Subdural hemorrhage in the posterior fossa caused by a ruptured cavernous carotid artery aneurysm after a balloon occlusion test

✓Given the relatively benign natural history of cavernous carotid artery aneurysms and based on anecdotal reports in the literature of subarachnoid hemorrhage (SAH) or subdural hemorrhage (SDH) from these aneurysms, observation is warranted and typically recommended. In this case report, the authors describe a woman who harbored a partially thrombosed, giant cavernous aneurysm that ruptured after she underwent a balloon occlusion test (BOT) and predominately led to an SDH. The authors believe that this occurrence is the first such report in the English literature. They discuss possible mechanisms for this event and the literature related to SAH or SDH from cavernous aneurysms, including why cavernous aneurysms cause such hemorrhages. The authors also recommend that attention be paid to such lesions regarding the possibility of aneurysmal rupture following a BOT.

Radiographic imaging of the distal dural ring for determining the intradural or extradural location of aneurysms

The effectiveness of several anatomical and radiological landmarks proposed to determine whether an aneurysm is located intradurally or extradurally is still debated. In anatomical and radiological studies, we examined the relationships of the distal dural ring (DDR) to the internal carotid artery (ICA) and surrounding bony structures to aid in the localization of aneurysms near the DDR. Anatomical relationships were examined by performing dissections on 10 specimens (5 formalin-fixed cadaveric heads). After the position of the DDR, optic nerve, and tuberculum sellae were marked with surgical steel wire, radiographs were taken in multiple projections. The only bony landmark consistently visible on radiographs was the planum sphenoidale. The superior border of the DDR is located at or below the level of the tuberculum sellae, which laterally becomes the superomedial aspect of the optic strut; thus, the optic strut marks the dorsal limit of the DDR. On 50 dry skulls, we measured the vertical distance between the planum sphenoidale and medial aspect of the optic strut (5.0 +/- 0.4 mm), the interoptic strut distance (14.4 +/- 1.4 mm), and the linear distance between the most posterior aspect of the planum sphenoidale (limbus sphenoidale) and the tuberculum sellae (6.0 +/- 0.5 mm). Using these measurements and the planum sphenoidale, tuberculum sellae, and optic strut as reference landmarks, we determined the location of the aneurysm relative to the DDR on angiographic images. In this way, we were able to identify whether lesions were intra- or extradural.

Delayed profound local brain hypothermia markedly reduces interleukin-1beta gene expression and vasogenic edema development in a porcine model of intracerebral hemorrhage

White matter (lobar) intracerebral hemorrhage (ICH) can cause edema-related deaths and life-long morbidity. In our porcine model, ICH induces oxidative stress, acute interstitial and delayed vasogenic edema, and up-regulates interleukin-1beta (IL-1beta), a proinflammatory cytokine-linked to blood-brain barrier (BBB) opening. In brain injury models, hypothermia reduces inflammatory cytokine production and protects the BBB. Clinically, however, hypothermia for stroke treatment using surface and systemic approaches can be challenging. We tested the hypothesis that an alternative approach, i.e., local brain cooling using the ChillerPad System, would reduce IL-1beta gene expression and vasogenic edema development even if initiated several hours after ICH. We infused autologous whole blood (3.0 mL) into the frontal hemispheric white matter of 20 kg pentobarbital-anesthetized pigs. At 3 hours post-ICH, we performed a craniotomy for epidural placement of the ChillerPad. Chilled saline was then circulated through the pad for 12 hours to induce profound local hypothermia (14 degrees C brain surface temperature). We froze brains in situ at 16 hours after ICH induction, sampled perihematomal white matter, extracted RNA, and performed real-time RT-PCR. Local brain cooling markedly reduced both IL-1beta RNA levels and vasogenic edema. These robust results support the potential for local brain cooling to protect the BBB and reduce injury after ICH.

Place of drug therapy in the treatment of carotid stenosis

Carotid stenosis is an important cause of transient ischaemic attacks and stroke. The cause of carotid stenosis is most often atherosclerosis; contributing to the pathogenesis of the lesion are endothelial injury, inflammation, lipid deposition, plaque formation, fibrin, platelets and thrombin. Carotid stenosis accounts for 10-20% of cases of brain infarction, depending on the population studied. Despite successful treatment of selected patients who have had an acute ischaemic stroke with tissue plasminogen activator and the promise of other experimental therapies, prevention remains the best approach to reducing the impact of ischaemic stroke. High-risk or stroke-prone patients can be identified and targeted for specific interventions. At this juncture, treatment of carotid stenosis is a well established therapeutic target and a pillar of stroke prevention. There are two main strategies for the treatment of carotid stenosis. The first approach is to stabilise or halt the progression of the carotid plaque through risk factor modification and medication. Hypertension, diabetes mellitus, smoking, obesity and high cholesterol levels are closely associated with carotid stenosis and stroke; control of these factors may decrease the risk of plaque formation and progression. The second approach is to eliminate or reduce carotid stenosis through carotid endarterectomy or carotid angioplasty and stenting. Carotid endarterectomy, which is the mainstay of therapy for severe carotid stenosis, is beyond the scope of this review. Anticoagulants seem to play little role (if any) in the medical (i.e. non-surgical) treatment of carotid stenosis. Adoption of a healthy lifestyle combined with the reduction of risk factors has been shown to lead to a reduction in the extent of carotid stenosis. The medical treatment of carotid stenosis should be based on the triad of the reduction of risk factors, patient education, and use of antiplatelet agents.

Bilirubin production and oxidation in CSF of patients with cerebral vasospasm after subarachnoid hemorrhage

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) remains a significant cause of mortality and morbidity; however, the etiology is, as yet, unknown, despite intensive research efforts. Research in this laboratory indicates that bilirubin and oxidative stress may be responsible by leading to formation of bilirubin oxidation products (BOXes), so we investigated changes in bilirubin concentration and oxidative stress in vitro, and in cerebral spinal fluid (CSF) from SAH patients. Non-SAH CSF, a source of heme oxygenase I (HO-1), and blood were incubated, and in vitro bilirubin production measured. Cerebrospinal fluid from SAH patients was collected, categorized using stimulation of vascular smooth muscle metabolism in vitro, and information obtained regarding occurrence of vasospasm in the patients. Cerebral spinal fluid was analyzed for hemoglobin, total protein and bilirubin, BOXes, malonyldialdehyde and peroxidized lipids (indicators of an oxidizing environment), and HO-1 concentration. The formation of bilirubin in vitro requires that CSF is present, as well as whole, non-anti-coagulated blood. Bilirubin, BOXes, HO-1, and peroxidized lipid content were significantly higher in CSF from SAH patients with vasospasm, compared with nonvasospasm SAH CSF, and correlated with occurrence of vasospasm. We conclude that vasospasm may be more likely in patients with elevated BOXes. The conditions necessary for the formation of BOXes are indeed present in CSF from SAH patients with vasospasm, but not CSF from SAH patients without vasospasm.

Local brain hypothermia for neuroprotection in stroke treatment and aneurysm repair

Hypothermia is well known to provide neuroprotection following various brain insults in experimental animals. Two recently completed clinical trials of whole body hypothermia in out-of-hospital cardiac arrest patients' demonstrated significantly improved survival rates and neurologic outcomes. These results provide new excitement and encouragement for clinical application of hypothermia in cerebrovascular disease. However, the intensive care challenges and adverse events (e.g. prolonged times to target temperatures, shivering and sedation, pneumonia) during the management of hypothermia, dampen enthusiasm for widespread application especially in elderly stroke patients. In this manuscript, we review recent hypothermia trials for stroke. We describe an alternate approach, i.e. local brain cooling, and discuss this new technique with reference to the extensive literature on the marked efficacy of hypothermia. We describe a new technology, the ChillerPad(TM) and ChillerStrip(TM) Systems developed by Seacoast Technologies, Inc. (Portsmouth, NH, USA). The latter device has received FDA approval and will be employed in a trial of local hypothermia for cerebral aneurysm repair. We present our experimental findings that profound local hypothermia does not damage cortical neurons. We also report that local hypothermia protects the blood-brain barrier and markedly reduces vasogenic edema development in an experimental intracerebral hemorrhage model. Lastly, we review potential mechanisms through which hypothermia provides blood-brain barrier protection and reduces edema formation. Clearly, hypothermia has a bright future for cerebrovascular disease treatment if brain cooling can be delivered in a manner that does not compromise the patient or the neurosurgical and intensive care settings. Local brain cooling may be just that new treatment approach.

Multiple, peripheral aneurysms of the anterior inferior cerebellar artery

In this case report, a 49-year-old woman developed subarachnoid hemorrhage in the right cerebellopontine angle cistern and blood into the fourth ventricle from a ruptured peripheral aneurysm of the anterior inferior cerebellar artery (AICA) located at the meatal loop. Concomitantly, a contralateral peripheral aneurysm was found in the posterior inferior cerebellar artery (PICA). A second peripheral aneurysm, not identified by previous angiography, was found in the caudomedial branch of AICA. We describe this diagnostic dilemma, management, and review the clinical presentation and location of 84 other peripheral AICA aneurysms reported in the literature.

Bilirubin as a cerebrospinal fluid marker of sentinel subarachnoid hemorrhage: a preliminary report in pigs

OBJECT

A model of subarachnoid hemorrhage (SAH) in pigs was developed to investigate bilirubin concentration in cerebrospinal fluid (CSF) as a potential marker of sentinel SAH.

METHODS

Seven male Yorkshire pigs received a 250-microl injection of either whole autologous arterial blood (four animals) or isotonic saline (three animals) into the cisternae magna in an effort to produce volumetrically a model of sentinel SAH and a control injection model, respectively. Cerebrospinal fluid volumes of 100 microl were then collected from both the lumbar cistern and cisternae magna at 1 to 2-hour intervals for a total of 24 hours postinjection. The CSF was then tested for bilirubin. Mean concentrations of bilirubin (+/- standard deviation [SD]) obtained from the lumbar cistern 24 hours following the injection of blood or saline were 4.38 +/- 1.04 microM in the SAH animals and 1.02 +/- 0.05 microM in the controls. At 24 hours postinjection, mean concentrations (+/- SD) of cisternae magna bilirubin were 7.29 +/- 1.33 microM and 1.33 +/- 0.14 microM in the SAH animals and controls, respectively. In the SAH group, both the lumbar cistern and cisternae magna bilirubin concentrations differed significantly from baseline values 12 hours following SAH.

CONCLUSIONS

Elevated concentrations of CSF bilirubin can be detected following a low-volume SAH, and the production of bilirubin occurred over a predictable time course. Twelve hours after hemorrhage, an elevated CSF bilirubin concentration was an indicator of hemolysis occurring in the subarachnoid spaces. The presence of bilirubin in CSF is a potential marker for differentiating SAHs from traumatic lumbar punctures in humans.

Aneurysms of the ophthalmic (C6) segment of the internal carotid artery: treatment options and strategies based on a clinical series

AIM

Treatment of ophthalmic segment aneurysms is technically demanding and still associated with a relatively high morbidity and mortality. The refinements of surgical techniques combined with the development of indirect methods of treatment have greatly improved the outcome in treating these lesions. We present our clinical experience and discuss treatment strategies.

METHODS

Seventy-eight consecutive patients with 88 ophthalmic segment aneurysms were admitted to our service from January 1997 to June 2003. Forty-three patients presented with unruptured aneurysms and 35 presented with subarachnoid hemorrhage (SAH). Management strategies included surgical clipping alone in 53 patients, clipping and hemicraniectomy in 2, coiling in 17, external carotid artery-middle cerebral artery (ECA/MCA) by-pass in 2, and coil occlusion of the internal carotid artery in 2. Two patients underwent no treatment.

RESULTS

In the group of 41 treated patients with unruptured aneurysms, 40 (97.6%) had good outcomes (GOS 1-2) and 1 patient had poor (GOS 3) outcome at discharge. Procedure-related morbidity was 15.7% (8/51 procedures), and permanent morbidity was 9.75% (4/41 patients). In the 35 patients who presented with SAH, mortality was 14.3% (5 patients); at discharge, 21 patients (60%) had good (GOS 1-2) and 9 (25.7%) poor (GOS 3) outcomes. The overall outcome was good (GOS 1-2) in 63 patients (80.8%) and poor (GOS 3-4) in 10 patients (12.8%). Overall mortality was 6.4% (5 patients all with SAH).

CONCLUSIONS

Direct obliteration of the aneurysm utilizing advanced surgical techniques is our preferred treatment approach, whenever possible. In case of unclippable large or giant aneurysms, the surgical or endovascular occlusion of the proximal internal carotid artery with or without an extracranial-intracranial by-pass is an option. A highly skilled team including a cerebrovascular and an endovascular surgeon is essential to achieve good outcomes in treating these lesions.

Fenestration of the Lamina Terminalis as a Valuable Adjunct in Aneurysm Surgery

OBJECTIVE:

Hydrocephalus, vasospasm, and frontobasal injury are common complications after aneurysmal subarachnoid hemorrhage (SAH) from anterior communicating artery aneurysms. Previous studies have suggested that fenestration of the lamina terminalis (FLT) during surgery may be associated with reduced rates of shunt-dependent hydrocephalus and vasospasm. We report 106 patients affected by anterior communicating artery aneurysms and Fisher Grade 3 aneurysmal SAH and the affect of FLT on shunt-dependent hydrocephalus, vasospasm, and frontobasal injury.

METHODS:

During a 3-year period, 53 patients underwent FLT and 53 did not. We prospectively evaluated admission and discharge clinical grades, hydrocephalus at admission, occurrence of clinical vasospasm, need for interventional vasospasm therapy, frontobasal hypodensity incidence, and permanent ventriculoperitoneal shunting requirement. Follow-up ranged from 3 to 35 months (mean, 17.9 mo).

RESULTS:

Shunting incidence after aneurysmal SAH with hydrocephalus was 4.25% in patients who underwent FLT and 13.9% in patients who did not (P< 0.001). Clinical cerebral vasospasm occurred in 29.6% of patients who underwent FLT and in 54.7% of patients who did not (P< 0.001). Frontobasal hypodensity was identified postoperatively in 0% of patients who underwent FLT and in 5% of patients who did not. Good outcome was reported in 69.81% of patients who underwent FLT and in 33.96% of patients who did not (P< 0.001). Poor outcome was associated with higher Hunt and Hess grades, need for ventricular drainage, elevated intracranial pressure, and multiple interventional vasospasm therapies. No complications were linked to FLT.

CONCLUSION:

FLT was associated with statistically significant decreases in shunting rates, incidence of vasospasm, and better outcomes. We recommend its routine use in patients with Fisher Grade 3 anterior communicating artery aneurysmal SAH.

The carotid-oculomotor window in exposure of upper basilar artery aneurysms: a cadaveric morphometric study

OBJECTIVE

The carotid-oculomotor window remains the traditional deep window in the exposure of aneurysms of the upper basilar artery. Although several techniques have been described to expand this window, few morphometric studies document either the degree of its expansion or its contribution to the exposure of the basilar artery. We review the microsurgical anatomy of the carotid-oculomotor window, describe expansion techniques, and analyze morphometrically the contribution of each step (i.e., extradural anterior clinoidectomy, mobilization of the internal carotid artery [ICA], and posterior clinoidectomy) to the expansion of the window and/or exposure of the artery.

METHODS

Ten formalin-fixed, alcohol-preserved, cadaver heads injected with pigmented silicone were prepared for bilateral dissection. The vertebrobasilar system was injected with pigmented silicone mixed with barium (1:1), rendering it radiopaque. After completing a frontotemporal-orbitozygomatic craniotomy, we performed dissection in two stages: Stage I consisted of a conventional transsylvian exposure of the upper basilar artery through the carotid-oculomotor window; and Stage II added anterior clinoidectomy, ICA mobilization, and posterior clinoidectomy. A clip was applied to the lowest accessible point of the basilar trunk at each stage. Measurements obtained during each stage included: 1). the transverse carotid-oculomotor distance, that is, anteriorly between the oculomotor foramen and ICA, and posteriorly between the oculomotor nerve and ICA; and 2). the exposed length of the basilar artery, as seen under the microscope and on angiograms.

RESULTS

Measurements were obtained before and after the addition of anterior clinoidectomy, mobilization of the ICA, and posterior clinoidectomy. Increases in expansion of the window and exposure of the upper basilar artery were documented as percentages of the control values. The anterior carotid-oculomotor distance averaged 7.1 mm (range, 5-10 mm) and 10.1 mm (range, 7-15 mm) before and after the additional surgical steps to expand the window, respectively. The posterior carotid-oculomotor distance averaged 12.7 mm (range, 9-18 mm) and 16.1 mm (range, 11-22 mm) before and after the additional surgical steps to expand the window, respectively. The exposed length of the basilar artery from the bifurcation to the clip was 4.2 mm (range, 1-13 mm) before expansion and 7 mm (range, 3-15 mm) after expansion.

CONCLUSION

Anterior clinoidectomy and ICA mobilization increased the carotid-oculomotor space 44% anteriorly and 28% posteriorly. Posterior clinoidectomy increased the exposed length of the basilar artery by 69%. Superficial wide field exposure, expansion of the carotid-oculomotor window, and increased exposure of the upper basilar artery facilitate both visualization of the aneurysm for clip application and the use of proximal vascular control as an adjunct to basilar aneurysm surgery.

LARGE SPHENOID WING MENINGIOMAS INVOLVING THE CAVERNOUS SINUS: CONSERVATIVE SURGICAL STRATEGIES FOR BETTER FUNCTIONAL OUTCOMES

OBJECTIVE

The ability to resect meningiomas that involve the medial and anterior compartments of the cavernous sinus has been refuted. In this retrospective study, we determined the efficacy of total resection of meningiomas that invade the cavernous sinus but are restricted to the lateral compartment.

METHODS

We reviewed the charts of 38 consecutive patients with sphenocavernous, clinoidocavernous, and sphenoclinoidocavernous meningiomas who underwent surgical treatment. We assessed early and late cranial nerve morbidity, extent of resection, and long-term outcome (mean, 96 mo).

RESULTS

In all patients, tumors exceeded 3 cm diameter. In 22 of 24 patients, total microscopic excision was achieved in tumors that involved only the lateral compartment of the cavernous sinus and touched or partially encased the cavernous internal carotid artery (i.e., modified Hirsch Grades 0 and 1, respectively). In 2 of 24 patients, remaining tumor infiltrated the superior orbital fissure. All 14 patients who had tumors that encased (with or without narrowing) the cavernous segment of the internal carotid artery (Hirsch Grades 2-4) underwent incomplete resection. Among 38 patients, mortality was 0%, late cranial nerve deficits remained in 6 (16%), and late Karnofsky Performance Scale scores exceeded 90 in 34 patients (90%). Four patients (10.5%) developed a recurrence or regrowth. Of 20 patients who were treated with either linear accelerator-based stereotactic radiosurgery or fractionated conformal radiotherapy, 11 had residual tumor and a moderate to high proliferative index, 4 had atypical tumors and 1 had angioblastic meningioma after total excision, 2 had regrowth, and 2 had recurrent tumors. In 18 (90%) of the 20 patients who underwent radiation, tumor size was reduced or controlled.

CONCLUSION

On the basis of this study and a review of the literature, we demonstrate that sphenocavernous, clinoidocavernous, and sphenoclinoidocavernous meningiomas of Hirsch Grades 0 and 1 can be excised from the lateral compartment of the cavernous sinus without postoperative mortality and with acceptable rates of morbidity. Residual tumor in the medial compartment (Hirsch Grades 2-4) may be treated with some form of radiation therapy or observation.

Outcomes of Cubital Tunnel Surgery among Patients with Absent Sensory Nerve Conduction

OBJECTIVE

To report the outcomes of cubital tunnel surgery for patients with absent ulnar sensory nerve conduction.

METHODS

The charts of 34 patients who exhibited clinical symptoms of ulnar nerve entrapment at the elbow and who had electromyography-confirmed prolonged motor nerve conduction across the cubital tunnel in association with absent sensory nerve conduction were reviewed. The mean age was 63 years, and the mean symptom duration was 17 months. Four patients had bilateral symptoms. Surgery was performed for 38 limbs, i.e., neurolysis for 21 limbs and subcutaneous transposition for 17 limbs. Fifteen limbs demonstrated associated ulnar nerve-related motor weakness. The mean postoperative follow-up period was 4 years (range, 3 mo to 11 yr).

RESULTS

Sensory symptoms (i.e., pain, paresthesia, and two-point discrimination) improved in 20 limbs (53%), and muscle strength improved in 2 limbs (13%). Improvements in sensory symptoms were not related to patient age, symptom duration, cause, severity of prolonged motor nerve conduction, select psychological factors, associated medical diseases, associated cervical pathological conditions, or type of surgery. Improvements in sensory symptoms were significantly decreased among patients who had experienced cervical disease for more than 1 year and patients with bilateral symptoms.

CONCLUSION

Patients with cubital tunnel syndrome who have absent sensory nerve conduction seem to experience less improvement of sensory symptoms after surgery, compared with all patients with cubital tunnel syndrome described in the literature. Bilateral symptoms and delayed surgery secondary to associated cervical spine disease seem to be significant negative factors for postoperative improvement of sensory symptoms. Sensory symptoms improved similarly among patients who underwent neurolysis or subcutaneous transposition

Evidence-based surgical treatment of carotid stenosis. Literature review

Carotid stenosis is an important cause of transient ischemic attacks and stroke. The cause of carotid stenosis is most often atherosclerosis, which accounts for 10% to 20% of brain infarction cases. Despite the introduction of tissue-plasminogen activator and other promising experimental therapies for select patients with acute ischemic stroke prevention remains the best approach to reduce its impact. Stroke-prone patients can be identified and targeted for specific interventions. At this juncture, treatment of carotid stenosis is a well-established therapeutic target and a pillar of stroke prevention. Two main strategies exist for the treatment of carotid stenosis. The 1st is stabilization or halting the progression of the carotid plaque formation with medications and modifications of risk factors (e.g., hypertension, diabetes, smoking, obesity, high cholesterol). The 2nd approach is the elimination or reduction of carotid stenosis by carotid endarterectomy or angioplasty and stenting. Carotid endarterectomy is the mainstay of therapy for symptomatic, severe carotid stenosis. Although its role for asymptomatic patients appears more limited, it is distinct for severe stenosis. Carotid angioplasty and stenting are techniques in maturation with the attractiveness of being less invasive that face the challenge of at least replicating the results of surgery. In this article, we will discuss the surgical management of symptomatic and asymptomatic carotid stenosis based on the evidence provided by the literature.

Visceral leishmaniasis and HIV co-infection: a rare case of pulmonary and oral localization

Visceral leishmaniasis (VL) has increased as a complicating infection in subjects with human immunodeficiency virus (HIV) in countries bordering the Mediterranean sea. The clinical course as well as organ involvement of VL are often atypical in HIV positive subjects. In this study a case of VL with pulmonary and oral mucose localisation in a patient with acquired immune deficiency syndrome (AIDS), is reported. These findings, together with the presence of the parasite in the peripheral blood smear, confirm that in HIV positive patients the impaired immune system allows the spreading and the atypical localisation of the Leishmania amastigotes more easily than in immuno-competent individuals. In endemic areas and in HIV positive subjects a systemic and careful parasitological follow-up is necessary to ensure that any clinical form of leishmaniasis is not overlooked.

Anatomic and Clinical Study of the Orbitopterional Approach to Anterior Communicating Artery Aneurysms

OBJECTIVE

To evaluate the orbitopterional approach to anterior communicating artery (AComA) aneurysms, on the basis of the quantification of this surgical exposure, compared with the pterional approach, in a cadaveric study and a retrospective review of data for 40 patients who underwent clipping of AComA aneurysms via the orbitopterional approach.

METHODS

In an anatomic study, four cadaveric heads underwent pterional craniotomies on the left side and orbitopterional craniotomies on the right side. A fifth head was initially subjected to bilateral pterional craniotomies and then underwent bilateral orbital osteotomies, for direct comparison of these approaches. Using frameless stereotaxy, we quantified the angles of exposure and surgical field depths provided by the pterional and orbitopterional craniotomies. In a clinical study, 40 patients who underwent clipping of AComA aneurysms via orbitopterional approaches were evaluated for basal brain injury, the need for resection of the gyrus rectus, dissection of the sylvian fissure, and approach-related complications. The incidence of postoperative hydrocephalus among patients with subarachnoid hemorrhage who underwent lamina terminalis fenestration was also reviewed.

RESULTS

The angles of observation were increased 46% in the axial plane (orbitopterional, 72.92 ± 6.57 degrees; pterional, 49.75 ± 2.27 degrees; P< 0.01) and 137.5% in the projection plane (orbitopterional, 8 ± 2.19 degrees; pterional, 19 ± 1.78 degrees; P< 0.01). The surgical window depth was decreased 13% with the orbitopterional approach (P< 0.05). Clinically, there was no incidence of frontobasal hypodensities on postoperative computed tomographic scans. Three patients (7.5%) required resection of the gyrus rectus. No patient required sylvian fissure dissection for aneurysm exposure. Two of 29 patients (6.9%) who survived subarachnoid hemorrhage required ventriculoperitoneal shunts despite lamina terminalis fenestration. No approach-related complications were recognized.

CONCLUSION

The orbitopterional approach improved the observation of the AComA complex and seemed to decrease the risk of intraoperative brain damage.

Anatomic and clinical study of the orbitopterional approach to anterior communicating artery aneurysms

OBJECTIVE

To evaluate the orbitopterional approach to anterior communicating artery (AComA) aneurysms, on the basis of the quantification of this surgical exposure, compared with the pterional approach, in a cadaveric study and a retrospective review of data for 40 patients who underwent clipping of AComA aneurysms via the orbitopterional approach.

METHODS

In an anatomic study, four cadaveric heads underwent pterional craniotomies on the left side and orbitopterional craniotomies on the right side. A fifth head was initially subjected to bilateral pterional craniotomies and then underwent bilateral orbital osteotomies, for direct comparison of these approaches. Using frameless stereotaxy, we quantified the angles of exposure and surgical field depths provided by the pterional and orbitopterional craniotomies. In a clinical study, 40 patients who underwent clipping of AComA aneurysms via orbitopterional approaches were evaluated for basal brain injury, the need for resection of the gyrus rectus, dissection of the sylvian fissure, and approach-related complications. The incidence of postoperative hydrocephalus among patients with subarachnoid hemorrhage who underwent lamina terminalis fenestration was also reviewed.

RESULTS

The angles of observation were increased 46% in the axial plane (orbitopterional, 72.92 +/- 6.57 degrees; pterional, 49.75 +/- 2.27 degrees; P < 0.01) and 137.5% in the projection plane (orbitopterional, 8 +/- 2.19 degrees; pterional, 19 +/- 1.78 degrees; P < 0.01). The surgical window depth was decreased 13% with the orbitopterional approach (P < 0.05). Clinically, there was no incidence of frontobasal hypodensities on postoperative computed tomographic scans. Three patients (7.5%) required resection of the gyrus rectus. No patient required sylvian fissure dissection for aneurysm exposure. Two of 29 patients (6.9%) who survived subarachnoid hemorrhage required ventriculoperitoneal shunts despite lamina terminalis fenestration. No approach-related complications were recognized.

CONCLUSION

The orbitopterional approach improved the observation of the AComA complex and seemed to decrease the risk of intraoperative brain damage.

Vasospasm following subarachnoid hemorrhage: evidence against functional upregulation of protein kinase C constrictor pathway

This study tested the hypothesis that vasospasm due to subarachnoid hemorrhage involves the functional upregulation of protein kinase C. Spasm of the rabbit basilar artery was achieved using a double hemorrhage model, which we previously demonstrated was endothelin-1 dependent. In situ effects of agents were determined by direct measurement of vessel diameter following their suffusion in a cranial window. Chelerythrine, a protein kinase C inhibitor, relaxed the spasm. However, relaxations to chelerythrine were not significantly greater in endothelin-1 constricted spastic vessels initially relaxed with the endothelin converting enzyme inhibitor, phosphoramidon, as compared to endothelin-1 constricted control vessels. These results suggest that subarachnoid hemorrhage induced vasospasm does not involve functional upregulation of protein kinase C.

Cocaine-induced endothelin-1-dependent spasm in rabbit basilar artery in vivo

Although cocaine-induced constriction of cerebral vessels may play an important negative role in the pathogenesis of cocaine-related stroke, the mechanism underlying the vasospasm remains unclear. This study investigated the role of endothelin-1 in mediating the spasm. Intracisternal cocaine infusion (10 microl/h via osmotic pump) into the cisterna magna of rabbits induced time- and concentration-dependent spasm. Maximal spasm was achieved with 100 microM cocaine infusate, and was observed as early as 0.5 days and reached a maximum at 2 days. Coinfusion of 100 microM cocaine with the endothelin receptor antagonist PD145065 (100 microM) prevented the spasm. Cerebral spinal fluid levels of cocaine and benzoylecgonine, a major cocaine metabolite, were below the limit of assay detection. This study demonstrates the novel finding that endothelin-1 mediates cocaine-induced cerebral vasospasm.

The One-Piece Orbitopterional Approach

The orbitopterional approach is an anterior skull base extension of the pterional approach that provides greater exposure to the anterior cranial fossa, supra- and parasellar regions, and anterior communicating artery complex. We describe the surgical technique in a stepwise manner to create a one-piece orbitopterional craniotomy flap; keyholes for the bone cuts are the MacCarty burr-hole and the anterolateral portion of the inferior orbital fissure. This one-piece technique is less complicated than the two-piece orbitopterional craniotomy and eliminates the need for complex reconstruction of cosmetically important areas (i.e., the orbit and forehead).

Repeated constriction to respiration-induced hypocapnia is not mimicked by isocapnic alkaline solution in rabbit basilar artery in situ

The purpose of this study was to test whether constriction of the cerebral vasculature in response to respiration-induced hypocapnia was mimicked by isocapnic alkaline solution. Since the regulation of the cerebral vasculature by hypocapnia necessitates vessels to constrict repeatedly in response to hypocapnic challenge, we tested whether repeated challenge with isocapnic alkaline solution was also associated with constriction. In contrast to our previous demonstration that repeated hypocapnic challenge elicited constrictions of similar magnitudes in rabbit basilar artery in situ, repeated challenge with isocapnic alkaline solution resulted in reduced constriction. Constriction to hypocapnia was also reduced following isocapnic alkaline solution. Since we previously demonstrated that constrictions to hypocapnia and isocapnic alkaline solution were endothelin-1 dependent, we tested whether the inhibition of hypocapnia- and isocapnic alkaline solution-induced constrictions following isocapnic alkaline solution was due to reduced endothelin-1 constriction. Endothelin-1 constriction was not reduced following isocapnic alkaline solution. Thus, constriction to isocapnic alkaline solution does not mimic constriction to hypocapnia. The results further suggest that the decreased constriction to isocapnic alkaline solution is due to blockade of endothelin-1 release, and that both hypocapnia and isocapnic alkaline solution share a common step in their endothelin-1 release pathways that can be inhibited by isocapnic alkaline solution.

C-tau biomarker of neuronal damage in severe brain injured patients: association with elevated intracranial pressure and clinical outcome

Following traumatic brain injury, the neuronally-localized intracellular protein MAP-tau is proteolytically cleaved (C-tau) and gains access to cerebrospinal fluid (CSF) and serum. The present study compared initial CSF C-tau levels, initial Glasgow Coma Scale (GCS) scores and elevated intracranial pressure (ICP) as predictors of clinical outcome. In this preliminary, prospective study of consecutive severe traumatic brain injured patients (TBI) clinical outcome was quantified with the Glasgow Outcome Scale (GOS) at discharge (n=28). Sensitivity and specificity of initial C-tau levels and initial GCS scores as predictors of clinical outcome is reported. To assess disease specificity C-tau levels were compared between TBI patients and neurologic (n=87) and non-neurologic control patients (n=67). Initial CSF C-tau levels were elevated 40,000 fold in TBI patients compared to either neurologic or non-neurologic control patients (P<0.001). Initial C-tau levels were correlated with clinical outcome (P=0.006) and were a significant predictor of dichotomized clinical outcome (P=0.011) demonstrating a sensitivity of prediction of 92% and a specificity of 94%. Initial C-tau levels were also a significant predictor of subsequent ICP with higher initial C-tau levels associated with elevated ICP (P=0.014). Initial GCS score were correlated with clinical outcome (P=0.026) and demonstrated a sensitivity of 50% and a specificity of 100% for predicting dichotomized clinical outcome. Statistical analysis indicated that initial C-tau levels and initial GCS scores were independent predictors of clinical outcome. The present preliminary study demonstrates that initial CSF C-tau levels are a significant predictor of ICP and clinical outcome with particular sensitivity for identifying severe TBI patients with good clinical outcome. Future studies employing a larger sample size and clinical outcome assessment at longer periods after hospitalization will be needed to determine the utility of initial C-tau levels as a clinical biomarker in TBI.

Indications for endovascular therapy for refractory vasospasm after aneurysmal subarachnoid hemorrhage: experience at the University of Cincinnati

BACKGROUND

Transluminal balloon angioplasty (TBA) and intra-arterial papaverine (IAP) appear to be valuable alternatives for the treatment of aneurysmal subarachnoid hemorrhage (SAH)-induced vasospasm refractory to maximal medical therapy. Although widely used, guiding principles for the implementation of TBA and IAP are not yet established. Based on our retrospective analysis, we define guidelines for endovascular therapy for refractory vasospasm based on our clinical results, adverse effects, and pattern of vasospasm.

METHODS

Medical records of 62 patients who experienced aneurysmal SAH-induced vasospasm refractory to hypervolemic, hypertensive, hyperdynamic therapy, and who were treated with IAP or TBA were reviewed. Fifty patients met the inclusion criteria for analysis. After careful scrutiny, two types of responses to endovascular treatment were identified. On the basis of that grouping, patients were divided into two groups according to the number of arterial segments involved, that is, monoterritorial and multiterritorial vasospasm. Multiple variables were analyzed.

RESULTS

Patients undergoing multiple endovascular procedures exhibited the worst outcomes. Patients in the monoterritorial group experienced a higher incidence of clinical improvement and better outcomes after endovascular treatment. Elevated intracranial pressure (ICP) and ICP-related deaths were more prominent in the multiterritorial group of patients. Sustained ICP elevation after administration of IAP was strongly associated with poor outcome in the multiterritorial group.

CONCLUSIONS

IAP is indicated as an early potential single-dose infusion in distal monoterritorial vasospasm, if angioplasty is impossible or unsafe. The use of IAP in bilateral diffuse vasospasm is discouraged because of the high susceptibility of these patients to develop elevated ICP. Multiple IAP infusions seem to have no significant impact on patient outcome. Balloon angioplasty seems to be indicated at an early juncture in patients with multiterritorial proximal vasospasm.