Mitochondria are fundamental for metabolic homeostasis in all multicellular eukaryotes. In the nervous system, mitochondria-generated adenosine triphosphate (ATP) is required to establish appropriate electrochemical gradients and reliable synaptic transmission. Notably, several mitochondrial defects have been identified in central nervous system disorders. Membrane leakage and electrolyte imbalances, pro-apoptotic pathway activation, and mitophagy are among the mechanisms implicated in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, and Huntington’s disease, as well as ischemic stroke. In this review, we summarize mitochondrial pathways that contribute to disease progression. Further, we discuss pathological states that damaged mitochondria impose on normal nervous system processes and explore new therapeutic approaches to mitochondrial diseases.

Subacute and chronic subdural hematomas are common and frequently recur after surgical evacuation. The effect of adjunctive middle meningeal artery embolization on the risk of reoperation remains unclear. In a prospective, multicenter, interventional, adaptive-design trial, we randomly assigned patients with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation to undergo middle meningeal artery embolization plus surgery (treatment group) or surgery alone (control group). The primary end point was hematoma recurrence or progression that led to repeat surgery within 90 days after the index treatment. The clinical secondary end point was deterioration of neurologic function at 90 days, which was assessed with the modified Rankin scale in a noninferiority analysis (margin for risk difference, 15 percentage points). A total of 197 patients were randomly assigned to the treatment group and 203 to the control group. Surgery occurred before randomization in 136 of 400 patients (34.0%). Hematoma recurrence or progression leading to repeat surgery occurred in 8 patients (4.1%) in the treatment group, as compared with 23 patients (11.3%) in the control group (relative risk, 0.36; 95% confidence interval [CI], 0.11 to 0.80; P = 0.008). Functional deterioration occurred in 11.9% of the patients in the treatment group and in 9.8% of those in the control group (risk difference, 2.1 percentage points; 95% CI, -4.8 to 8.9). Mortality at 90 days was 5.1% in the treatment group and 3.0% in the control group. By 30 days, serious adverse events related to the embolization procedure had occurred in 4 patients (2.0%) in the treatment group, including disabling stroke in 2 patients; no additional events had occurred by 180 days. Among patients with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation, middle meningeal artery embolization plus surgery was associated with a lower risk of hematoma recurrence or progression leading to reoperation than surgery alone. Further study is needed to evaluate the safety of middle meningeal artery embolization in the management of subdural hematoma. (Funded by Medtronic; EMBOLISE ClinicalTrials.gov number, NCT04402632.).

Whether the large effect size of endovascular thrombectomy (EVT) for stroke due to large-vessel occlusion applies to stroke due to medium-vessel occlusion is unclear. In a multicenter, prospective, randomized, open-label trial with blinded outcome evaluation, we assigned patients with acute ischemic stroke due to medium-vessel occlusion who presented within 12 hours from the time that they were last known to be well and who had favorable baseline noninvasive brain imaging to receive EVT plus usual care or usual care alone. The primary outcome was the modified Rankin scale score (range, 0 [no symptoms] to 6 [death]) at 90 days, reported as the percentage of patients with a score of 0 or 1. A total of 530 patients from five countries were enrolled between April 2022 and June 2024, with 255 patients assigned to the EVT group and 275 to the usual-care group. Most patients (84.7%) had primary occlusions in a middle-cerebral-artery branch. A modified Rankin scale score of 0 or 1 at 90 days occurred in 106 of 255 patients (41.6%) in the EVT group and in 118 of 274 (43.1%) in the usual-care group (adjusted rate ratio, 0.95; 95% confidence interval [CI], 0.79 to 1.15; P = 0.61). Mortality at 90 days was 13.3% in the EVT group and 8.4% in the usual-care group (adjusted hazard ratio, 1.82; 95% CI, 1.06 to 3.12). Symptomatic intracranial hemorrhage occurred in 14 of 257 patients (5.4%) in the EVT group and in 6 of 272 (2.2%) in the usual-care group. Endovascular treatment for acute ischemic stroke due to medium-vessel occlusion within 12 hours did not lead to better outcomes at 90 days than usual care. (Funded by the Canadian Institutes for Health Research and Medtronic; ESCAPE-MeVO ClinicalTrials.gov number, NCT05151172.).

Background The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US. Methods The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020. Results There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02). Conclusion We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center.

Adoption of middle meningeal artery embolization in the management of chronic subdural hematomas has led to a renewed interest in dural vascular anatomy. The readily identifiable major dural arteries and potential hazards associated with their embolization are well described. Less emphasized are several levels of intrinsic dural angioarchitecture, despite their more direct relationship to dural based diseases, such as subdural hematoma and dural fistula. Fortunately, microvascular aspects of dural anatomy, previously limited to ex vivo investigations, are becoming increasingly accessible to in vivo visualization, setting the stage for synthesis of the old and the new, and providing a rationale for the endovascular approach to subdural collections in particular. In contrast with traditional anatomical didactics, where descriptions advance from larger trunks to smaller pedicles, we present a strategic approach that proceeds from a fundamental understanding of the dural microvasculature and its relationship to larger vessels.