In the past, stereotactic surgery was a regular treatment for prominent unilateral tremor in Parkinson's disease (PD), but follow-up studies were usually short-term and always unblinded. We examined 17 PD patients in long-term follow-up (mean, 10.9 years after surgery) and used videotapes and the Unified Parkinson's Disease Rating Scale to blindly compare tremor ipsilateral and contralateral to the side of surgery. Since the patients were specifically selected for stereotactic surgery because of asymmetric tremor, and the surgical side chosen was contralateral to the predominant tremor, a sign of long-term efficacy would be current postoperative reversal of tremor side predominance. Upper extremity tremor was significantly better contralateral to the surgery compared with the ipsilateral side. We conclude that stereotactic surgery improved the absolute magnitude of tremor or ameliorated its rate of progression. Since asymmetric bradykinesia and dyskinesia were not a prerequisite for the choice of surgical side, we cannot make any conclusion about long-term impact of surgery on these features.

In 10 patients with lesions of the sensorimotor cortex cortical SEP were registered to identify the postcentral gyrus, and intra-operative ultrasound sonography served to locate the lesion. The combination of both techniques helped to find the optimal approach to the lesion. Postoperative results were considered favourable, as only one patient suffered transient postoperative deterioration, six were unchanged and in three patients the pre-operative motor deficits were improved. The combination of intra-operative ultrasound and neurophysiological identification of the sensorimotor cortex is concluded as being useful in surgery within this region.

Histological, immunocytochemical, and biological features of 38 giant cell gliomas were investigated. The invasion of these tumors and its giant cells by histiocytes, lymphocytes, plasma cells, and especially by eosinophilic granulocytes is viewed as an immune response, which may explain a favorable clinical course. Fifty-three percent of the patients were younger than 45 years at the time of surgery. The average postoperative survival of 27.4 months was clearly longer than in glioblastoma. These biological features suggest a differentiation from glioblastoma multiforme. The classification of this entity as "monstrocellular astrocytoma" is proposed.

Transcranial Doppler sonography is a noninvasive method of obtaining information about changes in cerebral hemodynamics and intracranial pressure. After severe head injuries the development of brain swelling and brain edema can be assessed and the efficacy of treatment monitored. Development of severe brain edema accompanied by a rapid increase in intracranial pressure can be recognized by a decrease in blood flow velocity and rise in the pulsatility index. In hydrocephalic children the behavior of the cerebral blood flow velocity and the pulsatility index will warn of an increase of the ventricular fluid pressure or a shunt insufficiency.

In the vast literature on intracranial arachnoid cysts, communication of long-term follow-up is rare. Therefore, we studied the case histories of 60 children and juveniles operated on in our hospital since 1951. The most favorable cases were patients with temporal cysts: 93% recovered fully or with only slight deficits. In other locations (frontal, parietal, occipital, infratentorial), the percentages for a favorable course were lower. The reason cannot be attributed to the operation procedures. Independent of the surgical procedure, there were no postoperative deaths after 1969. Long-term follow-up revealed that, depending on the location of the arachnoid cyst, a high percentage (62%-93% of patients) had normal physical and social development with satisfactory quality of life.