Comparative neuroanatomy of the lumbosacral spinal cord of the rat, cat, pig, monkey, and human.

The overall goal of this work was to create a high-resolution MRI atlas of the lumbosacral enlargement of the spinal cord of the rat (Sprague-Dawley), cat, domestic pig, rhesus monkey, and human. These species were chosen because they are commonly used in basic and translational research in spinal cord injuries and diseases. Six spinal cord specimens from each of the studied species (total of 30 specimens) were fixed, extracted, and imaged. Sizes of the spinal cord segments, cross-sectional dimensions, and locations of the spinal cord gray and white matter were quantified and compared across species. The lumbar enlargement spans spinal cord levels L3-S1 in rats, L4-S1 in cats, L3-S1 in pigs, L2/L3-L7/S1 in monkeys, and T12/L1-S1/S2 in humans. The enlargements in pigs and humans are largest and most similar in size (length and cross-sectional area); followed by monkeys and cats; and followed by rats. The obtained atlas establishes a neuroanatomical reference for the intact lumbosacral spinal cord in these species. It can also be used to guide the planning of surgical procedures of the spinal cord and technology design and development of spinal cord neuroprostheses, as well as precise delivery of cells/drugs into target regions within the spinal cord parenchyma.

Assessment of Frailty in Predicting Surgical Outcomes in Patients with Chronic Subdural Hematomas: Retrospective Chart Review.

BACKGROUND: The aim of this study is to determine if frailty, defined as modified frailty index (MFI) >2.7, correlated with worse postoperative outcomes in patients with chronic subdural hematomas (CSDHs). We also compare the predictive ability of the MFI with another widely used frailty measure, the Clinical Frailty Scale (CFS). METHODS: We conducted a retrospective chart review of elderly patients (≥65 years) who underwent a twist-drill craniostomy for the evacuation of CSDH at Hamilton General Hospital, Canada, between 2016 and 2018. The primary outcome was the modified Rankin Scale scores at discharge. Logistic regression analyses and receiver operating characteristic curves were carried out to further analyze the factors that influenced independence and functional improvement at discharge. RESULTS: Frail patients were significantly more dependent at discharge (P < 0.0001) and had a lower rate of functional improvement (P = 0.003). When compared with frailty measured by the MFI, frailty as measured by the CFS had a stronger association with functional independence (odds ratio [OR]: 0.081 [0.031, 0.211] vs. OR: 0.256 [0.124, 0.529]) and functional improvement (OR: 0.272 [0.106, 0.693] vs. OR: 0.406 [0.185,0.889]) on logistic regression analyses. Area under the receiver operating characteristic curve analyses showed that the inclusion of frailty into our predictive models improved accuracy. CONCLUSIONS: Elderly patients presenting with CSDH who are frail (MFI >0.27) have significantly worse functional outcomes following twist-drill craniostomies. Therefore assessing frailty in this population is important before managing these patients, and for this purpose the CFS is a superior predictor of postoperative function than the MFI.