Wade S. Smith

We identified Intermittent Cranial Accelerometric Pulses (ICAPs) also known as “Sleep Bursts” (SBs), as a novel phenomenon of brief (1-2 sec), often periodic bursts in cranial forces occurring during human sleep. Our goal was to characterize SBs in normal subjects, then compare SB in a cohort of subjects with neurodegenerative disease (NDD). We recorded 32 cognitively healthy subjects (23-87 years) and 13 subjects with NDD (51 – 84 years). SBs occurred in all 45 subjects. SBs occurred at 0.57 SB/min (once per 105 seconds) in controls and 0.40 SB/min (once per 150 seconds) in NDD (p = 0.0043). SB occurred with equal rates across all sleep stages in both groups. When occurring periodically, SBs had modal intervals (3.75 bursts/min (0.0625 Hz) - 2.67 bursts/min (0.044 Hz)). EEG power increased in the delta range 1-2 seconds before and following the SB. EEG delta power during a SB was significantly lower in all NDD subjects across sleep stages compared to controls. The relatively low frequency of SB events and synchronization with EEG power has no parallel in human sleep; we hypothesize that SBs may represent a brain-generated pulsatile component of brain glymphatic drainage.

BACKGROUND: In patients with acute ischemic stroke, infarct growth occurs despite successful reperfusion. Oxygen extraction fraction (OEF) has shown promising results in evaluating ischemic tissue viability and can now be quantified from routinely performed dynamic susceptibility contrast perfusion. We aimed to determine the association of OEF alterations within the ischemic tissue on pretreatment magnetic resonance imaging and infarct growth in patients who underwent successful reperfusion. METHODS: In this retrospective cohort study from the University of California, Los Angeles, between 2015 and 2020, patients were included if they had anterior circulation large vessel occlusion, achieved successful reperfusion (Thrombolysis in Cerebral Infarction ≥2b), had pretreatment dynamic susceptibility contrast perfusion and posttreatment magnetic resonance imaging within 48 hours from reperfusion. Dynamic susceptibility contrast-derived OEF values were quantified from the segmented ischemic core (apparent diffusion coefficient ≤620×10 ⁻⁶ mm ² /s) and penumbra tissue (time-to-maximum [Tmax] >6 s) on pretreatment magnetic resonance imaging and normalized to contralateral hemisphere (relative oxygen extraction fraction [OEF _r ]). Primary outcome was substantial infarct growth ≥10 mL, and secondary outcomes were continuous measures of infarct growth volume and penumbra-to-infarct conversion ratio. The associations between baseline clinical and imaging variables, including OEF _r and outcome measures, were tested by multivariate and regression analysis. RESULTS: Among 89 patients who met inclusion criteria, 33 (37%) patients had infarct growth ≥10 mL. Patients with infarct growth had significantly ( P r values compared with those without infarct growth. There was significant association between penumbra OEF _r and infarct growth (β=−2.9 [95% CI, −5.0 to −0.8]; P =0.007) and similarly for penumbra-to-infarct conversion ratio (β=−10.4 [95% CI, −19.6 to −1.2]; P =0.028). CONCLUSIONS: Our results showed penumbra-OEF _r is a promising imaging biomarker for predicting infarct growth in acute ischemic stroke following successful reperfusion. Although elevation of penumbra-OEF _r is protective, patients with lower penumbra-OEF _r values sustained further ischemic injury and infarct growth.

BACKGROUND AND IMPORTANCE: Acute intracerebral hematomas are known to induce significant mass effects within the brain, leading to critical complications such as cerebral midline shift, herniation, and increased intracranial pressure. The timing and efficacy of intracerebral hematoma evacuation remain subjects of ongoing debate in current literature. CLINICAL PRESENTATION: In our case report, we present a 74-year-old female patient diagnosed with basal ganglia hematoma. The resultant mass effect from the intracerebral hematoma led to middle cerebral artery (MCA) stenosis. Notably, early-stage minimally invasive hematoma evacuation was pivotal in facilitating successful revascularization of the MCA. CONCLUSION: Our case underscores the significance of prompt identification and management of MCA stenosis arising from intracerebral hematoma. Early intervention through minimally invasive hematoma evacuation proved instrumental in achieving successful MCA revascularization. These findings emphasize the critical role of timely interventions in mitigating potential complications associated with intracerebral hematoma.

BACKGROUND AND PURPOSE: Nearly 20% of patients with spontaneous SAH have no definitive source on initial DSA. The purpose of this study was to investigate the timing and yield of repeat DSA, to clarify the influence of initial CT bleed pattern, and to characterize sources of diagnostic error in this scenario. MATERIALS AND METHODS: We evaluated the yield of repeat DSA and clinical outcomes stratified by hemorrhage pattern on CT in consecutive patients with nontraumatic SAH with negative initial DSA findings at a referral center. Cases in which the culprit lesion was subsequently diagnosed were classified as physiologically occult (ie, undetectable) on the initial DSA, despite adequate technique and interpretation or misdiagnosed due to operator-dependent error. RESULTS: Two hundred forty-two of 1163 (20.8%) patients with spontaneous SAH had negative initial DSA findings between 2009 and 2018. The SAH CT pattern was nonperimesencephalic (41%), perimesencephalic (36%), sulcal (18%), and CT-negative (5%). Repeat DSA in 135/242 patients (55.8%) revealed a source in 10 patients (7.4%): 4 saccular aneurysms, 4 atypical aneurysms, and 2 arteriovenous shunts. The overall yield of repeat DSA was 11.3% with nonperimesencephalic and 2.2% for perimesencephalic patterns. The yield of the second and third DSAs with a nonperimesencephalic pattern was 7.7% and 12%, respectively. Physiologically occult lesions accounted for 6/242 (2.5%) and operator-dependent errors accounted for 7/242 (2.9%) of all angiographically occult lesions on the first DSA. CONCLUSIONS: Atypical aneurysms and small arteriovenous shunts are important causes of SAH negative on angiography. Improving DSAs technique can modestly reduce the need for repeat DSA; however, a small fraction of SAH sources remain occult despite adequate technique. These findings support the practice of repeating DSA in patients with a nonperimesencephalic SAH pattern.

Purpose of Review: Endovascular therapy for acute ischemic stroke secondary to large vessel occlusion (LVO) is time-dependent. Prehospital patients with suspected LVO stroke should be triaged directly to specialized stroke centers for endovascular therapy. This review describes advances in LVO detection among prehospital suspected stroke patients. Recent Findings: Clinical prehospital stroke severity tools have been validated in the prehospital setting. Devices including EEG, SSEPs, TCD, cranial accelerometry, and volumetric impedance phase-shift-spectroscopy have recently published data regarding LVO detection in hospital settings. Mobile stroke units bring thrombolysis and vessel imaging to patients. Summary: The use of a prehospital stroke severity tool for LVO triage is now widely supported. Ease of use should be prioritized as there are no meaningful differences in diagnostic performance amongst tools. LVO diagnostic devices are promising, but none have been validated in the prehospital setting. Mobile stroke units improve patient outcomes and cost-effectiveness analyses are underway.

Neurologists, neurointensivists, neurosurgeons, and intensivists worldwide at times are required to determine brain death/death by neurological criteria (BD/DNC

Cranial accelerometry is used to detect cerebral vasospasm and concussion. We explored this technique in a cohort of code stroke patients to see whether a signature could be identified to aid in the diagnosis of large vessel occlusion (LVO) stroke.

Background and Purpose—: The impact of transfer status on clinical outcomes in the DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) population is unknown. We analyzed workflow and clinical outcome differences between direct versus transfer patients in the DAWN population. Methods—: The following time metrics were analyzed for each group: (1) last known well to hospital arrival, (2) hospital arrival to eligibility imaging, (3) hospital arrival to arterial puncture, (4) qualifying imaging to arterial puncture, (5) last known well to arterial puncture, (6) last known well to reperfusion. The primary end point was the rate of functional independence (90-day modified Rankin Scale [mRS] score, 0–2). Using univariate unconditional logistic regression, we calculated odds ratios and 95% CIs for the association between clinically relevant time metrics, transfer status, and functional independence (mRS 0–2). Results—: A total of 206 patients were enrolled. Among these, 121 (59%) patients were transferred, and 85 (41%) patients presented directly to a thrombectomy capable center. Median time last seen well to hospital arrival time was similar between the 2 groups (678 versus 696 minutes). The time from hospital arrival to groin puncture was significantly longer in direct patients compared with transferred patients 140 minutes (interquartile range, 105.5–177.5 minutes) and 88 minutes (interquartile range, 55–125 minutes), respectively ( P P =0.817). Conclusions—: Although transfer patients had a faster door to puncture time, benefits of thrombectomy, and rates of mRS 0 to 2 in the treatment group were similar between direct and transferred patients in the DAWN population. These results may inform prehospital and primary stroke centers triage protocols in patients presenting in the late time window. Clinical Trial Registration—: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02142283.