We reported recently that during a memory-based smooth-pursuit task, most Parkinson’s disease (PD) patients exhibited normal cue-information memory but impaired smooth-pursuit preparation and execution. A minority of PD patients had abnormal cue-information memory or difficulty in understanding the task. To further examine differences between these two groups, we assigned an anti-saccade task and compared correct rates with various neuropsychological and motor symptom evaluations. The anti-saccade task requires voluntary saccades in the opposite direction to a visual stimulus, and patients with frontal cortical impairments are known to exhibit reflexive saccades (errors). We classified PD patients into 2 groups: one with normal cue-information memory during memory-based smooth-pursuit (n = 14), and the other with abnormal cue-information memory or with difficulty in understanding the memory task (n = 6). The two groups had significantly different anti-saccade correct rates and frontal assessment battery (FAB) scores (P < 0.01). Anti-saccade correct rates of individual patients (n = 20) correlated significantly with FAB scores (P < 0.01) but not with age, Hoehn-Yahr stage, unified PD rating scale (UPDRS) part III or mini-mental state examination (MMSE) scores. Among FAB subtests, significant correlation was obtained only with motor programming scores. These results suggest that performance of memory-based smooth-pursuit and/or anti-saccades depend on frontal cortical function or dysfunction.

We present the case of a 77-year-old man with a 10-year history of Parkinson disease (PD), who developed posterior reversible encephalopathy syndrome (PRES). We diagnosed the case as PRES based on clinical features and MRI findings. He experienced orthostatic hypotension and supine hypertension, including nocturnal hypertension. PRES may result from marked supine/nocturnal hypertension and fluctuation in blood pressure. In addition, exacerbated factors could be representative of neuroleptic malignant syndrome. The hypertensive effect of istradefylline should also not be excluded. We believe this is the first case report of a patient with PD developing PRES without vasopressor use.

A 40-year-old man presented with a series of generalized tonic–clonic seizures after febrile illness. He developed status epilepticus and required mechanical ventilation with anesthetics. Steroid pulse, intravenous immunoglobulin, and immunoadsorption therapy were administrated, and the status epilepticus improved; however, drug-resistant seizures remained. Despite the use of several antiepileptic drugs, seizures frequently occurred. Additional administration of potassium bromide resulted in significant suppression of seizures. Potassium bromide is regarded as an effective medication for pediatric refractory epilepsy after encephalitis. The present case is considered to be new-onset refractory status epilepticus (NORSE) syndrome based on clinical features, and potassium bromide could be effective in treating adult refractory epilepsy, such as NORSE syndrome.

A 87-year-old female presented with subacute progression of cognitive decline. Fluid-attenuated inversion recovery images of brain MRI showed multifocal high-intensity lesions. Thoracic CT image revealed the presence of thymoma, and serum autoantibody screening showed positivity for anti-gamma aminobutyric acid (GABA)_A receptor antibody. Histopathological analysis confirmed type B3 thymoma after thymectomy. The patient received both plasmapheresis and intravenous methylprednisolone therapy, and showed remarkable amelioration of clinical symptoms and MRI abnormal high intensity. However, after 2 month from the clinical recovery, the patient showed recurrence of brain lesions and intravenous methylprednisolone monotherapy was performed. Continuation of oral steroid therapy was required to maintain the quienscent state of inflammation within the central nervous system. Anti-GABA_A receptor antibody is a recently discovered novel autoantibody associated with autoimmue encephalitis. Due to the limited number of literature reported, clinical course and therapeutic response of GABA_A receptor antibody encephalitis remains elusive. Here we reported a rare case of GABA_A receptor antibody encephalitis with type B3 thymoma. Clinical, radiological and therapeutic courses described in our report highlight the importance of immunotherapy for treatment of the disease.

The patient was a 61-year-old woman with thyroid enlargement since her 20s. She began to fall down repeatedly towards the end of June 2015. She was admitted to our hospital in the middle of August because of difficulty in walking. Upon admission, she presented with neck tremor and was unable to maintain a sitting position due to ataxia of the trunk and limbs. We studied serum anti-neuronal antibodies and obtained a positive result for anti-amphiphysin antibody (AMPH-Ab). Cerebrospinal fluid analysis revealed elevated protein levels and IgG index. Other than the thyroid mass, a tumor was not detected. The resected thyroid specimen showed follicular adenoma. After performing immunotherapies, the cerebrospinal fluid protein levels and IgG index decreased, and her ataxia did not progress. When subacute cerebellar ataxia is suspected, studying AMPH-Ab should be considered.

An 51-year-old man had undergone surgery for Rathke’s cleft cyst by transsphenoidal approach on October 2015. After the surgery, cerebrospinal fluid (CSF) rhinorrhea arose. Surgical treatment of CSF rhinorrhea was performed by the same approach. Ten days after reoperation, he suffered from severe headache, high fever, and nuchal rigidity. CSF findings indicated bacterial meningitis. CSF culture showed methicillin-resistant Staphylococcus lugdunensis. He received vancomycin intravenously for 19 days and recovered from the bacterial meningitis with no serious complication.

We report the case of a 47-year-old woman with a 4-year history of progressive numbness in the distal portions of both her lower limbs, diarrhea alternating with periods of constipation, and orthostatic syncope. She demonstrated sensory dominant neuropathy and dysautonomia including orthostatic hypotension, paralytic ileus, and urinary retention. A systemic mutation analysis revealed a G47R mutation in transthyretin (TTR). Her general condition was so poor that we could not perform active treatment. Her consciousness had been impaired for a few months. She died at the age of 47 due to multiple organ failure. An autopsy revealed amyloid deposits in the subarachnoid space of the brainstem and the spinal cord as well as in the peripheral nerve and other organs. To date, this is the first case in which a G47R mutation is associated with leptomeningeal amyloidosis.

We report a case of a 55-year-old man who developed acute-onset narrowing of his visual field. He showed right homonymous hemianopsia without any other neurological symptoms and signs. Brain CT and MRI showed localized hemorrhage (about 1.6 ml) in the left lateral geniculate body (LGB). A cerebral angiography showed no vascular anomalies of cerebral vessels, and the left anterior choroidal artery and left lateral posterior choroidal artery could be visualized well. He had hypertension, polycythemia and dyslipidemia and was a habitual smoker and an alcoholic. In the literature, various kinds of visual field defects including hemianopsia, upper quadrant hemianopsia, lower quadrant hemianopsia, and horizontal sectoranopia have been reported in eight cases of LGB hemorrhage. Localized LGB hemorrhage was found in only one case out of 2,763 cerebral hemorrhage patients enrolled in our stroke registry for 11 years from 2005 to 2016. Localized hemorrhage of LGB very rarely occurred.

A 55-year-old woman was diagnosed with aseptic meningitis at the age of 43 and 44. She developed sudden fever and headache, and she showed nuchal rigidity. Cerebrospinal fluid examination revealed pleocytosis (cell count 208/mm³) and was positive for herpes simplex virus type 2 (HSV-2) DNA by PCR. Acyclovir was started on the first day of admission, and she was complete recovery. Preserved cerebrospinal fluid specimen from aseptic meningitis at the age of 44 was also positive for HSV-2 DNA by PCR. She was diagnosed with HSV-2 associated recurrent aseptic meningitis (Mollaret’s meningitis) with a recurrence after 11-year interval. She repeatedly relapsed genital herpes after 44 years old and she was treated with valacyclovir whenever genital herpes relapses. But she showed no genital herpes at the onset of meningitis. Because HSV-2 is one of the most significant causes of recurrent meningitis, we would like to stress that HSV-2 infection and antiviral therapy should always be kept in mind for a recurrent meningitis case.