Ryan A. Grant

Seizure control for intracranial arteriovenous malformations is directly related to treatment modality: a meta-analysis

Object Seizures are a common presenting sign of intracranial arteriovenous malformations (AVMs). The object of this meta-analysis was to determine if the modality selected to treat AVMs affects the rate of seizure outcomes. Methods All published data describing seizure status as an outcome goal over the past 20 years were included in this study. Seizure outcomes following microsurgery (MS), endovascular embolization for cure (EVE), or stereotactic radiosurgery (SRS) were compared using a validated random effect logistic regression approach. Results 24 studies, with a total of 1157 patients, were analyzed. Overall, the microsurgical group had the best seizure control (p<0.01), with the relative predicted rates of seizure outcome as follows: MS 78.3% (95% CI 70.1% to 85.8%); SRS 62.8% (95% CI 55.0% to 70.0%); and EVE 49.3% (95% CI 32.1% to 66.6%). Patients in the SRS group who had complete obliteration of their AVMs achieved the highest rate of seizure control (85.2% (95% CI 79.1% to 91.2%); p<0.01). The development of new onset seizures occurred more frequently in patients undergoing EVE (39.4% (95% CI 8.1% to 67.8%)) compared with MS (9.1% (95% CI 5.0% to 13.1%)) and SRS (5.4% (95% CI 3.0% to 7.8%)) (p<0.3 and p<0.01, respectively). Conclusions This is the first meta-analysis designed to study relative rates of seizure outcomes following the currently utilized AVM treatment modalities. In general, MS results in the highest proportion of seizure control. However, if SRS results in successful obliteration of the AVM, then this modality is the most effective in achieving seizure control.

Patient factors associated with 30-day morbidity, mortality, and length of stay after surgery for subdural hematoma: a study of the American College of Surgeons National Surgical Quality Improvement Program

OBJECTIVE Surgery for subdural hematoma (SDH) is a commonly performed neurosurgical procedure. This study identifies patient characteristics associated with adverse outcomes and prolonged length of stay (LOS) in patients who underwent surgical treatment for SDH. METHODS All patients in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) who were treated via craniotomy or craniectomy for SDH between 2005 and 2012 were identified. Patient demographics, comorbidities, and 30-day outcomes were described. Multivariate regression was used to identify predictors of adverse events. RESULTS A total of 746 surgical procedures performed for SDH were identified and analyzed. Patients undergoing this procedure were 64% male with an average age (± SD) of 70.9 ± 14.1 years. The most common individual adverse events were death (17%) and intubation for more than 48 hours (19%). In total, 34% experienced a serious adverse event other than death, 8% of patients returned to the operating room (OR), and the average hospital LOS was 9.8 ± 9.9 days. In multivariate analysis, reduced mortality was associated with age less than 60 years (relative risk [RR] = 0.47, p = 0.017). Increased mortality was associated with gangrene (RR = 3.5, p = 0.044), ascites (RR = 3.00, p = 0.006), American Society of Anesthesiologists (ASA) Class 4 or higher (RR = 2.34, p = 0.002), coma (RR = 2.25, p < 0.001), and bleeding disorders (RR = 1.87, p = 0.003). Return to the OR was associated with pneumonia (RR = 3.86, p = 0.044), male sex (RR = 1.85, p = 0.015), and delirium (RR = 1.75, p = 0.016). Serious adverse events were associated with ventilator dependence preoperatively (RR = 1.86, p < 0.001), dialysis (RR = 1.44, p = 0.028), delirium (RR = 1.40, p = 0.005), ASA Class 4 or higher (RR = 1.36, p = 0.035), and male sex (RR = 1.29, p = 0.037). Similarly, LOS was increased in ventilator dependent patients by 1.56-fold (p = 0.002), in patients with ASA Class 4 or higher by 1.30-fold (p = 0.006), and in delirious patients by 1.29-fold (p = 0.008). CONCLUSIONS Adverse outcomes are common after surgery for SDH. In this study, 18% of the patients died within 30 days of surgery. Factors associated with adverse outcomes were identified. Patients and families should be counseled about the serious risks of morbidity and death associated with acute traumatic SDH requiring surgery.

Efficacy and Safety of Higher Dose Stereotactic Radiosurgery for Functional Pituitary Adenomas: A Preliminary Report

OBJECTIVE Single fraction stereotactic radiosurgery (SRS) is a common adjuvant therapy for hormonally active pituitary adenomas when surgical resection fails to control tumor growth or normalize hypersecretory activity. Marginal doses of 20-24 Gy are used at many centers and here we report our outcome data in patients treated with a higher marginal dose of 35 Gy. METHODS Thirty-one patients with secretory pituitary adenomas (adrenocorticotropic hormone, n = 15; growth hormone, n = 13; prolactin, n = 2; thyroid-stimulating hormone, n = 1) were treated with 35 Gy to the 50% isodose line, and had a mean follow-up time of 40.2 months (range = 12-96). All patients were evaluated post-SRS for time to hormonal normalization, time to relapse, as well as incidence and time course of radiation-induced hypopituitarism and cranial neuropathies. RESULTS Initial normalization of hypersecretion was achieved in 22 patients (70%) with a median time to remission of 17.7 months. After initial hormonal remission, 7 patients (32%) experienced an endocrine relapse, with a mean time to relapse of 21 months. New endocrine deficiency within any of the five major hormonal axes occurred in 10 patients (32%). One patient (3%) developed new-onset unilateral optic nerve pallor within the temporal field 3 years after SRS. Three patients (10%) reported transient new or increasing frontal headaches of unclear etiology following their procedures. CONCLUSION Time to endocrine remission was more rapid in patients treated with 35 Gy, as compared to previously reported literature using marginal doses of 20-24 Gy. Rates of endocrine remission and relapse, post-SRS hypopituitarism, and radiation-induced sequelae were not increased following higher dose treatment.

Platelet function inhibitors and platelet function testing in neurointerventional procedures

Over the past decade there has been a growing use of intracranial stents for the treatment of both ischemic and hemorrhagic cerebrovascular disease, including stents to assist in the remodeling of the neck of aneurysms as well as the use of flow diverting devices for aneurysm treatment. With this increase in stent usage has come a growing need for the neurointerventional (NI) community to understand the pharmacology of medications used for modifying platelet function, as well as the testing methodologies available. Platelet function testing in NI procedures remains controversial. While pre-procedural antiplatelet assays might lead to a reduced rate of thromboembolic complications, little evidence exists to support this as a standard of care practice. Despite the routine use of dual antiplatelet therapy (DAT) with aspirin and a P2Y12 receptor antagonist (such as clopidogrel, prasugrel, or ticagrelor) in most neuroembolization procedures necessitating intraluminal reconstruction devices, thromboembolic complications are still encountered.1–3 Moreover, DAT carries the risk of hemorrhagic complications, with intracerebral hemorrhage (ICH) being the most potentially devastating.4 ,5 Light transmission aggregometry (LTA) is the gold standard to test for platelet reactivity, but it is usually expensive and may not be easily obtainable at many centers. This has led to the development of point-of-care assays, such as the VerifyNow (Accumetrics, San Diego, California, USA), which correlates strongly with LTA and can reliably measure the degree of P2Y12 receptor inhibition.6–9 VerifyNow results are reported in P2Y12 reaction units (PRUs), with a lower PRU value corresponding to a higher level of P2Y12 receptor inhibition and, presumably, a lower probability of platelet aggregation, and a higher PRU value corresponding to a lower level of P2Y12 receptor inhibition and, hence, a higher chance of platelet activation and aggregation. While aspirin resistance is perhaps less common, clopidogrel resistance may be more challenging as …

Delayed surgery after acute traumatic central cord syndrome is associated with reduced mortality.

Study Design. A retrospective study of surgically treated patients with acute traumatic central cord syndrome (ATCCS) from the National Trauma Data Bank Research Data Set. Objective. To determine the association of time to surgery, pre-existing comorbidities, and injury severity on mortality and adverse events in surgically treated patients with ATCCS. Summary of Background Data. Although earlier surgery has been shown to be beneficial for other spinal cord injuries, the literature is mixed regarding the appropriate timing of surgery after ATCCS. Traditionally, this older population has been treated with delayed surgery because medical optimization is often indicated preoperatively. Methods. Surgically treated patients with ATCCS in the National Trauma Data Bank Research Data Set from 2011 and 2012 were identified. Time to surgery, Charlson Comorbidity Index, and injury severity scores were tested for association with mortality, serious adverse events, and minor adverse events using multivariate logistic regression. Results. A total of 1060 patients with ATCCS met inclusion criteria. After controlling for pre-existing comorbidity and injury severity, delayed surgery was associated with a decreased odds of inpatient mortality (odds ratio = 0.81, P = 0.04), or a 19% decrease in odds of mortality with each 24-hour increase in time until surgery. The association of time to surgery with serious adverse events was not statistically significant (P = 0.09), whereas time to surgery was associated with increased odds of minor adverse events (odds ratio = 1.06, P < 0.001). Conclusion. Although the potential neurological effect of surgical timing for patients with ATCCS remains controversial, the decreased mortality with delayed surgery suggests that waiting to optimize general health and potentially allow for some spinal cord recovery in these patients may be advantageous. Level of Evidence: 3

Decompressive Hemicraniectomy for Pediatric Traumatic Brain Injury: Long-Term Outcome Based on Quality of Life

Aims: The impact of decompressive hemicraniectomy (DCH) on the overall outcome of pediatric brain injury patients has not been fully determined. In this paper, the authors performed a systematic review of patient outcome based on quality of life following DCH in a pediatric population. Methods: We describe our experience with decompressive craniectomy in pediatric patients and perform a literature review and pooled outcomes analysis to supplement these findings. A total of 13 children underwent DCH for intractable intracranial pressure in our institution from 2000 to 2008. Follow-up was available in 11 patients with 1 death (9%) and 7 survivors (70%) obtaining a favorable outcome (Glasgow Outcome Scale, GOS, scores = 4–5). Results: A literature review to determine the usefulness of DCH identified 17 articles that, when combined with our series, resulted in 186 pediatric DCH cases. Pooled outcomes found 42 deaths and 112 patients who had favorable outcomes at 6 months. The average 6-month mortality was 21.1%, and the pooled mean quality of life among survivors 0.75 (0.68–0.82), midway between moderate disability and good outcome. Conclusions: Based on our findings, DCH results in a majority of pediatric patients having a good outcome based on the GOS score.

Imaging of lumbar spinal surgery complications

AbstractLumbar spine surgery for spinal stenosis is a frequently performed procedure and was the fastest growing type of surgery in the US from 1980 to 2000. With increasing surgical invasiveness, postoperative complications also tend to be higher. Cross-sectional imaging techniques (CT and MRI) are more sensitive than radiographs and play an increasingly important role in evaluation of patients with lumbar spine surgery. Their use in patients with metallic implants is somewhat limited by artefacts, which can obscure pathology and decrease accuracy and reader confidence. Metal artefact reduction techniques have been developed, which can significantly improve image quality and enable early detection of postoperative complications. Complications can occur throughout postoperative course. Early complications include hardware displacement, incidental durotomy, postoperative collections—most commonly seroma, and less likely haematoma and/or infection. Incidental durotomy with CSF leak causing intracranial hypotension has characteristic MR brain findings and diagnosis of occult leak sites have been improved with use of dynamic CT myelography. Haematomas, even when compressing the thecal sac, are usually asymptomatic. Early infection, with nonspecific MR findings, can be diagnosed accurately using dual radiotracer studies. Delayed complications include loosening, hardware failure, symptomatic new or recurrent disc herniation, peri-/epidural fibrosis, arachnoiditis, and radiculitis.Teaching Points• CT and MRI play an increasingly important role in evaluation of patients with lumbar spine surgery • Complications can occur throughout the postoperative course and early detection is critical • Artefact reduction techniques can improve image quality for early and improved detection of complications

Anaesthesia for deep brain stimulation: a review.

Purpose of review Deep brain stimulation (DBS) is a well tolerated and efficacious surgical treatment for movement disorders, chronic pain, psychiatric disorder, and a growing number of neurological disorders. Given that the brain targets are deep and small, accurate electrode placement is commonly accomplished by utilizing frame-based systems. DBS electrode placement is confirmed by microlectrode recordings and macrostimulation to optimize and verify target placement. With a reliance on electrophysiology, proper anaesthetic management is paramount to balance patient comfort without interfering with neurophysiology. Recent findings To achieve optimal pain control, generous amounts of local anaesthesia are instilled into the planned incision. During the opening and closing states, conscious sedation is the prevailing method of anaesthesia. The preferred agents are dexmedetomidine, propofol, and remifentanil, as they affect neurocognitive testing the least, and shorter acting. All the agents are turned off 15–30 min prior to microelectrode recording. Dexmedetomidine has gained popularity in DBS procedures, but has some considerations at higher doses. The addition of ketamine is helpful for pediatric cases. Summary DBS is a robust surgical treatment for a variety of neurological disorders. Appropriate anaesthetic agents that achieve patient comfort without interfering with electrophysiology are paramount.

How Large Is the Typical Subarachnoid Hemorrhage? A Review of Current Neurosurgical Knowledge

BACKGROUND Despite the morbidity and mortality of subarachnoid hemorrhage (SAH), the average volume of a typical hemorrhage is not well defined. Animal models of SAH often do not accurately mimic the human disease process. OBJECTIVE The purpose of this study is to estimate the average SAH volume, allowing standardization of animal models of the disease. METHODS We performed a MEDLINE search of SAH volume and erythrocyte counts in human cerebrospinal fluid as well as for volumes of blood used in animal injection models of SAH, from 1956 to 2010. We polled members of the American Association of Neurological Surgeons (AANS) for estimates of typical SAH volume. Using quantitative data from the literature, we calculated the total volume of SAH as equal to the volume of blood clotted in basal cisterns plus the volume of dispersed blood in cerebrospinal fluid. The results of the AANS poll confirmed our estimates. RESULTS The human literature yielded 322 publications and animal literature, 237 studies. Four quantitative human studies reported blood clot volumes ranging from 0.2 to 170 mL, with a mean of ∼20 mL. There was only one quantitative study reporting cerebrospinal fluid red blood cell counts from serial lumbar puncture after SAH. Dispersed blood volume ranged from 2.9 to 45.9 mL, and we used the mean of 15 mL for our calculation. Therefore, total volume of SAH equals 35 mL. The AANS poll yielded 176 responses, ranging from 2 to 350 mL, with a mean of 33.9 ± 4.4 mL. CONCLUSIONS Based on our estimate of total SAH volume of 35 mL, animal injection models may now become standardized for more accurate portrayal of the human disease process.

Oversized self-expanding stents as an alternative to flow-diverters for blister-like aneurysms

Abstract Objective: Blister-like aneurysms (BLAs) are challenging to treat. Their friable nature makes them high risk for both traditional microsurgical and endovascular treatments. We discuss employing a single oversized self-expanding stent in the treatment of these treacherous lesions. Methods: A retrospective review from our institution was conducted. Five patients with BLAs were identified, who went on to be treated with a single oversized self-expanding stent, defined as 1 mm larger than the parent vessel, by the senior author (KRB), who is dual fellowship trained in both cerebrovascular/skull base microsurgery and endovascular neurosurgery. Additionally, a literature review was performed on BLAs treated with sole stenting and outcomes discussed. Results: Our five patients had complete aneurysm occlusion at long-term follow-up and all had good neurological outcomes. The literature review demonstrated that most aneurysms at long-term follow-up were either completed occluded or progressively becoming occluded, with patients overall having a good functional outcome based on the modified Rankin scale (mRS). Conclusion: In our experience, oversized self-expanding stents are a treatment option that should be considered for BLAs. This strategy avoids the need for dual antiplatelet therapy and therefore increases its utility in the case of subarachnoid hemorrhage (SAH).