This study reports eleven cases of reversible cerebral vasospasm syndrome (RCVS). Of the 11 patients, two were males and nine were females, with the average age of 47.9 ± 14.1 years. Many of these patients were young. The rates of severe, intractable and pulsative headache, generalized convulsions, and motor hemiparesis were 64%, 27%, and 36%, respectively. As complications of intracerebral lesions in the early stage of disease onset, convexal subarachnoid hemorrhage, lobar intracerebral hemorrhage, and posterior reversible encephalopathy syndrome were observed in 63%, 9%, and 45% of cases, respectively. Cerebral infarction occurred in 45% of cases at around 1–3 weeks after onset. Improvement of cerebral vasoconstriction was recognized in several cases from about the first month of onset. The post-partum period, migraine, transfusion, rapid amelioration for anemia, renal failure, bathing, and cerebrovascular dissection were suspected as disease triggers. Abnormally high blood pressure at onset was confirmed in 55% of cases. It is important to analyze the pathophysiology of RCVS associated with these triggers from the viewpoint of the breakdown of the blood-brain barrier.

A 28-year-old man noticed sensory disturbance in the distal parts of his four extremities and muscle weakness of his hands two weeks after cytomegalovirus (CMV) infection. He had splenomegaly, impairment of hepatic function and peripheral neuropathy with decreased tendon reflexes. Protein-cell dissociation was observed in the cerebrospinal fluid, and the nerve conduction study (NCS) showed the changes due to demyelination. Intravenous immunoglobulin therapy was performed for 5 days after the diagnosis of Guillain-Barré syndrome. He did not show any severe symptoms such as bulbar palsy and was discharged on day 16. Anti-GM2 and anti-GalNAc-GD1a IgM antibodies were detected and acute inflammatory demyelinating polyneuropathy following the CMV infection was confirmed. NCS showed the abnormal changes were normalized after 4 months. The levels of antibodies against moesin, which is a protein existing in trace amounts in node of Ranvier, were increased. However, the antibodies were not detected 4 months after therapy. These changes were well correlated to his clinical course.

Hashimoto’s encephalopathy has been described as an autoimmune disorder which demonstrates favorable response to corticosteroid therapy. However, steroid-resistant cases which require additional treatment are frequently reported, and there is no consensus how such cases should be treated. We present a 69 years-old man, who progressed cognitive dysfunction in the past three months. Anti-thyroid and anti-NH₂ terminal of alpha-enolase antibodies were positive. Because initial corticosteroid therapy was ineffective, cyclophosphamide (CPA) pulse therapy was added, and his cognitive function was immediately improved. He had no relapse after tapering dose of corticosteroid for three years. CPA pulse therapy should be considered for steroid-resistant Hashimoto’s encephalopathy.

A 52-year-old man presented with progressive dementia and left hemiparesis. He was treated for neurosyphilis at 44 years old in another hospital. An initial MRI revealed a widespread high-intensity area in the right temporal lobe on DWI. Findings on MRA were normal. He was treated initially with intravenous edaravone and glyceol, but neurological finding did not improved. Serological tests of serum and CSF demonstrated high titers of antibodies to Treponema pallidum. He was treated for relapsed neurosyphilis with daily penicillin G injections without improvement. Penicillin G was switched to erythromycin. After administration of erythromycin, neurological symptoms improved and MRI abnormality showed progression. This case could be considered as Lissauer form of general paresis because of left hemiparesis and MRI findings. Neurosyphilis should be considered in a case with revealing high density area in DWI.

An 86-year-old woman presented with generalized chorea in the face and extremities, which gradually progressed for two weeks. Cranial CT revealed a chronic subdural hematoma (CSDH) that covered the left parietal lobe. Discontinuation of amantadine did not improve the chorea. The hematoma was evacuated and the chorea completely subsided in a week. The pathogenesis leading to chorea in CSDH remains unclear. A unilateral hematoma presenting with generalized chorea similar to the present patient and two others with unilateral CSDH causing ipsilateral hemichorea have been reported. The rarity of these movement disorders due to CSDH indicates that these patients had a preclinical dysfunction within neuronal networks interconnecting basal ganglia the cerebral cortex. Our findings confirmed that CSDH could cause chorea, and further neuroimaging to evaluate cerebrovascular disease, taking a detailed family history and obtaining information about current medications might reveal factors likely to precipitate the development of chorea.

We report a case of meningeal carcinomatosis that needed to be distinguished from subarachnoid hemorrhage. A 67-year-old female with acute severe headache was admitted to a previous hospital. Since high intensity signal was detected within the parietal cerebral sulci on the right side on brain FLAIR MRI, cerebral angiography was performed due to suspicion of subarachnoid hemorrhage. However, no vascular abnormality was observed. Then, cerebral spinal fluid was collected, which showed an increase in cell count, suggesting meningitis. She was transferred to our hospital for evaluation of neurological disease. After admission to our hospital, there was an episode of hematemesis. Upper gastrointestinal endoscopy was performed, and advanced gastric cancer was found. She was diagnosed as having meningeal carcinomatosis due to gastric cancer. Meningeal carcinomatosis should be considered in addition to subarachnoid hemorrhage when a patient with acute headache shows high intensity signal within the cerebral sulci on brain FLAIR MRI.

A 70-year-old man, a urinary retention of unknown origin from 10 years ago, decreased cognitive function from 4 years ago, vision impairment advanced a year ago. Brain MRI with DWI showed high intensity erea in the cortico-medullary junction. We diagnosed as intranuclear inclusion body disease (NIID) because of p62-positive intranuclear inclusion bodies by skin biopsy. Electroretinogram revealed amplitude reduction in the cone response superiority. Nerve conduction test showed mild conduction velocity reduction. Furthermore, in the somatosensory evoked potential of the lower limb, latency of the first cortical component was prolonged. These electrophysiological abnormalities were considered to be associated with the pathological features of NIID.

An 80-year-old woman diagnosed with granulomatosis with polyangiitis (GPA) complained of a sustained, non-pulsatile headache. Her brain MRI diffusion-weighted images revealed a high-signal-intensity, space-occupying lesion in the sellar region that was rim-enhanced on gadolinium-enhanced T₁-weighted images. Pituitary involvement of GPA was initially suspected based on her condition; however, an abscess formation within an existing Rathke’s cleft cyst was also considered according to a previous MRI finding that had been conducted for an unrelated purpose. A trans-sphenoidal resection of the lesion revealed an abscess with foam cells. These findings were consistent with a diagnosis of a xanthogranuloma with abscess formation in the Rathke’s cleft cyst, and her headache was completely resolved without any immune therapy that is required for GPA. Thus, differential diagnosis of space-occupying lesions in the seller region should include xanthogranuloma with abscess formation, especially if a Rathke’s cleft cyst is detected as an antecedent finding.

A 49-year-old woman was admitted to our hospital with recurrent episodes of paresthesia attacks evolving in 5 to 15 minutes from the left hand to the left leg through the left trunk. Neurological examination revealed cortical sensory disturbance in her left hand. Although contrast-enhanced T₁-weighted MRI findings were unremarkable, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) MRI revealed abnormal leptomeningeal enhancement over the sulcus of the parietal lobe, including the sulcus around the postcentral gyrus. Because we assumed the cause of the recurrent sensory attack to be meningeal inflammation around the primary somatosensory cortex, we treated this patient by increasing the dose of prednisolone. The increase in prednisolone dose completely resolved the symptom, as well as the abnormal leptomeningeal enhancement on contrast-enhanced FLAIR MRI. In patients with suspected meningeal inflammation, contrast-enhanced FLAIR MRI, which is reported to be more sensitive than contrast-enhanced T₁-weighted MRI in detecting subtle abnormal leptomeningeal enhancement, should be the modality of choice.