Magnetoencephalographic investigation of somatosensory homunculus in patients with peri-Rolandic tumors.

In order to investigate functional topography of the hand somatosensory cortex in five patients with peri-Rolandic tumors (four frontal lobes and one parietal lobe), we recorded somatosensory evoked fields (SEFs) using magnetoencephalography (MEG) after stimulation of the median nerve (MN) and the five digits. The results obtained were compared with those of five normal healthy subjects. In all five patients, SEFs following MN and digit stimulation showed the previously described respective N20m and N22m components of primary sensory response. Single dipole modeling was applied to determine the three dimensional cortical representations of the N20m and N22m components. The cortical representations of the hand were identical to those of normal subjects, arranging in an orderly somatotopic way from lateral inferior to medial superior in the sequence thumb, MN, index, middle, ring, and little fingers. This sensory homunculus was confirmed by cortical recording of the somatosensory evoked potentials (SEPs) at the time of surgery. Thus, we demonstrate that SEFs, recorded on MEG in conjunction with source localization techniques, are useful to non-invasively investigate the functional topography of the human hand somatosensory cortex in pathological conditions.

[Quantitative evaluation of the effect of 3,4-diaminopyridine in a patient with Lambert-Eaton myasthenic syndrome using dynamic dynamometry].

We reported a 72-year-old woman with Lambert-Eaton myasthenic syndrome. The chief complaint was weakness and atrophy of the thigh muscles, which prevented her from climbing stairs even with a handrail. Sensory and autonomic function was normal without amblygeustia. There was no malignancy found, and her serum anti-V/Q type voltage-gated calcium channel antibody was negative. Administration of 3,4-diaminopyridine (DAP), known to accelerate acetylcholine release, was very effective and she became able to climb stairs without a handrail. For evaluation of the therapeutic effect of DAP, the initial compound muscle action potential (ICMAP) on evoked electromyogram has been recommended because it provides highly sensitive and reproducible results. Unfortunately this method is usually applied to several particular distal muscles for technical reasons. In the present case, evaluation of the quadriceps femoris muscle was most important because it was most responsible for her disability. We attempted to measure the angular velocity and the angular acceleration on knee extension movement using dynamic dynamometry. The angular velocity improved from 124 to 162 deg/sec and the angular acceleration from 220 to 390 deg/sec2. The results were more sensitive and more relevant to her demonstrable ADL improvement than grasping power increase and ICMAP improvement recorded at the distal muscles.

[Spontaneous improvement of subacute exacerbation in a case of sensory ataxic neuropathy associated with Sjögren's syndrome].

We reported a 66-year-old man with Sjögren's syndrome (sicca syndrome) presenting a sensory ataxic neuropathy, which showed spontaneous remission. He developed difficulty in standing and walking during recent several months. Neurological examinations showed sensory ataxia with areflexia in all extremities and mild distal-dominant decrease in the superficial sensation. Laboratory examinations of blood, urine, and cerebrospinal fluid were all unremarkable; the blood levels of vitamin B1, B2, B6 and B12 were low normal. Sensory nerve action potentials and somatosensory evoked potentials were absent. Cervical cord MRI revealed no abnormal signals. Severe loss of myelinated fibers and scattered myelin ovoids were seen in sural nerve biopsy. Tentative diagnosis at admission was subacute sensory neuropathy associated with malignancy. Screening examinations for malignancy were undertaken and all revealed negative. Because of coexisting sicca symptoms and positive Shirmer test (0 mm), a lip biopsy was performed and a diagnosis of Sjögren's syndrome was confirmed. Sensory ataxia improved gradually. Two years later, blood B1 levels were low but he remained able to walk. This case is an uncommon example of spontaneous symptomatic remission in sensory ataxic neuropathy associated with Sjögren's syndrome.

[A lumbosacral cord infarction causing focally accentuated atrophy of the peroneal muscles].

We report focally accentuated atrophy in a muscle due to a cryptogenic lumbosacral infarction. A 56-year-old female rapidly developed left-dominant weakness of lower thigh muscles, sensory loss of all modalities in the L5 and sacral dermatomes, and difficulty in voiding. MRI performed on day 9 showed gadolinium-enhanced lesions in the epiconus. The anterior horn lesion was most prominent in the left side of the epiconus. After one and a half months, the left lower thigh muscles became atrophic especially in the proximal part of the anterior lower thigh. After 4 months, on T2-weighted images, atrophy and high intensities were accentuated in the proximal part of the anterior lower thigh muscles where denervation potentials were abundant. A topographic relationship has been documented between the locus of a motor neuron in the anterior horn column and the position of its motor unit in the muscle. We consider that the distribution of denervation changes on muscle MRI corresponded with the anterior horn lesion on spinal MRI in our case.

[Beneficial effect of eyelid make-up (natural rubber latex) to induce a new fold in the treatment of blepharoptosis in myotonic dystrophy].

Blepharoptosis is one of the troublesome ocular complications of myotonic dystrophy. To correct drooping eyelids for two men with myotonic dystrophy, we used Eye Putti, a cosmetic made of natural rubber latex, which induces a new fold in the upper eyelid. The cosmetic rubber latex dramatically improved the sight of a 59-year-old patient who previously had a great difficulty in looking forward and had to bend his head backward to see an object because of severe blepharoptosis. The other patient aged 54 with moderate ptosis also had satisfactory improvement. Appropriate use did not prevent eye blinking and induce corneal erosion or skin rash. The cosmetic rubber latex was effective to patients who had no residual function of the levator palpebrae and frontal muscles. This daily treatment is simple and safe, therefore may have an advantage over surgical correction of blepharoptosis for patients not only with myotonic dystrophy, but with other neuromuscular disorders including oculopharyngeal muscular dystrophy.

Surgical management of intractable epilepsy associated with cerebral neurocytoma.

Neuronal neoplasms of the CNS constitute a rarely encountered group of tumors. This report concerns the surgical management of seizures encountered in four cases (ranging from 2 to 10 years-of-age at onset; consisting of two males and two females) of a recently recognized morphologically unique tumor, called 'cerebral neurocytoma'. All patients were associated solely with intractable complex partial seizures. The tumor involved the temporal lobe in two cases, and the frontal in two. Magnetoencephalography (MEG) clearly demonstrated an accumulation of equivalent current dipoles originating from the interictal spikes on the cortex around the tumor. On intra-operative electrocorticography (ECoG), the epileptogenic zone was topographically distinct from the region of the tumor. No definite ECoG activities were observed at the tumor site, although this tumor did consist of small mature neuronal cells. Either a complete or a subtotal resection of the tumor and the epileptogenic cortex was performed and, post-operatively, universal freedom from seizures was demonstrated in all patients. A histological examination of the epileptogenic cortex revealed the presence of minute cortical dysplasia or tumor involvement in the hippocampus. A resection of the epileptogenic cortex along with the tumor was thus found to improve the seizure outcome in patients with neurocytoma-associated epilepsy without inducing any identifiable neurological deficits attributable to the incremental resection.

Differential interaction of somatosensory inputs in the human primary sensory cortex: a magnetoencephalographic study.

OBJECTIVE: Somatosensory evoked magnetic fields (SEFs) were recorded to investigate the interaction of the somatosensory inputs using the modality of electrical finger stimulation in 6 normal subjects. METHODS: Electrical stimuli were given to the index (II), middle (III) or little (V) fingers individually, and also to pairs of either the II and III simultaneously, or the II and V simultaneously. The interaction ratio (IR) was calculated as the ratio of the SEF amplitude by simultaneous two-finger stimulation to the arithmetically summed SEF amplitudes of two individual-finger stimulations. RESULTS: SEFs showed 3 major components: N22m, P30m and P60m. The N22m and P60m revealed a clear somatotopic organization in the primary sensory cortex (S1) in the sequence of II, III and V, while the P30m showed a cluster with medial location compared with N22m and P60m in S1. The N22m had a significantly greater IR in II and III stimulation compared to that in II and V stimulation. The P60m also showed a similar trend in the IR but was greater than that of N22m. In contrast, the IR in P30m showed no such tendency. CONCLUSION: The interaction of S1 was most influenced when adjacent receptive fields were activated in the modality of electrical finger stimulation. Our results were consistent with the concept that the Brodmann's areas in S1 which produce the 3 components of the SEFs have different functional organization.

Anti-Ri-associated paraneoplastic cerebellar degeneration without opsoclonus in a patient with a neuroendocrine carcinoma of the stomach.

We report a case of a 63-year-old man suffering from anti-Ri-associated paraneoplastic cerebellar degeneration (PCD) with gastric cancer. The neurologic presentation was limited to severe cerebellar ataxia without opsoclonus. The gastric cancer was composed of both poorly differentiated adenocarcinoma and neuro-endocrine carcinoma. The patient's serum reacted with recombinant Ri antigen and the neuroendocrine tumor component. It is thus considered that PCD without opsoclonus in the present case was related to the gastric neuroendocrine tumor and anti-Ri antibody.

Neuromagnetic assessment of epileptogenicity in cerebral arteriovenous malformation.

Magnetoencephalographic (MEG) activities were recorded in five patients with cerebral arteriovenous malformation (AVM) who presented with epilepsy and no clinical history of intracranial hemorrhage, using a 37-channel DC superconducting quantum interference device (SQUID) system. While scalp-recorded electroencephalograms (EEG) failed to reveal paroxysmal discharge, MEGs demonstrated localized high frequency magnetic activity (HFMA). Magnetic source imaging (MSI) depicted the accumulation of equivalent current dipole (ECD) originating from HFMA around the nidus, and the ECD localization agreed well with spike localization on intraoperative electrocorticography (ECoG). These areas corresponded with the areas of hypoperfusion on single photon emission tomography and the intraoperative laser Doppler flow meter. We discussed the application of MEG in estimating interictal paroxysmal activity sources in patients with AVM and addressed the questions of its reliability and validity in source localization.

[Overloading to neck extensor muscles is an aggravating factor to induce further neck drop in isolated neck extensor myopathy (Katz). A case report].

A 78-year-old woman was hospitalized because of progressive anterior neck drop over 4 months prior to admission. She was normal except for mild weakness of her neck, trapezius and biceps brachii muscles. EMG revealed mild myopathic changes in the neck extensors, trapezius, deltoid and sternocleidomastoid muscles. Bilateral splenius capitis muscles had high intensities on T2-weighted and STIR pulse-sequenced MRI. However, there were no inflammatory changes in the right splenius muscle biopsy. Accordingly, the abnormal MRI finding seems not to result from an inflammatory process but from an physiological increase of intracellular water content due to sustained muscle contraction. Because apparent neuromuscular diseases responsible for neck drop were excluded, her clinical features met the criteria of isolated neck extensor myopathy (INEM, Katz). After strict bed-rest for one month, her neck drop improved dramatically. When she returned to the previous life style after discharge, her symptoms of the neck drop reappeared. Although the cause of INEM remains unclear, the present case indicates that the condition is reversible at least in the early stage of the disease, and the overloading to the neck extensor muscles is an aggravating factor of the neck drop in INEM.

[Juvenile parkinsonism with symmetrical hypoperfusion in the cerebellum--a case report].

We report a 24-year-old female presenting levodopa-responsive juvenile parkinsonism with symmetrical hypoperfusion in the cerebellum. At the age of 21, she noticed difficulty in brushing her teeth and writing with the right hand. She developed resting tremor in the right hand. These symptoms were dramatically relieved by levodopa. One year prior to the admission, she noticed dystonia and drug-induced motor fluctuations and her symptoms became worse. Neurological examinations disclosed resting and postural tremor in both hands and the right leg. Bradykinesia and cogwheel rigidity were noted on the right side. Deep tendon reflexes were slightly increased on the right side, while Babinski sign was negative. Slight lateropulsion was observed without retropulsion. Sensory, autonomic and cerebellar disturbances were not observed. No abnormalities were found in parkins gene or in the genes of spinocerebellar ataxia (SCA) 1,2,3,6,7,8 and alpha-synuclein. Cranial CT scan and brain MRI were normal, but technetium-99m ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) showed symmetrical hypoperfusion in the cerebellum. Other 5 patients presenting juvenile parkinsonism and 10 aged-matched normal controls in our hospital did not show hypoperfusion in the cerebellum on ECD SPECT. Cerebellar blood flow has not been measured in the previously reported cases of juvenile parkinsonism. These results suggested that etiopathogenesis in this patient was different from that in previously reported cases.

[Painful unilateral gynecomastia in a patient with myotonic dystrophy].

A 54-year-old patient with myotonic dystrophy presented unilateral painful gynecomastia, which occurred 3 months after aggravation of diabetes mellitus. Serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were slightly high. LH was elevated than 2 years before. Breast pain and gynecomastia disappeared by daily administration of 10 mg tamoxifen. He could not have intramuscular injection therapy because of marked muscle atrophy. Painful gynecomastia may be one of the endocrine complications in myotonic dystrophy.

[A case of Lyme disease with the triad of neurologic manifestations (meningitis, radiculoneuritis, facial nerve palsy) and dermatitis of the nail roots].

A 23-year-old man experienced dysesthesia of the distal parts of four limbs and spilling of drinking water from the right corner of his mouth. He also experienced low grade fever, headache, and nausea. Neurological examination showed weakness of the right frontal, orbicularis oculi and orbicularis oris muscles, atrophy and weakness of the interosseous muscles in both upper limbs and dysesthesia in the distal parts of four limbs. Laségue's sign was also positive on the left side. Examination of CSF showed lymphocytic pleocytosis and an increase of total protein. Serum antibody against Borrelia garinii was positive as determined by ELISA. The patient was diagnosed as a case of Lyme disease. His symptoms were not alleviated by administration of ceftriaxone (2 g/day) for 15 days, and dermatitis of nail roots appeared. Following administration of penicillin G at a high dose (12 million units/day) for 20 days, both neurologic symptoms and dermatitis were alleviated. Since B. garinii was reported to move preferentially toward the sites of low temperature, dermatitis of nail roots may be one of the characteristic features of Lyme disease caused by B. garinii.

[A case of bilateral brachial plexopathy after median sternotomy].

A 53-year-old man with bilateral brachial plexopathy after median sternotomy for cardiac surgery was described. When he was awakened six days after cardiac surgery, he experienced weakness and paresthesia of both upper limbs. Neurological examination revealed moderate to severe atrophy and weakness of right biceps, brachioradialis, left triceps, and distal muscles of both upper limbs, and paresthesia around the right thumb and the left hypothenar. Deep tendon reflex of the right biceps, triceps, brachioradialis and left triceps was absent. In addition, he showed Horner's syndrome at the left side. The results of needle EMG and nerve conduction study indicated the damage of the right upper trunk and left middle and lower trunks of the brachial plexus. Although brachial plexopathy following median sternotomy has previously been reported in Western literatures, there is only a single report of unilateral brachial plexopathy in Japan. This is the first report in Japan of the bilateral brachial plexopathy following median sternotomy, and suggests that brachial plexopathy should be recognized as a complication of median sternotomy.

[A case of Hopkins syndrome with onset at puberty].

The patient was a 15-year-old man who developed weakness of left leg 6 days after an acute asthmatic attack. Neurological examination revealed severe muscle weakness and atrophy at L5-S1 level and mild muscle weakness and atrophy at L2-4 level in the left leg. Deep tendon reflexes were normal in the upper limbs and slightly brisk in the lower limbs except for absence of Achilles tendon reflex on the left. His sensation was normal. Needle EMG revealed neurogenic changes in both the left (L2-S1) and right (L2-4) leg muscles. Motor nerve conduction study of the left tibial and peroneal nerves revealed a marked reduction of amplitude and mild reduction of MCV. F-wave was not evoked in either nerves. Sensory nerve conduction study of the left sural nerve was normal. The titers of anti-viral antibodies in the paired sera showed no significant changes in any viruses examined including echovirus, enterovirus, coxsackievirus and poliovirus type 1, 2 and 3. The serum IgE was elevated (1,300 IU/ml) and mite antigen-specific IgE was strongly positive. Spinal cord MRI revealed no abnormality in either thoracic or lumbar spinal cord. This patient was diagnosed as a rare case of Hopkins syndrome with onset at puberty.

Intrinsic epileptogenicity of focal cortical dysplasia as revealed by magnetoencephalography and electrocorticography.

Focal cortical dysplasia (FCD) is often associated with severe partial epilepsy. In this study, we performed magnetoencephalography (MEG) and electrocorticogrsphy (ECoG) on four patients with FCD-associated epilepsy to confirm the 'intrinsic' epileptogenicity of FCD. In all patients, we determined the three-dimensional locations of the magnetic sources of the interictal paroxysmal activities by a single dipole model, and then the estimated dipole localization was superimposed on the magnetic resonance image. The dipole clusters were located in the T2-prolonged lesions, namely in the FCD lesions themselves. All patients underwent surgery for their medically intractable epilepsy, and the acute and/or chronic ECoG were thereafter recorded. Either frequent or continuous paroxysmal activities were recorded from the ECoG electrodes which were placed over the surface of the FCD lesion, while few paroxysmal activities were observed on the normal appearing adjacent cortex. Intraoperative depth recordings were performed in a patient with the needle electrode inserted into the FCD lesion and they revealed these paroxysmal foci to be located not on the cortical surface but at a depth of 15 mm from the cortical surface where both abnormal giant neurons and bizarre large eosinophilic cells (so-called balloon cells) were also prominently observed on the postoperative histological sections. Following a lesionectomy combined with the removal of the underlying white matter, three patients demonstrated a favorable seizure outcome. Our findings thus suggest the FCD lesions to be highly and intrinsically epileptogenic lesions.