Association of Cortical Superficial Siderosis with Post-Stroke Epilepsy.

OBJECTIVE: To assess whether post-stroke epilepsy (PSE) is associated with neuroimaging findings of hemosiderin in a case-control study, and whether the addition of hemosiderin markers improves the risk stratification models of PSE. METHODS: We performed a post-hoc analysis of the PROgnosis of POST-Stroke Epilepsy study enrolling PSE patients at National Cerebral and Cardiovascular Center, Osaka, Japan, from November 2014 to September 2019. PSE was diagnosed when one unprovoked seizure was experienced >7 days after the index stroke, as proposed by the International League Against Epilepsy. As controls, consecutive acute stroke patients with no history or absence of any late seizure or continuing antiseizure medications at least 3 months after stroke were retrospectively enrolled during the same study period. We examined cortical microbleeds and cortical superficial siderosis (cSS) using gradient-echo T2*-weighted images. A logistic regression model with ridge penalties was tuned using 10-fold cross-validation. We added the item of cSS to the existing models (SeLECT and CAVE) for predicting PSE and evaluated performance of new models. RESULTS: The study included 180 patients with PSE (67 women; median age 74 years) and 1,183 controls (440 women; median age 74 years). The cSS frequency was higher in PSE than control groups (48.9% vs 5.7%, p < 0.0001). Compared with the existing models, the new models with cSS (SeLECT-S and CAVE-S) demonstrated significantly better predictive performance of PSE (net reclassification improvement 0.63 [p = 0.004] for SeLECT-S and 0.88 [p = 0.001] for CAVE-S at the testing data). INTERPRETATION: Cortical superficial siderosis was associated with PSE, stratifying stroke survivors at high risk of PSE. ANN NEUROL 2023;93:357-370.

Periodic discharges plus fast activity on electroencephalogram predict worse outcomes in poststroke epilepsy.

OBJECTIVE: Postseizure functional decline is a concern in poststroke epilepsy (PSE). However, data on electroencephalogram (EEG) markers associated with functional decline are scarce. Thus, we investigated whether periodic discharges (PDs) and their specific characteristics are associated with functional decline in patients with PSE. METHODS: In this observational study, patients admitted with seizures of PSE and who had scalp EEGs were included. The association between the presence or absence of PDs and postseizure short-term functional decline lasting 7 days after admission was investigated. In patients with PD, EEG markers were explored for risk stratification of short-term functional decline, according to the American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology. The association between EEG markers and imaging findings and long-term functional decline at discharge and 6 months after discharge, defined as an increase in the modified Rankin Scale score compared with the baseline, was evaluated. RESULTS: In this study, 307 patients with PSE (median age = 75 years, range = 35-97 years, 64% males; hemorrhagic stroke, 47%) were enrolled. Compared with 247 patients without PDs, 60 patients with PDs were more likely to have short-term functional decline (12 [20%] vs. 8 [3.2%], p < .001), with an adjusted odds ratio (OR) of 4.26 (95% confidence interval [CI] = 1.44-12.6, p = .009). Patients with superimposed fast-activity PDs (PDs+F) had significantly more localized (rather than widespread) lesions (87% vs. 58%, p = .003), prolonged hyperperfusion (100% vs. 62%, p = .023), and a significantly higher risk of short-term functional decline than those with PDs without fast activity (adjusted OR = 22.0, 95% CI = 1.87-259.4, p = .014). Six months after discharge, PDs+F were significantly associated with long-term functional decline (adjusted OR = 4.21, 95% CI = 1.27-13.88, p = .018). SIGNIFICANCE: In PSE, PDs+F are associated with sustained neuronal excitation and hyperperfusion, which may be a predictor of postseizure short- and long-term functional decline.

Harboring Cnm-expressing Streptococcus mutans in the oral cavity relates to both deep and lobar cerebral microbleeds.

BACKGROUND: Cerebral microbleeds (CMBs) influence long-term prognoses of stroke patients. Streptococcus mutans expressing the collagen-binding protein Cnm induces cerebrovascular inflammation, impairing blood brain barrier integrity and causing cerebral bleeding. Here, we examine the association of Cnm-positive S. mutans with CMBs. METHODS: Acute stroke patients were selected from a single-center registry database. Oral carriage of Cnm-positive or Cnm-negative S. mutans was determined using polymerase chain reaction assays. The associations of Cnm-positive S. mutans with CMB number and specifically the presence of >10 CMBs were examined using quasi-Poisson and logistic regression models, respectively. RESULTS: This study included 3154 stroke patients, of which 428 patients (median [interquartile range] age, 73.0 [63.0-81.0] years; 269 men [62.9%]) underwent oral bacterial examinations. In total, 326 patients harbored S. mutans. After excluding four patients without imaging data, we compared patients with Cnm-positive (n = 72) and Cnm-negative (n = 250) S. mutans. Harboring Cnm-positive S. mutans was independently associated with the presence of >10 CMBs (adjusted odds ratio 2.20 [1.18-4.10]) and higher numbers of deep and lobar CMBs (adjusted risk ratio 1.61 [1.14-2.27] for deep; 5.14 [2.78-9.51] for lobar), but not infratentorial CMBs, after adjusting for age, sex, hypertension, stroke type, National Institutes of Health Stroke Scale score, and cerebral amyloid angiopathy. CONCLUSIONS: Harboring Cnm-positive S. mutans was independently associated with a higher number of CMBs in deep and lobar locations. Reducing Cnm-positive S. mutans in the oral cavity may serve as a novel therapeutic approach for stroke.

Preclinical characterization of [18F]T-008, a novel PET imaging radioligand for cholesterol 24-hydroxylase.

PURPOSE: Cholesterol 24-hydroxylase (CH24H) is a brain-specific enzyme that plays a major role in brain cholesterol homeostasis by converting cholesterol into 24S-hydroxycholesterol. The selective CH24H inhibitor soticlestat (TAK-935) is being pursued as a drug for treatment of seizures in developmental and epileptic encephalopathies. Herein, we describe the successful discovery and the preclinical validation of the novel radiolabeled CH24H ligand (3-[18F]fluoroazetidin-1-yl){1-[4-(4-fluorophenyl)pyrimidin-5-yl]piperidin-4-yl}methanone ([18F]T-008) and its tritiated analog, [3H]T-008. METHODS: In vitro autoradiography (ARG) studies in the CH24H wild-type (WT) and knockout (KO) mouse brain sections were conducted using [3H]T-008. PET imaging was conducted in two adult rhesus macaques using [18F]T-008. Each macaque received two test-retest baseline scans and a series of two blocking doses of soticlestat administered prior to [18F]T-008 to determine the CH24H enzyme occupancy. PET data were analyzed with Logan graphical analysis using plasma input. A Lassen plot was applied to estimate CH24H enzyme occupancy by soticlestat. RESULTS: In ARG studies, binding of [3H]T-008 was specific to CH24H in the mouse brain sections, which was not observed in CH24H KO or in wild-type mice after pretreatment with soticlestat. In rhesus PET studies, the rank order of [18F]T-008 uptake was striatum > cortical regions > cerebellum, which was consistent with CH24H distribution in the brain. Pre-blocking with soticlestat reduced the maximum uptake and increased the washout in all brain regions in a dose-dependent manner. Calculated global occupancy values for soticlestat at a dose of 0.89 mg/kg were 97-98%, indicating maximum occupancy. CONCLUSION: The preclinical in vitro and in vivo evaluation of labeled T-008 demonstrates that [18F]T-008 is suitable for imaging CH24H in the brain and warrants further studies in humans.

Clinical and imaging features of nonmotor onset seizure in poststroke epilepsy.

OBJECTIVE: Motivated by the challenges raised by diagnosing poststroke epilepsy (PSE), especially in nonmotor onset seizure (non-MOS), we aimed to investigate the features of non-MOS, including seizure sequences, patient characteristics, and electrophysiological and imaging findings in PSE. METHODS: This observational cohort study enrolled patients with PSE whose seizure onset was witnessed. According to the International League Against Epilepsy (ILAE) 2017 seizure classification, we classified seizure-onset symptoms into the non-MOS and MOS groups. We compared the different clinical characteristics between the two groups. RESULTS: Between 2011 and 2018, we enrolled 225 patients with PSE (median age, 75 years), consisting of 97 (43%) with non-MOS and 128 (57%) with MOS. Overall, 65 (67%) of the patients without MOS had no subsequent convulsions. Multivariable logistic regression analysis showed significant associations of non-MOS with absence of poststroke hemiparesis (adjusted odds ratio [OR], 1.88; 95% confidence interval [CI], 1.03-3.42), frontal stroke lobe lesions (OR, 2.11; 95% CI, 1.14-3.91), and putaminal stroke lesions (OR, 2.51; 95% CI, 1.22-5.18) as negative indicators. Postictal single-photon emission computed tomography (SPECT) detected prolonged hyperperfusion in the temporal lobe more frequently in the non-MOS than in the MOS group (48% vs 31%; p = .02). The detection rate was higher than spikes/sharp waves in scalp electroencephalography, both in the non-MOS group (72% vs 33%; p < .001) and the MOS group (68% vs 29%; p < .001). SIGNIFICANCE: This study provides the clinical features of non-MOS in patients with PSE. Compared with the patients with MOS, patients with non-MOS showed less likely subsequent convulsive seizures, highlighting the clinical challenges. Postictal perfusion imaging and negative indicators of the non-MOS type may help diagnose and stratify PSE.

Tima nigroannulata (Cnidaria: Hydrozoa: Eirenidae), a New Species of Hydrozoan from Japan.

Tima nigroannulata sp. nov. is described from medusae collected in shallow waters of four prefectures on the Pacific coast of Japan (Miyagi, Fukushima, Kanagawa, and Miyazaki), as well as from cultures maintained at two aquaria (Enoshima Aquarium, Kanagawa Prefecture; Tsuruoka City Kamo Aquarium, Yamagata Prefecture). Adult medusae differ from those of other known species of the genus Tima Eschscholtz, 1829 in the following combination of characters: (1) umbrella usually hemispherical or higher, (2) marginal tentacles up to 50 or more in number; and (3) black pigment granules form a ring around the umbrella rim, and sometimes extend onto the tentacles and radial canals. Their hydroids, from aquarium cultures, have stolonal colonies with pedicels of varied length, vestigial hydrothecae, slender and vase- to club-shaped hydranths, and a whorl of about 20 filiform tentacles with an intertentacular web basally. Medusa buds develop singly within gonothecae that arise from the hydrothecal pedicels. The cnidomes of both hydroid and medusa stages comprise heteronemes, provisionally identified as microbasic mastigophores. Medusae of T. nigroannulata are confirmed as a unique, cohesive lineage by comparing mtDNA COI sequence fragments with those from two congeners, resulting in three well-supported reciprocally monophyletic clades, one representing each species. Records of the western Atlantic medusa Tima formosa L. Agassiz, 1862 from Japan overlap those of T. nigroannulata, and are believed to have been based on the new species described herein.

A Nationwide Multi-Center Questionnaire Survey on the Real-World State and Issues Regarding Post-Stroke Complications in Japan.

OBJECTIVES: Post-stroke complications affect stroke survivors across the world, although data on them are limited. We conducted a questionnaire survey to examine the real-world state and issues regarding post-stroke complications in Japan, which represents a super-aged society. MATERIALS AND METHODS: In 2018, a nationwide multi-center questionnaire survey was conducted in the top 500 Japanese hospitals regarding the number of stroke patients treated. Three questionnaires regarding post-stroke complications were mailed to the doctors responsible for stroke management. RESULTS: Responses were obtained from 251 hospitals (50.2%). The chief doctors responsible for stroke management answered the questionnaires. The number of stroke patients in the departments of neurology and neurosurgery was 338.3 ± 195.3 and 295.8 ± 121.8. Hospitals were classified using the categories secondary (n =142) and tertiary hospitals (n = 106); most hospitals were acute hospitals. Dementia was the most common complication (30.9%), followed by dysphagia (29.3%), and apathy (16.3%). Dementia was thought to be more common by neurologists than neurosurgeons, while apathy and bladder-rectal disorder were thought to be more common by neurosurgeons than neurologists (p = 0.001). The most difficult complication to treat was dysphagia (40.4%), followed by dementia (33.9%), epilepsy (4.1%), and fall (4.1%). Dementia was considered to lack clinical evidence regarding treatment (32.8%), followed by dysphagia (25.3%), and epilepsy (14.1%). Epilepsy was considered to lack clinical evidence among hospitals with a larger number of stroke cases (p = 0.044). CONCLUSION: This study revealed the current state and issues regarding post-stroke complications in Japan. Clinicians should be aware of the importance of post-stroke complications, although data on them remain unsatisfactory.

Oral Carriage of Streptococcus mutans Harboring the cnm Gene Relates to an Increased Incidence of Cerebral Microbleeds.

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMB) are associated with stroke and cognitive impairment. We previously reported a high prevalence of CMB in people with Streptococcus mutans expressing Cnm, a collagen-binding protein in the oral cavity. S.mutans is a major pathogen responsible for dental caries. Repeated challenge with S.mutans harboring the cnm gene encoding Cnm induced cerebral bleeding in stroke-prone spontaneously hypertensive rats. The purpose of this longitudinal study is to examine the relationship of cnm-positive S.mutans to the development of CMB. METHODS: We retrospectively investigated patients with stroke receiving oral microbiological examination and head 3T magnetic resonance imaging evaluations twice in the period 2014 to 2019, allowing >180-day interval. Patients with cnm-positive S.mutans were compared with those without. Quasi-Poisson regression models were used to explore associations between cnm-positive S.mutans and the increase in number of CMB between the 2 magnetic resonance imaging scans. RESULTS: A total of 111 patients were identified; 21 (19%) with cnm-positive S.mutans and 90 (81%) without. Clinical history, including blood pressure and the use of antithrombotic agents, were comparable between the 2 groups. New CMB were more commonly observed in patients with cnm-positive S.mutans (52% versus 23%; P=0.008). The incidence of CMB was significantly higher in the group with cnm-positive S.mutans, especially in deep areas, (incidence rate ratios [95% CI], 5.1 [1.9-13.6] for CMB in any brain region; 15.0 [5.4-42.0] for deep CMB), which persisted after adjusting for age, sex, hypertension, and renal impairment (4.7 [1.8-11.9] for CMB in any brain region; 13.9 [4.3-44.5] for deep CMB). CONCLUSIONS: This study demonstrates that cnm-positive S.mutans is associated with an increased incidence of CMB. Treatment for cnm-positive S.mutans infection may be a novel microbiota-based therapeutic approach for stroke and cognitive impairment.

Comparison of the Inducing Effect of Indole Compounds on Medusa Formation in Different Classes of Medusozoa.

Scyphozoa, Cubozoa and Hydrozoa are classes in the phylum Cnidaria that undergo metagenesis involving a dramatic morphological transition. In Scyphozoa and Cubozoa, when exposed to species- or strain-specific transition-inducing stimuli, asexually reproducing benthic polyps transform into sexually reproducing planktonic medusae. In Hydrozoa, exposure to species- or strainspecific transition-inducing stimuli causes formation of medusa buds in the polyp's body. In Aurelia aurita (Linnaeus, 1758) (Scyphozoa, Semaeostomeae), polyp-to-jellyfish transition is induced by some simple indole compounds. However, whether indole compounds can induce polyp-to-jellyfish transition in Cubozoa and Hydrozoa remains unknown. In the present study, we show that an indole compound, 5-methoxy-2-methylindole, induces polyp-to-jellyfish transition in Scyphozoa and Cubozoa. This inducing action suggests that the downstream steps of polyp-to-jellyfish transition are regulated by the same biochemical reactions in Scyphozoa and Cubozoa, irrespective of the type of transition-inducing environmental stimuli.

Discovery of a Novel Series of Pyrazolo[1,5-a]pyrimidine-Based Phosphodiesterase 2A Inhibitors Structurally Different from N-((1S)-1-(3-Fluoro-4-(trifluoromethoxy)phenyl)-2-methoxyethyl)-7-methoxy-2-oxo-2,3-dihydropyrido[2,3-b]pyrazine-4(1H)-carboxamide (TAK-915), for the Treatment of Cognitive Disorders.

It has been hypothesized that selective inhibition of phosphodiesterase (PDE) 2A could potentially be a novel approach to treat cognitive impairment in neuropsychiatric and neurodegenerative disorders through augmentation of cyclic nucleotide signaling pathways in brain regions associated with learning and memory. Following our earlier work, this article describes a drug design strategy for a new series of lead compounds structurally distinct from our clinical candidate 2 (TAK-915), and subsequent medicinal chemistry efforts to optimize potency, selectivity over other PDE families, and other preclinical properties including in vitro phototoxicity and in vivo rat plasma clearance. These efforts resulted in the discovery of N-((1S)-2-hydroxy-2-methyl-1-(4-(trifluoromethoxy)phenyl)propyl)-6-methyl-5-(3-methyl-1H-1,2,4-triazol-1-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (20), which robustly increased 3',5'-cyclic guanosine monophosphate (cGMP) levels in the rat brain following an oral dose, and moreover, attenuated MK-801-induced episodic memory deficits in a passive avoidance task in rats. These data provide further support to the potential therapeutic utility of PDE2A inhibitors in enhancing cognitive performance.