Stereotaxis and abnormal movements

A series is presented of 106 patients with extrapyramidal syndromes treated by stereotaxy. The importance of preoperative screening to assure favorable results is stressed. Surgical contraindications are elderly patients with dementia and akinesia. Axial dystonia and spasmodic torticollis respond poorly to stereotaxy; and bilateral interventions should be avoided.

Stereotactic mesencephalotomy versus multiple thalamotomies in the treatment of chronic cancer pain syndromes

Two neurosurgical centers, Bologna (Italy) and Freiburg (FRG), have compared results obtained with stereotactic mesencephalotomy (SM; Bologna) and multiple thalamotomies (MT; Freiburg) in the surgical treatment of chronic cancer pain syndromes. In total, 161 patients were operated, 109 in Bologna and 52 in Freiburg. In SM the lesions were single and centered on the spinothalamic tract at the mesencephalic level, while in MT the lesions were multiple in the thalamic nuclei (ventrocaudal parvocellular nucleus, nucleus limitans, lamella medialis, centromedian nuclei). The following results emerged after 2-7 months' follow-up: (1) in an antalgic sense, SM was much more beneficial, with 91 patients (83.5%) pain-free after the operation versus 27 patients (51.9%) who had only an attenuation of the pain syndrome after MT; (2) SM, compared to MT, is burdened by mortality and a higher morbidity [2 deaths (1.8%) vs. 0; 3 anesthesia dolorosa and 8 severe gaze palsies (10.1%) vs. only 1 case of permanent aphasia (1.9%)].

Laser-induced shockwave lithotripsy of gallstones

With the aid of a Q-switched Nd:YAG laser with energy transmission via a flexible glass fiber, it proves possible under laboratory conditions, to destroy gallstones reliably and reproducibly. Lithotripsy is effected mechanically via a laser-induced local shockwave.

Technical prerequisites and safety considerations for the use of the Nd:YAG laser in gastroenterology

The small divergence and the high monochromaticity of laser light and the resulting possibility of concentrating a very high light intensity at the focal point of a lens, are of decisive importance in laser therapy. By selecting suitable irradiation parameters, blood and lymph vessels can be sealed by local exposure to Nd:YAG laser light. All the prerequisites for using the Nd:YAG laser in gastroenterology for hemostasis and the treatment of tumors are met.

Extradural hematoma complicating middle fossa arachnoid cyst

Two cases of post-traumatic extradural hematoma complicating an arachnoid cyst of the middle cranial fossa in children are described. While subdural and intracystic hemorrhages are well-known complications from this malformation, the association with extradural hematoma has never been previously reported in the literature. The pathogenetic mechanisms are discussed and the particular vulnerability of intracranial arachnoid cysts is stressed.

Experimental investigation of neodymium-YAG laser induced shock waves for lithotripsy

Experiments on the endoscopic destruction of kidney stones by neodymium-YAG laser, either thermically or mechanically, are being carried out with various results. The thermal destruction is clinically not feasible, and the risk of damaging neighboring tissue is inevitable. The direct generation of shock waves with pulsed Q-switch systems seems to represent the only feasible endoscopic method subject to further development of suitable devices for clinical tests.

Anti-neurofilament antibodies in blood of patients with neurological diseases

A method has been developed to determine quantitatively the level of the anti-neurofilament antibodies in the blood of patients affected with different neurological diseases. In 7 out of the 52 patients, taken as controls and in 33 out of the 208 patients affected with neurological diseases, the antibody levels were increased. The increases were greater in 43 patients with Parkinson dementia and amyotrophic lateral sclerosis who originated from Guam. On the other hand, the levels were very low in 10 patients affected with subacute sclerosing panencephalitis and in 11 cases with Chagas' disease. In 24 cases with dementia of Alzheimer type, the levels were normal.

Biophysical fundamentals, technical prerequisites, and safety aspects for the application of the neodymium-YAG laser in urology

The relationship between the physical parameters of the biological objects and the parameters of the laser radiation is important when considering the interaction between laser radiation and biological molecules. A consideration of the dependence of absorption and scattering in the tissue on wavelength alone permits a simple explanation of the various thermal effects of the various laser systems used in surgery. The thermal properties of tissue may be assumed to be the same as those of water. As an example of a medical neodymium-YAG laser instrument the mediLas system is presented with different application instruments that are necessary for an efficient use of the laser. The prerequisite for the use of high-power laser in surgery is complete safety not only for the patient when determining the right irradiation dose, but also for the doctor and his staff.

Polycystic and ring-shaped intracranial meningiomas

Intracranial meningiomas may be associated with peritumoral, unilocular cysts. In two middle-aged women we have recently treated, CT scan revealed ring-shaped and polycystic tumors which proved to be meningiomas. This unusual aspect has previously received scant attention. In the first patient the cysts were intratumoral and the walls consisted entirely of meningiomatous tissue; in the second case the cysts were peritumoral and their connective walls contained scattered nests of tumor cells.

Infratentorial arachnoid cysts

The infratentorial compartment represents the second most common location of arachnoid malformations. Ten arachnoid cysts of the posterior fossa, operated on between 1970 and 1983, are reviewed. These lesions, although congenital and developmental in nature, may present at any age, and males are more frequently affected. A high rate of birth-related trauma (50% in this series) is conceivably due to fetal macrocranium, and the enlarged head and psychomotor retardation prevail in infancy and childhood. In arachnoid cysts occurring during adulthood, symptoms and signs more clearly indicate a dysfunction of the posterior fossa. Besides computerized tomography, pneumoencephalography and metrizamide techniques are recommended to rule out a Dandy-Walker syndrome in doubtful cases, and to obtain information about the cerebrospinal fluid (CSF) circulation. It is particularly important to establish the presence and type of communication of cysts with the CSF pathways. Although infratentorial cysts often communicate, they can be space-occupying masses because of increasing CSF retention, which may be due to a ball-valve mechanism or to inadequate communication. The frequently associated hydrocephalus (seven of the 10 cases in this series had hydrocephalus) seemed to be dependent mainly upon mechanical factors. The authors discuss the indications for intracranial surgery versus shunting procedures and report the results achieved by direct cyst excision.

[No correlation between suppressor cell function and disease activity in natural history studies of patients with systemic lupus erythematosus]

In ten patients with systemic lupus erythematosus lymphocyte suppressor cell function was repeatedly monitored over a period of nine months. The method used is based on the finding that in vitro addition of ConA to PWM-stimulated lymphocytes activates suppressor T cells which in turn inhibit immunoglobulin synthesis. Nine of ten SLE patients exhibited significant impairment of IgG suppression but no correlation was found between the outcome of the IgG suppressor cell assay and disease activity or the treatment protocol applied.

Stereotaxic biopsy and radioactive implantation for interstitial therapy of tumors of the pineal region

Stereotaxic biopsy was performed in 10 patients with tumors of the pineal region. On the basis of intraoperative tissue diagnosis, low-energy radioactive sources (125I) were implanted in seven patients for interstitial irradiation during the same stereotaxic procedure. Results were good in five cases. This therapeutic modality appears to be indicated in cases of proven low-grade malignancy, inasmuch as the implantation of radioactive sources in a highly malignant lesion carries the risk of severe, often irreversible, damage to the surrounding brain, because of possible seed migration.

Stereotactic Mesencephalic Tractotomy in the Treatment of Pancoast Syndrome

A series of 38 patients with Pancoast syndrome treated by means of stereotactic mesencephalic tractotomy (SMT) is presented. The immediate postoperative results were good in all patients with complete pain relief, and without any impairment of respiratory function (in contrast to percutaneous cervical cordotomy). After 1–7 months’ follow-up the analgesic effect was unchanged in 33 (86.8%) out of 38 patients. Six patients (15.7%) showed recurrence of pain on the same side, while 4 patients (10.5%) presented contralateral pain. Immediate postoperative side effects of oculomotor palsy (18.4%) and dysesthesias (28%) remained unchanged at follow-up in 6 patients (16%). The intervention was well tolerated by all patients, and there was no mortality.

Treatment of low malignancy brain neoplasms by means of stereotactic interstitial radiotherapy

The authors report their results of 37 patients with low malignancy brain tumors seated in deep or highly functional areas not amenable to traditional surgery, nor to conventional radiochemotherapy. In the past 5 years these patients were treated by means of stereotactic interstitial radiotherapy. The isotope employed in all cases was 125I. Stereotactic radioisotope implants were always preceded by multiple stereotactic biopsies affording precise histological diagnoses. A 6-month to 5-year follow-up shows a survival rate of 72.6% (29 patients), and of these patients, 80.9% (26 out of 29) had complete social reentry.

Primary intracranial lymphomas

We reviewed the cases of 16 patients with primary intracranial lymphomas. The clinical and radiological data proved to be helpful in suggesting the diagnosis, but only tumoral biopsy provided unequivocal diagnosis. In our cases radiotherapy proved to be the most effective treatment.

The use of the Nd-YAG laser in neurosurgery

Whereas the focused CO2 laser may be used as a cutting instrument in less vascularized tissue with limited trauma to the surrounding tissue, use of the defocused Nd-YAG laser results in homogeneous coagulation with an energy-dependent depth effect. Thus, residual tumor tissue may be cauterized selectively with a depth effect which can be predicted with satisfactory precision. Tumor shrinkage and demarcation based on different absorption properties facilitates dissection and, moreover, allows the preservation of healthy tissue. The excellent coagulating properties of the Nd-YAG laser render it especially effective in cases of highly vascularized meningeal tumors.

[Neodymium YAG laser in clinical urology. Current status and clinical experiences]

Of all the lasers available for medical applications only the Neodymium-YAG laser has been retained with a clear indication for open and endoscopic tumor destruction in urology. This is due to the biophysical properties of this laser. The main indications for Neodymium-YAG laser application are benign and malignant tumors of the glans penis and the penis shaft as well as multiple small tumors distributed over the urethra and bladder mucosa. But tumors of the ureter and renal pelvis can also be destroyed endoscopically with the laser. The advantages of Neodymium-YAG laser application are: the great radicality of the contact-free tumor destruction coupled with closure of the blood and lymphatic vessels of the tumor, no hemorrhages, no anesthesia, only conscious sedation, and above all, short operation times that make the procedure suitable for use in outpatients.

Biophysical basis and technical requisites for the use of Nd-YAG laser in neurosurgery

The different interactions between laser light and biological tissue are demonstrated for the CO2- and the Nd-YAG-laser by histological examinations. For Neurosurgery the following results became significant: The CO2 laser has become an important tool in contactless cutting and vaporization. The Nd-YAG-laser is suitable as a coagulator whenever the site and vascularity make the removal of a tumour difficult. For the various surgical techniques in Neurosurgery using the Nd-YAG laser, special laser attachments have been developed including micro-surgical and endoscopic instruments.

Extraneural metastases from primary pineal tumors. Review of the literature

Extraneural metastases from primary pineal tumors are extremely rare: only 15 such cases could be found in th literature. Another case is presented of a 10-year-old boy who developed multiple pulmonary and skeletal metastases from a presumed primary pineal germinoma. The incidence and pathogenesis of distant dissemination in the different types of pineal tumors are discussed, with special comment on the controversial role of the direct surgical approach and shunting of cerebrospinal fluid.

[Experiences with the Nd-YAG laser in the surgical treatment of intra- and suprasellar tumors]

The Neodym-YAG-laser has been used in 15 transcranial and 15 transsphenoidal operations of intra- und suprasellar tumors. The surgical results are reflected by ophthalmological and endocrinological controls. The incidence and nature of surgical complications is also reported. The practical experiences during the surgical procedure as well as the results are indicating, that the Nd-YAG-laser is superior to conventional surgical methods. In addition to a better control of bleeding, laser surgery allows a more radical removal and inactivation of tumor tissue without a higher risk of lesioning the adjacent structures.