Biomedical subjects
Publications and source records attributed to P W Ascher.
Childhood intervertebral disk calcification is a rare clinical entity and usually has a benign course, generally undergoing spontaneous resolution. However, rapid neurologic deterioration due to herniation, found in both of our cases of calcified cervical intervertebral disks, required urgent anterior discectomy and fusion, resulting in excellent recovery.
The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was a good to fair response in 261 patients (78.4%), and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.
Permanent (CSF-drainages for treatment of hydrocephalus in posterior fossa tumors have been used in the last few years, increasingly. The rare incidence of extracranial metastases and it's higher frequency in the same period of time has been remarkable. An additional case of metastasis via ventriculoperitoneal shunt is presented. Such deleterious complications of malignant CNS-tumors should be avoided, as progressively improving results with combined radio-chemotherapy have established a more encouraging prognosis.
The first use of a "bloodless" knife in neurosurgery was a real revolution in surgical technique. This innovation enables us to reach non-accessable regions of the brain with less damage to the surrounding tissue.
The volumes of the cerebral tissue, and internal and external cerebrospinal fluid spaces were calculated from the computer tomograms of 28 patients. On the basis of their different absorption coefficients, cerebral tissue and CSF space were outlines and their volumes calculated by computer. The ratio of cerebral tissue volume to CSF space volume was expressed as an index. This correlated well with an objective grading of severity of hydrocephalus. The index in patients without pathology was between 10.5 and 18.4. In cerebral atrophy the index was between 2.1 and 6.7 depending upon the severity. In occlusive hydrocephalus it was between 1.0 and 5.6. The changes in the volume of the CSF space after treatment can easily by demonstrated by appropriate changes in the index.
A comparison of stereophotogrammetry and computer tomography is made. Advantages of both methods are shown in some examples from neurosurgical practice.
The photogrammetric determination of the target point in stereotactic operations enables a simplification of the photographic equipment and an avoiding of calculating errors during the operation. This is possible on the one hand by excluding the X-ray distortion also without distance taking and, on the other, by the use of a computer which is connected up to the stereocomperator. In addition to the continuous mathematical controls, a visual control of the spatial picture on the stereocomperator is possible.
The introduction of X-ray stereophotogrammetry into neurosurgery permits the exact localisation of metal-dense foreign bodies, the spatial representation of cerebral tumours and their blood supply. The determination of the target point in stereotactic operations is carried out after adjustment of the reference points on the X-ray picture directly by the computer, the seat of the probe can be seen in the X-ray picture in its spatial relations. For intracranial aneurysms, the position, the size, and the topographic situation of the neck of the aneurysm can be determined, and thus the placing of the clip during the operation can be pre-planned and made simpler and safer. A description of the photographic technique and the interpretation by means of the new stereocomparator of Messrs. Zeiss is given.
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The Sharplan 791 type CO2-laser, specially adapted to neurosurgical requirements, was used in the surgery of 9 gliomas, 10 meningeomas, 6 patients presenting metastasis, 1 case of vascular malformation, intracranial interventions, 1 case of hippocampectomy, 2 cases of neurinomas, 2 intramedullar tumours of the spinal cord, 1 case of thoracic commissurotomy, 1 case of thoracic prolaps of intravertebral disc, 1 case of vertebral metastasis and in 3 cases of stump neurinoma. Detrimental effects on the patients as well as any hazards to the surgical staff have not been observed. The cutting effect was mainly used for the incision of soft part, in some cases also for the formation of bony cover. Moreover the CO2-laser beam was used for coagulation and vaporisation. Particular advantages are offered by the equipment when working under the surgical microscope. Topografic precision and energetic dosing make the equipment a valuable supplement of the surgical instruments, available until now.
Anticholinergic drugs retain their place even today in the treatment of Parkinson's disease in spite of the considerable success achieved by means of stereotactic surgery and substitution therapy with dopa or dopa derivatives. An investigation was made on 44 patients suffering from Parkinson's disease treated with the new anticholinergic drug, Sormodren (Knoll). Sormodren showed a selective action on the hyperkinetic and autonomic symptoms of this disease of the extrapyramidal system. Tolerance was good, no serious side effects being observed.
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