A low cost modification of an old Leksell stereotactic frame to allow CT-guided stereotaxy

The high cost of commercial CT-compatible stereotactic frames has restricted the availability of CT-guided stereotaxy for many neurosurgical centres. However, many of these centres do possess the standard stereotactic frames for projection radiography, of which the old type Leksell frame is probably the most common. We have devised a simple and low-cost modification to an old Leksell frame to allow CT-guided stereotaxy. The nature of the modifications allow complete freedom of positioning of the frame relative to the CT scanner and coordinate transformations can be performed simply and effectively. The modified frame has been used successfully for some 18 months and the modification has now been performed at two centres in the North West Regional Health Authority. We hope this modification will allow many other centres to embark on CT-guided stereotaxy.     

Hydrosyringomyelia associated with a Chiari I malformation in children and adolescents

The clinical presentation, radiological features, and results of surgical treatment were analyzed in 17 cases of hydrosyringomyelia associated with a Chiari malformation, in children and adolescents younger than 20 years of age. The initial symptoms were a skeletal abnormality (71%), such as scoliosis (11 patients) or pes cavus (1 patient), pain or numbness (24%), and motor weakness (6%). Frequently seen signs on admission were sensory deficit (100%), scoliosis (85%), muscle weakness (64%), muscle atrophy (35%), and lower cranial nerve palsy (35%). The characteristic neurological findings were unilateral sensory and motor deficits (65%) with decreased or absent deep tendon reflexes on the same side. The localization of the syrinx on the axial section varied according to the level, even in the same patient. In 11 patients with unilateral sensory disturbances or unilateral sensory and motor deficits, the syrinx was located in the region corresponding to the posterolateral portion on the same side as that of sensory disturbance at the cervical or thoracic level. On the other hand, in 6 patients with bilateral sensory and motor deficits, the syrinx was located in the central portion and extended into the posterolateral portion of the more affected side. A syringosubarachnoid shunt was placed in 16 patients, foramen magnum decompression without closure of the obex was performed in 1 patient, ventriculoperitoneal shunt in 1 patient, terminal syringostomy in 1 patient, and foramen magnum decompression with terminal syringostomy in 1 patient. In 15 of 17 patients (88%), the neurological symptoms improved after an average follow-up of 4 years and 1 month. We think that as a surgical treatment, placement of a syringosubarachnoid shunt is effective.     

Nucleolar organizer regions in meningioma

Seventy-eight cases of meningioma and related tumors were examined independently using a simple and reproducible argyrophilic method for the demonstration of nucleolar organizer regions (AgNORs) and staining with bromodeoxyuridine monoclonal antibody. The mean number of AgNORs per cell and the bromodeoxyuridine labeling index were shown to be linearly related (r = 0.84, P less than 0.001). The mean AgNOR number was 2.99 for meningeal sarcoma, 2.29 for anaplastic meningioma, 2.08 for hemangiopericytic meningioma. 1.72 for recurrent meningioma without atypical histological findings, and 1.52 for nonrecurrent meningioma. We noted that the mean number of AgNORs reflected the cellular kinetics of a tumor and was related to histological grade and clinical behavior.     

The AIDS problem in accident surgery

In trauma surgery there is a particularly high proportion of patients in the age group most at risk of infection with AIDS. The result of an epidemiological study in our patients (HIV screening of all patients scheduled for surgery at a trauma center over 18 months) showed a prevalence of 0.1%. Specific therapeutic strategies must be developed to deal with the weakened immunity of HIV-infected patients. Fracture treatment in HIV-infected hemophiliacs is a special problem. Homogenous bone transplantation is described with reference to HIV. The particular danger of injury in trauma surgery is also investigated. The chain of infection is illustrated and used to demonstrate the precautions that can be taken against nosocomial HIV infections. Following infection with fluids containing HIV, specific measures must be taken. The legal aspects of HIV-antibody testing in the Federal Republic of Germany are elucidated. Finally, the problems of general preoperative HIV-antibody testing are discussed.     

Otosclerosis involving the vestibular aqueduct and Menière's disease

The coexistence of otosclerosis and endolymphatic hydrops in the temporal bone have been described; however, the mechanism for the development of endolymphatic hydrops in otosclerosis remains unknown. Among 128 temporal bones with otosclerosis, involvement of the vestibular aqueduct by otosclerosis was observed in four temporal bones from two patients. In all four, the vestibular aqueduct was filled with active otosclerotic foci; the lumen of the endolymphatic duct and sac was narrowed as a result of fibrosis, and endolymphatic hydrops, more severe in the pars inferior than the pars superior, was observed. Collapse of the ductus reuniens and dilated saccule was seen in three temporal bones. Our study indicates that otosclerotic obstruction of the vestibular aqueduct may create a disturbance of the outflow and/or absorption of endolymph, leading to the development of endolymphatic hydrops and Meniere's disease, thus supporting the theory of longitudinal flow of endolymph.     

Cholesterol granuloma of the peritoneum

Cholesterol granulomas are common in the mastoid region but have rarely been reported in other areas. The authors report the case of a 40-year-old man who had a cholesterol granuloma of the peritoneum. They discuss the morphology of the condition and the difficulties of diagnosis. It is likely that chronic or recurrent inflammation plays a major role in the pathogenesis and that, when dealing with such lesions preoperatively or intraoperatively, a radical approach may not be necessary.     

Direct evidence of alpha-adrenoceptor binding in rat and human adrenal glands

In order to determine whether or not alpha-adrenoceptors are present in adrenal glands, radioligand receptor binding assay was performed in both Sprague-Dawley (SD) rat and human adrenal gland membranes. Radioligand binding assay using 3H-prazosin as an alpha 1-adrenoceptor ligand and 3H-yohimbine as an alpha 2-adrenoceptor ligand, clearly demonstrated alpha 1 and alpha 2 receptors present in both rat and human adrenal gland membranes. Maximal binding capacity (Bmax) and dissociation constant (Kd) of 3H-prazosin binding to the rat adrenal gland were 12.5 fmol/mg protein, and 0.11 nM, respectively. Those for the membrane preparations from adrenal cortex and medulla of the normal human were 16.3 fmol/mg protein, 0.34 nM and 16.3 fmol/mg protein, 0.27 nM, respectively. And those of the human pheochromocytoma were 25.6 fmol/mg protein, 0.15 nM, respectively. On the other hand, Bmax and Kd of 3H-yohimbine binding in the rat adrenal gland to were 22.9 fmol/mg protein, and 4.28 nM, respectively. Those for the membrane preparations from adrenal cortex and medulla of the normal human were 40.4 fmol/mg protein, 5.15 nM and 12.2 fmol/mg protein, 5.39 nM, respectively. And those of the human pheochromocytoma were 35.8 fmol/mg protein, and 1.08 nM, respectively. Bmax (35.8 fmol/mg protein) of 3H-yohimbine binding in the pheochromocytoma was significantly (p less than 0.01) greater than that (12.2 fmol/mg protein) in the human normal adrenal medulla, while Kd (1.08 nM) of this binding in the human pheochromocytoma was significantly (p less than 0.01) lower than that (5.39 nM) in the human normal adrenal medulla. Our data suggest that the alpha 2 receptor had greater affinity and binding site density to its agonist in the human pheochromocytoma than in the human normal adrenal medulla.