Fritz Mundinger

Long-term results of stereotaxy in the treatment of essential tremor.

In patients with severe tremor that is resistant to drug therapy, stereotactic coagulation can achieve a satisfactory and lasting reduction of the movement disorders. Very few long-term studies have been conducted following stereotactic operations. From 1964 to 1984, 104 patients with a diagnosis of essential tremor were operated on in the Division of Stereotaxy and Neuronuclear Medicine. After an average follow-up period of 8.6 years, 65 patients were examined. In 80%, the success of the stereotactic operation was still evident. Complete disappearance or substantial reduction of the tremor was determined in 69% and moderate improvement in 11.9% of the patients.

Computer-Assisted Stereotactic Brain Operations by Means Including Computerized Axial Tomography

With a computerized program system for stereotactic brain operations it becomes possible for the first time to react even before running a possible risk, e.g., in case of punctures in the midbrain, the brain stem, or in the hypothalamus, by simulating the operative procedure even before starting the operation itself. This is effected by the ability to change the penetration angle of the electrode or by choosing a different point of trepanation. The inclusion of computerized axial tomography, especially through the presentation of the CT scan, made to measure with the help of the linear transformation, and of the input of the cranial and ventricular coordinates through a digitizer, together with the coordinates resulting from the X-ray picture, brings the definition of the target point to a still greater optimum. Thus the safety and the precision of the stereotactic operation have been improved even further.

Ballism not related to vascular disease: A report of 16 patients and review of the literature

Sixteen patients with ballism not related to vascular disease are reported. Ballism was caused by subthalamic metastases and cerebral tumours in four patients, lesions after functional stereotaxy in three, presumed neurodegenerative disease in two, and by an ipsilateral intraventricular cyst after resection of a meningioma, cerebral toxoplasmosis with AIDS, severe head trauma and sepsis, late recurrence of rheumatic fever, meningoencephalitis, perinatal hypoxia, and conversion syndrome in one, respectively. Two patients had bilateral ballism, 11 had hemiballism, and three had monoballism. Involvement of the contralateral subthalamic nucleus was found in 10/13 patients with symptomatic unilateral ballism. One patient with presumed neurodegenerative disease had bilateral alterations of caudate and putamen on MR. The effect of different treatment strategies was evaluated. Treatment was directed to the underlying disease and/ or to the movement disorder. Response to pharmacotherapy was poor except in one patient. Five patients underwent various neurosurgical interventions. Functional stereotactic operations were performed in eight patients. Lesions were placed in the contralateral ventrolateral thalamus and the zona incerta, the internal pallidum, and in the zona incerta and the pulvinar thalami. Four out of eight patients had complete sustained relief of hemiballism after the operation. No patient was lost to follow-up, which ranged from 3 months to 27 years. After various therapeutic strategies ballism was no longer present in 10 patients and had improved in three, while another three patients did not benefit from therapy. Review of the literature illustrates the shift of aetiologic factors over decades underlying this rare symptom. A multidisciplinary approach should be considered in these patients to alleviate the severe and disabling movement disorder.

Evaluation of the effect of treatment on movement disorders in astrocytomas of the basal ganglia and the thalamus.

Twenty patients with movement disorders associated with astrocytomas (grade I-IV according to the WHO tumour classification) of the basal ganglia and the thalamus were evaluated for the effects of treatment. Five patients had more than one movement disorder when the histological diagnosis was verified by stereotactic biopsy. Twelve had tremors, eight hemidystonia, three hemichorea, and one hemichorea/ballismus, and myoclonus respectively. Ten patients died during the follow up period, and for the surviving patients follow up periods ranged from 6-21 years. The movement disorders changed over long periods of time related to therapeutic interventions. CSF shunt operations and percutaneous radiotherapy had no definite effect on the movement disorders. There was a moderate response to medical treatment in a few patients. Stereotactic aspiration of tumour cysts had a marked influence on the movement disorder in two patients, and functional stereotactic surgery abolished tumour induced tremor in one. Interstitial radiotherapy was performed in fifteen patients for treatment of the underlying neoplasm and resulted in different and variable alterations of the movement disorders. These differences may be explained by complex interactions involving structures affected primarily by the tumour, as well as by secondary functional lesions of adjacent structures.

Ventricular fluid neuropeptides in Parkinson's disease. II. Levels of substance P-like immunoreactivity.

Substance P-like immunoreactivity (SPLI) was determined in cerebrovascular fluid of patients with extrapyramidal motor diseases. Patients with Parkinsons disease (PD) showed a SPLI concentration decreased by 30% compared with patients without extrapyramidal disease. No differences were apparent for patients with dystonia. Fluid obtained from the foramen Monro showed higher SPLI concentrations than fluid from a lateral ventricle, indicating that hypothalamic sources are important for ventricular substance P. Lateral ventricular SPLI was particularly low in parkinsonian patients which raises the possibility of a decreased SPergic activity in basal ganglia occurring in PD.

Determination of intracerebral structures using osseous reference points for computer-aided stereotactic operations.

Computer-aided sterotactic neurosurgery can be improved and simplified by using craniocerebral parameters for the calculation of subcortical target points and avoiding an air-filling of the ventricles. This was achieved by selecting 403 pneumo-encephalographic studies at random, measuring the craniocerebral parameters according to age and sex. There is a correlation between the bony cranium and the brain axis. We established a formula and a table to determine in the plain X-ray the entrance of the foramen of Monroi with a standard deviation of +/- 1.5 mm and the inclination of the intracerebral basic line we used (foramen Monroi-commissura posterior). With this information various subcortical targets can be determined by means of computer programs.

Stereotactic Evacuation and Fibrinolysis of Cerebellar Hematomas

Despite modern diagnostic and operative methods, the mortality and morbidity rates of spontaneous cerebellar hematomas remain very high, i.e., according to a review of the literature as high as 45%. By stereotactic puncture, partial evacuation and fibrinolysis of the remaining hematoma with urokinase, much more favorable results can be achieved. As we could observe in long-term follow-up, only 1 patient out of 15 died within 2 months after operation. The method is effective, easy, exact, without risk and applicable at every age, so that actually there is no comparable alternative way of treatment.

Ventricular fluid neuropeptides in Parkinson's disease. I. Levels and distribution of somatostatin-like immunoreactivity.

We have measured somatostatin-like immunoreactivity SLI in cerebroventricular fluid of patients with Parkinsons disease (PD) and other extrapyramidal disorders with hyperkinesia. Patients with PD showed a significantly lower concentration of SLI when compared with levels in control patients with chronic stable multiple sclerosis or temporal lobe epilepsy. Less markedly decreased levels of SLI were also noted in patients with torsion dystonia. Of two patients with Huntingtons disease one showed a high and one a medium concentration of SLI. According to the site of the stereotactic cannula, verified by ventriculopathy, SLI concentrations in CSF specimen obtained from the foramen Monro tended to be higher than in specimen from a supraforaminal level. Of 5 other patients with lateral and third ventricle being accessible during the passage of the stereotactic cannula, 4 showed higher SLI concentrations in the third ventricle compared to the lateral ventricle. High performance liquid chromatographic analysis combined with radioimmunoassay showed molecular heterogeneity of SLI in CSF. The ratio of SST-14 to SST-28 was higher in the third ventricle than in the lateral ventricle.

Molecular size distribution of somatostatin-like immunoreactivity in the cerebroventricular fluid of neurosurgical patients

The molecular size distribution of somatostatin-like immunoreactivity (SLI) in the cerebroventricular fluid of patients with Parkinsons disease, dystonic syndromes, multiple sclerosis, basal and midline tumors, epilepsy and pain syndromes was investigated by separation with a Sephadex G-50f column and subsequent radioimmunoassay of the eluate. Marked heterogeneity of SLI was observed in most of the pools investigated. The most conspicuous feature of the elution profiles was the preponderance of the peak coeluting with synthetic somatostatin-14, whereas the peaks comigrating with synthetic somatostatin-28 and attributable to precursor-like SLI represented only minor or trace amounts of total immunoreactivity. These findings are consistent with the greater biological activity of somatostatin-14 in the human central nervous system, whereas somatostatin-28 appears to represent the more active form in the pituitary and in the intestinal mucosa. Solely in the case of brain tumor patients, some differences could be seen, resulting in an approximately equal distribution of somatostatin-14 and somatostatin-28 in two pools of ventricular fluid and by the detection of a degradation product of somatostatin-14 in another one. These observations could be explained by a lowered barrier function as a consequence of increased intracranial pressure in case of brain tumors, which is well in accordance with a markedly elevated total protein content being a sign of a lowered barrier function.

The Imaging-Compatible Riechert-Mundinger System

The Riechert-Mundinger stereotactic system [36, 37] as updated by Mundinger and Birg is compatible with computed tomography (CT) and magnetic resonance imaging (MRI) (figure 2–1) [1–4, 6]. Clinical experience with 9,000 operations in Freiburg, West Germany led to the development of this device, which offers some unique advantages. Any target within the brain can be reached from any site of the face or skull. After the base ring is attached to the patient’s skull, it is completely unmovable, even by involuntary movement of the patient. The ring is attached to a holder that can be fixed anywhere, which allows the operation to be performed with the patient either sitting, prone, or supine. If necessary the device can be removed easily from the table holder, as when epileptic seizures occur. It can be fixed in a position that does not correspond exactly to the anterior commissure—posterior commissure line without affecting precision in reaching the target. A special version of the base ring is available for MRI. For CT and MRI stereotaxy, the ring can be fixed in position to the imaging devices by means of an especially adapted holder, making coordinate calculations unnecessary. The stereotactic coordinates are taken directly from the CT or MRI images [5, 7, 21].