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108. Genetic heterogeneity of distal hereditary motor neuropathy type II
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Society Proceedings / Clinical Neurophysiology 120 (2009) e89–e126
the onset, the authors discovered asymmetric quadriparesis with atrophy, fasciculations, diffusely brisk reflexes, mute plantar responses, and normal cranial nerves. Electromyography revealed fibrillation and fasciculation potentials with large polyphasic potentials in the cervical, thoracic, and lumbar segments. Sensory nerve conduction and autonomic studies were normal. Magnetic resonance imaging of the brain and spine was normal, but for mild uniform gadolinium enhancement of lumbar nerve roots. Spinal fluid protein was 81 mg/dL with normal cell count and cytology. There was no evidence of systemic or paraneoplastic autoimmunity, sarcoidosis, or infection by enterovirus, West Nile virus, human T-cell lymphotropic virus type I, or human immunodeficiency virus. Monoclonal protein studies and full body computerized tomography and position emission tomography were normal. Six weeks later, there was definite bulbar weakness, tongue fasciculations, and a brisk jaw jerk reflex. Despite further methylprednisolone and intravenous immunoglobulin, progressive respiratory failure and dysphagia ensued. The patient died 10 months after the onset. Conclusion: The presence of modest lumbar root enhancement and cerebrospinal fluid protein elevation do not exclude the clinical diagnosis of ALS. Disruption of the blood nerve barrier, secondary to rapid neuronal degeneration, not inflammation, is suggested pathophysiologically. N.P. Young is a Junior Member Recognition Award Recipient. doi:10.1016/j.clinph.2008.10.124
107. Wound botulism after open fracture shows rapid improvement after antitoxin treatment—A.D. Galbreath, D.N. Johnson, V. Juel, D.B. Sanders (Durham, NC, USA) Introduction: In rare cases of wound botulism following limb fracture, improvement typically takes weeks to months, even with treatment. This case report suggests that using equine antitoxin treatment when botulism’s is suspected can improve recovery time. Case report: A 34-year-old man sustained an open fracture of his left mid-radius and ulna while playing soccer. He underwent debridement followed by open reduction and internal fixation with metal hardware. Nine days later he developed photophobia, blurred vision, progressive diplopia, and lid ptosis. During the following week, he developed dysarthria and dysphagia, and was referred with the presumptive diagnosis of myasthenia gravis. The examination revealed dilated pupils and sluggish reaction to light. There was complete bilateral eyelid ptosis and near-complete external ophthalmoplegia. The patient’s speech was of a nasal quality with severe, flaccid dysarthria. Reduction of strength in the arms and decreased tendon reflexes in the right arm were reported. Both generalized strength and tendon reflexes were normal in the legs. Electrodiagnosis revealed compound muscle action potential (CMAP) amplitude of the abductor digiti minimi (ADM) was low (3 mV) and increased 100% following 10 isometric exercises. There was a 10% decrement in CMAP amplitude during 3 Hz stimulation. Needle electromyography revealed unstable motor units without spontaneous activity. He received bivalent antitoxin (types A and B) within 24 h of admission. There was a near-complete resolution of symptoms within 6 days but facilitation (75%) of ADM CMAP amplitude remained. Following the treatment, there was no decremental response with 3 Hz stimulation. Conclusions: While awaiting confirmation of the diagnosis, clinical suspicion of botulism and characteristic electrodiagnostic findings should lead to prompt treatment. Antitoxin treatment may
lead to rapid improvement even when given 1 week after symptom onset. doi:10.1016/j.clinph.2008.10.125
108. Genetic heterogeneity of distal hereditary motor neuropathy type II—S. Lee 1, S. Moon 1, C. Ki 2 (1 Cheongju-si, South Korea, 2 Seoul, South Korea) Introduction: Distal hereditary motor neuropathy (dHMN) represents a rare and exclusive motor neuropathy of clinically and genetically heterogeneous conditions caused by degeneration of motor neurons leading to distal muscle weakness and muscle wasting. Case report: A family with autosomal dominant adult onset dHMN (Type II) is examined. Four patients spanning three generations (proband 47-year-old man, his sister, father, and father’s sister) developed mild symmetrical distal limb weakness, muscle wasting, and severe foot deformity after the third decade. Involvement of the lower extremities was more prominent than that of the upper extremities. No sensory or autonomic abnormalities were detected. Tendon reflexes were preserved. Nerve conduction studies indicated normal or slightly decreased motor conduction and completely normal sensory conduction. Needle electromyography revealed high amplitude, long duration, and polyphasic motor unit potentials without active spontaneous activities, which are indicative of longstanding neuropathy. Serum creatine kinase was not elevated. Mutations in heat shock proteins HSPB1, HSPB8, and Cu/Znsuperoxide dismutase (SOD1) genes were not found. Conclusion: This is the first case of dHMN type II reported in Korea. The study provides further evidence of the genetic heterogeneity of dHMN type II. doi:10.1016/j.clinph.2008.10.126
109. A clinical and electrophysiological profile of autosomal dominant distal axonal neuropathy—B.A. Ishpekova (Sofia, Bulgaria) Introduction: A rare variant of distal axonal neuropathy (DAN) predominantly involves the upper limbs. Objective: To determine the clinical and electrophysiological characteristics of patients with DAN. Method: An autosomal dominant DAN was identified in 30 people of a large six-generation Bulgarian family comprised 116 members. Needle electromyography of the distal and proximal upper and lower limb muscles examined the motor nerve conduction velocity in the median, ulnar, tibial, and peroneal nerves and the late responses (F and A waves). Sensory conduction was examined antidomically in the median, ulnar, and sural nerves. Results: The mean age of onset is 16 years (10–35) with selective weakness and wasting of the thenar, hypothenar and first dorsal interosseus muscles of the hands. Progression of the disease is very slow with some patients remaining ambulant at age 64. About 40% of the subjects report involvement in the feet. The gene that causes this disease has been mapped to the short arm of chromosome 7p. Electrophysiological and muscle biopsy findings indicate a chronic neurogenic pattern, nerve biopsy showed mild axonal degeneration, and muscle biopsy evidenced chronic neurogenic changes. The motor conduction velocity of all nerves fell below the normal range. The distal motor latencies were prolonged. Mild sensory deficits developed in some patients. The highest percent
Society Proceedings / Clinical Neurophysiology 120 (2009) e89–e126
the onset, the authors discovered asymmetric quadriparesis with atrophy, fasciculations, diffusely brisk reflexes, mute plantar responses, and normal cranial nerves. Electromyography revealed fibrillation and fasciculation potentials with large polyphasic potentials in the cervical, thoracic, and lumbar segments. Sensory nerve conduction and autonomic studies were normal. Magnetic resonance imaging of the brain and spine was normal, but for mild uniform gadolinium enhancement of lumbar nerve roots. Spinal fluid protein was 81 mg/dL with normal cell count and cytology. There was no evidence of systemic or paraneoplastic autoimmunity, sarcoidosis, or infection by enterovirus, West Nile virus, human T-cell lymphotropic virus type I, or human immunodeficiency virus. Monoclonal protein studies and full body computerized tomography and position emission tomography were normal. Six weeks later, there was definite bulbar weakness, tongue fasciculations, and a brisk jaw jerk reflex. Despite further methylprednisolone and intravenous immunoglobulin, progressive respiratory failure and dysphagia ensued. The patient died 10 months after the onset. Conclusion: The presence of modest lumbar root enhancement and cerebrospinal fluid protein elevation do not exclude the clinical diagnosis of ALS. Disruption of the blood nerve barrier, secondary to rapid neuronal degeneration, not inflammation, is suggested pathophysiologically. N.P. Young is a Junior Member Recognition Award Recipient. doi:10.1016/j.clinph.2008.10.124
107. Wound botulism after open fracture shows rapid improvement after antitoxin treatment—A.D. Galbreath, D.N. Johnson, V. Juel, D.B. Sanders (Durham, NC, USA) Introduction: In rare cases of wound botulism following limb fracture, improvement typically takes weeks to months, even with treatment. This case report suggests that using equine antitoxin treatment when botulism’s is suspected can improve recovery time. Case report: A 34-year-old man sustained an open fracture of his left mid-radius and ulna while playing soccer. He underwent debridement followed by open reduction and internal fixation with metal hardware. Nine days later he developed photophobia, blurred vision, progressive diplopia, and lid ptosis. During the following week, he developed dysarthria and dysphagia, and was referred with the presumptive diagnosis of myasthenia gravis. The examination revealed dilated pupils and sluggish reaction to light. There was complete bilateral eyelid ptosis and near-complete external ophthalmoplegia. The patient’s speech was of a nasal quality with severe, flaccid dysarthria. Reduction of strength in the arms and decreased tendon reflexes in the right arm were reported. Both generalized strength and tendon reflexes were normal in the legs. Electrodiagnosis revealed compound muscle action potential (CMAP) amplitude of the abductor digiti minimi (ADM) was low (3 mV) and increased 100% following 10 isometric exercises. There was a 10% decrement in CMAP amplitude during 3 Hz stimulation. Needle electromyography revealed unstable motor units without spontaneous activity. He received bivalent antitoxin (types A and B) within 24 h of admission. There was a near-complete resolution of symptoms within 6 days but facilitation (75%) of ADM CMAP amplitude remained. Following the treatment, there was no decremental response with 3 Hz stimulation. Conclusions: While awaiting confirmation of the diagnosis, clinical suspicion of botulism and characteristic electrodiagnostic findings should lead to prompt treatment. Antitoxin treatment may
lead to rapid improvement even when given 1 week after symptom onset. doi:10.1016/j.clinph.2008.10.125
108. Genetic heterogeneity of distal hereditary motor neuropathy type II—S. Lee 1, S. Moon 1, C. Ki 2 (1 Cheongju-si, South Korea, 2 Seoul, South Korea) Introduction: Distal hereditary motor neuropathy (dHMN) represents a rare and exclusive motor neuropathy of clinically and genetically heterogeneous conditions caused by degeneration of motor neurons leading to distal muscle weakness and muscle wasting. Case report: A family with autosomal dominant adult onset dHMN (Type II) is examined. Four patients spanning three generations (proband 47-year-old man, his sister, father, and father’s sister) developed mild symmetrical distal limb weakness, muscle wasting, and severe foot deformity after the third decade. Involvement of the lower extremities was more prominent than that of the upper extremities. No sensory or autonomic abnormalities were detected. Tendon reflexes were preserved. Nerve conduction studies indicated normal or slightly decreased motor conduction and completely normal sensory conduction. Needle electromyography revealed high amplitude, long duration, and polyphasic motor unit potentials without active spontaneous activities, which are indicative of longstanding neuropathy. Serum creatine kinase was not elevated. Mutations in heat shock proteins HSPB1, HSPB8, and Cu/Znsuperoxide dismutase (SOD1) genes were not found. Conclusion: This is the first case of dHMN type II reported in Korea. The study provides further evidence of the genetic heterogeneity of dHMN type II. doi:10.1016/j.clinph.2008.10.126
109. A clinical and electrophysiological profile of autosomal dominant distal axonal neuropathy—B.A. Ishpekova (Sofia, Bulgaria) Introduction: A rare variant of distal axonal neuropathy (DAN) predominantly involves the upper limbs. Objective: To determine the clinical and electrophysiological characteristics of patients with DAN. Method: An autosomal dominant DAN was identified in 30 people of a large six-generation Bulgarian family comprised 116 members. Needle electromyography of the distal and proximal upper and lower limb muscles examined the motor nerve conduction velocity in the median, ulnar, tibial, and peroneal nerves and the late responses (F and A waves). Sensory conduction was examined antidomically in the median, ulnar, and sural nerves. Results: The mean age of onset is 16 years (10–35) with selective weakness and wasting of the thenar, hypothenar and first dorsal interosseus muscles of the hands. Progression of the disease is very slow with some patients remaining ambulant at age 64. About 40% of the subjects report involvement in the feet. The gene that causes this disease has been mapped to the short arm of chromosome 7p. Electrophysiological and muscle biopsy findings indicate a chronic neurogenic pattern, nerve biopsy showed mild axonal degeneration, and muscle biopsy evidenced chronic neurogenic changes. The motor conduction velocity of all nerves fell below the normal range. The distal motor latencies were prolonged. Mild sensory deficits developed in some patients. The highest percent