Recent advances in genetic analysis technology have enabled a surprising progress in genetic diagnosis in the field of neurological disease research. High-throughput molecular biology techniques, such as microarrays and next-generation sequencing, are the major contributors to this progress and to new discoveries. Charcot-Marie-Tooth disease (CMT), a known hereditary motor and sensory neuropathy, is clinically and genetically heterogeneous. Genetic studies have revealed at least 35 disease causing-genes responsible for Charcot-Marie-Tooth disease. Genetic studies have revealed that abnormalities in the following factors are the cause of inherited neuropathies: myelin components, transcription factors controlling myelination, myelin maintenance system, differentiation factors related to the peripheral nerve, neurofilaments, protein transfer system, mitochondrial proteins, DNA repair, RNA/protein synthesis, ion channels, and aminoacyl-tRNA synthetase. On the other hand concomitant with the increase in the number of genes that must be screened for mutations, the labor and reagent costs for molecular genetic testing have increased significantly. Therefore, new methodology for detecting gene mutations is required. Based on the recent progress in DNA analysis methods, resequencing microarray appears to be an economical and highly sensitive method for detecting mutations. We have been screening CMT patients for mutations using originally designed microarray DNA chips since 2007, thencehaving identified disease causing mutations in MPZ, GJB1, PMP22, EGR2, MFN2, NEFL, PRX, AARS, GARS, DNM2, and SETX genes in CMT patients.

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We report on an autopsy case of corticobasal degeneration (CBD) with Lewy bodies in only the sympathetic ganglia. A 79-year-old man showed walking disturbance as an initial symptom, and developed dementia and bradykinesia within the next 2 years. Neurological examination revealed parkinsonism-like akinesia and rigidity in the trunk and neck without resting tremor. Brain magnetic resonance imaging showed frontal lobe atrophy predominantly on the right side. Cardiac uptake of meta-iodobenzylguanidine (MIBG) was reduced (H/M ratio: 1.14). A diagnosis of dementia with Lewy bodies (DLB) was made, but L-dopa treatment was not effective. Seven years later he died of pneumonia. On pathological examination, the frontal cortex and white matter were degenerated, predominantly on the right side. Gallyas-Braak silver staining and AT-8 immunostaining revealed neurofibrillary tangles, pretangles, argyrophilic threads, and astrocytic plaques in the cerebral cortex and basal ganglia, confirming the diagnosis of CBD. Lewy bodies, which were not seen in the central nervous system, were seen only in the sympathetic ganglia, and a severe loss of nerve fibers was apparent in the sympathetic nerve endings in the heart. MIBG is currently used to differentiate DLB from other parkinsonisms, such as CBD, multiple system atrophy, and progressive supranuclear palsy, because reduced cardiac uptake of MIBG represents a pathological change in the sympathetic nerve endings in the heart. However, the distribution of Lewy bodies cannot be determined from this finding. Thus, MIBG should not be used alone to confirm a diagnosis of DLB; other neurodegenerative diseases with incidental Lewy body disease, as in the present case, must be also considered.

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A 66-year-old woman developed bilateral facial paralysis as well as sensory and motor disturbances of extremities. Two months after the onset of paralysis, she also developed sensory disturbance of her trunk and vesicorectal disturbance, and her symptoms worsened gradually. Because the interferon-γ level in the cerebrospinal fluid was elevated, we suspected that her symptoms were caused by polyneuropathy and myelitis associated with infection. Her serum IgM and IgG antibodies against Borrelia garinii and B. afzelli were positive. Therefore, we diagnosed her as having neuroborreliosis. Her symptoms gradually improved after the combined administration of antibiotics and steroids. The present case report showed that it might be better to consider the possibility of neuroborreliosis when there are increasing concentrations of cytokine and chemokine, and that combination treatment with antibiotics and steroids can be used for the treatment of this disease.

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A 45-year-old man presented with fever, progressive mutism and memory loss, was admitted to our hospital. MR imaging and angiography suggested multiple foci of infarctions and vasculitis without Gadrinium-enhancement. CSF examination revealed pleocytosis with mononuclear cell dominance and elevated protein content. Adenosine deaminase activity was accelerated, and no malignant cell was found. Whole body CT imaging and Garium-scintigraphy were normal. Under the clinical diagnosis of tuberculous meningitis, anti-tubercular drugs with steroid were administered, resulting in marked attenuation of his neurological impairments. Four months later, his symptoms aggravated and restudy of Garium-scintigraphy revealed enhanced accumulation in the submandibular and abdominal lymphnodes. A lymph node biopsy revealed diffuse large B-cell lymphoma cells. In such a case of this clinical statue, careful and repeated observations should be required to establish the correct diagnosis of occult lymphoma.

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In multiple system atrophy (MSA), sleep-related breathing disorders are commonly observed, including vocal cord abductor paralysis (VCAP), which can cause sudden death. In its early stage, VCAP occurs only during sleep, but as the disease progresses, it appears when both awake and asleep. We encountered a 59-year-old obese woman who had been under continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea syndrome (OSAS) for approximately one year but later developed acute respiratory failure because of VCAP. VCAP was the predominant finding that led to the diagnosis of MSA in our patient. On laryngoscopic examination, the movement of the patient's larynx was normal during wakefulness, but VCAP, paradoxical movements of the vocal cord and a floppy arytenoid were observed during drug-induced sleep. We suggest that detection of VCAP and laryngopharyngeal abnormalities such as floppy arytenoid in the early stage of MSA is important for determining treatment options.

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A 73-year-old man was admitted for evaluation of sudden onset of dizziness, bilateral shoulder pain, and brachial diplegia. Neurological examination revealed severe bilateral weakness of the triceps brachii, wrist flexor, and wrist extensor muscles. There was no paresis of the lower limbs. His gait was ataxic. Pinprick and temperature sensations were diminished at the bilateral C6-C8 dermatomes. Vibration and position senses were intact. An MRI of the head revealed a right cerebellar infarction and occlusion of the right vertebral artery. An MRI of the cervical spine on T₂ weighted imaging (T₂WI) showed cord compression at the C3/4-C5/6 level secondary to spondylotic degeneration without any intramedullary signal changes of the cord. On the following day, however, high-signal lesions on T₂WI appeared in the C5-C6 spinal cord, suggesting cord infarction. Unilateral vertebral artery occlusion does not usually result in cervical cord infarction because of anastomosis of arteries. Because of the long-term mechanical compression in our case, it was likely that cervical cord ischemia was present before the onset of symptoms. On the basis of chronic cord compression, our case suggests that occlusion of a unilateral vertebral artery could cause cervical cord infarction.

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Here, we report brain abscess due to Fusobacterium necrophorum (F. necrophorum) in a 78-year-old healthy man. He developed convulsion and did not have any signs of meningitis. Although the brain magnetic resonance imaging findings of the left occipital lobe were typical of a brain abscess, his cerebrospinal fluid examination revealed only slight pleocytosis and mild increase in protein levels. Thus, it was difficult to rule out the possibility of metastatic brain tumor; the patient's condition was provisionally diagnosed as symptomatic epilepsy secondary to brain abscess. His convulsion disappeared soon after administration of antiepileptic, antibacterial, and steroid agents. A craniotomy was performed to evacuate the abscess, and F. necrophorum was identified by culturing the abscess contents. After the operation, he was treated with appropriate antibacterial agents, which resulted in resolution of the brain abscess. Although Fusobacterium species are gram-negative anaerobic bacilli commensal of the human oropharynx, we need to recognize that Fusobacterium species can be a primary pathogen causing brain abscesses and may leave residual neurological sequelae without early appropriate treatment.

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A 61-year-old man developed double vision subsequent to diarrheal illness. Mixed horizontal-vertical gaze palsy in both eyes, diminution of tendon reflexes, and gaze nystagmus were noted. His horizontal gaze palsy was accompanied by gaze nystagmus in the abducent direction, indicative of the disturbance in central nervous system. Neither limb weakness nor ataxia was noted. Serum anti-GQ1b antibody was detected. Brain magnetic resonance imaging (MRI) findings were normal. The patient was diagnosed as having acute ophthalmoparesis. The ophthalmoparesis and nystagmus gradually disappeared in 3 months. The accompanying nystagmus suggests that central nervous system disturbance may also be present with acute ophthalmoparesis.

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We report a case of fulminant brachial plexopathy with radicular involvement. A 25-year-old man developed acute total monoplegia in the left upper limb. Needle electromyography showed extensive acute denervation in the C5-T1 spinal segments, and peripheral sensory nerve conduction was normal, mimicking a pre-ganglionic lesion. However, left median somatosensory evoked potentials revealed abnormal Erb's point potential, suggesting a brachial plexus lesion. Corticosteroid treatment resulted in good recovery. These findings suggest that the primary pathophysiology was conduction block and this can explain the good clinical recovery in this patient.

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