Dorsal thoracic arachnoid web and the "scalpel sign": a distinct clinical-radiologic entity

Arachnoid webs are intradural extramedullary bands of arachnoid tissue that can extend to the pial surface of the spinal cord, causing a focal dorsal indentation of the cord. These webs tend to occur in the upper thoracic spine and may produce a characteristic deformity of the cord that we term the "scalpel sign." We describe 14 patients whose imaging studies demonstrated the scalpel sign. Ten of 13 patients who underwent MR imaging demonstrated T2WI cord signal-intensity changes, and 7 of these patients also demonstrated syringomyelia adjacent to the level of indentation. Seven patients underwent surgery, with 5 demonstrating an arachnoid web as the cause of the dorsal indentation demonstrated on preoperative imaging. Although the webs themselves are rarely demonstrated on imaging, we propose that the scalpel sign is a reliable indicator of their presence and should prompt consideration of surgical lysis, which is potentially curative.

Surgical management of intracranial gliomas--does radical resection improve outcome?

This paper discusses the arguments for and against radical tumor resection as a strategy for treatment of cerebral gliomas.

METHOD

Data from the Glioma Outcome Project were analyzed to determine whether survival could be related to extent of resection in 666 patients treated by biopsy or resection for malignant cerebral gliomas.

FINDINGS

Consistent survival advantages were noted for those patients treated with resection.

INTERPRETATION

This observational study, although undoubtedly reflecting selection bias, provides data that support resection as a major factor in survival after surgery for malignant gliomas.

Surgical management of intracranial gliomas--does radical resection improve outcome?

This paper discusses the arguments for and against radical tumor resection as a strategy for treatment of cerebral gliomas.

METHOD

Data from the Glioma Outcome Project were analyzed to determine whether survival could be related to extent of resection in 666 patients treated by biopsy or resection for malignant cerebral gliomas.

FINDINGS

Consistent survival advantages were noted for those patients treated with resection.

INTERPRETATION

This observational study, although undoubtedly reflecting selection bias, provides data that support resection as a major factor in survival after surgery for malignant gliomas.

Pilot study of electrical stimulation on median nerve in comatose severe brain injured patients: 3-month outcome

PRIMARY OBJECTIVE

To determine if electrical stimulation (ES) benefits (waking time, 3-month outcomes) treated coma patients.

RESEARCH DESIGN

Double blind randomized-controlled study.

METHODS AND PROCEDURES

Ten coma patients; six treatment and four controls, using the 'Respond Select' by EMPI.

EXPERIMENTAL INTERVENTIONS

Treatment group received radial nerve ES applied in 300 ms intermittent pulses at 40 Hz, 15-20m A 8 hours a day up to 14 days of coma; control group received sham stimulation.

MAIN OUTCOMES AND RESULTS

ES group emerged from coma mean 2 days earlier than controls, although this result was not statistically significant. At 3 months post-injury, there was no group difference in Glasgow Outcome Scale, although the ES group had improved function over controls as measured by the FIM/FAM (mean of 114 and 64.5, respectively, n.s.).

CONCLUSIONS

These data show an interesting trend, although statistical power was limited in this small pilot study, suggesting the need for a larger trial.

Electrophysiological evidence for afferent nerve fibers in human ventral roots

This study was designed to test the hypothesis that ventral roots in humans contain afferent nerve fibers. We made direct electrophysiological recordings of compound nerve action potentials in dorsal and ventral roots in children undergoing selective dorsal rhizotomy for spastic cerebral palsy. We stimulated the saphenous or sural nerves, which are pure sensory nerves, with electrical stimuli while systematically recording from ventral and dorsal roots from L3 to S2. In addition to the dorsal root nerve action potentials which we expected, we found smaller compound nerve action potentials, which were clearly afferent, in the ventral roots. This confirms the limited amount of experimental evidence that ventral roots do contain some afferent nerve fibers. The functional significance of these observations is not yet clear.

Invasion of the internal carotid artery by cavernous sinus meningiomas

BACKGROUND

Meningiomas are the most common tumor involving the cavernous sinus. Although these tumors have been known to invade adjacent structures such as bone, soft tissue, and brain, invasion of the internal carotid artery (ICA) by meningiomas has only been recognized recently. The authors evaluate the extent of carotid wall involvement in nine patients with cavernous sinus meningiomas encasing the ICA who underwent en bloc resection of the cavernous sinus.

METHODS

The en bloc tumor-ICA specimens were fixed in formalin, embedded in paraffin, and sectioned on a rotary microtome. Hematoxylin and eosin, EVG, and HVG stains were performed and evaluated by light microscopy.

RESULTS

There were four males and five females with a mean age of 47 years. Eight patients had not undergone previous surgery, whereas one patient had been operated on before. In this latter case, however, the cavernous sinus was not entered during the first operation. In all patients, stenosis of the ICA was confirmed by preoperative angiography and/or magnetic resonance imaging (MRI). In seven cases, the tumors were excised en bloc along with the stenotic ICA segment. A petrous-to-supraclinoid ICA bypass was performed in these seven patients. In two cases, the tumor was excised with the stenotic artery, but no bypass was performed. The final pathological diagnosis was meningothelial meningioma. In all cases tumor cells were found in the adventitia of the cavernous carotid with stenosis of the arterial lumen. Compression and/or obliteration of the vasa vasorum within the adventia was noted in all specimens. In four cases, the tumor was found to have invaded the external elastic lamina. In two instances the external elastic lamina was disrupted and the tumor focally extended into the media.

CONCLUSIONS

These findings suggest that in the case of cavernous sinus meningiomas with encasement and stenosis of the intracavernous ICA, invasion of the vessel wall has occurred. The effect of these findings on the management of cavernous sinus meningiomas and the involved ICA is discussed.

A new technique for the surgical management of unstable thoracolumbar burst fractures: a modification of the anterior approach and an outcome comparison to traditional methods

This study was conducted to determine the safety, efficacy, and complication rate associated with the anterior approach in the use of a new titanium mesh interbody fusion cage for the treatment of unstable thoracolumbar burst fractures. The experience with this technique is compared with the senior authors' (C.S., R.W., and M.S.) previously published results in the management of patients with unstable thoracolumbar burst fractures.

Between 1996 and 1999, 21 patients with unstable thoracolumbar (T12-L3) burst fractures underwent an anterolateral decompressive procedure in which a titanium cage and Kaneda device were used. Eleven of the 21 patients had sustained a neurological deficit, and all patients improved at least one Frankel grade (average 1.2 grades). There was improvement in outcome in terms of blood loss, correction of kyphosis, and pain, as measured on the Denis Pain and Work Scale, in our current group of patients treated via an anterior approach when compared with the results in those who underwent a posterior approach.

In our current study the anterior approach was demonstrated to be a safe and effective technique for the management of unstable thoracolumbar burst fractures. It offers superior results compared with the posterior approach. The addition of the new titanium mesh interbody cage to our previous anterior technique allows the patient's own bone to be harvested from the corpectomy site and used as a substrate for fusion, thereby obviating the need for iliac crest harvest. The use of the cage in association with the Kaneda device allows for improved correction of kyphosis and restoration of normal sagittal alignment in addition to improved functional outcomes.

Detection of soluble E-selectin, ICAM-1, VCAM-1, and L-selectin in the cerebrospinal fluid of patients after subarachnoid hemorrhage

OBJECT

The goal of this study was to explore whether the levels of soluble adhesion molecules were elevated in cerebrospinal fluid (CSF) after subarachnoid hemorrhage (SAH). This association was suggested by the known inflammatory response in vasospasm and the role of vascular adhesion molecules in regulating leukocytic adhesion to, and migration across, vascular endothelium.

METHODS

A prospective analysis was performed on CSF samples obtained in 17 patients who had suffered a recent aneurysmal SAH and in 16 control patients by using quantitative enzyme-linked immunosorbent assays for E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and L-selectin. Levels of soluble forms of E-selectin (p=0.0013), ICAM-1 (p=0.0001), and VCAM-1 (p=0.048) were found to be elevated in the CSF of patients after SAH compared with levels in the CSF of norminal controls, patients with unruptured aneurysms, and patients tested months after SAH occurred. In addition, individual patients tested at the time of their initial ictus demonstrated a fall in adhesion molecule levels over time. Levels of E-selectin (p=0.044) were highest in patients who later developed moderate or severe vasospasm.

CONCLUSIONS

Adhesion molecules are known to be involved in white cell adherence to the endothelium and subsequent diapedesis and migration in which a role in initiation of tissue damage is postulated. The authors have demonstrated the elevation of three adhesion molecules, with severely elevated levels of E-selectin seen in patients who later develop vasospasm. A correlation with a role of vascular adhesion molecules in the pathogenesis of cerebral vasospasm is suggested.

Surgical treatment of thoracolumbar fractures

Many studies indicate that spinal canal decompression and stabilization lead to improved neurologic recovery in patients with incomplete neurologic deficits. It is recognized that surgical stabilization of unstable thoracolumbar injuries with complete neurologic deficit or without deficit reduces hospital stay, improves spinal alignment, shortens rehabilitation, and results in fewer medical complications. Unfortunately, many aspects of management remain controversial. For many injuries, more than one treatment method has been shown to be efficacious, although certain injuries have improved outcome with specific treatment modalities. This article is an overview of indications for surgery, operative approaches, types of instrumentation, and treatment options for specific thoracolumbar injuries.

Decompressive bifrontal craniectomy in the treatment of severe refractory posttraumatic cerebral edema

OBJECTIVE

The management of malignant posttraumatic cerebral edema remains a frustrating endeavor for the neurosurgeon and the intensivist. Mortality and morbidity rates remain high despite refinements in medical and pharmacological means of controlling elevated intracranial pressure; therefore, a comparison of medical management versus decompressive craniectomy in the management of malignant posttraumatic cerebral edema was undertaken.

METHODS

At the University of Virginia Health Sciences Center, 35 bifrontal decompressive craniectomies were performed on patients suffering from malignant posttraumatic cerebral edema. A control population was formed of patients whose data was accrued in the Traumatic Coma Data Bank. Patients who had undergone surgery were matched with one to four control patients based on sex, age, preoperative Glasgow Coma Scale scores, and maximum preoperative intracranial pressure (ICP).

RESULTS

The overall rate of good recovery and moderate disability for the patients who underwent craniectomies was 37% (13 of 35 patients), whereas the mortality rate was 23% (8 of 35 patients). Pediatric patients had a higher rate of favorable outcome (44%, 8 of 18 patients) than did adult patients. Postoperative ICP was lower than preoperative ICP in patients who underwent decompression (P = 0.0003). Postoperative ICP was lower in patients who underwent surgery than late measurements of ICP in the matched control population. A statistically significant increased rate of favorable outcomes was seen in the patients who underwent surgery compared to the matched control patients (15.4%) (P = 0.014). All patients who exhibited sustained ICP values above 40 torr and those who underwent surgery more than 48 hours after the time of injury did poorly. Evaluation of the 20 patients who did not fit into either of those categories revealed a 60% rate of favorable outcome and a statistical advantage over control patients (P = 0.0001).

CONCLUSION

Decompressive bifrontal craniectomy provides a statistical advantage over medical treatment of intractable posttraumatic cerebral hypertension and should be considered in the management of malignant posttraumatic cerebral swelling. If the operation can be accomplished before the ICP value exceeds 40 torr for a sustained period and within 48 hours of the time of injury, the potential to influence outcome is greatest.

Maturation of intracranial immature teratomas. Report of two cases

Immature teratomas arising within the central neuraxis are rare neoplasms. These tumors contain diverse cell lineages that retain an embryonal character and display phenotypic differentiation attributed to the three classic germ layers. The clinical management of these lesions is unclear, due in part to their low incidence and to an incomplete understanding of their natural history. Although the potential for phenotypic differentiation and cellular maturation within immature teratomas arising in the gonads is well documented, this has not been described in the intracranial tumors. In the present report, the authors describe two cases of intracranial immature teratomas, one involving the pineal region and the other involving the left frontotemporal lobes, which underwent cellular differentiation and maturation. At initial resection, the tumors from both cases were composed predominantly of primitive neuroepithelial tissue that was admixed with immature and differentiating mesenchymal and epithelial structures. No foci of germinoma, endodermal sinus, choriocarcinoma, or embryonal carcinoma tissue were present. Subsequent resections in both cases revealed an absence of immature tissue. The tumor in Case 1 contained only differentiated epithelial and mesenchymal tissue with no neuroepithelial component, whereas the tumor in Case 2 demonstrated abundant mature neuronal and glial tissue. These two cases from different intracranial sites suggest that spontaneous maturation may be a significant aspect of the natural history of intracranial immature teratomas.

Medical management in the endovascular treatment of carotid-cavernous aneurysms

Carotid-cavernous aneurysms account for between 1.9% and 9.0% of intracranial aneurysms. Entirely intercavernous aneurysms are believed to have a relatively benign course, with cranial nerve findings or headache being the usual initial symptomatology; however, subarachnoid hemorrhage or carotid-cavernous fistula formation can result from rupture. Over the past 15 years endovascular parent artery occlusion has essentially replaced surgical carotid occlusion as the treatment of choice. The authors describe a series of 39 consecutive patients at the University of Virginia Health Sciences Center who underwent endovascular treatment of a carotid-cavernous aneurysm. Aggressive invasive hemodynamic monitoring and maintenance of a state of normo- to mild hypervolemia in the asymptomatic patient was used throughout the periprocedural period. Rapid institution of hypervolemic-hypertensive therapy can reverse early neurological deficits related to hypoperfusion in these patients. Only one individual managed with this protocol developed neurological deficits not reversible with hypertensive-hypervolemic therapy. Heparin therapy was administered for 48 hours after occlusion, with patients receiving subsequent aspirin therapy for 6 months to combat distal embolism secondary to thrombosis. Long-term complications were not seen in patients receiving aneurysm trapping; however, two individuals with proximal carotid occlusion developed late optic neuropathy and one had recurrent transient ischemic attacks that ceased with supraclinoidal carotid clipping.

Surgical approaches for the correction of unstable thoracolumbar burst fractures: a retrospective analysis of treatment outcomes

The authors retrospectively studied 49 nonparaplegic patients who sustained acute unstable thoracolumbar burst fractures. All patients underwent surgical treatment and were followed for an average of 27 months. All but one patient achieved solid radiographic fusion. Three treatment groups were studied: the first group of 16 patients underwent anterior decompression and fusion with instrumentation; the second group of 27 patients underwent posterior decompression and fusion; and the third group of six patients had combined anterior-posterior surgery. Prior to surgical intervention, these groups were compared and found to be similar in age, gender, level of injury, percentage of canal compromise, neurological function, and kyphosis. Patients treated with posterior surgery had a statistically significant diminution in operative time and blood loss and number of units transfused. There were no significant intergroup differences when considering postoperative kyphotic correction, neurological function, pain assessment, or the ability to return to work. Posterior surgery was found to be as effective as anterior or anterior-posterior surgery when treating unstable thoracolumbar burst fractures. Posterior surgery, however, takes the least time, causes the least blood loss, and is the least expensive of the three procedures.

Extradural failure in glioblastoma multiforme: MRI demonstration

Glioblastoma multiforme is invariably associated with intracranial failure following conventional therapy. Extracranial as well as metastatic failure are rarely seen. Subtle extracranial abnormalities in most patients with glioblastoma multiforme are not indicative of convexity failure. However, in patients with high p53 and Ki67 immunoreactivity and in whom the dura was not closed at the time of craniotomy, the possibility of early extradural failure should be considered.

Multivariate analysis and prediction of outcome following penetrating head injury

Schemes for predicting outcome in craniocerebral missile injury have ranged from Cushing's analysis that was based on the physical characteristics of the injury to complex logistic analyses that incorporate radiographic, laboratory, and clinical data. Generation of predictive scales is discussed, focusing on the utility of the Glasgow Coma Scale (GCS) score at presentation, presence or absence of coagulopathy, and radiographic evidence of the volume and type of tissue damage.

Tumoral calcium pyrophosphate dihydrate deposition disease mimicking a cervical spine neoplasm: case report

A case of tumoral calcium pyrophosphate dihydrate crystal deposition disease involving the upper cervical spine is reported. It presented clinically, radiographically, and by preliminary intraoperative pathological evaluation as a possible malignant soft tissue tumor. An aggressive resection of the lesion was performed. This case differs from previous reports of calcium pyrophosphate dihydrate crystal deposition disease of the cervical spine by the size, location, and radiographic appearance of the lesion. We suggest that radical surgical procedures should not be performed without consideration of this diagnosis in lesions with similar presentations. A brief review of spinal and tumoral calcium pyrophosphate dihydrate crystal deposition is presented.

Neurosurgical considerations of cranial base surgery

Several craniotomies have been described that allow extensive resection of skull base and low-lying cranial tumors that involve little disfigurement to the patient. These techniques should be of interest to plastic surgeons as they may be called to aid their neurosurgical colleagues in exposing the anterior skull base or may be involved in combined procedures to resect tumors that involve the face, sinuses, orbit, and cranial vault.

Fusion with occipital bone for atlantoaxial instability: technical note

A technique is described of using autologous occipital bone for posterior atlantoaxial fusions. The advantages include the ease of harvest, the lack of postoperative discomfort, and the suitability of occipital bone for the fusion.

Surgeon's foot: a report of sural nerve palsy

Although compression neuropathies are encountered frequently in neurosurgical practice, involvement of the sural nerve is described rarely. We report a case of bilateral compression neuropathy of the sural nerve with an unusual mechanism of injury. The case is discussed, and the pertinent literature is reviewed.

Classification of civilian craniocerebral gunshot wounds: a multivariate analysis predictive of mortality

Management of cerebral gunshot injuries has changed considerably since Cushing's (1916) and Matson's (1948) classification schemes, developed during World War I and World War II, respectively. These military injuries are characterized by either very high mass, low-velocity shrapnel wounds or by high muzzle velocity missiles causing extensive destruction of tissue. The preponderance of low muzzle velocity weapons seen in clinical practice and the availability of computed tomographic (CT) evaluation within minutes after presentation has altered the range of prognostic indicators available to the neurosurgeon and the amount of relative importance placed on each factor. Raimondi and Samuelson (1970) noted this difference in wound ballistics and offered a classification scheme based on initial neurologic assessment. No well-defined classification system for civilian craniocerebral gunshot wounds has been proposed that evaluates and integrates clinical, laboratory, and neuroradiologic data. A retrospective study was performed on all 62 civilians with gunshot wounds to the head admitted to the University of Virginia Hospital between December, 1984, and November, 1990. The patient population consists of 86% males and 14% females, with an age range of 10-72 years; 60% self-inflicted wounds and 32% patients who died en route or immediately upon arrival at the hospital. The overall mortality rate was 55% at 1 week postinjury. Although we have demonstrated an association between some previously defined factors and prognosis in civilian injury, such as admission Glasgow Coma Scale (GCS) (p = 0.001) and initial pupillary response (p less than 0.001), we have also defined other significant predictors of outcome including abnormal coagulation states on admission (p less than 0.001) and the neuroradiologic examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Duraplasty in cranial base resection

Complications of cerebrospinal fluid leakage following cranial base surgery are a predominant source of morbidity and mortality. The physical properties of the dura in this region, advanced patient age, previous irradiation, and the extent of tumor resection often limit or complicate the reconstructive options available to cranial base surgeons. We describe a technique that delivers vascularized tissue to the dural wound by transposing a dural flap based on the axial pedicle blood supply from the middle meningeal artery. This "duraplasty" can allow primary closure of defects at the cranial base. The donor site, which is less gravitationally dependent, more accessible, and often not affected by radiation therapy, can be closed using traditional methods. Advantages, disadvantages, and indications for this technique are discussed.

Surgical treatment of metopic synostosis

Metopic synostosis can present with various skull abnormalities for which early surgical treatment can provide significant benefit to the patient. Correction of skull deformities associated with metopic synostosis requires accurate assessment of the full range of craniofacial defects within context of the patient's age. Alteration in the characteristics of cranial bone as the child grows older necessitates modifications in techniques used for bony remodeling. Changes in the rate of brain and cranial vault growth also must be considered for adjustments in fixation methods. Thus, both the patient's age and the severity of aesthetic deformity dictate the surgical techniques used in the correction of metopic synostosis.

Gastrointestinal myoelectric and clinical patterns of recovery after laparotomy

The objective of this study was to define the patterns of myoelectric activity that occur throughout the gastrointestinal tract during normal recovery from laparotomy. Electrodes were placed on the stomach, jejunum, and transverse colon of 44 patients undergoing laparotomy. Basal electric rhythms in all areas showed no changes in frequency after operation (up to 1 month). Gastric spike wave activity showed a gradient of increasing activity from fundus to antrum. Antral spike activity was unchanged during the study. Jejunal spike activity was present in the earliest recordings and occurred in 45.9% +/- 3.5% to 59.9% +/- 5.5% of slow waves. Recovery of normal colon discrete and continuous electric response activity occurred on postoperative day 5.9 +/- 1.5. Bowel sounds returned on day 2.4 +/- 0.5 and passage of flatus and stool occurred on day 5.1 +/- 0.2. The myoelectric parameters measured are not absolutely predictive of uneventful recovery from postoperative ileus but they are, as a group, more informative than any currently available clinical criteria.

Vascular lesions involving the cranial base: combined surgical and interventional radiologic approach

Advantages and possible complications of combined surgical and interventional radiologic approach to vascular lesions involving the cranial base are presented in three case examples. The methodology and technology of endovascular embolization and occlusion techniques, selection of embolic materials, functional testing to prevent neurologic injury and surgical implications of these treatment modalities are discussed. Emphasis is placed on individualization of each combined approach relative to the aforementioned factors.

Neurosurgical applications of fibrin glue: augmentation of dural closure in 134 patients

In a wide variety of neurosurgical procedures performed on 134 patients over a 3-year period, fibrin glue has been applied as an adjunct to dural closure. Overall success at preventing cerebrospinal fluid (CSF) leakage was 90% (121 of 134, 90% effective). In patients considered to be at high risk for CSF leakage intraoperatively but without pre-established fistulae (Group 1), the success rate was higher (111 of 119, 93% effective). In patients with pre-established CSF fistulae (Group 2), the success rate was lower (10 of 15, 67% effective). As single donor sources of concentrated fibrinogen are now available with reduced risks of blood-borne disease transmission, fibrin glue may be a valuable clinical tool for the neurosurgeon.