Need For Craniotomy Research Articles

Outcomes of Surgically Treated Giant Pituitary Tumours

To evaluate the outcomes of patients with giant pituitary tumours (GPTs) who underwent a purely binasal endoscopic transsphenoidal surgery (BETS) and compare their outcomes with those achieved through craniotomy and microscopic transsphenoidal surgery (MTS). Seventy-two consecutive patients with GPTs (greater than 10 cm3 in volume) who were treated surgically with BETS, craniotomy, or MTS from October 1994 to July 2009 were reviewed for clinical outcomes, degree of tumor resection, recurrence rates, and surgical complications. The BETS group had significantly better mean reduction of tumor volume (91%) than the craniotomy (63%, p = 0.001), and the MTS (63%, p = 0.010) groups. Gross total resection rates were also higher for BETS patients than for craniotomy patients (p = 0.010). Improvements in vision and headaches were noted in 96% and 100% of patients in the BETS group, respectively; these rates were similar to those in the craniotomy and MTS groups. Of the four patients with hormone-secreting tumours in the BETS group, three remained in remission. The median length-of-stay (four days) for the BETS group was shorter (p = 0.010), and surgical complications were less frequent (p = 0.037) and less severe compared to the craniotomy group. There were no differences in the recurrence rates: 79% percent of patients in the BETS group, 69% in the craniotomy group, and 79% in the MTS group were recurrence free at last follow-up (p = 0.829). Treatment of GPT with BETS offers excellent oncologic and clinical outcomes and can frequently obviate the need for craniotomy in these patients.

Assessment of platelet transfusion for reversal of aspirin after traumatic brain injury

Platelet transfusion is utilized increasingly for traumatic brain injury (TBI) for the reversal of aspirin (ASA) therapy. Assessment of platelet inhibition and reversal by platelet transfusion after TBI has not been adequately characterized. A retrospective cohort analysis of TBI patients at a level I trauma center (January 2008-December 2009) was performed. The Aspirin Response Test (ART; VerifyNow) was used to assess platelet inhibition in TBI patients and guide platelet transfusion in patients with ASA-induced suppression. A follow-up ART was obtained after platelet administration. Primary endpoints were progression of intracranial hemorrhage on computed tomography, need for craniotomy, and mortality. We analyzed 84 patients (median age, 78 [interquartile range, 64-86)]; 54% male). ASA use was documented in 36 (42%) patients. Initial ART indicated platelet dysfunction in 54 (64%) patients, including 42% of patients without a documented history of ASA use. Of the patients with a documented history of ASA, 2.4% had a normal ART. Of those with an initial ART of <550 ASA response units, 45 received platelets. Repeat ART demonstrated reversal of inhibition in 29 patients (64.4%). Initial responders to transfusion received a greater volume of platelets, suggesting a dose-response relationship. Logistic regression revealed a trend toward higher mortality in nonresponders to transfusion (P = .09). Receiver operating characteristic curve analysis revealed that ART results increased prediction of poor outcome compared with ASA history alone (area under the curve = 0.760 and 0.775, respectively). The ART should be used to better target and guide platelet transfusions in TBI patients with known or suspected ASA use history. Patients with occult platelet dysfunction can be identified, unnecessary platelet transfusions avoided, and the adequate volume of platelets administered to correct drug-induced dysfunction. A dose-response relationship between quantity of platelets transfused and reversal of ASA inhibition was observed.

Transorbital and Transnasal Endoscopic Repair of a Meningoencephalocele

A 71-year-old female with a history of thyroid eye disease (TED) presented for evaluation of a skull base mass noted on neuroimaging. She had previously undergone bilateral orbital decompressions and strabismus surgery and had no neurologic symptoms. Successful resection of the menigoencephalocele and repair of the skull base defect was performed through a combined transnasal endoscopic and transorbital approach, obviating the need for craniotomy.

Intracranial Abscess from Acute Sinusitis without Craniotomy

Objective: To evaluate the success of treatment of intracranial abscess occurring from acute sinus disease without utilizing craniotomy. Method: Retrospective chart review based at a tertiarty care children’s medical center. Children were evaluated from 1995 to 2010 with intracranial abscess formation from acute sinusitis. The main outcome measures were treatment modalities for acute intracranial and sinus disease. Results: Twenty-five children were evaluated from 1995 to 2010 with acute sinusitis resulting in brain abscesses. Over the first 10 years, 15 were treated successfully with an intracranial procedure and sinus surgery. Over the past 5 years, 10 cases of intracranial abscess were encountered, with 5 out of 10 treated successfully without the need for craniotomy. 4 out of 5 had small epidural abscesses treated with endoscopic sinus surgery and intravenous antibiotic, and 1 out of 5 had a small epidural and subdural abscess treated with medical therapy alone. Conclusion: Medical management of intracranial abscess along with medical or surgical treatment of acute sinusitis may be a viable option for certain children with small epidural abscesses caused by acute sinusitis.

Risk Factors for Conversion to Permanent Ventricular Shunt in Patients Receiving Therapeutic Ventriculostomy for Traumatic Brain Injury

Intracranial pressure is routinely monitored in patients with severe traumatic brain injury (TBI). Patients with TBI sometimes develop hydrocephalus, requiring permanent cerebrospinal fluid (CSF) diversion. To quantify the need for permanent CSF diversion in patients with TBI. Patients who received a ventriculostomy after TBI between June 2007 and July 2008 were identified, and their medical records were abstracted to a database. Sixteen of 71 patients (22.5%) receiving a ventriculostomy required a ventriculoperitoneal or ventriculoatrial shunt before discharge from the hospital. The average number of days between ventriculostomy and shunt was 18.3. Characteristics that predispose these patients to require permanent CSF diversion include the need for craniotomy within 48 hours of admission (odds ratio, 5.20; 95% confidence interval, 1.48-18.35) and history of culture-positive CSF (odds ratio, 5.52; 95% confidence interval, 1.19-25.52). Length of stay was increased in patients receiving permanent CSF diversion (average length of stay, 61 vs 31 days; P = .04). Patient discharge disposition was similar between shunted and nonshunted patients. In this retrospective study, 22% of TBI patients who required a ventriculostomy eventually needed permanent CSF diversion. Patients with TBI should be assessed for the need for permanent CSF diversion before discharge from the hospital. Care must be taken to prevent ventriculitis. Future studies are needed to evaluate more thoroughly the risk factors for the need for permanent CSF diversion in this patient population.

The Impact of Platelets on the Progression of Traumatic Intracranial Hemorrhage

The purpose of this study was to analyze the association of the initial platelet count with mortality and progression of intracranial hemorrhage (ICH) in blunt traumatic brain injured (TBI) patients. All blunt trauma patients with severe TBI admitted from January 2006 to December 2007 were retrospectively identified. Patients with a chest, abdomen, or extremity AIS score >3 were excluded to minimize the impact of concomitant injuries on the outcomes of the patients. All brain computed tomography scans were reviewed to analyze ICH progression. Discrete platelet cutoff values were entered into a multiple regression model to detect critical thresholds associated with ICH progression and mortality. Of 626 TBI patients, 310 (49.5%) had a minimum of two brain computed tomography scans and were able to have ICH progression evaluated. Patients with platelets <175,000/mm3 had a significantly increased risk for ICH progression (OR [95% CI]: 2.09 [1.07-4.37]; adjusted p = 0.043). ICH progression was associated with increased need for craniotomy (OR [95% CI]: 3.27 [1.28-8.33]; adjusted p = 0.013) and mortality (OR [95% CI]: 3.41 [1.11-10.53]; adjusted p = 0.033). A platelet count <100,000/m3 was an independent predictor for mortality (OR [95% CI]: 9.5 [1.3-71.4]; adjusted p = 0.029). A platelet count <100,000/mm3 is associated with a ninefold adjusted risk of death, and a platelet count <175,000/mm3 is a significant predictor of ICH progression. The impact of early correction of the admission platelet count warrants further validation.

Posttraumatic Cerebral Infarction: Incidence, Outcome, and Risk Factors

Outcome in patients with traumatic brain injury (TBI) is often affected by secondary insults including posttraumatic cerebral infarction (PTCI). The incidence of PTCI after TBI was previously reported to be 2% with no mortality impact. We suspected that recent advances in imaging modalities and treatment might affect incidence and outcome. We sought to define the incidence and mortality impact of PTCI. We also identified risk factors associated with PTCI. We retrospectively reviewed all patients admitted between 2004 and 2006 with severe TBI (brain Abbreviated Injury Scale [AIS] score >2, Glasgow Coma Scale score [GCS] <9). Demographics, injury specifics, and clinical data were abstracted. All brain imaging studies were reviewed with an attending trauma radiologist. Statistical analysis of outcome data were performed using chi and Student's t test and multivariate analysis was performed using logistic regression to identify independent risk factors. Of the 384 patients identified with severe TBI; 93% sustained a blunt injury, 75% were men. Mortality was 21%, and 48% had a brain AIS score of 5. Mean age was 36 years (11-90 years), admission GCS score was 5 (3-8), and Injury Severity Score was 32 (9-75). Thirty-one (8%) had a confirmed PTCI. The PTCI group had a significantly increased mortality (45% vs. 19%, p < 0.002), hospital length of stay (LOS) (25 days vs. 18 days, p < 0.02), and intensive care unit LOS (21 days vs. 15 days, p < 0.03). In multivariate analysis, sex, age, Injury Severity Score, Revised Trauma Score, admission GCS, and brain AIS were not associated with PTCI; whereas the presence of blunt cerebral vascular injury [odds ratio (OR) 4.0, 95% confidence interval (CI) 1.9-8.7], the need for craniotomy (OR 3.0, 95% CI 1.2-6.9), or treatment with recombinant factor VIIa (OR 3.1, 95% CI 1.1-8.0) were each independently associated with an increased risk of PTCI. The incidence of PTCI in patients with severe TBI is higher after severe brain injury than previously thought. PTCI has a significant impact on mortality and LOS. The presence of a blunt cerebral vascular injury, the need for craniotomy, or treatment with factor VIIa are risk factors for PTCI. Recognition of this secondary brain insult and the associated risk factors may help identify the group at risk and tailor management of patients with severe TBI.

Transarterial Embolization for Intractable Oronasal Hemorrhage Associated With Craniofacial Trauma: Evaluation of Prognostic Factors

This study analyzed the outcomes for clinical application of transarterial embolization (TAE) to treat intractable posttraumatic oronasal hemorrhage in patients who suffered from craniofacial injuries. The charts and radiologic and operative records of 34 patients from January 2002 to December 2007 were retrospectively reviewed. Inclusion criteria focused on the patients whose intractable posttraumatic oronasal hemorrhage associated with craniofacial trauma required TAE treatment. The patients' survival was correlated with prognostic factors with Spearman's rank correlation coefficients. Wilcoxon signed ranks test was used to analyze the differences between the severity of shock before and after TAE, and Fisher's exact test was used to analyze unvaried factors. TAE successfully stopped the posttraumatic oronasal hemorrhage in 27 of 34 patients (79.4%). The internal maxillary artery was the most common hemorrhaging vessel requiring embolization. Successful hemostasis by TAE significantly contributed to patient survival (p = 0.001). In addition, higher Glasgow Coma Scale score (>/=8) at presentation, lower shock index (calculated as heart rate/systolic blood pressure; </=1.1 and 0.8, before and after TAE, respectively), and injury severity score </=32 positively contributed to the patients' higher survival rate (p < 0.05). During the acute treatment of posttraumatic oronasal hemorrhage, need for craniotomy was not correlated with patient survival, but need for laparotomy to treat the second abdominal hemorrhagic source decreased the rate of patient survival (p = 0.023). TAE may stop intractable posttraumatic oronasal hemorrhage when conventional packing fails to achieve hemostasis. Glasgow Coma Scale score at presentation, shock index before and after TAE, injury severity score, and need for emergent laparotomy can be used to predict the patient prognosis.

Intracerebral hemorrhage after thrombolytic therapy managed with ventricular drainage

Intracerebral hemorrhage (ICH) after thrombolytic treatment for acute myocardial infarction (AMI) is a serious complication causing significant morbidity and mortality. Drainage of the haematoma by craniotomy is associated with poor outcome. We present a patient who received tissue plasminogen activator (t-PA) for acute myocardial infarction; he subsequently developed an ICH with ventricular system extension. The patient was managed by insertion of an external ventricular drain. The hemorrhage was successfully evacuated by insertion of the external ventricular drain. This was unexpected as ICH are usually viscous and difficult to aspirate in the acute phase. This suggests that ICHs following thrombolytic therapy remain liquid for up to 10 h. External ventricular drains can be used in the management of patients with ICH complicating thrombolytic therapy for management of acute myocardial infarction or ischemic stroke. This reduces the need for craniotomy and associated morbidity and mortality.

A Numerical Investigation of the Time Reversal Mirror Technique for Trans-skull Brain Cancer Ultrasound Surgery

Introduction: The medical applications of ultrasound on human brain are highly limited by the phase and amplitude aberrations induced by the heterogeneities of the skull. However, it has been shown that time reversing coupled with amplitude compensation can overcome these aberrations. In this work, a model for 2D simulation of the time reversal mirror technique is proposed to study the possibility of targeting any point within the brain without the need for craniotomy and to calculate the acoustic pressure field and the resulting temperature distribution within the skull and brain during a High Intensity Focused Ultrasound (HIFU) transcranial therapy. Materials and Methods: To overcome the sensitivity of the wave pattern to the heterogeneous geometry of the skull, a real MRI derived 2D model is constructed. The model should include the real geometry of brain and skull. The model should also include the couplant medium which has the responsibility of coupling the transducer to the skull for the penetration of ultrasound. The clinical substance used as the couplant is water. The acoustic and thermal parameters are derived from the references. Next, the wave propagation through the skull is computed based on the Helmholtz equation, with a 2D finite element analysis. The acoustic simulation is combined with a 2D thermal diffusion analysis based on Pennes Bioheat equation and the temperature elevation inside the skull and brain is computed. The numerical simulations were performed using the FEMLAB 3.2 software on a PC having 8 GB RAM and a 2.4 MHz dual CPU. Results: It is seen that the ultrasonic waves are exactly focalized at the location where the hydrophone has been previously implanted. There is no penetration into the sinuses and the waves are reflected from their surface because of the high discrepancy between the speed of sound in bone and air. Under the focal pressure of 2.5 MPa and after 4 seconds of sonication the temperature at the focus reached 51 °C and the temperature of the pre-target bone increased to 56.31 °C. In the post-target region the temperature of the sphenoid bone increased to 47.1 °C while the temperature of the occipital bones reached up to 46 °C. It is also shown that by using a cold water cooling system and cooling down the pre-target bones to 20 °C before sonication, the maximum pre-target bone temperature will not exceed 40 °C and hence the pre-target bone cells will remain intact. Discussion and Conclusion: In this study, it is well demonstrated that by using the time reversal mirror technique it is possible to target any point within the skull without the need for craniotomy. Although at higher acoustic frequencies compared to the lower ones such as 300 kHz the ultrasound undergoes more severe aberrations while passing through media having geometrical heterogeneity and discrepant sound velocities, the simulations performed in this work show that even at such frequencies it is still possible to correct these aberrations using the time reversal mirror technique. The thermal simulations show that by using this method the temperature of the deep seated tumors can be increased to cytotoxic temperature in a few seconds.

Endoscopic Management of Sinus Disease with Frontal Lobe Displacement

Advanced inflammatory disease of the paranasal sinuses may result in erosion of the skull base with frontal lobe impingement. We present a series illustrating minimally invasive management of this process. We review 15 consecutive cases of advanced sinus inflammatory disease with frontal lobe displacement. Clinical presentation, diagnostic evaluation, and treatment modalities are described. Patients ranged in age from 19 to 83 years, and 13/15 were men. Presenting symptoms in all patients included progressive headache (15/15), frontal pressure (15/15), orbital involvement and visual symptoms (6/15), and new-onset seizure (1/15). Implicated diagnoses included mucocele (7/15), classic allergic fungal sinusitis (3/15), and both (5/15). Initially, 14 patients were treated endoscopically, with image-guided navigation in 12 patients. Four patients underwent trephination for combined above/below marsupialization, and three patients also underwent orbital decompression. Two patients failed initial endoscopic management. One of these was salvaged endoscopically and the other required cranialization. Another patient was managed via cranialization in the primary setting. In all cases, mucosa was observed directly against dura. No cerebrospinal fluid leaks were encountered. One patient expired 1 month postoperatively secondary to congestive heart failure. Mean follow-up in the remaining 14 patients was 13.6 months. Follow-up imaging revealed reexpansion of the frontal lobe into the decompressed space. Advanced sinus inflammatory disease associated with frontal lobe compression may have indolent presentation but significant morbidity. Minimally invasive techniques averted the need for craniotomy in 13/15 patients in this series.

Intracranial complications of pediatric sinusitis

To study intracranial extension of pediatric sinusitis, an infrequent but potentially fatal complication. Ten-year retrospective review at a tertiary children's hospital identified 21 cases of intracranial complications of sinusitis. Thirteen males and eight females with mean age of 13.3 years were identified. Overall 18 of 21 (81%) exhibited abscess formation, most commonly epidural. Only 3 of 21 (14%) had meningitis alone. All but 4 patients were managed surgically, requiring craniotomy in 13 of 21 (61.9%) and endoscopic sinus surgery (ESS) in 10 of 21 (48%). Seven patients (33%) required multiple operations during admission. Nineteen patients (90%) had a total of 30 organisms cultured. Oral flora was observed in 12 of 21 (57%). Polymicrobial infections, seen in 9 of 21 (43%), were significantly associated with the need for craniotomy (P=0.02). Mean hospital stay was 15 days, and mean length of IV antibiotic was 5 weeks. Intracranial complications of pediatric sinusitis often require craniotomy. Oral flora and polymicrobial infections were prominent in this series. C-4.

Is Repeated Head Computed Tomography Necessary for Traumatic Intracranial Hemorrhage?

This study was performed to determine the need for repeat head computed tomography (CT) in patients with blunt traumatic intracranial hemorrhage (ICH) who were initially treated nonoperatively and to determine which factors predicted observation failure or success. A total of 1,462 patients were admitted to our level II trauma center for treatment of head injury. Seventeen per cent (255/1,462) were diagnosed with ICH on initial head CT. Craniotomy was initially performed in 15.7 per cent (40/255) of patients with ICH. Two hundred sixteen patients with ICH were initially observed. Ninety-seven per cent (179/184) of observed patients with ICH and repeat head CT never underwent a craniotomy, 2.7 per cent (5/184) of patients with ICH initially observed underwent craniotomy after repeat head CT, and four patients (80%) had deteriorating neurologic status. Multivariate analysis revealed the following significant admission risk factors were associated with a need for repeat head CT indicating the need for craniotomy: treatment with anticoagulation and/or antiplatelet medications, elevated prothrombin time (PT), and age greater than 70 years. In patients with blunt traumatic intracranial hemorrhage initially observed, there is little utility of repeated head CT in the absence of deteriorating neurologic status. The only admission risk factors for a repeat CT indicating the need for craniotomy were advanced age and coagulopathy.

Morbidity and Mortality from Surgical Treatment of Unruptured Cerebral Aneurysms at Research Institute for Brain and Blood Vessels-Akita

Although the necessity of craniotomy for an unruptured cerebral aneurysm (UCA) is controversial, surgery is warranted if surgical risks are less than the risks of natural history. In this study, we investigated the need for craniotomy for UCAs on the basis of surgical risk. History of cerebrovascular disorders, aneurysm site and size, surgical complications, and clinical outcome were investigated in 368 patients (134 men, 234 women; ages 31-79 yr) who underwent craniotomy for treatment of UCA at our institute between 1993 and 2000. We investigated 549 aneurysms. The mean size was 6.0 mm. Sites affected were the anterior cerebral artery (101 aneurysms), internal carotid artery (224 aneurysms), middle cerebral artery (201 aneurysms), and vertebrobasilar artery (23 aneurysms). The most common previous cerebrovascular disorders were subarachnoid hemorrhage (58 patients, 15.8%) and cerebral infarction (41 patients, 11.1%). Eight patients experienced permanent neurological deficits, for a total morbidity of 2.2%. One patient died, for a total mortality of 0.3%. For UCAs less than 10 mm in size, the morbidity was 0.6% and the mortality was 0%. For UCAs greater than 10 mm in size, the morbidity was 6.1% and the mortality was 1.2%. For UCAs in the anterior cerebral artery or middle cerebral artery, the morbidity was 0.3%. Temporary deficits were more frequently observed in patients older than 70 years of age than in patients 70 years of age or less. Surgical treatment is a viable alternative for patients 70 years of age or less with UCAs less than 10 mm in size or UCAs located in the anterior cerebral artery or middle cerebral artery, because the surgical risk of treating such UCAs is sufficiently lower than the annual rupture rate of UCAs (2.3%) and the mental stress suffered by patients with untreated UCAs.

The midface degloving approach for intracranial tumours

Although many approaches to the anterior clivus and parasellar region have been described, safe access to this area remains difficult. The authors describe the use of the midface degloving approach as a route for resection of intracranial lesions of the anterior skull base. Six cases are presented: two sellar meningiomas, a trigeminal neuroma, a pituitary adenoma, fibrous dysplasia and fibrosis of the trigeminal nerve within Meckel's cave. The midface degloving approach has allowed excellent exposure, avoids any visible scarring and obviates the need for craniotomy. The approach is a useful adjunct to the armamentarium of the surgeon operating in this area and indeed may allow removal of lesions that could not safely be removed transcranially.

Emergency department discharge of patients with a negative cranial computed tomography scan after minimal head injury.

To determine the negative predictive value of cranial computed tomography (CT) scanning in a prospective series of patients and whether hospital admission for observation is mandatory after a negative diagnostic evaluation after minimal head injury (MHI). Hospital admission for observation is a current standard of practice for patients who have sustained MHI, despite having undergone diagnostic studies that exclude the presence of an intracranial injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that admission will allow prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge. In a prospective, multiinstitutional study during a 22-month period at four level I trauma centers, all patients with MHI were evaluated using the following protocol: a standardized physical and neurologic examination in the emergency department, cranial CT scanning, and then admission for observation. MHI was defined as either a documented loss of consciousness or evidence of posttraumatic amnesia and an emergency department Glasgow Coma Scale score of 14 or 15. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, need for craniotomy, and death. Two thousand one hundred fifty-two consecutive patients fulfilled the study protocol. The CT was interpreted as negative for intracranial injury in 1,788, positive in 217, and equivocal in 119. Five patients with CT scans initially interpreted as negative required intervention. There was one craniotomy in a patient whose CT scan was initially interpreted as negative. This patient had facial fractures that required surgical intervention and elevation of depressed intracranial fracture fragments. The negative predictive power of a cranial CT scan based on the preliminary reading of the CT scan and defined by the subsequent need for neurosurgical intervention in the population fully satisfying the protocol was 99.70%. Patients with a cranial CT scan, obtained on a helical CT scanner, that shows no intracerebral injury and who do not have other body system injuries or a persistence of any neurologic finding can be safely discharged from the emergency department without a period of either inpatient or outpatient observation. Implementation of this practice could result in a potential decrease of more than 500,000 hospital admissions annually.

Extradural extranasal combined transmaxillary transsphenoidal approach to the cavernous sinus: a minimally invasive microsurgical model.

The authors have previously described an extradural transmaxillary approach to the anterior compartment of the cavernous sinus. In an effort to expand the surgical access to that area without necessitating a craniotomy or wide transfacial dissection, they present a modification of the transmaxillary approach to the sellar region and cavernous sinus. The approach was developed on 12 fresh and 12 embalmed cadaveric specimen, and 2 dry skulls. The initial sublabial incision is followed by a maxillotomy to expose the course of the infraorbital nerve (terminal branch of maxillary branch of the trigeminal nerve) on the roof of the maxillary sinus. The route of the infraorbital nerve is traced to the pterygopalatine fossa as a guide to the foramen rotundum. Superomedial drilling of the foramen rotundum is then performed to reveal the contents of the superior orbital fissure. After the nerves are safely identified in the superior orbital fissure, medial enlargement of the window into the cavernous sinus is made possible by drilling the lateral and posterior wall and septum of the sphenoid sinus. The combined transmaxillary transsphenoidal approach offers an excellent exposure of the sellar and infrasellar region. The approach offers clear visualization of the ipsilateral loop of the carotid artery, the pituitary fossa, and the cranial nerves of the ipsilateral cavernous sinus. Mean operative reach is 38 mm from the posterior wall of the maxillary sinus to the ipsilateral carotid loop and 56 mm to the contralateral loop. The width of the operative window is 26 mm at the base within the cavernous sinus. The model offers a minimally invasive approach that avoids the need for craniotomy or violating the nasal cavity. It may be safely employed to access vascular as well as invasive lesions of the sellar and infrasellar region. The approach offers excellent visualization of the ipsilateral intracavernous carotid artery with both proximal and distal control, as well as cranial nerves III, IV, VI, V2, the hypophyseal region, and the medial aspect of the contralateral cavernous sinus.

Changes in the Extracellular Concentrations of Amino Acids in the Rat Striatum During Transient Focal Cerebral Ischemia

Although considerable evidence supports a role for amino acids in transient global cerebral ischemia and permanent focal cerebral ischemia, effects of transient focal cerebral ischemia on the extracellular concentrations of amino acids have not been reported. Accordingly, our study was undertaken to examine the patterns of changes of extracellular glutamate, aspartate, GABA, taurine, glutamine, alanine, and phosphoethanolamine in the striatum of transient focal cerebral ischemia, as evidence to support their pathogenic roles. Focal ischemia was induced using the middle cerebral artery occlusion model, with no need for craniotomy. Microdialysis was used to sample the brain's extracellular space before, during, and after the ischemic period. One hour of middle cerebral artery occlusion followed by recirculation caused neuronal damage that was common in the frontoparietal cortex and the lateral segment of the caudate nucleus. During 1 h of ischemia, the largest increase occurred for GABA and moderate increases were observed for taurine, glutamate, and aspartate. Alanine, which is a nonneuroactive amino acid, increased little. After recirculation, the levels of glutamate and aspartate reverted to normal baseline values right after reperfusion. Despite these rapid normalizations, neuronal damage occurred. Therefore, uptake of excitatory amino acids can still be restored after 1 h of middle cerebral artery occlusion, and tissue damage occurs even though high extracellular levels of glutamate are not maintained.

PRIORITIES IN THE MANAGEMENT OF MULTIPLE TRAUMA

Setting priorities in the management of patients with suspected injuries to both the head and the abdomen is difficult and depends on the likelihood of different injuries. Eight hundred trauma patients were retrospectively reviewed to determine the likelihood of a surgically correctable cerebral injury. All 800 patients, at the time of initial evaluation, were thought to have potentially correctable injuries to both the head and the abdomen. Of these, 52 had a head injury requiring craniotomy; 40 required a therapeutic celiotomy. Only three patients required both craniotomy and therapeutic celiotomy. There were more cases of delay in therapeutic celiotomy because of negative results of computed tomographic (CT) scanning of the head (13 cases) than there were delays in craniotomy because of nontherapeutic celiotomy (four cases). Need for craniotomy, based on emergency department evaluation, was indicated by the presence of lateralizing neurologic signs. Low Glasgow Coma Scale score, anisocoria, fixed/dilated pupils, loss of consciousness, facial or scalp injuries, and age were of no independent value in predicting the need for craniotomy. Patients with surgically correctable injuries of both the head and the abdomen are rare. In stable patients with altered mental status and potential injuries to both the head and the abdomen, the abdomen is best evaluated first by diagnostic paracentesis. If paracentesis does not return gross blood, CT scanning of the head should be done.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereotactic Radiosurgery Using the 201 Cobalt-60 Source Gamma Knife

Although Lars Leksell introduced the concept of stereotactic radiosurgery 40 years ago, the role of radiosurgery in the treatment of vascular malformations and benign or malignant intracranial tumors is only now being defined. Radiosurgery can be definitive therapy for small or medium-sized arteriovenous malformations and histologically benign tumors. For patients with more complex or recurrent tumors and for patients with vascular malformations that have not been eliminated by open surgery or endovascular embolization, radiosurgery has an adjunctive and often decisive therapeutic role. Selected malignant tumors, especially solitary metastases, have responded dramatically to radiosurgery, obviating the need for craniotomy and prolonged hospitalization in this group of patients.