A scoping review analyzing 21 selected publications was conducted to determine “whether the varicella zoster virus (VZV) is a risk factor for dementia”. One meta-analysis concluded that VZV infection increases dementia risk, while another meta-analysis contradicts this finding. Several reports have shown an increased risk of dementia associated with VZV infections of the eyes and central nervous system. Additionally, a third meta-analysis reported that VZV vaccination reduces dementia. Therefore, VZV infection may be a risk factor for dementia. However, most of the reviewed articles were retrospective cohort studies, which limits the strength of conclusions that can be drawn. To provide more robust evidence, prospective cohort studies and clinical trials are needed to evaluate the impact of VZV itself, as well as the effectiveness of vaccines and antiviral therapies.

Headaches are a common complaint in the emergency department (ED). Understanding the characteristics and outcomes of headaches, especially in undiagnosed patients, is important for improving headache care in the ED. We conducted a retrospective study of 171 headache patients at the ED of Kagawa Prefectural Central Hospital, with a follow-up for the primary and undiagnosed headache groups via telephone to assess long-term outcomes. Primary, secondary, and undiagnosed headaches accounted for 15.2%, 58.4%, and 26.3% of cases, respectively. All life-threatening secondary headaches were successfully excluded with imaging tests performed on 73.7% of cases, despite the low rate of treatment in the ED (18.1%). Among the undiagnosed headache cases, the recurrence of severe headaches was low (11.9%), though awareness of chronic headaches was high (47.6%). Emergency physicians should be aware of the possibility that patients at an ED presenting an undiagnosed headache may include chronic headache patients. Seamless collaboration between the ED and headache specialists is needed to manage undiagnosed headaches in the ED.

We investigated the 992 consecutive patients with acute embolic stroke and identified potential embolic sources (PES) for 88.3% applying transesophageal echocardiography (TEE). We classified patients into 3 groups, the Group A (n ‍= ‍560): PES were identified after general examinations, the Group B (n ‍= ‍366): PES were identified after TEE or long-term EEG monitoring and the Group C (n ‍= ‍66): TEE could not be performed. In Group A, continuous atrial fibrillation (cAf) was most prevalent (n ‍= ‍464, 82.8%), succeeded by myocardial infarction (n ‍= ‍39, 6.9%) and Trousseau syndrome (n ‍= ‍27, 4.8%), etc. In Group B, paroxysmal atrial fibrillation (pAf) was most prevalent (n ‍= ‍168, 45.9%), succeeded by paradoxical embolism (n ‍= ‍77, 21.0%) and aorto-embolism (n ‍= ‍77, 19.3%). We investigated the association of topographic diffusion-weighted imaging patterns (DWI) with PES. DWI was determined based on the arterial supply. Middle cerebral arteries were particularly divided into 4 segments, i.e., M1~M4. Moreover, M2 segments were subdivided into superior and inferior branches. The infarcts of larger caliber arteries such as internal carotid artery, M1 and M2, and multiple cortical branches were mostly associated with atrial fibrillation including cAf and pAf. Striatocapsular infarction were significantly associated with paradoxical embolism. Multiple small scattered infarcts were predominant in aorto-embolism as well as paradoxical embolism, Trousseau syndrome and thrombocytosis. The associations of DWI with different PES have their distinctive characteristics and may help predict PES in patients with embolic stroke of undetermined source. DWI pattern may be determined by the composition of thrombi and hydrodynamics of cerebral vasculature.

A 68-year-old woman presented with a one-month history of polyarthritis and fever, followed by myalgia and muscle weakness involving the proximal limbs, neck, trunk, and distal upper extremities. Myositis was suspected based on an elevated serum CK level. Chest CT revealed interstitial pneumonia. Commercial laboratory tests, including ELISA and immunoblot, were positive for anti-Ro-52 antibodies but negative for anti-aminoacyl transfer RNA synthetase (ARS) antibodies. However, muscle pathology revealed perifascicular necrosis and perimysial pathology, strongly suggesting anti-synthetase syndrome (ASS). Further investigation using RNA immunoprecipitation (RIP) assay identified positive anti-EJ antibodies, leading to the diagnosis of ASS. In addition, anti-Ku and anti-U1 RNP antibodies were co-positive. These findings highlight that, even when ELISA and immunoblot were negative for specific antibodies, RIP assay is necessary when ASS is suspected based on myopathologic findings.

A 72-year-old woman with a seven-year history of Parkinson’s disease, characterized by gait instability, rigidity, and postural instability, was admitted to our department for evaluation of recurrent episodes of hypoxemia and altered consciousness. During hospitalization, she experienced recurrent episodes of respiratory failure, prompting the measurement of anti-IgLON5 antibodies, which were found to be positive, leading to a diagnosis of anti-IgLON5 disease. The respiratory failure could not be attributed to vocal cord paralysis or respiratory muscle weakness, leading to the hypothesis that subglottic laryngeal spasm was the cause. Treatment with steroid pulse therapy resulted in improved ventilation. While several cases of anti-IgLON5 disease presenting with respiratory failure due to respiratory muscle weakness have been reported, this case suggests that subglottic laryngeal spasm may also be an underlying cause of respiratory failure in anti-IgLON5 disease.

A 57-year-old male patient with a history of daily contact with stray cats was transferred to our hospital with weakness in the left limb and mild disturbance of consciousness. At presentation, he had no fever or signs of meningeal irritation. Cerebrospinal fluid examination revealed lymphocytic pleocytosis; however, the cerebrospinal culture was negative. Computed tomography of the thorax and abdomen showed no abnormalities. Gadolinium-enhanced brain MRI revealed multiple contrast-enhanced lesions in the periventricular white matter and enhanced lateral ventricles. Under the suspicion of cerebral toxoplasmosis, trimethoprim-sulfamethoxazole was administered, but his symptoms gradually worsened. Histopathological findings of the first brain biopsy did not reach the definitive diagnosis. The tissue culture detected Propionibacterium acnes. Despite changes in antibiotics (ceftriaxone and ampicillin), his symptoms progressed. The second brain biopsy revealed diffuse proliferation of atypical glial cells with irregular size of nuclei and necrosis. The diagnosis was glioblastoma, IDH-wild type, CNS WHO grade 4. The radiological findings in this case were initially recognized as isolated multiple lesions with surrounding vasogenic edema, but we authors should have suspected the brain tumor which spreads through the corpus callosum. Multifocal glioblastomas, a rare type of glioblastoma, has worse prognosis than unifocal glioblastoma. This case also emphasizes the importance of the appropriate timing of brain biopsy and careful validation of biopsy sampling.

We present the case of a 33-year-old man with progressive weakness in the left wrist and finger extensors. Initially, posterior interosseous nerve (PIN) palsy was suspected. However, nerve conduction studies detected conduction block and ultrasonography demonstrated swelling between the elbow and spiral groove in the left radial nerve. Anti-GM1 IgM antibodies were positive, leading to a diagnosis of possible multifocal motor neuropathy (MMN). Although MMN usually represents multifocal pure motor neuropathies, the involvement of a single nerve allows for diagnosis of possible MMN. PIN palsy of indeterminate etiology should prompt consideration, underscoring the utility of ultrasonography in the diagnostic process.

A 79-year-old woman was diagnosed with Sjögren’s syndrome (SjS) at the age of 73 years by lip biopsy, gum test, and salivary gland scintigraphy with positive antinuclear (ANA), positive anti-centromere (ACA), and negative anti-Ro/SS-A antibodies. Seven days before admission, the patient developed gait disturbance, which progressed to difficulty in walking two days before admission. She was hospitalized because of subacute gait disturbance. Neurological examination showed gait disturbances characterized by small steps, wide-based gait, left upper limb clumsiness, and frontal lobe dysfunction. Laboratory tests confirmed positive ANA and ACA and negative anti-Ro/SS-A and anti-La/SS-B antibodies. Cerebrospinal fluid analysis showed mildly elevated protein levels and increased monocyte count. Brain MRI showed hyperintensity in the bilateral frontal regions on fluid-attenuated inversion recovery (FLAIR)/contrast-enhanced T₁-weighted imaging, and N-isopropyl-p-¹²³I-iodoamphetamine single-photon emission computed tomography (¹²³I-IMP SPECT) showed decreased accumulation in the frontal region. After excluding cancerous, infectious, and immune-mediated causes, ACA-single-positive SjS-related meningitis was diagnosed. The patient responded well to steroid therapy. The patient was able to walk short distances and showed improvement in frontal lobe function. Follow-up MRI and ¹²³I-IMP SPECT demonstrated the resolution of previous abnormalities. Knowingly, there have been no reported cases of SjS-related meningitis with positive ACA. Considering that anti-Ro/SS-A antibodies are involved in the pathogenesis of meningitis, this case is extremely rare. We propose that ACA-positive SjS be considered in the differential diagnosis of aseptic meningitis.