Laszlo Solymosi

Surgical treatment of extratemporal epilepsy: clinical, radiologic, and histopathologic findings in 60 patients.

Summary: Purpose and Methods: The aim of this study was to analyze clinical, radiologic, and histopathologic findings in 60 consecutive patients with medically intractable extratemporal epilepsy who were operated on between November 1987 and May 1993.

Depth electrode implantation in the length axis of the hippocampus for the presurgical evaluation of medial temporal lobe epilepsy: a computed tomography-based stereotactic insertion technique and its accuracy.

OBJECTIVE An individualized computed tomography-based stereotactic technique for the longitudinal insertion of intrahippocampal electrodes is presented and its accuracy described. METHODS The technique makes use of one well reproducible target in the hippocampal head and of the approximate inclination of the anteroposterior length axis of the hippocampus, for which the orbital floor is taken as an auxiliary landmark. It was used in 141 patients with medically intractable complex partial seizures. In 106 patients, magnetic resonance imaging (MRI) was available for assessment of implantation accuracy. Each of the 212 electrodes was plotted on topographic drawings and its goodness of fit rated. RESULTS Whereas hippocampal head and body were hit by 97 and 96% of the electrodes, respectively, the amygdala was hit by only 75% of the electrodes and mainly at its basal margin. For 93% of the electrodes, the inclination in a sagittal plane corresponded exactly to that of the hippocampus. The implantation morbidity amounted to 5.7%, whereas permanent neurological deficit occurred in one (0.7%) of the 141 patients. CONCLUSION This computed tomography-based protocol proved to be reliable and hence can be considered as an adequate alternative to MRI-based stereotactic implantation if MRI is not available or if a single MRI-based stereotactic set-up is unreliable because of intolerable distortions.

Paragangliomas of the spinal canal

Paragangliomas are tumors arising in the paraganglia and rarely occur in the spinal canal. In the literature, 11 such cases have been reported. We present 7 additional cases, 3 of which were epidural in location in contrast to previously described intradural cases. The problems of histological diagnosis of these tumors are discussed. The value of determination of biogenic amines in the tumor tissue or the urine has been pointed out.

Subarachnoid hemorrhage of unknown etiology.

During a 10-year-period, 80 of 510 (16%) patients with primary subarachnoid hemorrhage (SAH) had negative angiographic studies. On admission, 70 of 80 patients (88%) were in grades I-II according to Hunt and Hess, 9 (11%) in grade III, and 1 (1%) in grade IV. The most frequent CT feature was preponderance of subarachnoid blood in the peripontine cistern as observed in 35 of 51 cases (69%) in whom blood was visible on CT. During hospitalization, 3 patients (4%) rebled, and 3 others (4%) had an infarction. However, in all of these complicated cases maximum hemorrhage was outside the peripontine cistern. Outcome after hospitalization as assessed by the Glasgow-Outcome-Scale (GOS) was favorable (GOS 1 and 2) in all patients who had maximum blood in the peripontine cistern, but only in 62% showing preponderance of blood outside the peripontine cistern, and 4 of them (25%) had died (GOS 5). These differences are statistically significant (p < 0.001). Long-term outcome of 56 patients as graded according to the Activities of Daily Living (ADL) system was favorable in 88% of cases with peripontine hemorrhage who returned to normal activities (ADL 1). At the same time, another patient with diffuse hemorrhage had died. Thus, overall mortality was 8.9% at a mean observation time of 5.5 years. In conclusion, SAH of unknown etiology generally has a good prognosis, although a nonneglegible percentage of patients have persistent minor side-effects. In our experience, maximum blood in the peripontine cistern particularly indicates a favorable outcome, since all patients with this CT pattern survived in a good condition.

Diagnosis and treatment of frontobasal skull fractures

During a five-year-period (January 1990 to December 1994) a total of 67 patients were operated on for frontobasal skull fractures. The indication for surgical treatment was based on the evidence of fractures encroaching paranasal sinuses or the cribriform plate on high-resolution axial or coronal CT scans. The following clinical signs indicating frontobasal trauma were observed: 25 patients (37%) showed rhinoliquorrhea, 14 (21%) had racoons eyes, and 2 (3%) had meningitis. Distinct dura laceration was observed intraoperatively in 64 of 67 patients (96%). In our experience, high resolution CT has proven to be a sensitive diagnostic tool for frontobasal skull fractures. With respect to the high coincidence of fractures and dura lacerations, the indication for surgical treatment based on CT findings seems to be justified.

A characteristic ventricular shape in myelomeningocele-associated hydrocephalus? A CT stereology study.

We measured the volume of the supratentorial ventricles in 39 consecutive children with myelomeningocele (MMC) and associated hydrocephalus, using a stereological method based on the Cavalieri the-orem of systematic sampling. We distinguished the following groups: newborns before and after cerebrospinal fluid shunting (14), a somewhat larger group of newborns with an untreated MMC-associated hydrocephalus (25) and a group of shunted children at a mean age of 1.5 years (28). We paid special attention to the shape of the lateral ventricles, looking separately at the anterior and posterior halves. The measurements were compared with a healthy control group (10) and with children with hydrocephalus unrelated to MMC (15). The average volume ratio of the posterior to the anterior half of the lateral ventricles was 1.05±0.39 in nonhydrocephalic children, 1.11±0.55 in untreated hydrocephalic children without MMC, and 2.15±0.65 in MMC-associated hydrocephalus prior to shunting. These ratios did not change significantly after shunting. This confirms our impression that MMC-associated hydrocephalus shows a characteristic shape, with a disproportionate enlargement of the posterior part of the lateral ventricles, in clear contrast to the normal-width frontal horns. This shape is reminiscent of the fetal ventricular shape. It reveals disturbance of brain development in children with MMC, which goes beyond the classic description of the Chiari malformation.

Multiple spinal hemangioblastomas in a case of Lindau's disease

A 32-year-old man with Lindaus syndrome is presented. After an initial operation for cerebellar hemangioblastoma and laser coagulation of retinal tumors, other retinal tumors, a second cerebellar tumor, and four spinal hemangioblastomas occurred 10 years later; cystic lesions of both kidneys and of the pancreas could also be shown. There is no family history. Consequences for further diagnostic procedures in patients with hemangioblastomas are discussed.

Diagnosis of neurinoma in the region of the jugular foramen - a case report

Neurinomas in the region of the jugular foramen are extremely rare, are difficult to diagnose before surgery, and have seldom been described in the literature. The typical jugular foramen syndromes (Collet-Sicard syndrome, Vernets paralysis) may be caused by many various disorders. The diagnostic problems are illustrated using one of our cases as an example. The differential diagnosis was made before surgery using currently available radiologic techniques. The tentative diagnosis “neurinoma of the hypoglossal nerve” was confirmed intraoperatively and histologically.

Narrow Sulci at the Medial Brain Surface: A Feature of Normal-Pressure Hydrocephalus in Computerized Tomography ?

In computerized tomography (CT), obliterated cerebral sulci represent a common sign of raised intracranial pressure, which is found in obstructive hydrocephalus; the sign more or less fails in malresorptive hydrocephalus and is totally missing in ex vacuo hydrocephalus. Whereas it is hardly possible to distinguish between a malresorptive and an ex vacuo hydrocephalus on the basis of the sulci of the convexity, the sulci of the medial brain surface seem to present themselves as a differentiating feature. Figure 1 shows a malresorptive hydrocephalus with open sulci at the convexity, but not at the medial brain surface. Figure 2 shows an ex vacuo hydrocephalus with wide sulci both at the medial brain surface and at the convexity.

Depth Electrodes in the Presurgical Evaluation of Epilepsy

The use of depth electrodes in the presurgical evaluation of epilepsy remains a matter of debate in view of subdural recordings, which seem to offer equally valuable information without penetrating the brain. We therefore verified our implantation procedure regarding its invasiveness and benefit.