a randomised double-blind placebo-controlled trial of this drug in 23 adult patients with refractory partial seizures. Fifteen patients showed an improvement on LTG treatment, with a greater than 50% decrease in total seizure count in 7 patients. Fourteen patients experienced fewer simple and complex partial seizures, with 8 patients benefitting by more than a 50% decrease in seizure frequency. The drug was well tolerated over the 2 month treatment period. The plasma concentration of concomitant antiepileptic drugs remained unchanged. No haematological or chemical abnormalities were noted.

Reversibility of hemodynamic hypofrontality in schizophrenia.

Regional cerebral blood flow (CBF) was studied in 51 young schizophrenics. A significant decrease of CBF was seen in frontal and prefrontal regions (hypofrontal pattern) in chronic patients whose disease had evolved for more than 2 years and who were in remission. This hypofrontal pattern was reversible, as it disappeared during exacerbation of the disease. In 10 patients who had not been treated with neuroleptics for several weeks, we found a dopaminergic hypersensitivity in the frontal lobes, as a weak dose of piribedil restored near-normal frontality. This may reflect either the role of neuroleptic washout or a primitive dopaminergic depletion, as proposed by some authors in the chronic form of schizophrenia.

[A case of centronuclear myopathy in adults with facio-scapulo-peroneal topography]. / Un cas de myopathie centro-nucléaire de l'adulte de topographie facio-scapulo-péronière.

A 34 year-old man had complained since childhood of weakness of the right lower limb. His mother had a myopathy. Examination showed weakness and amyotrophy of the antero-external regions of the legs, mainly on the left, moderate weakness of the right scapular girdle and slight facial weakness. Serum creatine kinase was increased. Electromyogram and CT scan images were of the myogenic type. Biopsy showed a centronuclear myopathy. The course was slowly progressive. Centronuclear myopathy is rare in adults. The facio-scapulo-humeral localization has been described in numerous other pathologic types of myopathy.

[Urinary stress incontinence in women: contribution of electromyography of the striated urethral sphincter]. / Incontinence urinaire d'effort féminine: apport de l'électromyographie du sphincter strié urétral.

Fourteen women within their menopausal period and suffering from stress urinary incontinence were studied. Electromyographic studies show that sphincter weakness is almost constant (9/14), usually associated with a bladder instability and/or a lack in abdominal urethral transmission, both conditions being known as possible causes of urinary stress incontinence. However, neurological causes at the origin of urinary stress incontinence, such as neurogenous sphincter, may be found (3/14). Electromyography, coupled with urodynamic evaluation, therefore presents itself as the most accurate method for a good assessment of correct pathophysiology in urinary stress incontinence and thereby for good therapeutic prescription.

[Dopaminergic hypersensitivity in migraine: a diagnostic test? (author's transl)]. / Hypersensibilité dopaminergique dans la migraine: un test diagnostique?

A dopaminergic agonist, piribedil, was administered by intravenous infusion (0.1 mg/kg over 30 minutes) to 20 patients known to suffer from migraine and 20 subject free from any kind of headache. Neither changes in cerebral blood flow (CBF), as measured by the 33Xenon inhalation technique, nor peripheral side-effects were noted in the control group. Patients with migraine exhibited an 18 p. cent increase in CBF and a 32 p. cent decrease in mean arterial pressure and rapidly developed nausea severe enough to discontinue the infusion in most cases. Prior administration of domperidone, a neuroleptic drug which does not cross the blood-brain barrier, suppressed the nausea and fall in blood pressure but had no effect on the increase in CBF. This study confirms the existence of central and peripheral hypersensitivity to dopaminergic agents in patients with migraine. The piribedil test could be used to distinguish genuine migraine from ordinary cephalalgia in patients prone to headache.

Effects of a dopaminergic agonist (piribedil) on cerebral blood flow in man.

In baboons, the intravenous administration of piribedil, a dopaminergic agonist, was associated with marked dose dependent increases in CBF and cerebral oxygen consumption. We have studied the effects of piribedil on CBF in 20 normal, human volunteers of comparable ages. Ten received 0.1 mg/kg piribedil intravenously for 30 min; the other ten received 0.2 mg/kg. In the first group, CBF did not vary significantly, in the second group, there was a mean increase in CBF of 21.8% (p less than or equal to 0.005). In man, as in animals, piribedil provokes an increase of CBF.