Risk assessment of early therapeutic anticoagulation following cranial surgery: an institutional case series.

OBJECTIVE: Postoperative thrombotic complications represent a unique challenge in cranial neurosurgery as primary treatment involves therapeutic anticoagulation. The decision to initiate therapy and its timing is nuanced, as surgeons must balance the risk of catastrophic intracranial hemorrhage (ICH). With limited existing evidence to guide management, current practice patterns are subjective and inconsistent. The authors assessed their experience with early therapeutic anticoagulation (≤ 7 days postoperatively) initiation for thrombotic complications in neurosurgical patients undergoing cranial surgery to better understand the risks of catastrophic ICH. METHODS: Adult patients treated with early therapeutic anticoagulation following cranial surgery were considered. Anticoagulation indications were restricted to thrombotic or thromboembolic complications. Records were retrospectively reviewed for demographics, surgical details, and anticoagulation therapy start. The primary outcome was the incidence of catastrophic ICH, defined as ICH resulting in reoperation or death within 30 days of anticoagulation initiation. As a secondary outcome, post-anticoagulation cranial imaging was reviewed for new or worsening acute blood products. Fisher's exact and Wilcoxon rank-sum tests were used to compare cohorts. Cumulative outcome analyses were performed for primary and secondary outcomes according to anticoagulation start time. RESULTS: Seventy-one patients satisfied the inclusion criteria. Anticoagulation commenced on mean postoperative day (POD) 4.3 (SD 2.2). Catastrophic ICH was observed in 7 patients (9.9%) and was associated with earlier anticoagulation initiation (p = 0.02). Of patients with catastrophic ICH, 6 (85.7%) had intra-axial exploration during their index surgery. Patients with intra-axial exploration were more likely to experience a catastrophic ICH postoperatively compared to those with extra-axial exploration alone (OR 8.5, p = 0.04). Of the 58 patients with postoperative imaging, 15 (25.9%) experienced new or worsening blood products. Catastrophic ICH was 9 times more likely with anticoagulation initiation within 48 hours of surgery (OR 8.9, p = 0.01). The cumulative catastrophic ICH risk decreased with delay in initiation of anticoagulation, from 21.1% on POD 2 to 9.9% on POD 7. Concurrent antiplatelet medication was not associated with either outcome measure. CONCLUSIONS: The incidence of catastrophic ICH was significantly increased when anticoagulation was initiated within 48 hours of cranial surgery. Patients undergoing intra-axial exploration during their index surgery were at higher risk of a catastrophic ICH.

Clinical Outcomes After Nonoperative Management of Large Acute Traumatic Subdural Hematomas in Older Patients: A Propensity-Scored Retrospective Analysis.

BACKGROUND: Large (≥1 cm) acute traumatic subdural hematomas (aSDHs) are neurosurgical emergencies. Elderly patients with asymptomatic large aSDHs may benefit from conservative management. OBJECTIVE: To investigate inpatient mortality after conservative management of large aSDHs. METHODS: Single-center retrospective review of adult patients with traumatic brain injury from 2018 to 2021 revealed 45 large aSDHs that met inclusion criteria. Inpatient outcomes included mortality, length of stay, and discharge disposition. Follow-up data included rate of surgery for chronic SDH progression. Patients with large aSDHs were 2:1 propensity score-matched to patients with small (<1 cm) aSDHs based on age, Injury Severity Scale, Glasgow Coma Scale, and Rotterdam computed tomography scale. RESULTS: Median age (78 years), sex (male 52%), and race (Caucasian 91%) were similar between both groups. Inpatient outcomes including length of stay ( P = .32), mortality ( P = .37), and discharge home ( P = .28) were similar between those with small and large aSDHs. On multivariate logistic regression (odds ratio [95% CI]), increased in-hospital mortality was predicted by Injury Severity Scale (1.3 [1.0-1.6]), Rotterdam computed tomography scale 3 to 4 (99.5 [2.1-4754.0), parafalcine (28.3 [1.7-461.7]), tentorial location (196.7 [2.9-13 325.6]), or presence of an intracranial contusion (52.8 [4.0-690.1]). Patients with large aSDHs trended toward higher progression on follow-up computed tomography of the head (36% vs 16%; P = .225) and higher rates of chronic SDH surgery (25% vs 7%; P = .110). CONCLUSION: In conservatively managed patients with minimal symptoms and mass effect on computed tomography of the head, increasing SDH size did not contribute to worsened in-hospital mortality or length of stay. Patients with large aSDHs may undergo an initial course of nonoperative management if symptoms and the degree of mass effect are mild.

Diagnostic accuracy of somatosensory evoked potentials during intracranial aneurysm clipping for perioperative stroke.

Somatosensory evoked potentials (SSEPs) are utilized during aneurysm clipping to detect intraoperative ischemia. We assess the diagnostic accuracy of SSEPs in predicting perioperative stroke during aneurysm clipping. A retrospective review was conducted of 429 consecutive patients who underwent surgical clipping for ruptured and unruptured cerebral aneurysms with intraoperative SSEP monitoring from 2006 to 2013. The relationship between perioperative stroke and SSEP changes was analyzed by calculating the sensitivity, specificity, and area under a Receiving Operating Characteristic curve. Sensitivity and specificity were 42% and 90%, respectively. Area under the curve was 0.66 (95% confidence interval, 0.53-0.79). Reclassification of reversible temporary clip changes to correct for paradoxical classification of SSEP false positives raised the sensitivity from 42 to 65% (p = 0.041, Chi squared test). EEG (electroencephalography) changes increased the specificity (98% vs. 90%, p < 0.001, McNemar's test), but not sensitivity (48% vs. 42%, p = 0.621, McNemar's test) of SSEPs for perioperative stroke. A stepwise logistic regression model selected SSEP amplitude loss (p = 0.006, OR = 3.7 [95% CI 1.5-9.2]) and the SSEP change duration (p = 0.034, OR = 1.8 [95% CI 1.1-3.1]) as independent predictors of perioperative stroke. SSEP changes induced by temporary clipping were highly reversible compared to other SSEP changes (94% vs. 60%, p = 0.003, Fisher exact test), and typically responded to clip removal or readjustment. SSEP changes have high specificity and modest sensitivity for perioperative stroke. Stroke risk is a function of both the magnitude of SSEP amplitude loss and the duration of its loss. Given the modest sensitivity, patients may benefit from multimodal monitoring including motor-evoked potentials during cerebral aneurysm surgery.

Recording single- and multi-unit neuronal action potentials from the surface of the dorsal root ganglion.

The dorsal root ganglia (DRG) contain cell bodies of primary afferent neurons, which are frequently studied by recording extracellularly with penetrating microelectrodes inserted into the DRG. We aimed to isolate single- and multi-unit activity from primary afferents in the lumbar DRG using non-penetrating electrode arrays and to characterize the relationship of that activity with limb position and movement. The left sixth and seventh lumbar DRG (L6-L7) were instrumented with penetrating and non-penetrating electrode arrays to record neural activity during passive hindlimb movement in 7 anesthetized cats. We found that the non-penetrating arrays could record both multi-unit and well-isolated single-unit activity from the surface of the DRG, although with smaller signal to noise ratios (SNRs) compared to penetrating electrodes. Across all recorded units, the median SNR was 1.1 for non-penetrating electrodes and 1.6 for penetrating electrodes. Although the non-penetrating arrays were not anchored to the DRG or surrounding tissues, the spike amplitudes did not change (<1% change from baseline spike amplitude) when the limb was moved passively over a limited range of motion (~20 degrees at the hip). Units of various sensory fiber types were recorded, with 20% of units identified as primary muscle spindles, 37% as secondary muscle spindles, and 24% as cutaneous afferents. Our study suggests that non-penetrating electrode arrays can record modulated single- and multi-unit neural activity of various sensory fiber types from the DRG surface.

Risk Factors for In-Hospital Seizures and New-Onset Epilepsy in Coil Embolization of Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVE: This study aimed to determine risk factors for inpatient seizures and long-term epilepsy in patients receiving coil embolization for aneurysm-associated subarachnoid hemorrhage. METHODS: A retrospective chart review was conducted for patients admitted to the University of Pittsburgh Medical Center from 2010 to 2014 for subarachnoid hemorrhage. Only patients with coil embolization were included. Variables such as subdural hematoma, cerebral infarction, postoperative vasospasm, cerebral edema, and mass effect were collected. After discharge, patients were followed up to determine whether epilepsy had developed. The χ2 test was used to assess univariate associations. Multivariable associations were assessed with a binary logistic regression model. RESULTS: The study included 175 patients, of whom 16 (9.1%) of the patients had seizures while they were inpatients. Five out of 73 patients met the criteria for epilepsy at follow-up. None of the patients with epilepsy after discharge had electrographic seizures while hospitalized. Vasospasm (odds ratio [OR] 6.88, 95% confidence interval [CI] 1.81-26.25), and Hunt and Hess grade 5 (OR 26.16, 95% CI 3.95-173.49) were significantly associated with in-hospital seizures in a multivariable analysis. Epileptiform discharges on electroencephalogram (EEG) were significantly associated with mass effect findings on brain imaging (OR 3.5, CI 1.05-11.69). CONCLUSION: Hunt and Hess grade 5 and vasospasm are independent risk factors for in-hospital seizures. In addition, mass effect is an independent risk factor for epileptiform discharges on EEG. Patients with these risk factors may benefit from continuous EEG. Our results may indicate that there is no association between electrographic seizures and development of epilepsy.

Perioperative stroke after cerebral aneurysm clipping: Risk factors and postoperative impact.

Stroke is a devastating complication after intracranial aneurysm clipping. Understanding the risk factors that prognosticate perioperative stroke may help to identify patients that would benefit from neuroprotective therapy. This study assesses patient-specific independent predictors of perioperative stroke in relation to surgical aneurysm clipping. Additionally, this study evaluates the postoperative complications of stroke. We performed a retrospective chart review of 437 patients with ruptured and unruptured intracranial aneurysms, which underwent surgical clipping from 2006 to 2013. Multivariate logistical regression was utilized to assess the effect of age, race, gender, subarachnoid hemorrhage, Hunt and Hess (H/H) grade, aneurysm location, and intraoperative somatosensory evoked potentials (SSEPs) changes on the frequency of perioperative stroke. Thirty-five (8.0%) patients developed a stroke within 24h postoperatively. Patients with significant intraoperative SSEP changes were 7.33 (95% confidence interval [CI]: 3.51-15.31) times more likely to develop perioperative strokes. In patients who presented with H/H grade 5, the odds ratio for developing perioperative stroke was 9.21 (95% CI: 1.28-66.13) respectively. In the absence of aneurysm rupture, patients presenting with new-onset stroke were more likely to suffer postoperative complications, stay in the intensive care unit longer, and be discharged to in-patient rehabilitation compared to patients without new-onset stroke. This study suggests that severity of subarachnoid hemorrhage based on the patient's clinical condition increases the risk of perioperative stroke in patients with surgical aneurysm clipping. SSEP changes and high-grade H/H scores can serve as independent predictors of perioperative stroke, with the latter having the greatest predictive value.

Somatosensory Evoked Potentials During Temporary Arterial Occlusion for Intracranial Aneurysm Surgery: Predictive Value for Perioperative Stroke.

BACKGROUND: Temporary arterial occlusion (TAO) is valuable for minimizing intraoperative rupture risk during intracranial aneurysm microsurgery; however, it may be associated with ischemic injury. This study aims to identify surgical and intraoperative neurophysiologic monitoring factors that predict perioperative stroke risk after TAO. METHODS: We performed a retrospective chart review of 177 intracranial aneurysm surgeries at our institution in which TAO was performed before placement of a permanent clip under monitoring with somatosensory evoked potentials (SSEPs) and electroencephalography. Perioperative stroke was defined as a new-onset neurologic deficit that developed within 24 hours postoperatively that was correlated with hypodensity on postoperative computed tomography. RESULTS: Ten (6%) patients developed perioperative stroke in the vascular territory of TAO. SSEP changes were observed in 50% (5/10) of patients with perioperative stroke and in 14% (24/167) of patients without stroke (P = 0.003). Mean maximum single-episode TAO duration for patients who developed perioperative stroke was 12.6 minutes (95% confidence interval 8.1-17.1) and TAO duration for patients without stroke was 8.0 minutes (95% confidence interval 7.3-8.7; P = 0.026). In patients with SSEP changes, risk of stroke was particularly elevated with unruptured aneurysms (P = 0.013) compared with patients with ruptured aneurysms. Temporary clip location, number of occlusive episodes, onset and duration of intraoperative neurophysiologic monitoring changes, and rupture status were not predictive of perioperative stroke. CONCLUSIONS: SSEP changes and increased single-episode TAO duration are independently associated with increased perioperative stroke risk. SSEP changes are most predictive for perioperative stroke in unruptured cases.

Cerebral venous sinus thrombosis in pregnancy and puerperium: A pooled, systematic review.

Pregnancy and puerperium are risk factors for cerebral venous sinus thrombosis (CVST); however studies describing diagnosis and management in this population are limited. The objective of this study was to amalgamate published case reports and series regarding diagnosis and management of CVST in pregnancy and puerperium. Searches of PubMed and the Cochrane library were performed using search terms "pregnancy"/"puerperium" and "sinus occlusion"/"sinus thrombosis". Studies were included in our pooled analysis if they included individual patient symptoms, management approach and follow-up condition. Multivariate regression was utilized to assess the effect of non-modifiable factors on excellent outcome (mRS 0). Sixty-six patients were included. Mean duration of symptom onset to diagnosis was 5.9days (95% CI 4.2-7.6). Clot involvement of the superior sagittal sinus was seen in 67% of cases, the transverse/sigmoid in 64% and of the deep venous system in 15% of cases. Management approaches included anticoagulation (91% of patients), IA (intra-arterial) thrombolysis alone (26%), and IA thrombectomy with IA thrombolysis (8%). Fifty-nine percent of patients were mRS 0 at follow-up; 94% were mRS 0-2. Presentation with headache alone was associated with excellent outcome on multivariate analysis (p=0.04); coma/obtundation predicted against excellent outcome (p=0.03). As compared to IA thrombolysis alone, patients undergoing IA thrombolysis with IA thrombectomy demonstrated a trend toward better outcome (p=0.10).

Ventral Spontaneous Durotomy Following Vaginal Delivery.

BACKGROUND: Dural breaches have a diverse etiology, including spontaneous rupture and trauma. Most cases resolve with bed rest; in refractory cases, an epidural blood patch can be placed to obstruct further leakage. We discuss a unique case of a spontaneous ventral durotomy following vaginal delivery that was managed with injections of autologous blood through bilateral transforaminal needles. CASE DESCRIPTION: A previously healthy, 36-year-old pregnant woman presented to the inpatient maternity ward with positional occipital headaches and neck pain 24 hours after normal spontaneous vaginal delivery. Two dorsally placed epidural blood patches provided only transient relief. Computed tomography myelography revealed ventral cerebrospinal fluid leak. Targeted therapy was provided with computed tomography-guided ventral placement of a blood patch. CONCLUSIONS: Spontaneous durotomy is a rare phenomenon and should be considered in patients who present with positional headaches. Ventrally targeted therapy via an epidural blood patch should be considered to provide optimal relief.

Accessibility, reliability, and usability of neurosurgical resources.

OBJECTIVE Closing the knowledge gap that exists between patients and health care providers is essential and is facilitated by easy access to patient education materials. Although such information has the potential to be an effective resource, it must be written in a user-friendly and understandable manner, especially when such material pertains to specialized and highly technical fields such as neurological surgery. The authors evaluated the accessibility, usability, and reliability of current educational resources provided by the American Association of Neurological Surgeons (AANS), Healthwise, and the National Institute for Neurological Disorders and Stroke (NINDS). METHODS Online neurosurgical patient education information provided by AANS, Healthwise, and NINDS was evaluated using the LIDA scale, a website quality assessment tool, by medical professionals and nonmedical professionals. A high achieving score is regarded as 90% or greater using the LIDA scale. RESULTS Accessibility scores were 76.7% (AANS), 83.3% (Healthwise), and 75.0% (NINDS). Average usability scores for the AANS, Healthwise, and NINDS were 73.3%, 82.6%, and 82.9%, respectively, when evaluated by medical professionals and 78.5%, 80.7%, and 75.9%, respectively, for nonmedical professionals, respectively. Average reliability scores were 58.5%, 53.3%, 72.6%, respectively, for medical professionals and 70.4%, 66.7%, and 78.5%, respectively, for nonmedical professionals when evaluating the AANS, Healthwise, and NINDS websites. CONCLUSIONS Although organizations like AANS, Healthwise, and NINDS should be commended for their ongoing commitment to provide health care-oriented materials, modification of this material is suggested to improve the patient education value.