Comparison of the Prevalence of Ruptured and Unruptured Cerebral Aneurysms in a Poor Urban Minority Population.

BACKGROUND: Most ruptured cerebral aneurysms are small (<7 mm). Evidence suggests low rupture rates for such lesions (<1% per year). Population studies demonstrate a prevalence rate of 3.2%. This study simultaneously estimates the prevalence of aneurysms in a single geographic population while reporting the observed rate of aneurysmal subarachnoid hemorrhage (aSAH) in the same geographic region composed of a poor urban minority demographic. METHODS: This is an institutional review board-approved, Health Insurance Portability and Accountability Act of 1996-compliant retrospective study performed between 2005 and 2011 at a single center. Part 1 used the electronic medical record to identify all patients with a magnetic resonance angiography demonstrating a cerebral aneurysm. Part 2 used the electronic medical record to identify all patients from the same geographic area presenting with aSAH during the study period. RESULTS: A total of 11,160 subjects had a magnetic resonance angiography from the study area. In this group, 422 intradural cerebral aneurysms were incidentally discovered. Ninety-one percent were less than 10 mm (mean 5.49, standard deviation 4.6). Twenty-one percent were aneurysms of the anterior communicating artery complex. Fourteen percent were of posterior communicating artery origin. A total of 237 patients had aSAH. Ninety-two percent of the aneurysms were less than 10 mm (mean 6 mm, standard deviation 3.2 mm). Both groups were composed of poor urban minority patients. CONCLUSIONS: The observed annual rate of rupture of small anterior circulation aneurysms in this study was .06%-.15% per year. The extrapolated population prevalence of such aneurysms (4.0%-1.5%) may explain the observed rate of rupture of these small aneurysms in a poor urban minority population.

The Effect of July Admission on Inpatient Morbidity, Mortality, and Discharge Disposition After Endovascular Coiling in Subarachnoid Hemorrhage.

OBJECTIVE: To investigate effect of July admission on short-term outcome after endovascular coiling of patients with subarachnoid hemorrhage (SAH) owing to ruptured aneurysms. METHODS: Data from the National Inpatient Sample (2012-2014) were gathered. Adult patients with SAH who underwent endovascular therapy at a teaching hospital were identified. Admissions during July were compared with other months as well as based on admission quarter (AQ): AQ1 (July to September), AQ2 (October to December), AQ3 (January to March), and AQ4 (April to June). Outcome measures included inpatient morbidity (death, iatrogenic stroke, or myocardial infarction), inpatient mortality, and nonroutine discharges. RESULTS: The National Inpatient Sample database yielded 8515 patients with a diagnosis of SAH who underwent endovascular coiling between 2012 and 2014. Among these, 665 (7.8%) were admitted in July, and 7850 (92.2%) were admitted in other months. Overall, there were no differences in any of the examined outcomes, including morbidity (15.0% vs. 17.3%, P = 0.513), mortality (10.5% vs. 11.8%, P = 0.665), or nonroutine discharge (57.1% vs. 59.7%, P = 0.567), for patients admitted in July versus other months. Based on AQ, 24.5% of patients were admitted in AQ1, 26.0% in AQ2, 23.8% in AQ3, and 25.7% in AQ4. Similar to July versus other month admissions, there were no significant differences in outcomes based on AQ. CONCLUSIONS: Based on findings of this national investigation, patients with SAH owing to ruptured aneurysms who undergo endovascular therapy during the beginning of the academic year in July may not have worse short-term outcome compared with patients with admissions during other months.

The Nationwide Burden of Neurological Conditions Requiring Emergency Neurosurgery.

BACKGROUND: Neurosurgical emergencies are an important cause of disability and mortality. OBJECTIVE: To examine the nationwide burden of neurological conditions requiring emergency neurosurgery. METHODS: The Nationwide Inpatient Sample database (2002-2011) was queried to identify adult patients with a primary discharge diagnosis of a neurosurgical condition who were admitted urgently/emergently or through a trauma center and underwent surgical intervention within 2 days of admission. Diagnostic groups were ranked based on their inpatient complication and mortality burden, and their contribution to total complications, deaths, hospital charges, and length of stay (LOS) was assessed. All analyses were weighted to produce national estimates. RESULTS: After application of discharge weights, 810 404 patients who underwent emergency neurosurgery were identified. The average complication rate for the entire sample was 8.8%, the mortality rate was 11.2%, average charges were $106 802, and average LOS was 9.0 days. The top 4 diagnostic groups ranked by complication/mortality burden accounted for 76% of all complications, 96% of all deaths, 81% of all charges, and 82% of all days in the hospital for the entire study sample. This was equal to 62 648 complications, 86 683 deaths, $69 billion in charges, and 5962 932 days. These 4 diagnostic groups included (1) acute cerebrovascular disease, (2) intracranial injury, (3) spinal cord injury, and (4) occlusion or stenosis of precerebral arteries. CONCLUSION: Acute cerebrovascular disease, intracranial injury, spinal cord injury, and occlusion/stenosis of precerebral arteries requiring emergency neurosurgery carry an important nationwide burden in terms of complications, deaths, charges, and LOS. Efforts in prevention and/or treatment of these conditions should continue.

Monitoring of muscle motor evoked potentials during cerebral aneurysm surgery: intraoperative changes and postoperative outcome.

OBJECT: The authors in this study evaluated muscle motor evoked potentials (MMEPs) elicited by transcranial electrical stimulation (TES) and direct cortical stimulation as a means of monitoring during cerebral aneurysm surgery. The analysis focused on the value and frequencies of any intraoperative changes and their correlation to the postoperative motor status. METHODS: One hundred nineteen patients undergoing surgery for 148 cerebral aneurysms were included in the study. Muscle motor evoked potentials were elicited by a train of five constant-current anodal stimuli with an individual pulse duration of 0.5 msec and a stimulation rate of 2 Hz. Stimulation intensity was up to 240 mA for TES and up to 33 mA for direct cortical stimulation. The MMEPs were continuously recorded from the abductor pollicis brevis and tibialis anterior muscles bilaterally and from the biceps brachii and extensor digitorum communis muscles contralateral to the surgical side. The motor status was evaluated immediately after surgery and 7 days later. In 97% of the patients MMEPs were recordable for continuous neurophysiological monitoring of the vascular territory of interest throughout the surgery. In 14 patients significant intraoperative MMEP changes occurred, resulting in a transient motor deficit in one patient and a permanent motor deficit in six. The permanent loss of MMEPs in three patients was followed by a permanent severe motor deficit in one patient and severe clinical deterioration in the other two. CONCLUSIONS: Data in this study demonstrated that MMEPs are a useful means of intraoperative neurophysiological monitoring of motor pathway integrity and predicting postoperative motor status. The intraoperative loss of MMEPs reliably predicts both severe and permanent postoperative motor deficits.

De novo neurogenesis and acute stroke: are exogenous stem cells really necessary?

Recent studies documenting the phenomenon of de novo neurogenesis within the adult brain have propelled this area of research to the forefront of neuroscience investigations and stroke pathogenesis and treatment. Traditional theories have suggested that the central nervous system is incapable of neural regeneration; hence the emergence of the field of stem cell biology as a discipline devoted to uncovering novel forms of neural repair. However, several recent experimental observations have shown that the adult brain is capable of ongoing neurogenesis in discrete regions of the uninjured brain and additional forms of endogenous neural regeneration in the presence of an inciting event (induction neurogenesis). Induction neurogenesis has the potential for providing new insights into the cause and treatment of acute stroke syndromes.

Intraoperative factors associated with surgical outcome in patients with unruptured cerebral aneurysms: the experience of a single surgeon.

OBJECT: Some well-known predictors of clinical outcomes in patients with ruptured aneurysms are not useful for forecasting outcome in patients with unruptured aneurysms. The goal of this study was to analyze outcomes in patients harboring unruptured cerebral aneurysms in different locations and to create a predictive tool for assessing both favorable outcome and morbidity in a large series of unruptured aneurysms. METHODS: The authors analyzed data from 387 patients with nonruptured intracranial cerebral aneurysms who underwent surgery for clip placement. Intraoperative data were reviewed and seven factors that might influence outcomes were identified. These included the following: 1) aneurysm size larger than 10 mm; 2) presence of a broad aneurysm neck; 3) presence of plaque calcification near the aneurysm neck; 4) application of clips to more than one aneurysm during the same surgery; 5) temporary occlusion; 6) multiple clip applications and repositioning; and 7) use of multiple clips. The entire group of patients with unruptured aneurysms was divided into two subgroups on the basis of outcome. Each patient was subsequently assessed to formulate the factor accumulation index (FAI), the sum of different factors observed in a given patient. The subgroup of patients with expected outcomes was composed of 312 patients, whereas the subgroup of unexpected outcomes consisted of 31 patients. Depending on the anatomical locations of the aneurysms, the combined mortality-morbidity rate ranged from 5.7 to 25%, with the best results for patients harboring ophthalmic artery aneurysms and the worst results for those with vertebrobasilar system (VBS) aneurysms. The majority of patients with expected outcomes who harbored aneurysms of the middle cerebral artery, the internal carotid artery, and the VBS had a lower FAI, whereas the majority of patients with unexpected outcomes had a higher FAI. CONCLUSIONS: It is possible to predict outcomes in patients with unruptured cerebral artery aneurysms by calculating the FAI. The rate of postoperative morbidity increases with the FAI within the range of three to four factors.

Neurophysiological criteria for intraoperative prediction of pure motor hemiplegia during aneurysm surgery. Case report.

The value of motor evoked potentials (MEPs) as an intraoperative neurophysiological monitoring tool for detecting selective subcortical ischemia of the motor pathways during intracerebral aneurysm repair is described and the use of such measures to predict postoperative motor status is discussed. The authors present the case of a 64-year-old woman in whom there was an incidental finding of two right middle cerebral artery (MCA) aneurysms. During the aneurysm clipping procedure, an intraoperative MEP loss in the left abductor pollicis brevis and tibial anterior muscles occurred during an attempt at permanent clip placement. There were no concurrent changes in somatosensory evoked potentials. Postoperatively, the patient demonstrated a left hemiplegia with intact sensation. A computerized tomography scan revealed an infarct in the anterior division of the MCA territory, including the posterior limb of the internal capsule. In this patient, intraoperative neurophysiological monitoring with MEPs has been shown to be a sensitive tool for indicating subcortical ischemia affecting selective motor pathways in the internal capsule. Therefore, intraoperative loss of MEPs can be used to predict postoperative motor deficits.

Distal anterior inferior cerebellar artery aneurysms. Report of four cases.

Aneurysms of the distal anterior inferior cerebellar artery (AICA) are rare; fewer than 100 cases have been reported. The authors detail their experience with four cases and present endovascular as well as microsurgical management options. The medical records and neuroimaging studies obtained in four patients who were treated at a single institution were reviewed. Clinical presentations, neuroimaging and intraoperative findings, and clinical outcomes were analyzed. There were three men and one woman; their mean age was 43 years. Two patients presented with acute subarachnoid hemorrhage (SAH), and two presented with ataxia and vertigo (one with tinnitus, the other with hearing loss). Angiographic studies demonstrated aneurysms of the distal segment of the AICA. In one patient with von Hippel-Lindau syndrome and multiple cerebellar hemangioblastomas, a feeding artery aneurysm was found on a distal branch of the AICA. Three of the patients underwent successful surgical obliteration of their aneurysms, one by clipping, one by trapping, and one by resection along with the tumor. The fourth patient underwent coil embolization of the distal AICA and the aneurysm. All patients made an excellent neurological recovery. Patients with aneurysms in this location may present with typical features of an acute SAH or with symptoms referable to the cerebellopontine angle. Evaluation with computerized tomography, magnetic resonance (MR) imaging, MR angiography, and digital subtraction angiography should be performed. For lesions distal to branches coursing to the brainstem, trapping and aneurysm resection are viable options that do not require bypass. Endovascular obliteration is also a reasonable option, although the possibility of retrograde thrombosis of the AICA is a concern.

Intentional partial coil occlusion followed by delayed clip application to wide-necked middle cerebral artery aneurysms in patients presenting with severe vasospasm. Report of two cases.

The treatment of ruptured cerebral aneurysms in patients presenting with vasospasm remains a particular challenge. The authors treated two patients harboring Hunt and Hess Grade 1 subarachnoid hemorrhages from middle cerebral artery (MCA) aneurysms associated with severe local angiographically demonstrated yet asymptomatic vasospasm on presentation. Because both aneurysms had wide necks and were located at the MCA bifurcation, they were believed to be anatomically suitable for microsurgical clip application. Severe M, vasospasm was believed to be a relative contraindication to open surgery, however. An intentionally staged endovascular and microsurgical treatment strategy was planned in each patient. Partial coil occlusion of the aneurysmal dome was performed to prevent the lesion from rebleeding and was followed by balloon angioplasty of the spastic vessel. Early treatment of the severe spasm appeared to prevent significant delayed neurological ischemic deficit. Following resolution of the vasospasm, definitive clipping of the aneurysms was performed on Day 13 post embolization. One patient had a good clinical recovery and was discharged without neurological deficit. The other patient's hospital course was complicated by the occurrence of a postoperative posterior temporal infarct requiring partial temporal lobectomy, although she eventually had a good recovery with only a small visual field deficit. Based on data obtained in these two patients, one can infer that ruptured wide-necked MCA aneurysms associated with severe local vasospasm may best be treated using a staged combined treatment plan. Delayed clip application might be performed more safely 4 to 6 weeks postocclusion, or later, than at 2 weeks.

Alternative management considerations for ethmoidal dural arteriovenous fistulas.

BACKGROUND: Ethmoidal dural arteriovenous fistulas (EDAFs) are an unusual type of intracranial vascular lesion that commonly present with acute hemorrhage. They are often best treated surgically; however, recent endovascular advances raise questions concerning the best therapeutic approach. METHODS: We present 7 cases of EDAFs managed at this institution over a 6-year period, which demonstrate the broad spectrum of clinical behavior associated with the lesions. Four patients presented with intracranial hemorrhage, 1 patient with rapidly progressive dementia, 1 patient with a proptotic, red eye, and 1 with a retro-orbital headache. RESULTS: One patient underwent no treatment, 1 underwent embolization alone, 2 underwent embolization and resection, and 3 patients underwent resection alone. There was complete obliteration of the EDAF in all of the patients who underwent surgical resection. Embolization was performed through the external carotid circulation and not the ophthalmic artery. There were no treatment-related neurologic deficits. CONCLUSIONS: Treatment is best managed with a multidisciplinary approach, which emphasizes complete resection of the lesions with assistance from interventional neuroradiology techniques. However, each patient must be evaluated independently as treatment may vary depending on the angioarchitecture of the lesion.

Marvelous medicine: the untold story of the Wade-Dahl-Till valve.

On December 5, 1960, 4-month-old Theo Dahl, the only son of best-selling author Roald Dahl (1916-1990), had his skull shattered in a horrific traffic accident. What began as a personal tragedy for the Dahl family would soon evolve into a dogged crusade by Dahl to expand upon preexisting valve technology with the goal of developing a shunt that would not become obstructed. Based upon exclusive access to private archives of the Dahl estate, as well as interviews with those involved, this article tells the intricate tale of one famous father's drive to significantly alter the natural history of pediatric hydrocephalus. Dahl's collaboration with British toymaker Stanley Wade and pioneering pediatric neurosurgeons Joseph Ransohoff, Kenneth Shulman, and Kenneth Till to create the Wade-Dahl-Till (WDT) valve is examined in detail. The ensuing rift between the American and British contingents, the valve's multiple design revisions, and the goal of creating an affordable shunt for children in developing countries are among the issues addressed. The development of the WDT valve marked a significant turning point in the surgical management of pediatric hydrocephalus in general and in shunt valve technology in particular.

Attenuation of interleukin-1beta by pulsed electromagnetic fields after traumatic brain injury.

Traumatic Brain Injury (TBI) is a major cause of morbidity and mortality in civilian and military populations. Interleukin-1beta (IL-1ß) is a pro-inflammatory cytokine with a key role in the inflammatory response following TBI and studies indicate that attenuation of this cytokine improves behavioral outcomes. Pulsed electromagnetic fields (PEMF) can reduce inflammation after soft tissue injuries in animals and humans. Therefore, we explored whether PEMF signals could alter the course of IL-1ß production in rats subjected to closed-head contusive weight-drop injuries (Marmarou method) and penetrating needle-stick brain injuries. Protein levels, measured by the Biorad assay, were not altered by injuries or PEMF treatment. In addition, we verified that IL-1ß levels in cerebrospinal fluid (CSF) were proportional to injury severity in the contusion model. Results demonstrate that PEMF treatment attenuated IL-1ß levels up to 10-fold in CSF within 6h after contusive injury and also significantly suppressed IL-1ß within 17-24h after penetrating injury. In contrast, no differences in IL-1ß were seen between PEMF-treated and control groups in brain homogenates. To the authors' knowledge, this is the first report of the use of PEMF to modulate an inflammatory cytokine after TBI. These results warrant further studies to assess the effects of PEMF on other inflammatory markers and functional outcomes.

Motor evoked potential monitoring during cerebral aneurysm surgery: technical aspects and comparison of transcranial and direct cortical stimulation.

OBJECTIVE: This study evaluates technical aspects, handling, and safety of intraoperatively applied transcranial electrical stimulation (TES) and direct cortical stimulation (DCS) for eliciting muscle motor evoked potentials (mMEPs) during cerebral aneurysm surgery. METHODS: In 119 patients undergoing cerebral aneurysm surgery, mMEPs were evoked by a train of five stimuli with individual pulse duration of 0.5 milliseconds, a repetition rate of 2 Hz, and constant current anodal stimulation. The maximal stimulation intensity was 240 mA for transcranial and 33 mA for direct stimulation. mMEPs were recorded continuously from the abductor pollicis brevis, from tibial anterior muscles bilaterally, and from the biceps brachii and extensor digitorum communis muscles contralateral to the side operated on. RESULTS: In 118 (99%) of 119 patients, transcranially evoked mMEPs were monitorable for the vascular territory of interest. DCS was performed successfully in 95 (95%) of 100 patients. In 86 (99%) of 87 patients with internal carotid artery, middle cerebral artery, or posterior circulation aneurysms, mMEPs from upper-extremity muscles were obtained with DCS. In 11 (55%) of 20 patients with anterior communicating artery, anterior cerebral artery, or pericallosal aneurysms, mMEPs from the lower-extremity muscles could be recorded. The incidence of seizures was 0.84% for TES and 1% for DCS. Minor and inconsequential subdural bleeding after positioning of the strip electrode occurred in 2%. CONCLUSION: The cogent comprehensive combination of transcranial and direct cortical electrical stimulation allows for the continuous mMEP monitoring of the cerebral vascular territory of interest in 99% of the patients with cerebral aneurysms. Unwarranted effects of electrode placement and stimulation are rare and without clinical consequences.