Long-Term Results of Endoscopic Endonasal Marsupialization of Rathke Cleft Cysts With Bioabsorbable Steroid-Eluting Stents-Technical Case Series and Review of the Literature.

BACKGROUND: Rathke cleft cysts (RCCs) are common benign skull-base lesions arising from embryologic remnants of Rathke pouch. Though frequently asymptomatic, RCCs can become symptomatic because of compression of adjacent neural structures. Transcranial and neuroendoscopic surgical treatments have been described for symptomatic RCCs, but recurrence rates remain as high as 30%. Bioabsorbable steroid-eluting (BASE) stents significantly decrease adhesions and recurrent ostia obstruction after endoscopic sinus surgery. We sought to use BASE stents to aid marsupialization of symptomatic RCCs. OBJECTIVE: To present long-term results of our initial experience with endoscopic-endonasal fenestration and placement of BASE stents for RCCs. METHODS: Patients undergoing neuroendoscopic transsphenoidal fenestration of RCCs with BASE stent placement were identified and their medical records retrospectively reviewed. RESULTS: Four patients underwent neuroendoscopic transsphenoidal fenestration and BASE stent placement from March 2016 to April 2018 for symptomatic RCCs. After the cyst contents were evacuated, a BASE stent was deployed in the cyst fenestration to prevent cyst wall regrowth or closure and facilitate marsupialization to the sphenoid sinus. No perioperative complications were encountered, and all patients reported symptom resolution by 2 weeks postoperatively. Postoperative endoscopic evaluation demonstrated epithelization of the cyst wall opening and patent marsupialization into the sphenoid sinus in all cases. After a mean follow-up of 56 ± 12 months, all patients remained asymptomatic with baseline visual function and no radiographic evidence of recurrence. CONCLUSION: Bioabsorbable steroid-eluting stent placement is a safe, facile, viable augmentation of neuroendoscopic technique for symptomatic RCCs with the potential to reduce long-term recurrence rates.

Chronic Pain: Prevalence and Management.

Chronic pain is a distinct complication that profoundly affects the lives of individuals with sickle cell disease (SCD). Chronic SCD pain emerges with increasing age and is very prevalent in adults. The pathophysiology of chronic SCD pain is likely distinct from acute SCD pain and therefore needs a different treatment approach. Clinical trials evaluating the treatment of chronic SCD pain are lacking and treatment currently relies on evidence from other chronic pain conditions. Continued investigations into the underlying causes of chronic SCD pain are needed, and clinical trials focused on chronic pain therapy are imperative.

Attitudes Toward Neurosurgery Education for the Nonneurosurgeon: A Survey Study and Critical Analysis of U.S. Military Training Techniques and Future Prospects.

BACKGROUND: The U.S. military requires medical readiness to support forward-deployed combat operations. Because time and distance to neurosurgical capabilities vary within the deployed trauma system, nonneurosurgeons are required to perform emergent cranial procedures in select cases. It is unclear whether these surgeons have sufficient training in these procedures. METHODS: This quality-improvement study involved a voluntary, anonymized specialty-specific survey of active-duty surgeons about their experience and attitudes toward U.S. military emergency neurosurgical training. RESULTS: Survey responses were received from 104 general surgeons and 26 neurosurgeons. Among general surgeons, 81% have deployed and 53% received training in emergency neurosurgical procedures before deployment. Only 16% of general surgeons reported participating in craniotomy/craniectomy procedures in the last year. Nine general surgeons reported performing an emergency neurosurgical procedure while on deployment/humanitarian mission, and 87% of respondents expressed interest in further predeployment emergency neurosurgery training. Among neurosurgeons, 81% had participated in training nonneurosurgeons and 73% believe that more comprehensive training for nonneurosurgeons before deployment is needed. General surgeons proposed lower procedure minimums for competency for external ventricular drain placement and craniotomy/craniectomy than did neurosurgeons. Only 37% of general surgeons had used mixed/augmented reality in any capacity previously; for combat procedures, most (90%) would prefer using synchronous supervision via high-fidelity video teleconferencing over mixed reality. CONCLUSIONS: These survey results show a gap in readiness for neurosurgical procedures for forward-deployed general surgeons. Capitalizing on capabilities such as mixed/augmented reality would be a force multiplier and a potential means of improving neurosurgical capabilities in the forward-deployed environments.

An independent, external validation and component analysis of the Surviving Penetrating Injury to the Brain score for civilian cranial gunshot injuries.

OBJECTIVE: The Surviving Penetrating Injury to the Brain (SPIN) score utilizes clinical variables to estimate in-hospital and 6-month mortality for patients with civilian cranial gunshot wounds (cGSWs) and demonstrated good discrimination (area under the receiver operating characteristic curve [AUC] 0.880) in an initial validation study. The goal of this study was to provide an external, independent validation of the SPIN score for in-hospital and 6-month mortality. METHODS: To accomplish this, the authors retrospectively reviewed 6 years of data from their institutional trauma registry. Variables used to determine SPIN score were collected, including sex, transfer status, injury motive, pupillary reactivity, motor component of the Glasgow Coma Scale (mGCS), Injury Severity Score (ISS), and international normalized ratio (INR) at admission. Multivariable logistic regression analysis identified variables associated with mortality. The authors compared AUC between models by using a nonparametric test for equality. RESULTS: Of the 108 patients who met the inclusion criteria, 101 had all SPIN score components available. The SPIN model had an AUC of 0.962. The AUC for continuous mGCS score alone (0.932) did not differ significantly from the AUC for the full SPIN model (p = 0.26). The AUC for continuous mGCS score (0.932) was significantly higher compared to categorical mGCS score (0.891, p = 0.005). Use of only mGCS score resulted in fewer exclusions due to missing data. No additional variable included in the predictive model alongside continuous mGCS score was a significant predictor of inpatient mortality, 6-month mortality, or increased model discrimination. CONCLUSIONS: Given these findings, continuous 6-point mGCS score may be sufficient as a generalizable predictor of inpatient and 6-month mortality in patients with cGSW, demonstrating excellent discrimination and reduced bias due to missing data.

Spreading Diffusion-Restriction Events in the Gyrencephalic Brain After Subarachnoid Hemorrhage Revealed by Continuous Magnetic Resonance Imaging.

BACKGROUND: How widely spreading depolarizations (SDs) propagate through the gyrencephalic brain, including sulci and deeper cortical areas, remains an important clinical question. Here, we investigated SDs that occur spontaneously after subarachnoid placement of autologous blood clots in sulci of the juvenile swine brain. METHODS: To investigate the three-dimensional spread of waves, animals underwent continuous diffusion-weighted magnetic resonance imaging (DW-MRI) for up to 6 h following clot placement. SD is the mechanism of the cytotoxic edema of developing infarction that is diagnosed by DW-MRI, and DW-MRI also captures transient diffusion restriction caused by SD in less injured or healthy brains. Here, images (b = 0, 375, and 750) were acquired across five coronal slices with 1.25 × 1.25-mm in-plane resolution and 5-mm slice thickness, and the protocol was repeated every 6.83-9.15 s. Spatial drift correction, temporal smoothing, and signal intensity normalization were applied to generate videos of diffusion signal intensity changes for each coronal slice. RESULTS: Review of video data from five animals revealed ten discrete events consisting of focal diffusion restriction that propagated through cerebral cortex. All events originated in the cortex surrounding the sulcal clot, either in the gyrus (n = 4) or in the sulcal depth (n = 6). In six cases, two to three independent waves spread simultaneously in medial, lateral, and antero-posterior directions. Waves traveled within sulcal walls, traversed the depths of sulci to re-emerge on the adjacent gyrus, and, in three cases, spread fully around the dorsolateral convexity. One event spread deep to olfactory regions along midline cortex, and no events were observed contralateral to the subarachnoid clot. CONCLUSIONS: Together, these results suggest that SDs in the injured gyrencephalic brain originate near the injury focus and can spread extensively through the cortex to wide and deep uninjured regions. These findings have implications for transient neurologic deficits in the neurocritically ill patient and relevance to patient monitoring and therapeutics.

Improving patient care in neurosurgery through postoperative telephone calls: a systematic review and lessons from all surgical specialties.

OBJECTIVE: Postoperative telephone calls are a simple intervention that can be used to improve communication with patients, potentially affecting patient safety and satisfaction. Few studies in the neurosurgical literature have examined the effect of a postoperative telephone call on patient outcomes, although several exist across all surgical specialties. The authors performed a systematic review and analyzed studies published since 2000 to assess the effect of a postoperative telephone call or text message on patient safety and satisfaction across all surgical specialties. METHODS: A search of PubMed-indexed articles was performed on June 12, 2021, and was narrowed by the inclusion criteria of studies from surgical specialties with > 50 adult patients published after 1999, in which a postoperative telephone call was made and its effects on safety and satisfaction were assessed. Exclusion criteria included dental, medical, and pediatric specialties; systematic reviews; meta-analyses; and non-English-language articles. Dual review was utilized. RESULTS: Overall, 24 articles met inclusion criteria. The majority reported an increase in patient satisfaction scores after a postoperative telephone call was implemented, and half of the studies demonstrated an improvement in safety or outcomes. CONCLUSIONS: Taken together, these studies demonstrate that implementation of a postoperative telephone call in a neurosurgical practice is a feasible way to enhance patient care. The major limitations of this study were the heterogeneous group of studies and the limited neurosurgery-specific studies.

Safety and efficacy of remote electrical neuromodulation for the acute treatment of chronic migraine: an open-label study.

INTRODUCTION: Remote electrical neuromodulation (REN) is an acute treatment of migraine. The results from several studies in patients with episodic migraine suggest that REN is an effective and safe acute treatment of migraine. A recent pilot study provided initial support that REN is effective in patients with chronic migraine as well. OBJECTIVES: The current study aimed to validate and provide further evidence for the safety and efficacy of REN in a large sample of patients impacted by chronic migraine. METHODS: In this open-label, single-arm study, patients with chronic migraine treated their headaches with the REN device (Nerivio, Theranica Bio-Electronics Ltd, Israel) for 4 weeks. Participants used an electronic diary to record their symptoms at treatment initiation, 2 hours after treatment, and 24 hours after treatment. The primary end point was the percentage of subjects who achieved pain relief at 2 hours posttreatment. Secondary end points included pain freedom and improvement of associated symptoms and functional disability. RESULTS: One hundred twenty-six subjects were enrolled into the study, of which 91 subjects had an evaluable treatment with REN. Pain relief and pain disappearance at 2 hours were achieved by 59.3% (54/91) and 20.9% (19/91) of modified intent-to-treat subjects, respectively (with worst-case sensitivity analysis indicating 54.5% and 19.2%, respectively). Sustained pain relief at 24 hours was observed in 64.4% (29/45) of those who achieved pain relief at 2 hours (with worst-case sensitivity analysis indicating 45.6%). The findings of the study show that REN has a favorable effect on nausea, photophobia, and phonophobia and improves functional ability. One device-related adverse event was reported. CONCLUSIONS: Remote electrical neuromodulation treatments results in the relief of migraine headaches and associated symptoms, thus offering a drug-free acute treatment option for people with chronic migraine. TRIAL REGISTRATION: ClinicalTrials.gov NCT04194008.

Insights into potential targeted nonsurgical therapies for the treatment of moyamoya disease.

Since its initial description in 1957 as an idiopathic disease, moyamoya disease has proved challenging to treat. Although the basic pathophysiology of this disease involves narrowing of the terminal carotid artery with compensatory angiogenesis, the molecular and cellular mechanisms underlying these changes are far more complex. In this article, the authors review the literature on the molecular and cellular pathophysiology of moyamoya disease with an emphasis on potential therapeutic targets.

Diminishing returns with successive device passes in mechanical thrombectomy for stroke.

BACKGROUND: Multiple device passes are associated with complications and poor functional outcomes following mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO). OBJECTIVE: To characterize the relationship between number of device passes, complications, angiographic outcomes, and clinical outcomes in MT for ELVO. METHODS: This is a single-center, retrospective cohort study. Individual device passes for MT were evaluated for any change in Thrombolysis in Cerebral Infarction (TICI) score, successful revascularization (TICI 2b or 3), and complications. Outcomes were compared among groups requiring multiple passes with various cut-off points. Risk factors for unfavorable clinical outcome [90 day modified Rankin Scale > 2] were assessed using multivariate analysis. RESULTS: Successful revascularization was achieved in 75% of 163 patients and 36% required only one device pass. After the second pass, the likelihood of angiographic improvement significantly decreased (p < 0.001). Using multiple cut-off points, higher post-procedural NIHSS scores, mortality rates, and unfavorable 90-day outcomes were associated with a greater number of passes. Multivariate analysis revealed ICA thrombus (comparison: M2, OR: 25, 95% CI 2-275, p = 0.01) and failed revascularization (OR: 68, 95% CI 3.12-1489, p = 0.01) as the only significant predictors of unfavorable clinical outcome. Nonetheless, the likelihood of favorable clinical outcome was higher in patients with an ICA occlusion who were revascularized in < 2 vs. ≥ 2 (44 vs 4%, p = 0.01) or < 3 vs. ≥ 3 (32 vs. 0%, p = 0.02) passes. CONCLUSION: The likelihood of angiographic improvement in patients with ELVO significantly decreases after the second pass. A greater number of passes is associated with worsened clinical outcomes.

U.S. Neurosurgical Response to COVID-19: Forging a Path Toward Disaster Preparedness.

INTRODUCTION: The worldwide COVID-19 pandemic poses challenges to healthcare capacity and infrastructure. The authors discuss the structure and efficacy of the U.S. Navy's response to COVID-19 and evaluate the utility of this endeavor, with the objective of providing future recommendations for managing worldwide healthcare and medical operational demands from the perspective of Navy Neurosurgery. MATERIALS AND METHODS: The authors present an extensive review of topics and objectively highlight the efforts of U.S. Navy Neurosurgery as it pertains to the humanitarian mission during the COVID-19 pandemic. RESULTS: During the humanitarian mission (March 27, 2020-April 14, 2020), the response of active duty and reserve neurosurgeons in the U.S. Navy was robust. Neurosurgical coverage was present on board the U.S. Navy Ships Mercy and Comfort, with additional neurosurgical deployment to New York City for intensive care unit management and coverage. CONCLUSIONS: The U.S. Navy neurosurgical response to the COVID-19 pandemic was swift and altruistic. Although neurosurgical pathologies were limited among the presenting patients, readiness and manpower continue to be strong influences within the Armed Forces. The COVID-19 response demonstrates that neurosurgical assets can be rapidly mobilized and deployed in support of wartime, domestic, and global humanitarian crises to augment both trauma and critical care capabilities.

The Evolution of Flow-Diverting Stents for Cerebral Aneurysms; Historical Review, Modern Application, Complications, and Future Direction.

In spite of the developing endovascular era, large (15-25 mm) and giant (>25 mm) wide-neck cerebral aneurysms remained technically challenging. Intracranial flow-diverting stents (FDS) were developed to address these challenges by targeting aneurysm hemodynamics to promote aneurysm occlusion. In 2011, the first FDS approved for use in the United States market. Shortly thereafter, the Pipeline of Uncoilable or Failed Aneurysms (PUFS) study was published demonstrating high efficacy and a similar complication profile to other intracranial stents. The initial FDA instructions for use (IFU) limited its use to patients 22 years old or older with wide-necked large or giant aneurysms of the internal carotid artery (ICA) from the petrous segment to superior hypophyseal artery/ophthalmic segment. Expanded IFU was tested in the Prospective Study on Embolization of Intracranial Aneurysms with PipelineTM Embolization Device (PREMIER) trial. With further post-approval clinical data, the United States FDA expanded the IFU to include patients with small or medium, wide-necked saccular or fusiform aneurysms from the petrous ICA to the ICA terminus. However, IFU is more restrictive in South Korea than in United States. Several systematic reviews and meta-analyses have sought to evaluate the overall efficacy of FDS for the treatment of cerebral aneurysms and consistently identify FDS as an effective technique for the treatment of aneurysms broadly with complication rates similar to other traditional techniques. A growing body of literature has demonstrated high efficacy of FDS for small aneurysms; distal artery aneurysms; non-saccular aneurysms posterior circulation aneurysms and complication rates similar to traditional techniques. In the short interval since the Pipeline Embolization Device was first introduced, FDS has been firmly entrenched as a powerful tool in the endovascular armamentarium. As new FDS are developed, established FDS are refined, and delivery systems are improved the uses for FDS will only expand further. Researchers continue to work to optimize the mechanical characteristics of the FDS themselves, aiming to optimize deploy ability and efficacy. With expanded use for small to medium aneurysms and posterior circulation aneurysms, FDS technology is firmly entrenched as a powerful tool to treat challenging aneurysms, both primarily and as an adjunct to coil embolization. With the aforementioned advances, the ease of FDS deployment will improve and complication rates will be further minimized. This will only further establish FDS deployment as a key strategy in the treatment of cerebral aneurysms.

Direct enhancement of readiness for wartime critical specialties by civilian-military partnerships for neurosurgical care: residency training and beyond.

Military neurosurgery has played an integral role in the development and innovation of neurosurgery and neurocritical care in treating battlefield injuries. It is of paramount importance to continue to train and prepare the next generation of military neurosurgeons. For the Army, this is currently primarily achieved through the military neurosurgery residency at the National Capital Consortium and through full-time out-service positions at the Veterans Affairs-Department of Defense partnerships with the University of Florida, the University of Texas-San Antonio, and Baylor University. The authors describe the application process for military neurosurgery residency and highlight the training imparted to residents in a busy academic and level I trauma center at the University of Florida, with a focus on how case variety and volume at this particular civilian-partnered institution produces neurosurgeons who are prepared for the complexities of the battlefield. Further emphasis is also placed on collaboration for research as well as continuing education to maintain the skills of nondeployed neurosurgeons. With ongoing uncertainty regarding future conflict, it is critical to preserve and expand these civilian-military partnerships to maintain a standard level of readiness in order to face the unknown with the confidence befitting a military neurosurgeon.

Safety and efficacy of brain injury guidelines at a Level III trauma center.

BACKGROUND: Patients with mild to moderate traumatic brain injury (TBI) are often primarily managed by emergency medicine and trauma/acute care physicians. The Brain Injury Guidelines (BIG) were developed at an American College of Surgeons-accredited Level 1 trauma center to triage mild to moderate TBI patients and help identify patients who warrant neurosurgical consultation. The BIG have not been validated at a Level III trauma center. We hypothesized that BIG criteria can be safely adapted to an American College of Surgeons-accredited Level III trauma center to guide transfers to a higher echelon of care. METHODS: We reviewed the trauma registry at a Level III trauma center to identify TBI patients who presented with an Abbreviated Injury Severity-Head score greater than zero. Demographic data, injury details, and clinical outcomes were abstracted with primary outcome measures of worsening on second computed tomography of the head, neurosurgical intervention, transfer to a Level I trauma center, and in-hospital mortality. Patients were classified using the BIG criteria. After validating the BIG in our cohort, we reclassified patients using updated BIG criteria. Updated criteria included mechanism of injury, reclassification of anticoagulation or antiplatelet use, and replacement of the neurologic examination component with stratification by admission Glasgow Coma Scale (GCS) score. RESULTS: From July 2013 to June 2016, 332 TBI patients were identified: 115 BIG-1, 25 BIG-2, and 192 BIG-3. Patients requiring neurosurgical intervention (n = 30) or who died (n = 29) were BIG-3 with one exception. Patients with GCS score of less than 12 had worse outcomes than those with a GCS score of 12 or greater, regardless of BIG classification. Anticoagulant or antiplatelet use was not associated with worsened outcomes in patients not meeting other BIG-3 criteria. The updated BIG resulted in more patients in BIG-1 (n = 109) and BIG-2 (n = 100) without negatively affecting outcomes. CONCLUSION: The BIG can be applied in the Level III trauma center setting. Updated BIG criteria can aid triage of mild to moderate TBI patients to a Level I trauma center and may reduce secondary overtriage. LEVEL OF EVIDENCE: Care management, level IV.

Subarachnoid blood acutely induces spreading depolarizations and early cortical infarction.

See Ghoshal and Claassen (doi:10.1093/brain/awx226) for a scientific commentary on this article. Early cortical infarcts are common in poor-grade patients after aneurysmal subarachnoid haemorrhage. There are no animal models of these lesions and mechanisms are unknown, although mass cortical spreading depolarizations are hypothesized as a requisite mechanism and clinical marker of infarct development. Here we studied acute sequelae of subarachnoid haemorrhage in the gyrencephalic brain of propofol-anaesthetized juvenile swine using subdural electrode strips (electrocorticography) and intraparenchymal neuromonitoring probes. Subarachnoid infusion of 1­2 ml of fresh blood at 200 µl/min over cortical sulci caused clusters of spreading depolarizations (count range: 12­34) in 7/17 animals in the ipsilateral but not contralateral hemisphere in 6 h of monitoring, without meaningful changes in other variables. Spreading depolarization clusters were associated with formation of sulcal clots (P < 0.01), a high likelihood of adjacent cortical infarcts (5/7 versus 2/10, P < 0.06), and upregulation of cyclooxygenase-2 in ipsilateral cortex remote from clots/infarcts. In a second cohort, infusion of 1 ml of clotted blood into a sulcus caused spreading depolarizations in 5/6 animals (count range: 4­20 in 6 h) and persistent thick clots with patchy or extensive infarction of circumscribed cortex in all animals. Infarcts were significantly larger after blood clot infusion compared to mass effect controls using fibrin clots of equal volume. Haematoxylin and eosin staining of infarcts showed well demarcated zones of oedema and hypoxic-ischaemic neuronal injury, consistent with acute infarction. The association of spreading depolarizations with early brain injury was then investigated in 23 patients [14 female; age (median, quartiles): 57 years (47, 63)] after repair of ruptured anterior communicating artery aneurysms by clip ligation (n = 14) or coiling (n = 9). Frontal electrocorticography [duration: 54 h (34, 66)] from subdural electrode strips was analysed over Days 0­3 after initial haemorrhage and magnetic resonance imaging studies were performed at ∼ 24­48 h after aneurysm treatment. Patients with frontal infarcts only and those with frontal infarcts and/or intracerebral haemorrhage were both significantly more likely to have spreading depolarizations (6/7 and 10/12, respectively) than those without frontal brain lesions (1/11, P's < 0.05). These results suggest that subarachnoid clots in sulci/fissures are sufficient to induce spreading depolarizations and acute infarction in adjacent cortex. We hypothesize that the cellular toxicity and vasoconstrictive effects of depolarizations act in synergy with direct ischaemic effects of haemorrhage as mechanisms of infarct development. Results further validate spreading depolarizations as a clinical marker of early brain injury and establish a clinically relevant model to investigate causal pathologic sequences and potential therapeutic interventions.

Point-of-care testing in the acute management of traumatic brain injury: Identifying the coagulopathic patient.

BACKGROUND: The use of anticoagulants or antiplatelet medications has become increasingly common and is a well-established risk factor for worsening of hemorrhages in trauma patients. The current study addresses the need to investigate the efficacy of point-of-care tests (POC) as an adjunct to conventional coagulation testing in traumatic brain injury (TBI) patients. METHODS: A retrospective review of 190 TBI patients >18 years of age who underwent both conventional and POC testing as part of their admission coagulopathy workup was conducted. Coagulation deficiency was defined as an international normalized ratio (INR) >1.4, a reaction time (r-value) on rapid thromboelastography >50 seconds, or a VerifyNow Aspirin (VN-ASA) level of < 550 Aspirin Reaction Units. RESULTS: Among 190 patients, 91 (48%) disclosed a history of either warfarin or antiplatelet use or had documented INR >1.4. Of the 18 (9%) patients who reported warfarin use, 83% had elevated INR and 61% had elevated r-value. However, 41% of the patients without reported anticoagulant usage revealed significantly elevated r-value consistent with a post-traumatic hypocoagulable state. Of 64 (34%) patients who reported taking ASA, 51 (80%) demonstrated therapeutic VN-ASA. Interestingly, 31 of 126 (25%) patients not reporting ASA use were also noted to have therapeutic VN-ASA suggestive of platelet dysfunction. CONCLUSIONS: The coagulopathy POC panel consisting of r-TEG and VN-ASA successfully identified a subset of TBI patients with an occult coagulopathy that would have otherwise been missed. Standardization of these POC assays on admission in TBI may help guide patient resuscitation in the acute setting.

Application of emerging technologies to improve access to ischemic stroke care.

During the past 20 years, the traditional supportive treatment for stroke has been radically transformed by advances in catheter technologies and a cohort of prominent randomized controlled trials that unequivocally demonstrated significant improvement in stroke outcomes with timely endovascular intervention. However, substantial limitations to treatment remain, among the most important being timely access to care. Nonetheless, stroke care has continued its evolution by incorporating technological advances from various fields that can further reduce patients' morbidity and mortality. In this paper the authors discuss the importance of emerging technologies-mobile stroke treatment units, telemedicine, and robotically assisted angiography-as future tools for expanding access to the diagnosis and treatment of acute ischemic stroke.

Changes in computed tomography perfusion parameters after superficial temporal artery to middle cerebral artery bypass: an analysis of 29 cases.

Introduction Analysis of computed tomography perfusion (CTP) studies before and after superficial temporal artery to middle cerebral artery (STA-MCA) bypass is warranted to better understand cerebral steno-occlusive pathology. Methods Retrospective review was performed of STA-MCA bypass patients with steno-occlusive disease with CTP before and after surgery. CTP parameters were evaluated for change after STA-MCA bypass. Results A total of 29 hemispheres were bypassed in 23 patients. After STA-MCA bypass, mean transit time (MTT) and time to peak (TTP) improved. When analyzed as a ratio to the contralateral hemisphere, MTT, TTP, and cerebral blood flow (CBF) improved. There was no effect of gender, double vessel versus single vessel bypass, or time until postoperative CTP study to changes in CTP parameters after bypass. Conclusions Blood flow augmentation after STA-MCA bypass may best be assessed by CTP using baseline MTT or TTP and ratios of MTT, TTP, or CBF to the contralateral hemisphere. The failure of cerebrovascular reserve to improve after cerebral bypass may indicate irreversible loss of autoregulation with chronic cerebral vasodilation or the inability of CTP to detect these improvements.

Are we underestimating the burden of traumatic brain injury? Surveillance of severe traumatic brain injury using centers for disease control International classification of disease, ninth revision, clinical modification, traumatic brain injury codes.

BACKGROUND: The epidemiology of traumatic brain injury (TBI) is often studied through the use of International classification of disease, ninth revision, clinical modification (ICD-9-CM), diagnosis codes from the Centers for Disease Control and Prevention TBI Surveillance System. Recent studies suggest that these codes may underestimate the burden of TBI because of inaccuracies and low sensitivity. OBJECTIVE: To determine the sensitivity and specificity of ICD-9-CM codes in a severe TBI population. METHODS: We retrospectively reviewed medical records of all hospital admissions including computed tomography of the head at a single center to identify severe blunt TBI patients, their injuries, and the neurosurgical procedures performed. We calculated sensitivity and specificity by comparing ICD-9-CM diagnosis and procedure codes assigned by hospital coders with medical records, the gold standard. RESULTS: In 2008, there were 148 qualifying admissions. These codes were 89% sensitive for the presence of any severe TBI. However, one-fifth of these cases were identified only with a code defining a nonspecific head injury. Next, we studied types of TBI by categories defined by the Centers for Disease Control and Prevention (morbidity groups) and by ICD-9-CM codes for types of injury (any skull fracture, intracranial contusion, intracranial hemorrhage, concussion/loss of consciousness) and found widely varying sensitivity and specificity for both. In general, these codes had higher specificity than sensitivity. Both sensitivity and specificity were > 80% for only 2 categories: any skull fracture and intracranial hemorrhage. In contrast, we found high sensitivity and specificity for neurosurgical procedures (97% and 94%). CONCLUSION: ICD-9-CM codes were sensitive for the presence of any severe TBI, but further classification of specific types of TBI was limited by variable sensitivity/specificity. Use of these codes should be supplemented by other methodology.

The AIS-2005 Revision in Severe Traumatic Brain Injury: Mission Accomplished or Problems for Future Research?

The Abbreviated Injury Scale (AIS) is commonly used to score injury severity and describe types of injuries. In 2005, the AIS-Head section was revised to capture more detailed information about head injuries and to better reflect their clinical severity, but the impact of these changes is largely unknown. The purpose of this study was to compare AIS-1998 and AIS-2005 coding of traumatic brain injuries (TBI) using medical records at a single Level I trauma center. We included patients with severe TBI (Glasgow Coma Scale 3-8) after blunt injury, excluding those who were missing medical records. Detailed descriptions of injuries were collected, then manually coded into AIS-1998 and AIS-2005 by the same Certified AIS Specialist. Compared to AIS-1998, AIS-2005 coded the same injuries with lower severity scores [p<0.01] and with decreased mean and maximum AIS-Head scores [p<0.01]. Of the types of traumatic brain injuries, most of the changes occurred among cerebellar and cerebral injuries. Traumatic hypoxic brain injury secondary to systemic dysfunction was captured by AIS-2005 but not by AIS-1998. However, AIS-2005 captured fewer loss of consciousness cases due to changes in criteria for coding concussive injury. In conclusion, changes from AIS-1998 to AIS-2005 result in significant differences in severity scores and types of injuries captured. This may complicate future TBI research by precluding direct comparison to datasets using AIS-1998. TBIs should be coded into the same AIS-version for comparison or evaluation of trends, and specify which AIS-version is used.