Multifocal motor neuropathy (MMN): clinical and electrophysiological observation in a patient before and during therapy with intravenous immunoglobulins (IVIG)

Society proceedings / Electroencephalography and clinical Neurophysiology 95 (I 995) 4P-8P exacerbations of weakness and that a considerable degree of progressive motor and sudomotor axonal loss can be found although there is an apparent long-term clinical stabilization of the neuropathy. 5. Gold neuropathy - a case report. - M. Corboz and M.R. Magistris (Geneva) Gold salts are used for the treatment of rheumatoid arthritis since 1927. Polyneuropathy as a complication of this treatment is a rare condition, and only the most recent cases have been studied electrophysiologically. We report a 46-year-old man, presenting with a rheumatoid arthritis since October 1992. A treatment consisting of sodium aurothiomalate started in October 1993, the total dosis received being 1625 mg. In January 1994, he complained of numbness and burning sensation of both hands and feet. Physical examination revealed hypoactive tendon reflexes and diminished deep sensation in lower limbs. There was no sign of activity of the rheumatoid arthritis. Blood tests and urine analysis were normal. EMG disclosed a sensory axonal polyneuropathy. Gold treatment was discontinued. During the following 3 months, there was little improvement and EMG remained unchanged. Besides the gold neuropathy, the differential diagnosis of this subacute sensory polyneuropathy encompasses also the following conditions: neuropathy associated with rheumatoid arthritis, nutritional deficiency, other toxics, paraneoplastic state. Gold neuropathy consists either of a sensory, motor, or sensorimotor axonal polyneuropathy; myokymias are sometimes associated. On the basis of the clinical context, it is concluded that the most likely diagnosis is gold neuropathy. This neuropathy deserves to be reminded because it is a rare and not yet fully understood condition. It has been suggested that the therapeutic effect of gold salts in rheumatoid arthritis could be related to a neurotoxic effect on periarticular nociceptive nerve fibres (Levine et al., Arthr. Rheum., 1987, 7: 897-901). 6. Multifocal motor neuropathy (MMN): clinical and electrophysiological observation in a patient before and during therapy with intravenous immunoglobulins (IVIG). - S. Beer, K.M. R6sler, R. Baumgartner, M. Sturzenegger and C.W. Hess (Bern) A 54-year-old man is described who suffered a progressive bilateral weakness of the hand extensors in 1984. Electromyographic evaluation suggested lesions of the posterior interosseus nerves, and a bilateral compression neuropathy was suspected. Surgical nerve release was unsuccessful. The correct diagnosis of a multifocal motor neuropathy (MMN) was established in 1993, when he presented with a foot drop and a palsy of the intrinsic hand muscles on the left side, without any sensory deficits. Serum anti-GM1 antibodies were greatly elevated. The extended electrophysiological work-up revealed focal partial motor conduction blocks (CB) of the left ulnar nerve at the forearm, and of the proximal lumbar plexus efferents to the left tibialis anterior muscle. All sensory conduction studies were normal. A treatment with IVIG (0.5 g × k g - 1 × d - ~ for 5 days) resulted in considerably improved strength of the affected muscles. Electrophysiologically, the CB of the ulnar nerve resolved completely within days. Our case demonstrates that (i) MMN has to be considered in the differential diagnosis of entrapment neuropathies, (ii) distal nerve conduction studies may be insufficient to establish the correct diagnosis in these cases, and (iii) IVIG may be an efficient therapy of CB in MMN. 7. Sympathetic skin response. Report of two cases with segmental abnormality. - M.P. Grau and M.R. Magistris (Geneva) Sympathetic skin response (SSR) is a slow reflex depolarization of the skin resulting from activation of the sudomotor sympathetic efferent fibres that follows a sudden stimulation. We report two cases of segmental sympathetic skin abnormality. Patient 1 is a 33-year-old man with traumatic LI paraplegia since 1990,

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who developed from July 1993 progressive pain, thermoalgesic anaesthesia, hyperhidrosis of the right arm and hemithorax, and areflexia of the right arm. Electroneuromyography revealed an absent SSR on the right hand and a mild bilateral carpal tunnel syndrome. MR1 disclosed a syringomyelic cavity from C1 to the conus medullaris associated with a spinal cord atrophy. Patient 2 is a 27-year-old man, in good health, who presented since 1987 an anhidrosis of the right hand, hyporeflexia and absent ankle jerks. Electroneuromyography showed an absent SSR on the right arm and absent H reflex from both soleus muscles. Laboratory, X rays and cervical magnetic resonance were normal. In conclusion, the SSR is abnormal in case of loss of autonomic regulation. Numerous conditions may lead to segmental SSR abnormality. We report a case of hyperhidrosis associated with a posttraumatic syringomyelia and a case of anhidrosis of undetermined origin. 8. Hereditary hyperekplexia: clinical and electrophysiologic characteristics illustrated in a representative case. - P. Fuhr and T. Yilmaz (Basel) A 35-year-old woman who was treated for anxiety and depression complained about falling attacks. She startled excessively and on occasions fell since early childhood. Pregnancy and birth had been normal but she had learned to walk only at age 2.5-3 years. Two of her 3 siblings and 3 of 6 children of an affected sister had similar symptoms. Physical examination was normal except for startle responses to unexpected sounds and jerky head retractions to nose-taps. The EEG showed intermittent theta waves on the anterior left side. The acoustic and somatosensory evoked potentials were normal. The responses of the blink reflex had normal latencies but spread to the neck and proximal arm muscles with latencies below 40 msec. Nose-tapping produced reflex responses in all paravertebral and proximal arm muscles (latencies between 14 msec, orbicularis oculi, and 25 msec, IA paralumbar muscles). Somatic and emotional symptoms vanished when she was treated with clonazepam. The patient exhibits all characteristic signs of hereditary hyperekplexia: autosomal dominant inheritance, begin in childhood, falls without unconsciousness, exaggerated acoustic startle reflex, non-habituating head retraction to nose-taps, abnormal spread of the blink reflex, and good response to treatment with clonazepam. 9. Transcranial Doppler and angiographic findings in adolescent stretch syncope. - M. Sturzenegger, D.W. Newell, C. Douville, S. Byrd and K. Schoonover (Bern, Seattle, WA, USA) We report the clinical, angiographic and Doppler findings of 2 young patients with recurrent syncope induced by neck hyperextension during stretching. Transcranial Doppler monitoring was performed of both posterior cerebral arteries during head manoeuvres. There were reproducible rapid drops of blood flow velocities to an average of 28% and 41% respectively of baseline values while performing neck hyperextension. These drops were regularly associated with the patients' symptoms and were not found during head rotation or flexion. When returning to a neutral head position there was a transient increase of the blood flow velocities to an average of 131% and 136% of baseline values (reactive hyperemia). Routine 4-vessel angiography on each patient was normal except very small posterior communicating arteries in I patient. Dynamic angiography showed evidence of extracranial craniocervical artery compression in both patients. We therefore conclude that decreased blood flow to the posterior circulation is an important factor in the pathogenesis of adolescent stretch syncope. I0. Confusional state due to non-convulsive generalized status epilepticus. - R. Wullimann, C. Bassetti and C.W. Hess (Bern) The aim of this study was to assess clinical and EEG features, aetiology and prognosis of non-convulsive generalized status epilepticus (NGSE).