Stereotactic biopsy and treatment of brain stem lesions: combined study of 33 cases (Bologna-Marseille)

Intraaxial brain stem tumours are rarely treated by open surgical technique. In Bologna and Marseille, 23 and 10 stereotactic biopsies respectively were performed in patients with brain stem mass lesions. The mortality due to biopsy was 3% (1 pat.); while the morbidity was temporary in 6 cases (18%) and permanent in one patient (3%). The approach to the brain stem was via a frontal burr hole. 7 times, after biopsy and histological diagnosis, radioisotope implant of the neoplasm was performed with 125I (iodine). From the histological diagnoses of the lesions the following was found: only 40% of the young patients had highly malignant tumours; 83% of the adults had neoplasms (not all of the malignant type), while 17% of the verified lesions were non-neoplastic. Since a diagnosis of the lesion nature is impossible with current neuroradiological means, the authors noting a variety of masses found in their experience, emphasize the importance of stereotactic biopsy, as a scarcely invasive method to give a precise diagnosis and a possible treatment.

[First laser irradiation of a bile duct carcinoma under endoscopic control]

For the first time a hepatic-duct carcinoma was treated palliatively with percutaneous endoscopic Neodym-YAG laser irradiation. This enlarged the lumen of the bile duct encased by tumour. The method can be combined with prosthetic as well as radiotherapeutic procedures. The equipment consists of an ordinary choledochoscope and a laser apparatus. The choledochoscope merely needs minimal technical modification of the outer valve of its working channel. Biopsies under endoscopic control make it possible to obtain tissue samples adequate for histological examination before treatment is begun.

Late recurrence of bleeding in a chronic extradural hematoma

Recurrence of bleeding from the inner capsule occurred in a chronic extradural haematoma in a 15-year-old boy 4 months after the original trauma. The case is presented to emphasize the potential hazards of nonsurgical treatment of chronic extradural hematomas.

Parasites in sheep grazing on Kikuyu (Pennisetum clandestinum) pastures in the winter rainfall region

Regular worm counts were done post-mortem on sheep that had grazed on Kikuyu pastures at the Elsenburg Research Station near Stellenbosch, a winter rainfall region. Major species were Trichostrongylus colubriformis, Trichostrongylus axei, while Ostertagia circumcincta was usually present in large numbers. Minor species were Haemonchus contortus, Nematodirus spathiger, Dictyocaulus filaria, Oesophagostomum venulosum, Trichuris spp., Chabertia ovina and larvae of the arthropod Oestrus ovis. Muellerius capillaris caused the formation of nodules in the lungs but were not counted. The trial started in April 1982 and was concluded in March 1984. One hundred and four sheep died or were slaughtered and 99 were examined post-mortem during this period. Total worm burdens rose to a peak of 88,763 (range 67,281-124,735) worms in March 1983, i.e. sheep mortality was such that the flock had to be treated with an anthelmintic in April 1983 to prevent further losses. Kikuyu pastures provide shade, form an excellent mat, the humus layer under the grass retains moisture and is an excellent incubator for preinfective larvae and a protector for infective larvae. If these qualities are combined with more than 100 mm of rain in spring and summer, Kikuyu pastures are a paradise for the free-living stages.

Comparative investigations of the effects of the neodymium:YAG laser at 1.06 microns and 1.32 microns on tissue

The beneficial deep homogeneous coagulation of neodymium (Nd):YAG laser radiation at 1.06 microns owing to low absorption and high scattering in tissue has been documented widely. For another Nd:YAG laser wavelength at 1.32 microns the absorption coefficient of water and saline is approximately ten times higher than at 1.06 microns. This results in more efficient energy conversion into heat in tissue at 1.32 microns. The extinction coefficient in blood at 1.32 microns is only one-third of that at 1.06 microns. We would expect this to result in less heat dissipation by blood and deeper penetration in tissue at 1.32 microns. Nevertheless, at this wavelength scattering also contributes to an effective, uniform distribution of the laser light in the tissue. Animal experiments have been done to examine the effect of wavelength, irradiation time, and beam geometry on tissue damage and to assess its possible clinical uses. The results imply that the 1.32 microns wavelength will produce further indications for the use of the Nd:YAG laser in surgery.

Late considerations in the treatment of low-grade malignancy cerebral tumors with iodine-125 brachytherapy

The authors report their series of 45 patients harboring inoperable, low-grade cerebral neoplasms, treated in the past 6 years with 125I stereotactic brachytherapy. The majority of these tumors were grade I and II astrocytomas and oligodendrogliomas (82.2%). A 2.6- to 6-year follow-up shows good results in 65.6% with reduction or disappearance of the lesions on CT images and good social reentry. Nine patients (23.7%) died prior to follow-up. Young patients (less than 40 years) responded well to interstitial radiotherapy, while patients over 40 with the same histological findings of low-grade tumors responded poorly to this type of treatment. Diffuse infiltrating cortico-subcortical tumors, optochiasmatic gliomas, hypothalamic and lower brainstem neoplasms do not respond satisfactorily to 125I radioisotope implantations.

Stereotactic surgery in the management of deep intracranial lesions in infants and adolescents

Over a period of 5 years, 34 pediatric patients underwent stereotactic surgery for deep-seated brain lesions: 32 patients proved to have a brain tumor, and in 2 cases the lesion was not tumoral; 15 patients with low-grade astrocytomas were treated with 125I interstitial radiotherapy. The importance of stereotactic surgery is emphasized because of its relative safeness, diagnostic reliability, and the possibility of eventual brachytherapy.

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.