Stiff-person syndrome associated with invasive thymoma: a case report.

We report a case of a 40-year-old female with continuous muscle stiffness and painful muscle spasms. The symptoms worsened over a two-week period after onset. Electrophysiological examinations revealed continuous muscle discharge, which was markedly reduced by intravenous administration of diazepam. High levels of anti-glutamic acid decarboxylase (GAD) antibodies were detected in both serum and cerebrospinal fluid, suggesting that the patient suffered from stiff-person syndrome. Steroid pulse therapy and immunoadsorption therapy alleviated the clinical symptoms and decreased the anti-GAD antibody titer. A chest CT revealed the presence of an invasive thymoma. Neither anti-acetylcholine receptor (AChR) antibodies nor symptoms of myasthenia gravis (MG) were observed. The patient underwent a thymectomy and postoperative radiotherapy. These treatments further alleviated the clinical symptoms. The present case is the first that associates stiff-person syndrome with invasive thymoma, and not accompanied by MG. The autoimmune mechanism, in this case, may be triggered by the invasive thymoma.

Polymyositis as a paraneoplastic manifestation of hepatocellular carcinoma.

A case of hepatocellular carcinoma associated with polymyositis is reported. A 70-year-old man noticed muscular weakness mainly in the proximal limb muscles. The clinical course, a raised level of serum creatine kinase and electromyographic findings suggested polymyositis, and the pathological findings on muscle biopsy were compatible with this diagnosis. Computed tomography of the upper abdomen revealed a mass lesion in segment VII and VIII of the liver, which was diagnosed pathologically as hepatocellular carcinoma. The patient underwent systematic resection of segment VII and the dorsal part of segment VIII of the liver. After surgery, the weakness improved and the serum creatine kinase level normalized without medical treatment for the polymyositis. The relief of neurological symptoms and signs after complete resection of the tumor strongly suggests paraneoplastic polymyositis, which has been described only rarely in association with hepatocellular carcinoma.

A severe case of subacute sarcoid myositis.

A 46-year-old woman presented progressive proximal weakness and dysphagia. Her serum creatine kinase and myoglobin levels were markedly elevated. Chest X-rays revealed bilateral swelling of the hilar lymph nodes. Needle electromyography demonstrated active denervation and early recruitment. MRI of her skeletal muscle showed focal high intensities on T1-weighted images that were associated with diffusely increased signal intensities on T2-weighted images. Muscle biopsy revealed infiltration of inflammatory cells associated with non-caseating granulomas, and there was widespread segmental fiber necrosis, where necrotic fibers appeared regardless of these granulomas. Immunohistochemical analysis of the surface markers of the infiltrating cells showed CD68- and CD4-positive cells infiltrating into the central area of the granuloma, while CD8-positive cells infiltrating into the endomysium and the periphery of the granulomas. The characteristic histology of the granuloma confirmed the diagnosis of sarcoidosis. The diffuse muscle pathology was consistent with the patient's severe clinical course.

[Involuntary movements observed in a patient with Russian spring summer encephalitis].

A 38-year-old woman had an episode of headache, fever and convulsion in October, 1993. She became alert in two weeks, though weakness and atrophy remained in the upper limb muscles. She was diagnosed as Russian spring summer encephalitis (RSSE) based on several serological studies. Three kinds of involuntary movements were noted after recovery. These were spontaneous muscle jerks in the left arm, action tremor in the right arm and pathological associated-movement in the right leg. The movements were studied physiologically by electroencephalogram (EEG)-electromyogram (EMG) polygraphic recordings, jerk-locked averaging (JLA), magnetencephalography (MEG), and sensory evoked potentials (SEPs). The jerky movements in her left arm were observed at rest and aggravated by emotional stress. EEG-EMG polygraph showed that the jerks were sometimes associated with small spikes thus were considered to be due to epilepsia partialis continua (EPC). JLA analysis revealed a pre-myoclonus spike on the right hemisphere which preceded the onset of the jerk in the left first dorsal interosseous muscle by 25.2ms, which was equal to the magnetic cortical latency of that muscle. Jerk-locked magnetic field, obtained by averaging neuromagnetic activities with respect to the onset of myoclonus, showed that the spike preceding the jerk, originated from the right motor cortex. The spontaneous spikes were localized mainly on the right motor cortex. Sensory evoked potentials (SEPs) were normal in both size and latency. No hyperexcitability of the sensory cortex was demonstrated even by using paired stimulation SEPs. Based on these results, we conclude that the jerky movements in this patient were produced by abnormal spontaneous discharges in the motor cortex. The action tremor had a frequency of 4-5 Hz and its clinical features were compatible with cerebellar tremor. This is thought to result from a lesion in the left thalamus, affecting the cerebellothalamic pathways. Her right leg unintentionally moved whenever she began to move the hands. This was considered to be a pathological associated-movement due to dysfunction of the pyramidal tracts.

Results of endoscopic management of carpal tunnel syndrome.

This paper is a retrospective study of 27 women with carpal tunnel syndrome (39 hands) who underwent a new endoscopic operative procedure utilizing the Universal Subcutaneous Endoscope system developed by the lead author. Operations on 199 hands were performed under local anesthesia on an outpatient basis. The etiology was considered idiopathic in all cases. Complete preoperative and postoperative clinical and electrophysiologic data were analyzed in 39 hands. The follow-up period ranged from 12 to 45.8 months (mean, 18.3 months). Symptoms of sensory disturbances disappeared in an average of 20 weeks in all patients. Electrophysiologic studies showed definite improvement when compared with preoperative studies. No complications were recorded. Clinical and electrophysiologic results showed that the less-invasive management of carpal tunnel syndrome by endoscopy is safe and effective.

[Magnetoencephalographic studies on spike foci using a 37-channel biomagnetometer system].

We report the results of a clinical trial of Magnetoencephalography (MEG) on spike foci in patients with epilepsy, which was performed from December 1990 to June 1991 at The University of Tokyo Hospital. Fifty patients with focal epilepsy; 26 primary epilepsy, 24 secondary epilepsy (7 brain tumor, 4 arteriovenous malformation, 4 encephalitis, 3 porencephaly, 2 arachnoid cyst, 1 brain abscess, 1 hemimegaloencephaly, 1 Lance-Adams syndrome, 1 hygroma), and ten normal subjects were enrolled in this study. MEG data were recorded using a 37-channel biomagnetometer system SMI-1001 (BTi Magnes, Biomagnetic Technologies, Inc., San Diego). A simultaneous 19-channel EEG recording with linked-ear reference was also obtained. The overall study was completed safely and none of the normal subjects showed abnormal paroxysmal MEG activity. Two patients showed interictal EEG spikes which would not have been noticed without first noting the presence of corresponding prominent MEG spikes. On the whole, the MEG signal seemed to have a wider frequency bandwidth than EEG. In most cases, the source localization predicted by MEG corresponded well with the EEG findings. The relative accuracy of MEG spike source localization was estimated to be within a cubic centimeter from the cases which showed tightly clustered localization of individual spikes. High-pass filtering reduced interference by superimposed slow wave activity, thereby improving the localization of spike sources. These results demonstrate that 37-channel biomagnetometer system could be a useful tool for analyzing epileptic spike sources.

Endoscopic management of carpal tunnel syndrome.

This article describes a subcutaneous endoscopic operative procedure for carpal tunnel syndrome and analyzes its effectiveness using electrophysiological data. Subcutaneous transverse carpal ligament release under universal subcutaneous endoscope (USE) was performed using local anesthesia without pneumotourniquet in 54 hands of 45 patients since June 1986. The mean follow-up period was 13.8 months. Sensory disturbances began to subside immediately after the operation and disappeared within 2 months in all cases. After the disappearance of sensory disturbances, we performed postoperative electrophysiological studies in 27 patients (33 hands). Postoperative electrophysiological data were significantly improved in all cases. Patients did not suffer from any serious complications such as motor branch injuries of the median nerve, hypesthesia of the palm, or injuries of the superficial palmar arch. From these results, we conclude that the transverse carpal ligament can be safely incised by this procedure.

Central motor and sensory conduction in adrenoleukomyeloneuropathy, cerebrotendinous xanthomatosis, HTLV-1-associated myelopathy and tabes dorsalis.

Central motor and sensory conduction was studied by percutaneous electrical stimulation of brain and spinal cord and by somatosensory evoked potential techniques respectively, in patients with adrenoleukomyeloneuropathy, cerebrotendinous xanthomatosis, human T-cell lymphotropic virus-1-associated myelopathy and tabes dorsalis. The results were all consistent with clinical and neuropathological findings in these disorders. Conductions in the corticospinal tract and posterior column could be evaluated separately with these two techniques. Percutaneous electrical stimulation technique would be useful for investigating conduction in the corticospinal tract in patients with spinal cord disorders.

Free functional musculocutaneous transfer: electrophysiological studies.

Transplanted autogenous muscles were electrophysiologically studied in 2 patients with forearm crush injury. Only fibrillation action potentials and positive sharp waves were seen at 1 month after the operation. Low-amplitude and short-duration muscular unit potentials (MUPs) appeared at 3 months and high-amplitude, long-duration and polyphasic MUPs were frequently seen at 6-7 months after the transplantation. The distal latencies of the evoked motor responses were gradually shortened from time to time and eventually became normal at about 1 year after the grafting. The mean consecutive difference became normal at about 6 months after the normalization of the distal latencies. We conclude that the motor endplate is functionally completed at about half a year after the completion of the myelination of the grafted nerve.

Accumulation of glycogen in sural nerve axons in adult-onset type III glycogenosis.

A 42-year-old man with adult-onset type III glycogenosis (Cori's disease) developed a gradually progressive polyneuropathy with markedly reduced activity of muscle amylo-1,6-glucosidase and glycogen accumulation within all elements of biopsied sural nerve, including axons, as shown by ultrastructural assessment.