Efficacy of bilateral subthalamic nucleus (STN) stimulation in Parkinson's disease.

BACKGROUND: Deep brain stimulation (DBS) has, for the most part, replaced irreversible stereotactic coagulations in the surgical treatment of advanced Parkinson's disease. This study was undertaken to evaluate the benefits of bilateral STN stimulation related to its potential risks and side effects. METHOD: Twenty-nine consecutive Parkinsonian patients treated with STN-DBS were prospectively followed-up. Effects on Parkinsonian symptoms were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS). The evaluation was performed preoperatively and included postoperative follow-up evaluations at one and twelve months. All evaluations were made during the patient's best on-medication phase and postoperative follow-ups were conducted under both stimulator-on and stimulator-off conditions by a blinded neurologist. A neuropsychologist also evaluated the patients at every visit. FINDINGS: Two patients were excluded from the analysis because of severe surgical complications and three for an infection demanding the removal of the stimulator material. Other complications and side effects were clearly milder and temporary. At twelve months after surgery dyskinesia scores in the UPDRS were 53% lower than preoperative values. The results of the UPDRS motor scores improved 31.4% and activities of daily living (ADL) scores increased 19% compared with the preoperative situation. Also, the daily levodopa dose was 22% lower. Neuropsychological changes were minor, except for some deterioration in verbal fluency. CONCLUSION: The majority of Parkinsonian patients experienced significant and long lasting relief from their motor symptoms and an improvement in ADL functions due to DBS-STN therapy when evaluated at the best on-medication phase.

Late CT-findings in non-surgically treated lumbar disc herniations.

Eighteen patients with non-surgically treated lumbar disc herniation underwent follow-up CT examination at an average of 5.2 years (range 4.3-6.1 years) after their initial examination. In 12 of the patients disc herniation had resolved, although only five of these patients had complete relief of symptoms. Although disc herniation has a tendency to heal spontaneously, there is poor correlation between the morphological changes and the relief of pain.

Stereotactic radiotherapy instead of conventional epilepsy surgery. A case report.

A case report is made on a 29 year old male suffering from drug resistant epilepsy with a left temporal focus and normal neuroradiological findings. Instead of the conventional partial temporal resection, the focus was stereotactically irradiated in five fractions using a standard linear accelerator (6 MeV), to a total dose equivalent of 10 Gy in a single shot. Two months after the treatment the frequency of seizures decreased and the patient has been free of attacks since the seventh postirradiation month, up to 27 months by now, and in excellent condition. Noninvasive stereotactic radiotherapy may turn out to be a rational way to eliminate an epileptic focus.

"Whole body" stereotaxy: application of stereotactic endoscopy to operations of herniated lumbar discs.

In order to minimize surgical trauma of operations for lumbar disc prolapses, a modified Laitinen's stereotactic frame was utilized in nine patients. Stereotactic localization of the lesion could be done accurately in all cases. Percutaneous prolapsectomy and nucleotomy was performed successfully in three patients as a blind stereotactic procedure, whereas in the remaining six cases a microsurgical or conventional operation was needed to accomplish the removal of the prolapse or the discal mass. Application of the endoscopic technique to lumbar disc operations is anticipated to make the percutaneous stereotactic prolapsectomy and nucleotomy a rational alternative to contemporary more invasive procedures.

Stereotactic endoscopy applied to operations of herniated lumbar disks: technical note.

A modification of the standard Laitinen stereotactic device is described for use in three-dimensional localization of a herniated lumbar disk. A similar alteration of several other stereotactic devices into a 'whole body,' which would be applicable to endoscopic operations of the lumbar spine, could be easily done, if the frame includes a semicircular arc with a radius of 15 cm or more.

Epilepsy after operative treatment of ruptured cerebral aneurysms.

A retrospective analysis of 183 consecutive patients operated on for ruptured cerebral aneurysms and surviving at least one year revealed appearance of postoperative epilepsy in 14 cases (8 per cent) on an average of 10 months (range 0-23 months) after the operation. Factors associated with the development of secondary epilepsy were localization of the aneurysm on the middle cerebral artery, temporary clipping intraoperatively, wrapping technique to treat the aneurysm, and vasospasm seen on the postoperative control angiogram. Intra-operative and/or postoperative ischaemia seems to be the crucial phenomenon favouring the development of epilepsy. Identification of the risk factors may help to focus the anti-epileptic prophylaxis in cases prone to develop seizures.

Development of posttraumatic epilepsy.

Ten out of 55 patients with closed cerebral injury were documented to develop posttraumatic epilepsy in a prospective follow-up study comprised of repeated clinical, CT, CBF, and neuropsychological examinations. Primary convulsions, focal intracerebral hemorrhagic lesions at the acute stage, and pronounced, mainly subcortical atrophy, as well as impaired local CBF 3-12 months after the injury were the factors which were associated significantly often with posttraumatic epilepsy. Antiepileptic prophylaxis should be focused in cases presenting these risk factors, and might be wise to be continued for several years, at least in patients with chronic alcoholism.

Relief of epilepsy by radiosurgery of cerebral arteriovenous malformations.

129 patients with inoperable cerebral arteriovenous malformations (AVM) were treated by stereotactic proton beam irradiation. Symptomatic epilepsy was present in 29 patients (22.5%) before the treatment. It was markedly relieved by the radiosurgery leading to cessation of the seizures in 16 patients, the persisting seizure-free follow-up period ranging from 2 to 8 years (mean 4.5 years). In no case was the epilepsy worsened by radiosurgery. The positive effect on epilepsy was not strictly dependent on the angiographic result, suggesting that the ionizing radiation by itself could lead to inhibition of epileptic activity around the AVM.

Shape-factor intensity analyses of brain slices in surgery for epilepsy.

A special shape-factor intensity (SFI) quantification method for analysing of macro- and microrecordings of brain activity during surgery for epilepsy is illustrated. Comparative analyses show that epileptic activity may be characterized as different from normal brain activity by both macro-and microtechniques. The possible advantages of brain slice technique in comparison with direct peroperative microrecording are discussed; absence of artifacts from respiratory and pulsatory movements of the brain is stressed. The slice technique cannot be advocated for routine use in epilepsy surgery as it requires advanced neurophysiological knowledge.

New diagnostic and therapeutic tools in stereotaxy.

A definitive pathoanatomic diagnosis was achieved in 14 biopsies of deep cerebral tumors in which the Laitinen CT adapter was utilized. In 5 patients, a third-ventricular colloid cyst was aspirated or resected by stereotactic endoscopy, with excellent results after a mean follow-up time of 2.5 years. Several instruments, including a diagnostic ultrasound probe, an ultrasonic aspirator, a combination laser and an endoscope can be used stereotactically when mounted on a special instrument carrier. Integration of the Laitinen stereotactic device and the CT adapter was developed to allow noninvasive stereotactic radiotherapy in a conventional fractionation schedule by a standard linear accelerator. Technical experiences using this radiosurgical system in over 30 sessions for treating inoperable cerebral arteriovenous malformations are promising, but the follow-up time is too short for evaluating the clinical effect.

Histopathological and immunohistochemical changes in neurosurgically resected epileptic foci.

Neurosurgical resection of an epileptic focus was performed in eleven patients suffering from drug resistant focal epilepsy. The clinical result was favourable in nine cases and corresponds to the earlier results. The routinely processed biopsy specimens obtained from the brain resections were stained with haematoxylin-eosin and with specific antisera to GFAP, S-100, NSE, laminin, and fibronectin using the peroxidase-antiperoxidase technique. The main pathological finding was gliosis in eight cases, neuronal degeneration in two cases, and a vascular malformation in one case. The anti-GFAP as a specific marker of astrocytes made the astroglial proliferation clearly visible, demonstrating an astroglial scar in four cases and a moderately to strongly increased amount of astroglial cells in another four cases. Anti-S-100 and anti-fibronectin are not as specific markers. They stained both neurones and glial cells with comparable results to that of anti-GFAP but with a lower specificity and sensitivity. Anti-NSE showed decreased amounts of neurones in most of the heavily gliotic lesions and also stained glial cells in some cases. Anti-laminin stained the pial and vascular basement membranes and revealed an increased vasculature in two cases. From these results, it appears that GFAP immunostaining is a highly demonstrative means for the visualization of astrogliosis in epileptic lesions and may be of help in identifying slight focal changes. An exact demonstration of neuronal loss or other neuronal changes still waits for a more specific marker than NSE. A favourable clinical outcome after neurosurgery seems to be associated with the patients showing a clearly gliotic brain lesion in one temporal lobe.

Stereotactic neurosurgery: new aspects of an old method.

Seventy-seven patients underwent 93 stereotactic operations during a five-year period 1980-1984 at the Department of Neurosurgery, Oulu University Central Hospital, Oulu, Finland. Thirty patients were cases of general neurosurgery, consisting of 27 stereotactic biopsies of deep-seated brain tumors with a diagnostic accuracy of 89% (24/27), and three evacuation-aspiration procedures. Two-thirds of the operations (63/93) belonged to the field of functional neurosurgery, the most frequent procedure being stereotactic ventrolateral thalamotomy. In the treatment of drug resistant Parkinsonian tremor and rigidity the success rate was 70% in bilateral and over 90% in unilateral procedures. Operative mortality was 1.1% (1/93 operations) and morbidity 3.2%. Stereotactic technique is mandatory for diagnostic biopsies of deep-seated cerebral lesions. Its combination with computerized tomography ensures better resolution of the lesions and enables more radical therapeutic procedures to be undertaken. Furthermore, stereotactic operations are still indicated in selected cases of medically refractory disorders, especially in epilepsy and involuntary movement disorders.

Ball and spring or slit and core valve for hydrocephalus shunting?

Ventriculoperitoneal or ventriculoatrial shunting is the main method used in the management of hydrocephalic children. It is, however, associated with frequent complications. In order to reduce the risk of complications several types of shunts have been developed. In vitro studies have been performed to compare different types of shunts (1), but clinical studies concerning the efficiency of different shunt constructions are scanty (2). In the present study the Hakim-Cordis valve and the Pudenz-Heyer valve were compared in a series of 148 patients who had undergone 573 shunt operations for hydrocephalus. No significant differences were observed in the efficiency of these two shunts, though there was an increased rate of catheter rupture for the Pudenz-Heyer valve and an increased tendency for development of slit ventricles for the Hakim-Cordis valve. The patency rate for the Pudenz-Heyer valve proved to be statistically significantly higher (p less than 0.001) than that for the Hakim-Cordis valve, while there was a slight difference in the tolerance for high CSF protein levels favoring the Hakim-Cordis valve.

Somatosensory evoked potentials in evaluation of decompressive surgery of cervical spondylosis and herniated disc.

Somatosensory evoked potentials (SEPs) were studied in patients with cervical radiculopathy and/or myelopathy caused by spondylosis or herniated disc. SEP-recordings were performed before and after operation using an averaging technique by stimulating the median nerve separately at both wrists, with surface electrodes at three different levels: Erb's point, 7th cervical spine and inion. During the follow-up time all patients showed improvement of clinical symptoms. The preoperative SEP recording was abnormal in one or more parameters in all patients. Notable improvement (6-36 months postoperatively) of these abnormalities was observed in 12 out of 14 radiculopathy patients and in 4 out of 9 myelopathy patients. Only in the radiculopathy series could a statistically significant improvement (p less than 0.01) be found in two SEP parameters (amplitude N13 and relative amplitude difference of N13 amplitude). Therefore SEP abnormalities are commonly present in cervical radiculopathy and particularly in cervical myelopathy, and seem to be quite persistent postoperatively, even though clinical improvement especially in the form of pain relief is achieved.

Surgery of vertebrobasilar aneurysms and nimodipine.

Five patients among 60 consecutive patients suffering from recent subarachnoid hemorrhage were operated for ruptured vertebrobasilar aneurysm. Topical nimodipine treatment was given during the operation after clipping and continued systemically for three weeks. One out of the five patients developed symptoms which could be ascribed to delayed arterial vasospasm. Nimodipine may be advantageous in preventing ischemic complications when used prophylactically. Further investigation is needed to elucidate its efficacy in cases of vertebrobasilar aneurysms and conventional timing of surgery.

Preliminary experiences with CO2-laser and ultrasonic aspirator in brain surgery.

The basic problems and potential of CO2-laser and ultrasound aspirator in brain surgery are presented on the basis of experience with the Sharplan 733A CO2-laser and the Sonotec ultrasound aspirator. Complete removal of meningiomas and gliotic scar and partial removal of malignant astrocytomas by CO2-laser and ultrasound aspirator was performed. There were no complications related to the surgical procedure. The main advantage of the CO2-laser was precise cutting of neural tissue and rapid evaporation for debulkment of tumor. The ultrasound aspirator was especially useful for rapid internal debulkment by fragmentation and aspiration of soft tumors. On the basis of these experiences the surgical theater should be equipped with these and other instruments in such a way that they can be readily and interchangeably used in any neurosurgical procedure.

Surgery on pituitary adenomas in patients in a subarctic region.

The present series consists of 18 consecutive patients with pituitary adenomas operated on between 1977 and 1979 using the transfrontal route. Ten adenomas were 10, 20 or 30 times the normal maximum size of the pituitary measured according to Di Chiro and Nelson's (2) index (Table 2). Tumours without obvious suprasellar growth were operated on using the trans-sphenoidal route and thus are not included in the present series. Large and giant pituitary adenomas are preferably removed by the transfrontal route and using microsurgical techniques. Really poor vision associated with very large tumours seem to improve but not to normal level. A blind eye stays blind. Less poor vision returns to normal (Table 4). Prolactin values associated with giant prolactinomas are extremely high and may remain raised even after apparently radical extirpation. Isolated tumour-containing sellar crypts associated with these large tumours may be responsible for this observation. Postoperative radiotherapy and bromocriptine administration therefore seem advisable. Further operations may be necessary on patients with extensive posterior or lateral growths. Redundant partially intraosseous tumour fragments may be more easily removed later, possibly owing to the beneficial effects of radiation therapy. It is hoped that large and giant adenomas in the future will pass into history, even in the peripheral parts of the world. The trans-sphenoidal approach is always a better solution than the transfrontal approach whenever it can be carried out, but it requires earlier diagnosis.

Distribution of exogenous cyclic adenosine 3', 5'-monophosphate in rabbits and cats.

The appearance and disapperance of total radioactivity in plasma and cerebrospinal fluid (CSF) were studied after a single intravenous injection of tritium-labelled cyclic adenosine 3', 5'-monophosphate (cAMP) into rabbits and cats. The radioactivity was rapidly cleared both from plasma and relatively stable when compared to plasma cAMP level. Exogenous cAMP in plasma does not seen to distribute into CSF by a simple diffusion.