The Japanese Society of Neurology and Psychiatry was founded in 1902 as a joint society of Neurology and Psychiatry, but was renamed the Japanese Society of Psychiatry and Neurology in 1935 because of the stagnation of activities of Neurology and the rise of those of Psychiatry. After World War II, activities of Neurology were restored and the Japanese Society of Neurology (JSN) independent from the Societies of Internal Medicine and Psychiatry was established in 1960 after overcoming many difficulties. In 1975, neurology was approved by law as one of the specialized fields of medicine. After that, neurology and JSN developed dramatically, both in research and medical practices. As of 2018, JSN had 9,000 members and more than 5,500 board-certified neurology specialists. JSN successfully hosted the World Congress of Neurology twice in 1981 and 2017. In 2002, JSN accepted the offer to join the Japanese Board of Medical Specialties as one of the subspecialties of Internal Medicine. In 2018 JSN enacted a new policy to upgrade the neurology specialist from a subspecialty of Internal Medicine to an independent major medical field. Lessons of the 116 years of history of the Society would teach us a sensible way to achieve the goals.

Three hypotheses have been proposed so far regarding the pathophysiology of migraine: one is the “vascular theory”, which posits cerebral vascular dysfunction as the etiological factor. The second is the “neuronal theory”, which suggests that migraine is triggered by cortical spreading depression. The third is the “trigemino-vascular theory”, which postulates that migraine is triggered by inflammation of trigeminal nerves and vessels around trigeminal ganglion cells. Nowadays, the “trigemino-vascular theory” is widely accepted. However, recent advances in imaging analysis indicate that the origin of migraine lies in a premonitory phase which precedes the aura phase. Modern imaging techniques such as functional MRI and PET reveal high activity of the hypothalamic area during the premonitory phase of migraine. These findings suggest that hypothalamic activation might be a generator of a migraine attack. On the other hand, current analyses show that the photosensitivity of migraine (photophobia) could be caused by dysfunction of the newly discovered intrinsically photosensitive retinal ganglion cells (ipRGCs). In the absence of visual signaling from rods and cones, light activation of ipRGCs expressing melanopsin photopigment is sufficient to produce photophobia during migraine. The ipRGCs project to the hypothalamus; their activation might be the trigger for migraine attacks. Significant advances in molecular biology and imaging in recent years have clarified the previous hypotheses of migraine pathophysiology.

Background: Metabolic insult causing re-expression of old stroke (MICROS), one of the stroke mimics, is characterized by reappearance of impairment of past stroke and can be mistaken for a stroke recurrence. The aim of the present study was to identify the clinical characteristics of MICROS in emergency stroke care, and to investigate predictive factors for distinguishing MICROS from stroke recurrences. Methods: In our Stroke Center, 519 consecutive patients admitted with suspected stroke in June 2016 to December 2017. MICROS was defined as an acute deterioration of neurological deficits of the previous stroke despite no evidence for stroke recurrences. Among the 70 patients with a past history of stroke, 14 were MICROS, 5 were transient ischemic attack, 15 were other stroke mimics, and 36 were stroke recurrences, respectively. We evaluated the clinical characteristics of MICROS and compared MICROS with stroke recurrences. Results: The causes of MICROS were infectious disease (including influenza and pneumonia) in 4, transient somnolence after syncope in 4, hypo/hyperglycemia in 2, medication overdoses in 1, and anxiety in 3. Eight of the 14 MICROS patients were admitted within 4 hours after the symptom onset. In MICROS patients, fever (>37°C) was observed more frequently than those with stroke recurrences though the difference was not statistically significant. Conclusion: MICROS might be associated with fever, syncope, or serum glucose abnormality. MICROS patients sometimes visit the hospital emergency room within 4 hours, thus, distinction between MICROS and true stroke recurrences is important.

Epilepsy surgery for patients with drug-resistant epilepsy after anti-N-methyl-D-aspartate (NMDA) receptor encephalitis has been rarely reported. The present study reports two patients with anti-NMDA receptor encephalitis, who later underwent epilepsy surgery due to drug-resistant epilepsy. The patients had refractory status epilepticus in the acute phase. The cerebrospinal fluid was positive for anti-NMDA receptor antibodies. Systemic corticosteroid therapy and plasma exchange were effective. Seizure control, however, worsened over several months after discharge, and was refractory to antiepileptic drugs. They underwent palliative epilepsy surgery, and their seizure control improved. Epilepsy surgery should be considered in patients with drug-resistant epilepsy after anti-NMDA receptor encephalitis.

The patient was a 50-year-old woman. Pembrolizumab was started for bladder cancer recurrence. From the day after the second administration, ptosis, diplopia, restriction of eye movement, muscle weakness, fatigue resistance, increase in serum creatine kinase (CK) level, and muscle pain were observed. Tests for anti-acetylcholine receptor (AChR) antibody and anti-muscle specific kinase (MuSK) antibody were negative. Electrophysiological examination of the neuromuscular junction showed negative results, and electromyography revealed no myogenic changes. We considered that the immune checkpoint inhibitor caused neuromuscular damage. The patient’s symptoms were gradually improved by immunotherapy, such as steroid and plasma exchange. In this case, tests for the anti-titin antibody, an anti-striational antibody, were positive. We considered that myasthenia gravis-like symptoms and serum CK level elevation might have been caused by impairment of excitation-contraction coupling, and not the neuromuscular junction.

A 66-year-old woman was admitted to our institution with sudden-onset weakness of her left upper limb. Neurological examination revealed monoplegia and sensory loss of the limb. A brain MRI did not find evidence of an acute ischemic stroke. Her medical history revealed that she had fallen and bruised her shoulder 3 days earlier. Detailed physiological examination revealed that there was a mild subcutaneous ecchymosis with tenderness in the left shoulder. An additional contrast-enhanced chest CT scan showed a fracture of the clavicle diaphysis and a pooling contrast agent demonstrating a 60*40 mm mass near the left subclavian artery (SUB-A) which suggested a pseudoaneurysm. We determined that her symptoms were due to compression of the brachial plexus by immediate growth of a traumatic SUB-A pseudoaneurysm (TSAP) due to her earlier fall. For reduction of pressure to the brachial plexus by the TSAP and prevention of rupture, an endovascular treatment team performed endovascular internal trapping of the left SUB-A just distal to the orifice of the left vertebral artery and a cardiovascular surgeon performed percutaneous drainage of the pseudoaneurysm. After the procedure, the palsy and sensory loss of the left hand gradually improved. A TSAP could be one of the causes of sudden-onset palsy of the upper limb within a few days after a fall.

A 22-year-old female was admitted to our hospital due to acute onset of severe headache, confusion, and deterioration of consciousness. Results of initial examinations did not suggest cerebrovascular diseases, encephalitis, or nonconvulsive status epilepticus. Over the next several weeks, her level of consciousness fluctuated in parallel with the severity of headache. The electroencephalogram, recorded during a symptomatic episode, showed lack of posterior dominant rhythm, and the single-photon emission CT (SPECT) also revealed a decrease in cerebral blood flow predominantly in the occipital lobes. Administration of sodium valproate and topiramate, recommended as treatment for migraine, dramatically ameliorated her headache and consciousness. Although this was an adult-onset case, her symptoms and clinical course were similar with the diagnosis of ICHD-3-unlisted confusional migraine rather than other listed subtypes of migraine with aura. Further accumulation of similar adult-onset cases is necessary to clarify the nature of this illness.

A 73-year-old man with a 5-day history of continuous hiccup, fever, and rapidly progressing paraplegia was admitted to our hospital. On admission, he exhibited dysarthria, complete paraplegia, and insentience of both lower limbs. Head and spine MRI showed abnormal, asymmetric lesions in the white matter, basal ganglia, and brainstem, and multiple spinal cord lesions. Test for serum anti-AQP4 antibody was negative. Evaluation of human leukocyte antigen (HLA)-B51 was negative; however, HLA-B54 was positive. Although skin lesions were absent, we considered neuro-Sweet disease and high-dose steroid therapy was initiated. The hiccup disappeared gradually, and he regained the ability to walk with a cane 30 days after the onset. Subsequently, the patient tested positive for serum anti-myelin oligodendrocyte glycoprotein (MOG) antibody. It is important to consider MOG antibody-related disease as potential diagnosis in patients exhibiting clinical features of neuro-Sweet disease except for the absence of skin lesions.

A 69-year-old man was admitted to our hospital because of dysesthesia in right palm and left upper limb, gait disturbance, and muscle weakness in both lower limbs. At the same time of neurological impairment appeared, he developed pemphigoid. Lumber MRI showed swelling of cauda equina nerve root. We diagnosed as chronic inflammatory demyelinating polyneuropathy based on an electrophysiological examination, and 2 courses of intravenous immunoglobulin therapy (IVIG) were initiated. After the treatments, symptoms improved immediately. However, thrombocytopenia was seen after each treatment which began on the second day of treatment start, reaching the lowest point from about 10 to 14 days, and improved naturally from 10 to 15 days after the end of IVIG. Difficulty in hemostasis was seen during dialysis due to thrombocytopenia. As a cause of thrombocytopenia, formation of IgG-platelet complexes could be considered, and the presence of multiple inflammatory diseases which activated Fcγ receptors play key roles could be a risk for IVIG related thrombocytopenia.

A 69-year-old man was admitted to our hospital with a 1-year history of progressive easy fatigability while walking. He presented with proximal muscle weakness dominant in the lower extremities, hoarseness, and mild dysphagia. Muscle pseudo-hypertrophy was observed in the gastrocnemius. A biopsy specimen from the left deltoid muscle revealed amyloid deposition in the blood vessels and ring-like fibers. These findings suggested amyloid myopathy. The serum and urine immunofixation electrophoresis detected κ type Bence-Jones proteins, and bone marrow examination showed an increase in atypical plasma cells; thus, we established a diagnosis of multiple myeloma. Thereafter, he experienced frequent diarrhea, and the gastrointestinal endoscopy revealed extensive amyloid deposition in the upper and lower digestive tract. We started treatment with lenalidomide and dexamethasone; however, his condition worsened, and he died of aspiration pneumonia. Amyloid myopathy indicated systemic AL amyloidosis; therefore, muscle biopsy was necessary in this case.