脳表ヘモジデリン沈着症

Cerebral small vessel disease (SVD) is the most common age-related brain pathology. Magnetic resonance imaging (MRI) is the reference standard for identifying SVD biomarkers, including white matter hyperintensity, recent small subcortical infarcts, lacunes, perivascular spaces, cerebral microbleeds, and cortical superficial siderosis. However, SVD is usually detected only when patients undergo conventional high-field MRI, limiting early identification, longitudinal monitoring, and equitable access to brain health evaluation. Low-field portable MRI systems (<0.1T) offer point-of-care acquisition with reduced infrastructure requirements and have demonstrated concordance with conventional MRI for multiple acute brain pathologies. We review the emerging evidence for portable MRI-based detection of SVD features, with an emphasis on white matter hyperintensity. Future portable MRI work on SVD should prioritize longitudinal validation, standardized reporting, and integration into pragmatic vascular prevention trials.

Superficial siderosis (SS) is a rare, progressive neurological disorder with the most common symptoms being progressive sensorineural hearing loss, ataxia and myelopathy. We aim to report a rare case of the classical type of SS with early cognitive manifestation.An older lady presented with gradual onset hearing loss for 10 years, a decline in episodic memory, executive functions and visuospatial abilities, along with progressive worsening of ataxia and frequent falls for 2 years. After evaluation, a diagnosis of the classical variant of SS was considered. She was started on amantadine up to 200 mg/day, deferiprone up to 1000 mg/day, vitamin E supplementation and donepezil. There was a modest improvement in ataxia and frequency of falls.

Cerebral amyloid angiopathy (CAA) is associated with transient focal neurological episodes (TFNEs), which are brief, stereotyped symptoms. As these may occur regularly, pharmacological treatment of TFNEs is needed but remains poorly investigated. To systematically evaluate the available evidence on the use of pharmacological treatment to reduce the frequency, severity, or duration of TFNEs in patients with CAA. A systematic literature search of PubMed and Embase was conducted. Eligible studies included observational studies, interventional trials, and case reports or series that assessed pharmacological interventions for TFNEs in patients with confirmed CAA. Nine case reports/series involving 13 patients met the inclusion criteria. The mean age was 75.15 years, with a predominance of sensory and motor TFNE symptoms. One EEG recording out of nine reported paroxysmal activity whereas the rest showed no epileptiform activity. Antiseizure medications (levetiracetam) were the most common treatment. Eleven patients experienced complete remission, and two had partial improvement. Most patients exhibited convexity subarachnoid hemorrhage or cortical superficial siderosis on imaging. Although symptomatic improvement following pharmacological treatment was commonly reported, the current evidence is limited to descriptive case reports without control groups. The unpredictable course of TFNEs and absence of long-term follow-up complicate treatment evaluation. Larger, controlled studies or observational studies are needed to establish effective and evidence-based treatment strategies for TFNEs in CAA.

BACKGROUND: Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rare subtype of CAA, and it is correlated with pathological evidence of inflammation against amyloid-β in the walls of blood vessels and the surrounding tissue. Limited data exist on the prevalence of clinical, neuroimaging, and genetic characteristics in CAA-ri. METHOD: A systematic review and meta-analysis pooled data from published studies on CAA-ri. Random-effects models were used to calculate pooled prevalence rates, and heterogeneity was assessed using I2 and τ2 statistics. RESULTS: We identified 4 prospective and 22 retrospective cohort studies comprising 553 patients with CAA-ri (mean age, 70.9 years; women, 51.29%). Prevalence rates were: cognitive decline at presentation 66% ([95% CI 50-80%]; I2 = 69.6%, τ2 = 1.92, p < 0.001), focal neurological deficits 53% ([95% CI 43-63%]; I2 = 47.4%, τ2 = 0.33, p = 0.009), seizures 33% ([95% CI 26-41%]; I2 = 47.4%, τ2 = 0.33, p = 0.009), headache 29% ([95% CI 23-35%]; I2 = 34.3%, τ2 = 0.13, p = 0.08), lobar cerebral microbleeds 96% ([95% CI 87-99%]; I2 = 49.3%, τ2 = 3.54, p = 0.008), gadolinium enhancing lesions 48% ([95% CI 35-61%]; I2 = 68.6%, τ2 = 0.79, p < 0.001), cortical superficial siderosis 42% ([95% CI 33-53%]; I2 = 53.1%, τ2 = 0.47, p = 0.004), and lobar macro hemorrhage 40% ([95% CI 16-71%]; I2 = 46.8%, τ2 = 2.51, p = 0.08), and ischaemic infarcts 15% ([95% CI 10-20%]; I2 = 23.7%, τ2 = 0, p = 0.26 = 23.7%, τ2 = 0, p = 0.26). The prevalence rate of the APOE (Apolipoprotein E) ε4/ε4 genotype was 42% ([95% CI 28-58%]; I2 = 77.8%, τ2 = 0.68, p < 0.001) while ε2/+ allele was 23% ([95% CI 12-39%]; I2 = 84.5%, τ2 = 0.84, p < 0.001. Finally, steroid therapy was the most commonly adopted treatment approach with a pooled prevalence of 79% (95% CI 64-88%; I2 = 76.8%, τ2 = 1.52, p < 0.001). Leave-one-out sensitivity analyses confirmed the robustness of pooled estimates across all outcomes. Subgroup analysis revealed a significantly higher prevalence of seizures in biopsy-confirmed cohorts compared to clinically diagnosed cases. Meta-regression identified significant associations between mean patient age and focal neurological deficits (p=0.037), headache (p=0.002), and lobar cerebral microbleeds (p=0.048). CONCLUSIONS: Cognitive decline and focal neurological deficits were the most common clinical features, while lobar cerebral microbleeds were the predominant neuroimaging finding. Forty-two percent of patients carried the homozygous APOE ε4/ε4 genotype, seventy-nine percent underwent steroid therapy, and favorable outcomes were observed in seventy-five percent of cases.

BACKGROUND AND OBJECTIVES: Cerebral amyloid angiopathy (CAA) is a small vessel disease characterized by hemorrhagic and nonhemorrhagic brain injuries. While cortical cerebral microinfarcts (CMI) have been associated with cortical superficial siderosis (cSS), the mechanisms linking these lesions remain unknown. This study aims to determine the spatiotemporal relationship between cortical CMI and cSS in CAA, with the hypothesis that cSS can promote local ischemic injury. METHODS: Patients with probable CAA (Boston Criteria v2.0) without previous symptomatic intracerebral hemorrhage or CAA-related inflammation were recruited from a prospective memory clinic-based cohort at Massachusetts General Hospital. CAA-related radiologic manifestations-including cortical CMI and cSS-were quantified at baseline and at the 24-month follow-up on 3-Tesla MRI. Multivariable logistic regression and generalized linear models were applied to assess associations between baseline radiologic features and radiologic progression. We also compared the local density of cortical CMIs in regions with and without overlaid cSS. RESULTS: Among 74 patients with probable CAA (age: 73.0 [67.9-78.2] years; 38% female), 26 (35%) had cortical CMIs (n = 135, 39% underlying cSS). Compared with CMI-negative CAA, those with CMI had a higher cSS prevalence (73% vs 40%; p = 0.006), cSS volume (1.3 [0.1-8.3] vs 0 [0-0.5] mL; p < 0.001), and lobar lacunes count (50% vs 19%; p = 0.005). At baseline, cortical CMI count demonstrated a nonlinear association with cSS volume (Exp(B) = 1.12 [95% CI 1.07-1.18]; p < 0.001) and with lobar lacunes count (Exp(B) = 1.65 [95% CI 1.52-1.80]; p < 0.001). The CMI density was markedly higher in cSS-covered vs non-cSS regions (median: 20.84 [0.00-56.95] vs 0.49 [0.11-0.89]n° cortical CMI/1,000 cm2; p = 0.010). Follow-up scans (n = 36) revealed 23 incident cortical CMIs (43% underlying cSS). Baseline cSS volume was independently associated with incident CMI (OR:1.41 [95% CI 1.02-1.95]; p = 0.036), whereas baseline CMI burden was not associated with cSS progression. DISCUSSION: Our findings demonstrate a close interplay between cortical CMI and cSS, with the spatiotemporal relationship supporting the hypothesis that convexity subarachnoid hemorrhage, and potentially resultant cSS, may trigger local ischemic injury. Given the sample size of the longitudinal cohort, we consider these data hypothesis-generating. Further studies should confirm this association and identify the driving pathophysiology, which may represent a new therapeutic target for preventing cSS-associated cortical injury.