The present review focuses an early history of Japanese amyotrophic lateral sclerosis (ALS) and the current significance in comparison to previously known and newly found reports on Japanese ALS. After a preliminary case report of ALS by Masamichi Hirai on 1890, 2 completed reports were simultaneously published within 2 weeks of 1891 by Momojiro Nakamura and Zenjiro Inoue, followed by Eikichi Watanabe’s report on 1892. After Shonosuke Hasegawa’s and Hiroshi Kawahara’s case reports on 1894–1896, Aihiko Sata first reported an autopsy case of ALS on 1897. The great contribution of Kinnosuke Miura was also introduced for the naming and pathogenesis in the early stage of ALS history in Japan during 1893-1911.

A 66-year-old man presented with headache and ophthalmalgia. Diplopia developed, and he was hospitalized. The left eye had abducent paralysis and proptosis. We diagnosed him with Tolosa-Hunt syndrome and administered methylprednisolone at 1 g/day for 3 days. However, the patient did not respond to treatment. No abnormality was found on his MRI or cerebrospinal fluid examination. Tests showed his serum immunoglobulin G4 and antineutrophil cytoplasmic antibody titers were within normal limits. He also had untreated diabetes mellitus (HbA1c 9.2). One week after first presenting with symptoms, herpes zoster appeared on the patient’s dorsum nasi, followed by keratitis and a corneal ulcer. Herpes zoster ophthalmicus with ophthalmoplegia was diagnosed. We began treatment with acyclovir (15 mg/kg) and prednisolone (1 mg/kg, decreased gradually). Ophthalmalgia and the eruption improved immediately. The eye movement disorder improved gradually over several months. It is rare that diplopia appears prior to cingulate eruption of herpes zoster ophthalmicus. We speculated that onset of the eruption was inhibited by strong steroid therapy and untreated diabetes mellitus.

A 78-year-old man presented with subacute progressive proximal weakness and dysphagia. A biopsy specimen from the left biceps femoris revealed evidence of necrotic and regenerating muscle fibers, but lymphocyte infiltration was not noted. The patient was diagnosed with necrotizing myopathy with anti-signal recognition particle (SRP) antibodies. Concomitant therapy with prednisolone and azathioprine caused the serum CK level to return to normal and it caused clinical manifestations to abate. One year later, however, muscle weakness worsened. Immunoelectrophoresis of serum revealed IgG M protein, and muscle pathology revealed amyloid deposits in numerous blood vessels and at the periphery of a few muscle fibers, and deposits stained positive for anti-λ light chain antibody. The patient was diagnosed with amyloid myopathy, and therapy for systemic amyloid light chain amyloidosis caused muscle weakness to diminish. Amyloidosis is believed to be the primary pathology in this case based on the patient’s response to treatment reaction, but the significance of a case involving both amyloid myopathy and necrotizing myopathy warranted examination.

A 26-year-old, otherwise healthy man presented with visual abnormality followed by loss of consciousness and convulsion. The patient then developed headache and fever 14 days later. Brain MRI showed hyperintensities in the left cingulate cortex. The cerrebrospinal fluid examinations showed mononuclear pleocytosis and positive PCR results for human herpesvirus 6 (HHV-6). A diagnosis of HHV-6 encephalitis and symptomatic epilepsy was made. The patient’s clinical symptoms improved promptly following acyclovir treatment. However, 3 months later the patient noticed dysesthesia in the trunk, the left upper limb and the right lower limb. Brain and spine MRI showed multiple brain white matter lesions, the middle cerebellar peduncle and cervical spinal lesions. The symptoms resolved following methylprednisolone pulse therapy only. We report an adult patient with HHV-6 encephalitis followed by acute disseminated encephalomyelitis whose initial presentation was epilepsy. HHV-6 encephalitis should be included in the differential diagnosis of encephalitis of unknown etiology in an immunocompetent adult.

A 64-year-old male developed headache, dizziness, and difficulty hearing, two years after an operation for chronic subdural hematoma due to head injury. These symptoms gradually worsened over the following 15 years. As he showed bloody cerebrospinal fluid (CSF) and marginal hypointensity on the surface of the brain and spinal cord on T₂/T₂*-weighted MRI, he was diagnosed with superficial siderosis (SS), although the source of the bleeding was unclear and anti-hemorrhagic drugs were ineffective. When he was admitted to our hospital, neurological examination disclosed horizontal gaze-evoked nystagmus, severe bilateral hearing loss, scanning speech, and limb and truncal ataxia. CISS (constructive interference in steady state) MRI detected a dural defect at the Th2–3 level on the anterior side of the spinal canal. On operation, a 2 mm × 6 mm size dural defect with blood clots was found at the Th2–3 level. After closure of the dural defect, bloody CSF became transparent, and his persistent headache, dizziness, and hearing impairment improved. Brain and whole spine MRI, especially CISS imaging, should be considered for detecting the source of bleeding in intractable cases of SS.