Complications of posterior cranial fossa surgery--an institutional experience of 500 patients.

BACKGROUND: The complication of the posterior fossa surgery is seldom described in the literature. The purposes of this retrospective study are to draw attention to the potential complications associated with posterior fossa surgery and to critically review the predisposing factors that might influence the complication rate. METHODS: We undertook a 10-year (1992-2002) retrospective study of all posterior fossa surgery performed at LSUHSC. A total of 500 patients were obtained from the operation database, and they were categorized into 5 groups based on the surgical approaches: (1) cerebellopontine angle lesion, (2) microvascular decompression for facial pain and spasm, (3) cerebellar lesions, (4) Chiari I decompression, and (5) petroclival lesions. Data collected for analysis included patient demographics, pathological characteristics of the lesions, and the postoperative complications that occurred as unexpected and undesirable events that prolonged hospital stay and may require surgical/medical intervention. RESULTS: Of the 500 patients reviewed, 220 (44%) patients had tumor resections at the cerebellopontine angle; 110 (22%) patients had microvascular decompression for trigeminal neuralgia and hemifacial spasm; 86 (17.2%) patients had cerebellar lesions; 60 (12%) patients had Chiari I decompression; and 24 (4.8%) patients required transpetrosal approaches for petroclival lesions. The overall complication rate in our study was 31.8%, affecting 159 patients. Cerebrospinal fluid leaks were the most frequently encountered, presenting in 65 (13%) patients followed by meningitis in 46 (9.2%) patients, wound infection in 35 (7%) patients, and CN palsies in 24 (4.8%) patients. Other complications that were observed to develop almost exclusively in patients undergoing cerebellar parenchymal tumor resection included cerebellar edema in 25 (5%) patients, hydrocephalus in 23 (4.6%) patients, cerebellar hematoma in 15 (3%) patients, and cerebellar mutism in 6 (1.2%) patients. The overall mortality rate related to surgery was 2.6% occurring in 13 patients. CONCLUSION: Posterior fossa surgery involves greater morbidity and mortality and has a wider variety of complications than surgery in the supratentorial compartment. These complications may be avoided by careful perioperative planning, strict adherence to aseptic technique, meticulous microsurgical dissection, proper wound closure, and the judicious use of prophylactic agent. A thorough understanding of the patient's history, neurological findings, imaging studies, operative anatomy, as well as all potential adverse events associated with the procedure is also essential to minimize complications.

Glioblastoma multiforme in two non-nuclear family members.

BACKGROUND: In spite of traditional and current epidemiological research, there have been few environmental risk factors identified for malignant brain tumors. It has been an equally difficult challenge to identify genetic causes for brain tumors because of the rarity of families with multiple affected individuals, which prevents the use of traditional methods of genetic analysis such as genetic linkage, sib-pair, or even population-based association studies. Thus, it is important to take advantage of rare occasions of familial brain tumors. METHODS: Identification and careful study of such families may provide important clues about the etiology of brain malignancies. We studied one family of which two nonnuclear family members were affected with pathologically diagnosed glioblastoma multiforme. Fluorescence in situ hybridization (FISH) assays were used on archival sections from each patient's tumor to investigate the loss and/or gain of important allelic endpoints. Tissue sections were prepared and processed for FISH. DNA probes for targeted gene loci were used to assess allelic gain/loss. FISH probes targeted regions including 19q13, 1p36, 10q/phosphate and tensin homolog (PTEN), chromosome 3, chromosome 7, chromosome 17/17q and p53/17p. RESULTS: FISH analyses identified distinct abnormalities in the two patients, suggesting that despite the familial connections and histologically similar tumors, genetic abnormalities are abundant and heterogeneous among these malignancies. CONCLUSION: These abnormalities, however, serve to contribute to valuable information regarding patient outcomes, albeit their precise roles in the etiology of this malignancy are yet to be determined.

Spinal cord compression in a patient with a pain pump for failed back syndrome: a chalk-like precipitate mimicking a spinal cord neoplasm: case report.

OBJECTIVE AND IMPORTANCE: The use of intrathecal morphine has been effective with few complications for chronic intractable pain of both benign and malignant origins. A rare but serious problem that exists is the formation of an inflammatory mass at the catheter tip of the pain pump. CLINICAL PRESENTATION: We report the case of a 67-year-old female patient with failed back syndrome who presented with sensory complaints and back pain. INTERVENTION: Magnetic resonance imaging revealed impingement on the thoracic cord by a mass. The mass was originally thought to be a spinal cord tumor; however, operation and chemical analysis of the mass showed that it was a bupivacaine precipitate at the tip of the catheter of the pain pump. CONCLUSION: This is the first such case, to our knowledge, of a bupivacaine precipitate mimicking a spinal cord tumor.

Role of stereotactic radiosurgery as a primary treatment option in the management of newly diagnosed multiple (3-6) intracranial metastases.

OBJECTIVE: The objective of this study was to assess the role of stereotactic radiosurgery in the management of newly diagnosed multiple intracranial metastases from known primary cancer locations. METHODS: Fifty (29 women and 21 men) patients received radiosurgery for newly diagnosed 3 or more metastatic brain tumors. Their mean age was 53 years. Lung cancer was the most common primary cancer (66%). RESULTS: Arrest in the growth of irradiated tumors was achieved in 41 (82%) patients. Eight patients (16%) required further intervention for tumors in other brain locations. Mean survival after diagnosis of brain disease was 12 months and the brain disease-controlled period was 19 months. The period of brain disease control prolonged (P=.03) with decreasing tumor volumes (<10 mL). Control of treated tumors positively affected survival after diagnosis of brain disease (P=.0001). CONCLUSION: Radiosurgery as an adjuvant improves survival in patients with cancer who have newly diagnosed multiple intracranial metastases by arresting the growth of tumors.

Surgical management of intracranial cavernous malformations: the Louisiana State University Health Sciences Center, Shreveport experience.

Intracranial cavernous malformations are vascular anomalies consisting of endothelium-lined caverns filled with blood at various stages of thrombosis and organized and separated by a collagenous stroma devoid of mature vessel wall elements. They represent a clinical challenge both in diagnosis and management due to the variety of presenting symptoms and neuroradiological features. This study analyzes the clinical manifestations and surgical outcomes in 16 patients with cavernous malformations who were treated surgically at the Louisiana State University Health Sciences Center in Shreveport. The most common presenting features were headache, seizure, and focal neurologic deficits. Three patients had deep lesions (two in the brainstem and one in the basal ganglion), and 13 patients had superficial lesions. All patients underwent surgery and had complete excision of the lesion. The overall outcome was satisfactory for all patients with significant symptom relief over a mean follow-up period of 60 months. The optimal management of cavernous malformations should be determined on a case-by-case basis and, when indicated, surgery provides good outcome.

Diffuse back pain and urological symptoms: recognizing tethered cord syndrome early.

Tethered cord syndrome (TCS) is a rare entity in adults, with only about 100 cases being reported in the literature. It is a syndrome in which patients have neurologic, urologic, and orthopedic signs and symptoms. We present a case of a 40-year-old man with back pain and urinary incontinence who was diagnosed with tethered cord syndrome. After the cord de-tethering in the operating room, his pain improved. TCS is an important condition to consider in the differential diagnosis of an adult who presents with back pain and urological symptoms. Imaging studies should be done, and operative treatment may be required to alleviate the symptoms. TCS should be in the differential diagnosis of any patient who presents with back and lower extremity complaints with superimposed urological problems. If TCS is confirmed radiologically by MRI, surgery can be performed with reasonable results provided that the disease process has not progressed.

Factors influencing outcome in intracerebral hematoma: a simple, reliable, and accurate method to grade intracerebral hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) is a major public health problem. This subset of stroke often coexists with other serious medical problems such as hypertension, diabetes, and obesity. Management of hemorrhagic stroke is controversial and there is no standardized system for assessing presentation and predicting outcome of this disease. We propose a new grading system based on clinical and radiologic factors important in influencing outcome in ICH that can be used by the entire health care team. METHODS: We conducted a retrospective study of the last 50 patients who presented with hypertensive ICHs to Louisiana State University Health Sciences Center in Shreveport during 2001 to 2003. Significant predictors of outcome at 6 months as measured by the Glasgow outcome score (GOS) were determined and a grading system based on clot volume, hydrocephalus on initial computed tomographic scan, and focal neurologic deficit was formulated. RESULTS: Three factors observed to have significant association with GOS were presence of a focal neurologic deficit on initial presentation (P = .003), presence of hydrocephalus on initial computed tomographic scan (P < .0001), and clot volume (P = .003). Patients were scored on these variables as follows: neurologically intact (0 point), any focal neurological deficit (1 point); absence of hydrocephalus (0 point), presence of hydrocephalus (1 point); and clot volume less than 20 mL (1 point), 20 to 50 mL (2 points), and greater than 50 mL (3 points) [corrected] The scores were summed to assign an ICH grade to each patient for predicting his GOS at 6 months. Given the nonsignificant difference between a patient's grade and his actual observed GOS (mean difference 0.04, P = .79), as well as their significant correlation (correlation coefficient = 0.76, P < .0001), we believe our grading system is useful for predicting a patient's GOS. CONCLUSION: An accurate and reliable grading scale for ICH is helpful in standardizing the management of ICH, improving communication of patient presentation among health care workers, and predicting outcomes.

Transradial approach to coil embolization of an intracranial aneurysm.

PURPOSE: To report the use of a transradial approach to coil embolization of an intracranial aneurysm in a morbidly obese patient. TECHNICAL NOTE: When the transfemoral approach was inaccessible in a morbidly obese patient with a ruptured intracranial aneurysm, coil embolization was performed via a 6-F sheath placed in the radial artery. Multiple platinum coils were delivered to exclude the 14-mm basilar tip aneurysm. Because heparin was not reversed, the sheath was left in the artery for 24 hours then removed. The radial artery was pulsatile, and blood supply to the hand was good. CONCLUSIONS: The radial artery appears to be a suitable route for access to the intracranial vessels when the femoral artery is not available.

Gamma knife radiosurgery for trigeminal neuralgia: a study of predictors of success, efficacy, safety, and outcome at LSUHSC.

BACKGROUND: Trigeminal neuralgia (TN) is a painful condition of controversial origin; however, vascular compression of the root entry zone of the trigeminal nerve is thought to be responsible in some cases. Recently, stereotactic radiosurgery has been established as an alternative treatment for medically intractable TN. METHODS: Forty patients with medically refractory TN underwent gamma knife surgery for pain control at our institution. Dose planning was based on high-resolution, contrast-enhanced, axial, volume acquisition magnetic resonance images. Images were reviewed to detect vascular compression of the trigeminal nerve at the root entry zone by an observer blinded to the affected side and the outcome. Another observer, blinded to radiologic findings, conducted the patient follow-up. Results were classified as excellent and good (favorable outcomes) and failure (unfavorable) based upon the intensity of pain, frequency of episodes, pain medications, and need for additional interventions after radiosurgery. RESULTS: Pain was left-sided in 22 patients and right-sided in 18 patients. Vascular compression of the affected nerve at the root entry zone was demonstrable in 14 patients. Prescription dose ranged from 70 to 90 Gy. At a median follow-up of 14 months (range, 3-31 months), 16 patients (40%) had excellent pain control, 12 (30%) had good control, while 12 (30%) had failed treatment. The Kaplan-Meier actuarial pain control rate at 15 months was 82.25 +/- 0.8% (95%CI). Magnetic resonance detectable vascular compression did not affect the outcome (p = 0.6). Increasing marginal dose (> or =40Gy) was a significant predictor of favorable outcome (p = 0.015). CONCLUSIONS: gamma knife surgery is an effective and safe treatment for TN. In our study, we found that vascular compression of the nerve at the root entry zone was not a predictor of the outcome of gamma surgery for TN. The outcome improves with marginal prescription dose of 80 Gy or higher.

Pilocytic astrocytoma presenting as an intrinsic brainstem tumor: case report and review of the literature.

OBJECTIVE: Pilocytic astrocytomas are typically circumscribed, slow growing tumors found in children and young adults. This type of tumor can arise from various locations in the neuraxis. In the brainstem, pilocytic astrocytomas grow as dorsal exophytic masses. To our knowledge, pilocytic astrocytomas arising entirely within the brainstem have not been reported in the literature. CLINICAL PRESENTATION: A 22-year-old man presented with double vision for three months. A neurological exam revealed a right sixth nerve palsy. INTERVENTION: Magnetic resonance imaging revealed an intra-axial mass with a cystic center arising from within the brainstem. Intraoperative findings confirmed an intra-axial brainstem tumor. Histological analysis revealed that the tumor was a low-grade glioma most consistent with a pilocytic astrocytoma. CONCLUSION: This case report confirms that pilocytic astrocytomas can present as brainstem gliomas, and histopathology plays a major role in determining the aggressiveness of operative intervention.

Quantification of the advantages of the extended frontal approach to skull base.

This anatomic study evaluated the extent that a fronto-orbital osteotomy (FOO) added to a bilateral frontal craniotomy widened the exposure to the midline compartment of the anterior, middle, and posterior cranial fossae. The goal was to determine if osteotomy would significantly increase angles for two targets: the foramen magnum (FM) and anterior clinoid process (ACP). Stepwise dissections were performed on five cadaveric heads. A bilateral frontal craniotomy was made, followed by FOO. After the ethmoids were removed, the planum sphenoidale was drilled to enter the sphenoid sinus. Further drilling exposed the anterior clivus, which was drilled down to FM. Excellent exposure of the basilar artery, vertebral artery, and brain stem was achieved. With and without FOO, angles of exposure were measured for two targets: the ACP and FM. The angle of exposure after FOO increased markedly with an average gain of 76% for the ACP and of 80% for FM. Compared with a conventional bifrontal craniotomy, the addition of FOO increased the surgical exposure and minimized frontal lobe retraction for accessing lesions of the anterior, middle, and posterior cranial fossae.

Local cryoglobulin deposition in primary central nervous system lymphoma.

Primary central nervous system lymphomas (PCNSLs) represent malignant non-Hodgkin's B-cell lymphomas confined to the central nervous system. Recent years have brought a dramatic increase in the frequency of PCNSL in the immunocompromised and immunocompetent populations. Cryoglobulins are cold-precipitable immunoglobulins associated with a number of infectious, autoimmune, and neoplastic disorders. Although it is known that patients with hematologic malignancies (eg, B-cell lymphomas, chronic lymphocytic leukemia, plasma cell dyscrasias) may have cryoglobulinemias and cryoglobulin deposition in several organs (eg, kidney, liver skin, blood vessels, peripheral nervous system), PCNSL associated with cryoglobulin deposition has not been previously described. This report demonstrates localized cryoglobulin deposition within the tumor bed in an immunocompetent patient with PCNSL.