Brain Perfusion Single-Photon Emission Computed Tomography Using an Easy Z-Score Imaging System Predicts Progression to Neurodegenerative Dementia in Rapid Eye Movement Sleep Behavior Disorder.

INTRODUCTION: Longitudinal studies have reported that patients with idiopathic rapid eye movement sleep behavior disorder (IRBD) have an increased risk of developing synucleinopathies, such as Parkinson's disease and dementia with Lewy bodies (DLB). Clinical trials of disease-modifying therapies for IRBD patients require suitable biomarkers that can predict the short-term onset of neurodegenerative dementia. METHODS: We retrospectively examined if easy Z-score imaging system-specific volume-of-interest analysis (SVA) using brain perfusion single-photon emission computed tomography (SPECT) imaging or the cingulate island sign score can predict the short-term development of neurodegenerative dementia in 30 patients with IRBD. RESULTS: Ten patients (33.3%) who exceeded the thresholds for three indicators (severity, extent, and ratio) were included in an SVA-positive group, while 20 (66.7%) were included in an SVA-negative group. Nine (30.0%) IRBD patients had phenoconversion, of which eight had DLB and one had Parkinson's disease with dementia. In Kaplan-Meier analysis, patients in the SVA-positive group converted to neurodegenerative dementia in a significantly shorter period of time compared to patients in the SVA-negative group. CONCLUSIONS: These data suggest that SVA-positive IRBD patients have an increased short-term risk of developing neurodegenerative dementia.

[Absence of cortical lesions after the first seizure in a patient with anti-myelin oligodendrocyte glycoprotein-associated cortical encephalitis].

A 31-year-old man developed headache and generalized convulsions. At the time of the first seizure, there was no distinct MRI abnormality. He was admitted to the hospital with repeated seizures, left-sided hemiparesis, and left-sided neglect. He had a slight fever, elevated cerebrospinal fluid (CSF) pressure, and increased CSF cell count with predominance of mononuclear cells. A repeat MRI scan on day 8 after the recurrent seizure showed cortical edema in the right cerebral hemisphere on fluid-attenuated inversion recovery (FLAIR), abnormal high signal on DWI, and decreased apparent diffusion coefficient. The patient was diagnosed with aseptic meningoencephalitis and treated with antiviral drugs and methylprednisolone pulse therapy. Serum anti-myelin oligodendrocyte glycoprotein (MOG) antibody was subsequently detected, and prednisolone was added to treat the FLAIR-hyperintense lesions in anti-MOG antibody associated encephalitis with seizures (FLAMES). It is important to identify the clinical picture and typical images of FLAMES to allow early treatment.

Striatal dopamine transporter degeneration in right-handed REM sleep behavior disorder patients progresses faster in the left hemisphere.

OBJECTIVE: In right-handed patients with idiopathic rapid eye movement sleep behavior disorder (IRBD) or Parkinson's disease (PD), dopamine transporter (DAT) single-photon emission computed tomography (SPECT) shows a predominant nigrostriatal deficit in the left striatum. To confirm this hypothesis, we longitudinally investigated whether the nigrostriatal function is asymmetric in Japanese patients with IRBD. METHODS: In 91 polysomnography-confirmed IRBD patients, which included 87 right-handed IRBD patients who underwent 33 repeat DAT-SPECT scans, we retrospectively examined the striatal dopaminergic terminals in each hemisphere using DAT-SPECT. We calculated the values of interhemispheric laterality index for the right and left sides. RESULTS: The proportion of IRBD patients with lower SBR in the striatum was different between the left (n = 60, 69.0%) and right (n = 27, 31.0%) hemispheres. In the repeat DAT-SPECT scan (n = 33), the rate of decline in the striatum was greater on the left than on the right side, and the proportion of patients with lower decline rates in the left striatum (n = 25, 73.5%) was greater than the that in the right striatum (n = 3, 8.8%). The proportion of lower SBR side at baseline did not predict the development of PD or DLB. CONCLUSION: Right-handed IRBD patients have asymmetric nigrostriatal dopaminergic function, as evidenced by the faster estimated rate of decline for the left striatum than the right striatum. The left-right hemispheric striatal predominance of the nigrostriatal deficit in the right-handed prodromal PD or DLB patients represents a difference in the early pathological process of the disease.

[REM Sleep Behavior Disorder and α-synucleinopathy].

REM sleep behavior disorder (RBD) can progress to Parkinson's disease, Lewy body dementia, or multiple system atrophy within 20 years of onset. Accurate diagnosis of RBD is therefore important for early intervention. The development of markers that can more sensitively evaluate the effects of high-risk groups or candidate therapies that develop α-synucleinopathy in the short term is the key to a successful clinical trial. Clinical protocols for early diagnosis of α-synucleinopathy are currently being developed. The next stage will be to conduct clinical trials for candidate therapies.

Reduced dopamine transporter binding predicts early transition to Lewy body disease in Japanese patients with idiopathic rapid eye movement sleep behavior disorder.

PURPOSE: We examined dopamine transporter (DAT) binding in Japanese patients with idiopathic rapid eye movement sleep behavior disorder (IRBD) as a biomarker for the development of Lewy body disease (LBD). METHODS: [123I]FP-CIT SPECT (DAT-SPECT) scans of 74 IRBD patients were compared to those from healthy Japanese subjects, and the predictive value for conversion to LBD during a 5-year follow-up was evaluated. RESULTS: Baseline DAT deficits (Z-score ≤ -2.5) were observed in 25 (33.8%) of the IRBD patients. During follow-up, 25 patients (33.8%) developed LBD [19 Parkinson's disease and 6 dementia with Lewy bodies], with a mean latency of 2.4 ± 1.6 years from imaging. The receiver operating characteristics curve revealed that the Z-score of baseline DAT binding in the striatum of abnormal DAT-SPECT patients who later developed LBD differed from those who remained disease-free. Kaplan-Meier survival analysis showed an increased risk of LBD in patients with a Z-score ≤ -2.5 for DAT binding in the striatum of abnormal DAT-SPECT patients compared to patients with a Z-score > -2.5. CONCLUSIONS: DAT-SPECT identifies IRBD patients at short-term risk for developing LBD. Decreased DAT binding in the striatum (Z-score ≤ -2.5) predicts development of LBD within 5 years, and may be useful in future disease-prevention trials in IRBD patients.

[Cryptococcal meningoencephalitis in an immunocompetent patient caused by late onset exacerbation].

The case was a 29-year-old male with no previous history of serious disease. He developed headache and fever, which then worsened and he was admitted to our hospital. His temperature was 38.3°C and he had a stiff neck. In cerebrospinal fluid (CSF) tests, the opening pressure was high, the cell count was increased, and the CSF/serum glucose ratio was decreased. In addition, he was positive for cryptococcal antigen. According to these findings, he was diagnosed with cryptococcal meningoencephalitis and antifungal treatment was initiated. His symptoms then improved, but on day 18 after admission, he developed convulsions, and on day 28, right visual field defects appeared. Brain MRI showed disseminated lesions in the bilateral cerebral cortex. Despite a decrease of the cryptococcal antigenic value in the CSF, the IgG index was elevated. IL-6, 8 and 10 in CSF were high levels on Day 1, then gradually reduced as the symptoms improved. But on Day 28, worsening of symptoms, IL-10 was significantly increased dispite IL-6 and 8 reducing. Therefore, the exacerbation of his symptoms and expansion of the lesions were not caused by the Cryptococcus itself, and it was considered that they were due to the late deterioration of cryptococcosis, which responded to steroid treatment.