Brown, Robert D.

AbstractForensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri‐ and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty‐seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three‐point bending setup and recorded with a high‐speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri‐ versus postmortem fractures.

AbstractBackground and PurposeDuring the coronavirus disease 2019 (COVID‐19) pandemic many countries reported a decline in stroke volumes. The aim of this study was to analyze if the decline was related to the intensity of the COVID‐19 pandemic.MethodsThe first pandemic year (1 March 2020 to 28 February 2021) overall and during the three COVID‐19 waves were compared with the preceding year. Volumes of acute ischaemic stroke (AIS), subarachnoid hemorrhage, intracerebral hemorrhage and recanalization treatments (intravenous thrombolysis [IVT] and mechanical thrombectomy [MT]) were obtained from the National Register of Reimbursed Health Services. Door‐to‐needle time, onset‐to‐door time and National Institutes of Health Stroke Scale at admission were obtained from the Registry of Stroke Care Quality.ResultsDuring the pandemic year compared to the preceding year there were 26,453 versus 28,771 stroke admissions, representing an 8.8% decline (p < 0.001). The declines (−10%, −11%, −19%) appeared in COVID‐19 waves (spring 2020, autumn 2020, winter 2021) except for an increase (2%) during summer 2020. Admissions for AIS declined by 10.2% (p < 0.001), whilst hemorrhagic stroke volumes were minimally decreased. The absolute volumes of IVT and MT decreased by 9.4% (p < 0.001) and 5.7% (p = 0.16), respectively. However, the proportions of ischaemic stroke patients receiving IVT (18% vs. 18%; p = 0.72) and MT (6% vs. 6%; p = 0.28) remained unchanged.ConclusionsThere was a decline in stroke admissions, but such decline was not related to COVID‐19 incidence. The frequency of use of recanalization procedures (IVT, MT) and times (onset‐to‐door time, door‐to‐needle time) in AIS were preserved in the Czech Republic during the first year of the pandemic.

Objective: To determine the frequency and characteristics of symptomatic intracerebral hemorrhage in a population-based study Patients and Methods: The population-based Mayo Clinic Study of Aging included 4,994 participants age ≥50 years entered from 11/29/2004 to 3/11/2017. Participants with intracranial hemorrhage were identified using the Rochester Epidemiology Project medical records linkage system. Medical records of these individuals were reviewed. Each hemorrhage was classified as deep, lobar, or cerebellar intracerebral hemorrhage (ICH) or convexity subarachnoid hemorrhage (cSAH). Traumatic, subdural, non-convexal SAH, and epidural hemorrhages were excluded. Patient demographics, presence of hypertension, antithrombotic regimen, APOE genotype, and amyloid PET scan results were collected when available. Individuals with hemorrhages were matched 3:1 on age and gender to controls without symptomatic hemorrhage. Analyses within the cases and between the groups were performed. Results: Symptomatic hemorrhages were identified in 57 individuals for a frequency of 1.14%. Twenty-one were classified as deep, 26 lobar, 5 cerebellar, and 5 cSAH. Mean age at the time of hemorrhage was 80.9 years (SD ±7.9). 54.4% of hemorrhages occurred in men. Hypertension was present in 45.6%. Of those with lobar ICH or cSAH, 87.1% were on an antithrombotic compared to 65.6% of controls (p=0.02) and 32.3% of these were on warfarin compared to 12.9% of controls (p=0.01). APOE genotype was available in 54 of the 57. APOE e2 and/or e4 was found in 46.7% of those with lobar ICH/cSAH compared to 39.1% of controls (p=0.47) and 35.0% of those with deep ICH versus 39.3% of controls (p=0.73). Of the 31 with either lobar ICH or cSAH, 7 underwent amyloid PET scans; of these, 71.4% were abnormal compared to 42.9% of controls with mean SUVR of 1.911 and 1.565, respectively (p=0.08). Conclusions: Symptomatic ICH occurred in approximately 1 in 100 individuals age 50-94 years in this population-based study. In a matched case-control study, antithrombotic use (particularly warfarin) was statistically associated with the development of an ICH. While only a subset underwent amyloid PET, there was a trend towards greater amyloid load in those who developed a lobar or cSAH compared to controls.

Background and Purpose— Transient ischemic attacks are a frequent diagnosis in the emergency department setting, yet expert opinion as to the proper follow-up and need for hospitalization differs widely. Recently, an effort has been made to risk-stratify patients presenting with transient ischemic attacks through scoring systems such as the ABCD and ABCD2 scales. The aim of our study was to independently validate these scores using a population-based cohort. Methods— Using the data from the Rochester Stroke and Transient Ischemic Attack Registry and resources of the Rochester Epidemiology Project, medical records of all residents of Rochester, Minn, with a diagnosis of incident transient ischemic attack from 1985 through 1994 were examined (N=284). Patients were scored on the ABCD and ABCD2 scales and new scores were created by adding hyperglycemia and a history of hypertension. The end points of stroke and death were collected previously and were verified through the Rochester Epidemiology Project data. Results— Although our study did find that scores >4 had a statistically significant predictive value for future stroke, a substantial proportion of strokes within 7 days (9 of 36 cases [25%]) occurred in patients with low or intermediate risk scores (≤4) on the ABCD2 scale. Including history of hypertension and hyperglycemia on presentation increased the sensitivity of the score to identify patients who had a stroke within 7 days. Conclusions— Reliance on the ABCD and ABCD2 scores misses some patients who will have a stroke within 7 days of a transient ischemic attack. Adding hyperglycemia and a history of hypertension to the predictive model could be useful, but the value of these additions need to be evaluated further.

ABSTRACT OBJECTIVE Remote cerebellar hemorrhage (RCH) is an infrequent and poorly understood complication of supratentorial neurosurgical procedures. We retrospectively compared 42 patients who experienced RCH with a case-matched control cohort, to delineate risk factors associated with the occurrence of this complication. METHODS Between 1988 and 2000, 42 patients experienced RCH after supratentorial neurosurgical procedures at our institution. Diagnoses were made on the basis of postoperative computed tomographic or magnetic resonance imaging findings in all cases. The medical records for these patients were reviewed and compared with those for a control cohort of 43 patients, matched for age, sex, surgical lesion, and type of craniotomy, who were treated during the same period. RESULTS RCH most commonly occurred after frontotemporal craniotomies for unruptured aneurysm repair or temporal lobectomy and was frequently an incidental finding on postoperative computed tomographic scans. However, some cases of RCH were associated with significant morbidity, and two patients died. Preoperative aspirin use and elevated intraoperative systolic blood pressure were significantly associated with RCH (P = 0.026 and P = 0.036, respectively). Pathological findings for two cases demonstrated hemorrhagic infarctions in both. CONCLUSION RCH most commonly follows supratentorial neurosurgical procedures, performed with the patient in the supine position, that involve opening of cerebrospinal fluid cisterns or the ventricular system (such as unruptured aneurysm repair or temporal lobectomy). Preoperative aspirin use and moderately elevated intraoperative systolic blood pressure are potentially modifiable risk factors associated with the development of RCH. Although RCH can cause death or major morbidity, most cases are asymptomatic or exhibit a benign course. Cerebellar “sag” as a result of cerebrospinal fluid hypovolemia, causing transient occlusion of superior bridging veins within the posterior fossa and consequent hemorrhagic venous infarction, is the most likely pathophysiological cause of RCH.