Werner Hassler

The critical first minutes after subarachnoid hemorrhage

Six patients were observed during recurrent subarachnoid hemorrhage (SAH). Three each had an open skull and intact dura mater and demonstrated an extreme increase in intracranial pressure (ICP) that developed within 1 minute and then declined over several minutes. Three other patients were investigated with transcranial Doppler sonography before, during, and after recurrent bleeding, and their hemodynamics were studied. There is conclusive evidence that acute spontaneous SAH is often followed by an intracranial circulatory arrest lasting for several minutes and caused by a peak of ICP in the range of mean arterial levels. The mechanisms involved are discussed. There are strong indications that this temporary intracranial circulatory arrest promotes hemostasis, but may constitute a severe ischemic event.

Stereotactic puncture and lysis of spontaneous intracerebral hemorrhage using recombinant tissue-plasminogen activator.

We have tested a treatment protocol for intracerebral hemorrhage (ICH), consisting of stereotactic insertion of a catheter into the clot, hematoma lysis by the injection of a fibrinolytic agent, recombinant tissue-plasminogen activator (rt-PA), and closed system drainage of the liquefied clot. Fourteen patients underwent computed tomographically guided stereotactic hematoma puncture and silicone tube insertion within 72 hours of intracerebral hemorrhage. The majority (nine patients) suffered from ganglionic ICH, and the size of the hematoma ranged between 3 x 3 x 4 cm and 7 x 7 x 4 cm (mean, 5.2 x 4 x 3.6 cm). All patients had major neurological deficits with or without an impaired level of consciousness, but without signs of transtentorial herniation. The initial, then daily, dose (in milligrams) of rt-PA administered via the silicone tube equalled the maximal diameter (in centimeters) of the original and remaining clot as measured initially, then daily, by computed tomographic scan. The number of rt-PA injections was four in one patient, three in eight patients, two in four patients, and one in one patient, and the total dose of rt-PA required ranged from 5 to 16 mg (mean, 9.9 mg). After rt-PA injection, the tubing was clamped for 2 hours and then opened to drain spontaneously through a closed system against 0 cm of pressure. At follow-up 6.6 months (mean) after treatment (ranging from 3 to 13 months) and according to the Glasgow outcome score, one patient was Grade V, four were Grade IV, five were Grade III, two were Grade II, and two had died.(ABSTRACT TRUNCATED AT 250 WORDS)

Complications of burr-hole craniostomy and closed-system drainage for chronic subdural hematomas: a retrospective analysis of 376 patients

Abstract.Objective. Burr-hole craniostomy with closed-system drainage (BCD) is the most frequently used neurosurgical treatment of chronic subdural hematomas (cSDH).The surgical and medical complications of BCD have seldom been investigated systematically. The objective of this study was to define the frequency of surgical and medical complications following BCD for cSDH. Methods. The medical records of 376 patients managed by BCD were reviewed with respect to complications during the hospital stay. Results. Seventy-seven surgical complications (20.5%) were encountered . The most frequent minor complication after surgery was seizures (n 51, 13.6%). The most frequent major surgical complications were intracerebral hemorrhage and subdural empyema (n 8, 2.1% each). Four patients with intracerebral hemorrhage died, accounting for a surgical mortality rate of 1.1%. Fifty-nine medical complications (15.7%) occurred during the hospital stay. Pneumonia was the most frequent medical complication (n 29, 7.7%). Medical complications were fatal in 24 patients, accounting for a mortality rate of 6.4%. In 22 patients (5.8%), death was not related to a complication, but to the initial brain damage. The overall mortality rate was 13.3%. Conclusion. The rate of complications in patients with cSDH who underwent the BCD is high. The clinical relevance of medical complications has to be emphasized because of their substantial contribution to overall mortality.

Pterional Approach for Surgical Treatment of Olfactory Groove Meningiomas

We present our experience with the surgical treatment of olfactory groove meningiomas using a pterional approach. This approach provides the advantages of previous techniques, such as preserving the frontal brain and superior sagittal sinus, early devascularization of the tumor, and late dissection of tumor borders. Moreover, it also compensates for the shortcomings of other techniques, e.g., compression of frontal bridging veins, late dissection of dorsal tumor aspects involving vessels and optic nerves as well as facultative infection and cerebrospinal fluid fistula-related complications caused by opening of frontal sinuses. To date, 11 patients were treated in this way. As we encountered no surgical complications in our series we are encouraged to present our procedure.

Intramedullary cavernous angiomas

Two cases of histologically verified intramedullary cavernous angiomas at C3 and D5-6 are presented. Both patients suffered progressive myelopathy with intermittent improvement. In both cases preoperative diagnosis was possible by means of magnetic resonance imaging using spin echo techniques, fast imaging, and phase display, while spinal angiography was not helpful. Laminectomy and total removal of the tumors were performed with temporary increased neurological deficits. It is thought that magnetic resonance imaging provides a useful diagnostic tool in these tumors and is also essential for planning surgical strategy.

Flow velocity and pressure measurements in spinal dural arteriovenous fistulas.

During ten operations for spinal dural arterio-venous fistulas (AVF), intraoperative measurement of flow velocity and intravascular pressure was performed. Flow velocities were recorded using a miniaturized Doppler probe. Intravascular pressure changes in the draining veins beofre and after AVF removal was measured with small needles. Varying the pCO2 between 20 mm Hg and 60 mm Hg, the flow velocities in arteries supplying the spinal cord were investigated so that the vasomotoric reactivity of the peripheral vessel wall in cord tissue was investigated before and after AVF occlusion. The flow velocities in dural AVF feeders were not as high as those known from cerebral angioma feeders. In addition, they often showed lowered end-diastolic flow velocity as a dign of increased vascular resistance, thus proving impaired venous outflow from the spinal canal. After excision of the local fistula, the vessels supplying and draining the spinal cord showed improved circulation. In the former recipient veins, no further flow could be recorded.The venous pressure in dural AVF was about 70% of the systemic arterial pressure. Fistulas presenting a high shunt volume on angiography showed only moderately increased venous pressure and a more pronounced pressure drop after fistula occlusion as compared with low-volume fistulas. The CO2 reactivity of vessels supplying the spinal cord was normal before and after AFV removal.

Progressive spontaneous herniation of the thoracic spinal cord: case report.

OBJECTIVE AND IMPORTANCE We report one case of spontaneous thoracic spinal cord herniation. To our knowledge, this is the first case involving radiological documentation of the development of herniation. Clinical features and surgical techniques are also presented. CLINICAL PRESENTATION We describe the case of a 51-year-old female patient who experienced progressive Brown-Sequard syndrome for 2 years. Three magnetic resonance imaging examinations were performed; they revealed the progressive development of anterolateral spinal cord herniation at the level of T6 during those 2 years. INTERVENTION After laminectomy at T6, the herniated myelon was microsurgically removed and the neurological symptoms improved. CONCLUSION We present the possible causes, the proposed pathophysiological mechanisms, and the clinical and radiological development of this rare entity, with a review of the literature published to date. We propose that a preexisting weakness of the ventral dural fibers, combined with abnormal adhesion of the spinal cord to the anterior dural sleeve, leads to progressive herniation throughout life. Microsurgical treatment may halt the exacerbation of the neurological symptoms.

Radical osteoclastic craniectomy in sagittal synostosis.

We report our experience in the surgical treatment of sagittal synostosis using radical osteoclastic craniectomy in 60 consecutive patients. After surgery in children aged 6 months or younger (Group I), reossification usually started 2 weeks postoperatively and was complete within 6 months, resulting in an optimal skull contour. In children aged 7 to 12 months (Group II), reossification was prolonged and lasted for 12 months or longer. The skull contour normalized in its biparietal width and improved in sagittal diameter, remaining, however, slightly abnormal. In children older than 12 months (Group III), the skull contour partly improved in the biparietal diameter but did not change in the sagittal direction. Reossification was incomplete with persistent pseudosutures. Enlarged frontal subarachnoid spaces were reversible or improved in all patients independent of age at the time of surgery. We encountered no complications in our series. In our opinion, radical osteoclastic craniectomy is the simplest, most efficient, and most physiologically sound method for the treatment of sagittal synostosis in patients up to 6 months of age. This procedure allows the rapidly growing brain to form its skull vault, thus providing optimal cosmetic results. In older children, osteoplastic morcellation procedures should be the treatment of choice.

Cavernous angioma of the optic nerve: Case Report

The case of a 24-year-old woman with a cavernoma of the right optic nerve is presented. She suffered recurrent headaches and showed a deficit of the right nasal visual field. A computed tomography scan, a computed tomography cisternography, and magnetic resonance imaging revealed a lesion in projection on the right suprasellar cistern, yet angiography was inconspicuous. On operation, an angiomatous tumor of the right optic nerve with a surrounding hemorrhage was found. Histological examination of the specimen confirmed the intraoperative diagnosis of a cavernoma. Postoperatively, the right nasal visual field deficit increased slightly.

Periventricular neurocytoma: A pathological entity

Three cases of periventricular neurocytomas are presented. All patients had a large but well-circumscribed, hyperdense tumor with insignificant contrast enhancement in the lateral and third ventricle, causing hydrocephalus. Calcification was present in one patient. Angiography revealed a blush tumor enhancement in two cases. Surgical removal was complete in two patients and incomplete in one. Light microscopy showed a cell pattern that resembled either ependymoma or oligodendroglioma. However, in all cases the tumor was confirmed to be a neurocytoma by immunocytochemical analysis that showed reactivity for synaptophysin and/or neuron-specific enolase in a high percentage of neoplastic cells. With respect to the literature it is concluded that neurocytomas represent an individual pathological entity of supratentorial midline tumors. Complete surgical removal without irradiation is the recommended treatment.