Ch. Ohye

Clinical Pathology of Malignant Meningiomas

SummaryNineteen cases of malignant meningiomas-seven haemangiopericytic, two papillary and ten of the anaplastic type-were examined clinicopathologically. These were ten male and nine female patients and eleven of these received reoperation for recurrence.Tumours of the hemangiopericytic type had similar angiographic and macrooscopic features and malignant characteristics were found microscopically in some tumours. There were intratumoral cysts in both cases of the papillary type and these tumours had a high cellularity, an increased number of mitosis, haemorrhage and partially haemangiopericytic patterns. Six cases of the anaplastic type had changed from a benign type at recurrence and those tumours had variable features radiographically and macroscopically. Lack of typical arrangement, a large number of mitoses, increased cellularity, focal necrosis, brain infiltration, pleomorphism and anaplasia were found histologically. Four cases of the anaplastic type were diagnosed at the first operation and these tumours had apparently similar angiographic and macroscopic features, but with variable organoid structures and malignant forms, microscopically. Electron microscopic features are also described.In malignant meningiomas, the recurrence rate was high even in cases of total removal. The outcome for these patients was good in the papillary type, relatively good in the haemangiopericytic type and poor in the anaplastic type. From these results therapeutic indications are also suggested.

Estimation of the neural noise within the human thalamus.

We systematically studied neural noise patterns in 18 Parkinsonian patients with the aid of an amplitude averaging circuit for quantitative estimation of the neural noise level. In our anterolateral to posteromedial tracks, the following results were obtained and discussed from practical points of view. 1. It is demonstrated that the variation of the neural noise level along the descent of the electrode corresponds well to different subcortical structures, and is therefore reliable for identifying them precisely. 2. In and around the VL nucleus, there were some differences in the neural noise pattern between the medial and lateral groups. In the medial group (4 cases), upper borders of the thalamus were clearly delineated, but lower borders were not. Steep increases of the noise level were found about + 10 mm above IC-line probably corresponding to the entrance of VL nucleus and the upper half of the VL showed the highest level. On the other hand, in the lateral group (6 cases), intrathalamic noise patterns were not so characteristic as medial group and noise levels were lower. In three cases upper borders of the thalamus were not so distinct. Lower borders were, on the contrary, more clearly distinguished than the medial group. 3. Cases with simultaneous recordings with two electrodes in parallel with frontal section were reported. This method was proved to be useful in delineating the lateral edge of the thalamus, especially in the case with dilatation of the third ventricle. 4. In the Vim nucleus, high levels of the neural noise were demonstrated. Activity of kinesthetic neurons were mostly found, if any, among the higher noise levels.

Physiologically controlled selective thalamotomy for the treatment of abnormal movement by Leksell's open system.

SummaryIn the course of stereotaxic thalamotomy by Leksells open system in 20 cases of abnormal movement, recording and stimulation of the subcortical structures have been performed by means of two semimicro-electrodes introduced parallel to the frontal plane. Taking advantage of simultaneous recording and electrical stimulation through these two electrodes, several critical points in the caudate nucleus and thalamus have been clearly delineated. Thus in each individual case an outline of the thalamic configuration in the frontal plane could be obtained, so that the final therapeutic lesion was placed with good precision at the lowermost border of VL or Vim nucleus. It has been shown that the physiologically determined minimum lesion resulted in satisfactory alleviation of the abnormal movements without notable untoward effects.

Recording and Stimulation of the Ventralis Intermedius Nucleus of the Human Thalamus

Extracellular recording of the spontaneous and evoked activity in and around the thalamic ventralis intermedius (V.i.m.) nucleus and electrical stimulation of the recorded point were alternated during

CT-Oriented Microrecording Guided Selective Thalamotomy

A further trial of CT-oriented microrecording guided stereotactic selective thalamotomy was conducted at the Centro Internacional de Restauración Neurológica, Havana City as treatment of resting tremor in 11 patients with idiopathic Parkinsons disease (PD), and in 3 other patients with intentional tremor associated with multisystemic atrophy and cerebral palsy. Three of the parkinsonian patients had undergone fetal mesencephalic tissue transplantation with significant improvement of the most debilitating symptoms of PD and stabilization of the motor state, but predominantly unilateral tremor had impaired them progressively despite increased levodopa doses. A Leksell frame was used with a novel surgical planning system and electrophysiological recordings to identify the optimal target point inside the ventralis intermedius. In all but 1 case, the tremor was totally arrested. No persistent complications were observed.

Delayed brain hemorrhage associated with prophylactic whole brain irradiation for pediatric malignant brain tumor: a case report

Intraparenchymal hemorrhage in the left frontal lobe suddenly occurred in a 7-year-old girl who had undergone partial removal of an undifferentiated brain stem glioma and received craniospinal (30 Gy) and posterior fossa booster (20 Gy) irradiation at the age of 20 months. The brain hemorrhage was thought to be delayed irradiation effect. Follow-up neuro-imaging at age 9 years showed two more small occult chronic and subacute hemorrhages in the brain. The possibility of repeated hemorrhage as a delayed reaction to brain irradiation is emphasized.

Adjunctive treatment for recurrent childhood ependymoma of the IV ventricle: chemotherapy with CDDP and MCNU.

The prognosis of recurrent IV-ventricle ependymoma in children is poor. Three cases of recurrent ependymoma were treated with combination chemotherapy usingcis-diamine dichloro platinum (II) (CDDP) and methyl-6-(3-(2-chloroethyl)-3-nitrosoureido)-6-deoxy-α-d-glucopyranoside (MCNU). The patients were 2-, 3-, and 6-year-old boys. The interval between the first operation with irradiation and recurrence was 1 year and 5 months to 2 years. Two cases showed a recurrence at the original site; in the other case, a right sylvian tumor deposit was found via computed tomography. The therapeutic regimen for recurrnt ependymomas was as follows: (1) the tumor was debulked if possible; (2) additional local irradiation of 30 Gy was administered; (3) combined treatment of 100 mg/m2 CDDP and 80 mg/m2 MCNU over 24 h was given 5 times with an interval of 6 weeks between treatments. The patients tolerated the therapy well with only mild side effects. Remission lasted 1 year in two patients and has lasted for 8 months in one.

Undifferentiated gliomas of the brain stem

Undifferentiated gliomas of the brain stem were confirmed surgically in two young children. The patients were treated by aggressive irradiation of the entire neuraxis, similar to that administered for medulloblastoma. Therapy resulted in a good prognosis and there was no tumor recurrence.