Biomedical subjects

Robert F Spetzler

Publications and source records attributed to Robert F Spetzler.

At least 19 recordsLinked to original sources

PubMed2006

Invasive intracerebral schwannoma mimicking meningioma in a child.

CASE REPORT: An 8-year-old boy presented to the emergency department after a generalized tonic-clonic seizure that lasted for 5 min. Magnetic resonance imaging showed a 2x2 cm, intraaxial, contrast-enhanced cortical lesion in the posterior right frontal lobe. On several images the lesion appeared to be dural-based and was presumed to be a meningioma. The patient was placed on dilantin and returned 1 month later for elective surgical resection. OUTCOME: At surgery, a rim of intact pia was identified between the dura and the tumor. Although initial frozen-section analysis was consistent with meningioma, subsequent immunohistochemical staining and review at an outside institution established the diagnosis of intracerebral schwannoma. The patient's postoperative course was uncomplicated and he remains seizure-free with no sign of recurrence at 18 months. CONCLUSION: Intracerebral schwannomas are uncommon cortical lesions in children. Imaging characteristics alone can be misleading; neuropathological support is essential for accurate diagnosis.

Brain Neoplasms↗

PubMed2006

Update on evidence for a genetic predisposition to cerebral vasospasm.

Considerable evidence links cerebral vasospasm to the decreased bioavailability of endothelial nitric oxide synthase (eNOS) after aneurysmal subarachnoid hemorrhage (SAH). In recent studies from the cardiology literature, researchers have suggested that a genetic predisposition to coronary vasospasm might develop as the result of a T-786C single nucleotide polymorphism (SNP) in the eNOS gene. The authors of this study attempted to determine if there may be a similar genetic predisposition toward cerebral vasospasm. The authors prospectively identified 28 patients with Fisher Grade 3 SAH from a group of 51 consecutive patients with ruptured intracranial saccular aneurysms. Genomic DNA was isolated from a peripheral blood sample obtained with permission from each patient. Gene microarray technology was used to assay the samples for the presence and distribution of certain key eNOS gene polymorphisms. Clinical, radiological, and genomic data were analyzed. The finding of eNOS T-786C SNP could be used to significantly differentiate between the presence and severity of cerebral vasospasm (p = 0.04). The findings from this preliminary study support similar findings in the coronary vasospasm literature as well as the hypothesis that a predisposition toward cerebral vasospasm may be related partially to genetic factors, which needs to be confirmed in a larger study. Such gene-based information may be important in rapidly identifying patients at increased risk of vasospasm after SAH, independent of their Fisher grade. In this article, the authors review key studies in this area.

Animals↗

PubMed2006

Hemorrhage of cavernous malformations during pregnancy and in the peripartum period: causal or coincidence? Case report and review of the literature.

There is growing evidence to suggest that pregnancy may increase the risk of hemorrhage from cavernous malformations (CMs). In the present case, a 21-year-old primigravida was admitted to the authors' neurosurgical service after a cesarean section. Three weeks before admission she had experienced rapidly progressive bilateral lower-extremity paresthesias. Spinal magnetic resonance (MR) imaging revealed the presence of an intramedullary thoracic lesion. On T2-weighted MR images, heterogeneous signal intensity with a rim of decreased intensity was demonstrated in the spine. The mass was successfully resected, and 1 year later the patient's symptoms had resolved completely. This is the fourth reported case of a spinal intramedullary CM that became symptomatic during pregnancy. The pathogenesis and management of this entity are reviewed.

Adult↗

PubMed2006

Intraoperative rupture of brainstem cavernous malformation. Case report.

Although cavernous malformations (CMs) are an important cause of intracranial hemorrhage, the natural history of these lesions is controversial. Both retrospective and prospective studies undertaken to define risk factors for hemorrhage from CMs have consistently identified the location of a lesion as a factor that has a significant impact on the rate of rupture, and brainstem CMs consistently have a higher rate of symptomatic hemorrhage than those at other locations. The mechanism underlying this disparity in rupture rates, however, remains obscure. Most authors attribute the difference, at least partially, to the sensitivity of the brainstem to hemorrhage. Regardless, the specific factors that cause a given CM to rupture are unknown. The authors report their first encounter with an intraoperative rupture of a CM in the brainstem. This case underscores the risks encountered during the surgical approach to brainstem CMs and may provide insight into the pathophysiological mechanisms underlying the rupture of these lesions.

Adult↗

PubMed2006

Are cavernous sinus hemangiomas and cavernous malformations different entities?

Cavernous hemangiomas that occur within the cavernous sinus (CS) are different from cerebral cavernous malformations (CMs) clinically, on imaging studies, and in their response to treatment. Moreover, CMs are true vascular malformations, whereas hemangiomas are benign vascular tumors. Because of these differences, the authors suggest that these two entities be analyzed and grouped separately. Unfortunately, despite these differences, much confusion exists in the literature as to the nature, behavior, and classification of these two distinct lesions. This confusion is exacerbated by subtle histological differences and the inconsistent use of nomenclature. The authors use the term "cavernous malformation" to refer to intraaxial lesions only; they prefer to use the term "cavernous sinus hemangioma" to refer to extraaxial, intradural hemangiomas of the CS.

Brain Neoplasms↗

PubMed2006

Rudolf Ludwig Karl Virchow: pathologist, physician, anthropologist, and politician. Implications of his work for the understanding of cerebrovascular pathology and stroke.

The history of apoplexy and descriptions of stroke symptoms date back to ancient times. It was not until the mid-nineteenth century, however, that the contributions of Rudolf Ludwig Karl Virchow, including his descriptions of the phenomena he called "embolism" and "thrombosis" as well as the origins of ischemia, changed the understanding of stroke. He suggested three main factors that conduce to venous thrombosis, which are now known as the Virchow triad. He also showed that portions of what he called a "thrombus" could detach and form an "embolus." Thus, Virchow coined these terms to describe the pathogenesis of the disorder. It was also not until 1863 that Virchow recognized and differentiated almost all of the common types of intracranial malformations: telangiectatic venous malformations, arterial malformations, arteriovenous malformations, cystic angiomas (possibly what are now called hemangioblastomas), and transitional types of these lesions. This article is a review of the contributions of Rudolf Virchow to the current understanding of cerebrovascular pathology, and a summary of the life of this extraordinary personality in his many roles as physician, pathologist, anthropologist, ethnologist, and politician.

Anthropology↗

PubMed2006

The history of neurosurgical procedures for moyamoya disease.

Almost 50 years of research on moyamoya disease (1957-2006) has led to the development of a variety of surgical and medical options for its management in affected patients. Some of these options have been abandoned, others have served as the basis for the development of better procedures, and many are still in use today. Investigators studying moyamoya disease during this period have concluded that the best treatment is planned after studying each patient's presenting symptoms and angiographic pattern. The surgical procedures proposed for the treatment of moyamoya disease can be classified into three categories: direct arterial bypasses, indirect arterial bypasses, and other methods. Direct bypass methods that have been proposed are vein grafts and extracranial-intracranial anastomosis (superficial temporal artery-middle cerebral artery [STA-MCA] anastomosis and occipital artery-MCA anastomosis). Indirect techniques that have been proposed are the following: 1) encephaloduroarteriosynangiosis; 2) encephalomyosynangiosis; 3) encephalomyoarteriosynangiosis; 4) multiple cranial bur holes; and 5) transplantation of omentum. Other options such as cervical carotid sympathectomy and superior cervical ganglionectomy have also been proposed. In this paper the authors describe the history of the development of surgical techniques for treating moyamoya disease.

Europe↗

PubMed2006

Isolated Langerhans cell histiocytosis of the infundibulum presenting with fulminant diabetes insipidus.

INTRODUCTION: Langerhans cell histiocytosis (histiocytosis X) is a rare disorder that can manifest with solitary bony lesions or disseminated disease in various tissues. A common manifestation of the disease is diabetes insipidus even in the absence of neural involvement. Disseminated disease often involves the central nervous system, but only six isolated lesions in the infundibulum have been reported. CASE REPORT: An 18-year-old male had failed to develop secondary sexual characteristics. He also had diabetes insipidus for more than 1 year. Magnetic resonance imaging (MRI) of the brain showed a 1-cm homogeneously enhancing mass in the region of the infundibulum. No other lesions were found in other organ systems. The patient underwent an orbitozygomatic osteotomy and pterional craniotomy. The lesion, which was adherent to the infundibulum, was partially resected. Microscopic analysis showed multiple lymphocytes and eosinophils with Langerhans cells that stained positive for S-100. Langerhans cell histiocytosis was diagnosed, and the patient was discharged on postoperative day 6 with no neurological deficits. His diabetes insipidus persisted, and he underwent intensity-modulated radiation therapy to the sellar region. CONCLUSIONS: Isolated Langerhans cell histiocytosis of the infundibulum is rare. The usual presentation is hypothalamic-pituitary axis dysfunction and diabetes insipidus. Patients with diabetes insipidus of unknown origin should undergo MRI of the sellar region to rule out infundibular abnormalities.

Adolescent↗

PubMed2006

Bedside twist drill craniostomy for chronic subdural hematoma: a comparative study.

BACKGROUND: Although the bedside twist drill craniostomy is used to treat chronic subdural hematomas, the efficacy of this technique has not been compared with that of standard treatments (operative bur hole or craniotomy). METHODS: Twist drill craniostomy was compared with operative bur hole or craniotomy in a prospective nonrandomized trial. The inclusion criteria were computed tomographic evidence of chronic subdural hematoma (isodense or hypodense compared with brain) and symptoms indicating the need for drainage. Selection of the procedure depended on the on-call surgeon's preference. Clinical success of the procedure, recurrence, length of hospitalization, complications, and neurologic outcome were compared. RESULTS: Between August 2001 and October 2002, 79 consecutive patients with 91 chronic subdural hematomas were treated (67 unilateral and 12 bilateral) at our institution. Fifty-five patients were treated with twist drill craniostomy and 24 with bur hole or craniotomy. There were no differences in the mean age of presentation, thickness of hematoma, length of hospitalization, reoperation rate, mortality rates, or ability to be discharged to home between the 2 groups. There was no difference in the neurologic outcomes in the 57 of the 79 patients available for follow-up. CONCLUSIONS: Twist drill craniostomy performed at the bedside is just as effective in treating chronic subdural hematomas as bur holes or craniotomy in the operating room. This procedure can most often be the first line of treatment in patients with symptomatic chronic subdural hematomas.

Aged↗

PubMed2006

Analysis of pain resolution after surgical resection of intramedullary spinal cord cavernous malformations.

OBJECTIVE: To determine the short- and long-term effects of surgical resection of intramedullary spinal cavernous malformations on preoperative pain. METHODS: Between 1988 and 2003, 53 intramedullary spinal cavernous malformations were surgically managed. A retrospective analysis of this cohort revealed 23 (43%) patients who presented with pain as a clinically relevant feature. Long-term evaluation of pain outcomes was available in 21 patients. Pain outcomes were characterized as improved, unchanged, or worse compared with preoperative and immediate postoperative status. RESULTS: Seven patients presented with radiculopathy, 12 with central pain, and four with both. Immediately after surgery, pain symptoms improved in 18 (78%) patients, were unchanged in 5 (22%), and were worse in none compared with the patients' preoperative status (n = 23). During the follow-up period, 11 (52%) patients improved, nine (43%) remained at their preoperative baseline, and one (5%) was worse compared with their preoperative levels of pain. The difference in postoperative and long-term pain status was statistically significant (P = 0.031). CONCLUSION: The surgical efficacy for improving pain related to intramedullary spinal cavernous malformations may be worse than implied in the literature. Although pain relief immediately after surgery is good, we found that recurrence is common and that only approximately 50% of patients report long-term benefit. Despite the significant limitations of this retrospective study, these data may serve as a guide when counseling patients preoperatively to help them to maintain realistic expectations about outcomes.

Adolescent↗

PubMed2006

Resolution of hemifacial spasm after surgical obliteration of a tentorial arteriovenous fistula: case report.

OBJECTIVE AND IMPORTANCE: We describe a patient with a tentorial dural arteriovenous fistula who presented with ipsilateral hemifacial spasm. CLINICAL PRESENTATION: A 50-year-old man sought treatment for left facial twitching that worsened over 6 months. Magnetic resonance imaging and catheter angiography demonstrated a left tentorial dural arteriovenous fistula. INTERVENTION: The patient underwent a retrosigmoid craniotomy and ligation of the draining vein at the site of the fistula. Intraoperative angiography showed complete obliteration of the fistula. The patient's hemifacial spasm improved significantly after the fistula was obliterated. CONCLUSION: Posterior fossa arteriovenous fistulas can present with a hemifacial spasm related to compression of the facial nerve by arterialized leptomeningeal veins. Microsurgical obliteration of the fistula can resolve the related symptoms.

Arteriovenous Fistula↗

PubMed2006

Multilayer image grid reconstruction technology: four-dimensional interactive image reconstruction of microsurgical neuroanatomic dissections.

OBJECTIVE: Cadaveric dissection is the gold standard for training physicians in various surgical specialties. However, limitations in acquiring and storing sufficient cadaveric material, recent pressures in training opportunities, and progress in digital image technology have led to advances in virtual or artificial visual means to augment surgical training. For training neurosurgeons, the appearance of reality is still crucial for learning anatomic structures and procedures. We developed a four-dimensional (including time) multilayer digital image reconstruction technology (MIGRT) that allows users to manipulate a "volumetric" set of photographic image data from exquisite cadaveric intracranial dissections and to navigate through stages of neurosurgical procedures as the dissection progresses. METHODS: A robotic microscope with two digital cameras was used to capture dissection images, usually in stereoscopic mode. A grid space was created to define positions at which images are captured. Images were acquired from identical angles at the same grid coordinates but at different stages of various dissections. RESULTS: Image data are reconstructed according to the sequence of acquisition into a multilayer image grid system by the MIGRT software. The single interactive, four-dimensional montage is viewable a on common computer platform. CONCLUSION: MIGRT uniquely focuses on capturing anatomic content that preserves natural appearances, including procedure, texture, and color, which is far superior and preferable to images and a reconstructed image environment based on artificial or animated concepts. MIGRT shows time-dependent changes in procedures, provides depth perception by stereoscopy or unique sequential motion, and allows simultaneous interactivity at each step of the procedure.

Brain↗

PubMed2006

Comparative analysis of anterior petrosectomy and transcavernous approaches to retrosellar and upper clival basilar artery aneurysms.

OBJECTIVE: To compare two techniques, transcavernous approach (TcA) and anterior petrosectomy (AP), used to manage retrosellar and upper clival basilar artery (BA) aneurysms. METHODS: AP and TcA were carried out on nine sides of cadaver heads. With use of a computerized tracking system, the area of surgical exposure in the ventral surface of the brain stem, the superficial area of exposure, and the linear exposure of the BA were evaluated. The angles of approach in the horizontal and vertical axes were measured using a robotic microscope. The caudal extent of exposure was determined by an aneurysm clip applied to proximal BA, and the distance between the clip and the floor of the sella was quantified after performing TcA. RESULTS: TcA (1127.3 +/- 438.4 mm2) provided a greater superficial exposure than AP (697.7 +/- 219.1 mm2) (P = 0.01). There were no statistical differences in the deep working exposure (P = 0.303) between TcA (206.9 +/- 40.7 mm2) and AP (260.2 +/- 137.1 mm2). The linear exposure of the BA was greater for AP (22.7 +/- 6.2 mm2) than for the TcA (12.8 +/- 2.9 mm2) (P = 0.004). The caudal extent of exposure averaged 6.1 mm from the floor of the sella. No differences were found in horizontal angles (P = 0.596); however, vertical angles were significantly greater for the TcA than AP (15.2 +/- 3.4) (P = 0.004). CONCLUSION: From an anatomic standpoint, the TcA offers more advantages than the AP, when approaching retrosellar BA aneurysms, except for those cases in which proximal control is the principal issue and the neck of the aneurysm is located more than 6.0 mm below the floor of the sella.

Analysis of Variance↗

PubMed2006

Management of cranial base chondrosarcomas.

OBJECTIVE: Chondrosarcomas are rare, infiltrative, progressive lesions that occur at the cranial base. Their intimate association with cranial nerves and major vessels of the head and neck often precludes complete surgical resection. METHODS: Between 1983 and 2003, 23 patients (14 females, 9 males) were treated at our institution with the diagnosis of chondrosarcoma of the cranial base (mean age at presentation, 43 yr). A retrospective chart review was performed to evaluate presentation, management, and adjunctive treatment. All living patients were contacted for a current examination and disease status. RESULTS: The 23 patients underwent 43 surgical resections. Follow-up ranged from 8 months to 25 years (mean, 97 mo). Ten patients underwent various adjuvant radiation therapies. Five patients have died. Four patients have no evidence of disease, and 13 have residual tumor. One was lost to follow-up. Of 14 patients with 5 years of follow-up, 13 are living. Therefore, the absolute 5 year survival rate is 93%. The 10 year survival rate is 71%. CONCLUSION: Because of the intricate nature of the cranial base, a team approach is preferable for managing these challenging lesions. Maximum cytoreductive surgery should be pursued as an initial strategy to minimize neurological injury. Adjuvant stereotactic radiosurgery can be used to treat residual disease or small recurrences. This cohort also illustrates that patients with chondrosarcomas have better long-term survival rates than patients with chordomas of the cranial base.

Adolescent↗

PubMed2006

Long-term clinical and angiographic follow-up of unclippable wrapped intracranial aneurysms.

OBJECTIVE: This is the largest contemporary series examining long-term clinical and angiographic follow-up of unclippable wrapped intracranial aneurysms. METHODS: The presentation, location and shape of aneurysm, wrapping technique, outcome at discharge and last follow-up, and change in aneurysm at last angiographic follow-up were reviewed retrospectively in 74 patients with wrapped or clip-wrapped aneurysms. Patients in whom wrapping was used in conjunction with primary clipping were excluded. RESULTS: Of the 74 patients, 11 were lost to follow-up. The mean age of the remaining 63 patients (16 males, 47 females) was 56.5 years (range, 13-89 yr). Fifty-one aneurysms were located in the anterior circulation, and 17 were located in the posterior circulation. Fourteen patients presented with a ruptured aneurysm. Seventeen aneurysms were fusiform. Seven aneurysms were clip-wrapped, and 61 were wrapped with cotton. At discharge the Glasgow Outcome Scale (GOS) score was 5 in 54 patients and 4 in 5 patients. Two patients died from their presenting hemorrhage, and one from a medical comorbidity. The mean clinical follow-up was 44.1 months (range, 1-120 mo). One patient under clinical follow-up experienced subarachnoid hemorrhage. The mean angiographic follow-up of 34 patients was 41.8 months (range, 3-120 mo). During this follow-up period, no patient's aneurysm changed in size or configuration. CONCLUSION: Wrapping or clip-wrapping of unclippable intracranial aneurysms is safe and seems to confer protection against aneurysmal growth or subarachnoid hemorrhage.

Adolescent↗

PubMed2006

Surgical management of distal coil migration and arterial perforation after attempted coil embolization of a ruptured ophthalmic artery aneurysm: technical case report.

OBJECTIVE AND IMPORTANCE: Distal coil migration is a rare but hazardous complication of aneurysm coil embolization. Various microsnare devices have been developed to address this problem. We describe the surgical management of a case in which microsnare retrieval failed. CLINICAL PRESENTATION: A 34-year-old woman presented with subarachnoid hemorrhage. Magnetic resonance imaging, computed tomography angiography, and conventional angiography showed an approximately 2.5-mm ophthalmic artery aneurysm. Using balloon remodeling, a 2 x 4-cm coil was deployed into the aneurysm fundus. While the coil pusher was being removed after deployment, the microcatheter advanced abruptly into the aneurysm. The coil mass was dislodged and migrated into the angular branch of the middle cerebral artery. Contrast extravasation was noted during attempted retrieval with a microsnare device. TECHNIQUE: Computed tomographic scans showed a subarachnoid hemorrhage in the territory of the left frontotemporal operculum. A left modified orbitozygomatic approach was performed. The coil mass was removed from the angular artery and a thromboembolectomy was performed. The artery was repaired and the pseudoaneurysm was clip ligated. The ophthalmic artery aneurysm was clip ligated. The patient recovered without deficits. CONCLUSION: Distal coil migration and arterial perforation can be treated surgically with a good clinical outcome.

Adult↗

PubMed2006

Quantification and comparison of telovelar and transvermian approaches to the fourth ventricle.

OBJECTIVE: To quantify the exposure to the fourth ventricle obtained with the telovelar and transvermian approaches. METHODS: The telovelar, with and without C1 posterior arch removal, and transvermian approaches were performed on six cadaveric heads. The area of surgical exposure was calculated from triangles formed by defined anatomic points. A robotic microscope was used to determine the "angle of approach" for the same points. RESULTS: The maximal allowable vertical angle of attack to the obex of the fourth ventricle was significantly greater with the telovelar approach than with the transvermian approach (P < 0.002), but there was no difference at the rostral fourth ventricle. The maximal allowable horizontal angle of attack at the level of the obex, Luschka, and rostral fourth ventricle was significantly greater with the telovelar than with the transvermian approach (P < 0.001). Removal of the C1 posterior arch with the telovelar approach significantly increased the vertical angle of approach to the obex (P < 0.001) and rostral aspect of the fourth ventricle (P = 0.005) compared with the telovelar alone. The telovelar approach with C1 arch removal offered a larger working area than the transvermian approach (P < 0.001). CONCLUSION: Except for the vertical angle to the rostral aspect of the fourth ventricle, the telovelar approach provides greater angle of exposure in all planes than the transvermian approach. Removal of the C1 posterior arch obviates this sole advantage of the transvermian approach. The telovelar approach offers a corridor through noneloquent arachnoid planes and a safe and capacious working environment.

Cerebellum↗

PubMed2006

Outcome of oculomotor nerve palsy from posterior communicating artery aneurysms: comparison of clipping and coiling.

OBJECTIVE: Recovery of posterior communicating artery aneurysm-induced oculomotor nerve palsy (ONP) after aneurysm coiling has been reported. However, the coil mass may compromise recovery of the nerve. Therefore, we compared the outcome of coiling and clipping for this indication. METHODS: We retrospectively compared the outcomes of ONP in 13 patients, six of whom underwent endovascular coiling and seven of whom underwent surgical clipping. RESULTS: Six of the seven surgical patients with ONP recovered completely, compared with two of the six patients in the endovascular group. Of the patients with more than 1 year of follow-up, all six surgical patients recovered completely, compared with two of four endovascular patients (P = 0.05). In addition, preoperative complete or partial ONP also was associated with degree of resolution by survival analysis (P = 0.03). All patients with partial ONP in the surgical group and two of three patients in the endovascular group recovered without residual deficits, whereas three of the four patients with complete ONP in the clipping group and none in the coiling group recovered completely. Regardless of the treatment method, time to complete resolution of ONP was 6 months in both groups. CONCLUSION: Clipping posterior communicating artery aneurysms was associated with a higher probability of complete recovery from ONP than coiling. Degree of preoperative ONP also affected recovery. If patients can tolerate surgery, it should be considered the treatment of choice.

Adult↗