Microscopic stucture of the lamina terminalis: implications for microsurgical third ventriculostomy.

OBJECTIVE: The neurosurgical approach through the lamina terminalis (LT) is a commonly used technique for management of the third ventricle region pathology. Furthermore, LT fenestration is a recommended procedure during surgery of ruptured intracranial aneurysms. Though the LT is a rudimentary structure in adult human brain, its neurosurgical significance is eliciting increasing interest. The aim of the presented study is to characterize the LT histologically, with special attention to the previously recommended area of LT fenestration and to the localization and structure of the organum vasculosum lamina terminalis (OVLT). METHODS: The study was performed on tissue sampled from eight formalin-fixed brains. Paraffin sections taken from various levels of the LT were routinely stained with hematoxylin and eosin (H&E) and by immunohistochemical methods. RESULTS: The LT in the inferior part bordering the optic recess and immediately above the optic chiasm exhibited paucicellular, mainly fibrillar, glial tissue with scanty neural elements and small vessels. At about halfway along the length of the LT an area of loose structure, with an increased number of glial cells, small neurons and thin-walled vessels corresponding to the OVLT was observed. In the majority of examined cases the OVLT was poorly developed and was therefore sometimes overlooked. The superior segment of the LT near the anterior commissure disclosed again paucicellular and slightly loosened fine fibrillar tissue. CONCLUSIONS: The results of the present microscopic study confirm the opinion that the inferior segment of the LT is the most convenient place for safe incision. Its thinnest middle part immediately above the optic recess is composed mainly of gliotic tissue. Above, prominent loosened tissue and the rather rudimental structure of the OVLT seem to be additional favorable factors for a safe fenestration of the LT.

[Extended translabyrinthine approach in treatment of vestibular schwannomas]. / Poszerzona droga przezblednikowa w leczeniu guzów nerwu przedsionkowo-slimakowego.

Results of removal of vestibular schwannomas using translabyrintine approach were presented. 12 unilateral neuromas were operated. Large neuromas with diameter above 2 cm constituted 75% of all cases. The total resection of tumors was achieved in 10 patients. In all cases anatomical integrity of facial nerve was conserved. In 7 patients facial nerve function was in stage I-III (House Brackmann classification). There were not life threatening complications. Authors underline, that the translabyrintine approach permits to obtain enough wide insight to ponto-cerebellar angle to remove safely, both little and large, vestibular schwannomas.

[Application of the insulating material teflon--pladgets (Genzyme-USA) during the microvascular decompression]. / Zastosowanie materialu izolacyjnego teflon--pladgets firmy Genzyme--USA w operacjach konfliktu naczyniowo-nerwowego nerwu trójdzielnego.

Various isolation materials have been used in the treatment of trigeminal neuralgia due to neuro-vascular conflict. Surgical treatment (MVD) currently utilizes for isolation soft teflon pladgets, which are, after appropriate preparation, placed in the form of wool between the conflicted structures. The material was used in 20 surgical procedures. The definite advantage of this material as compared to others is the possibility to position it correctly between the blood vessel and the nerve without additional fixation with e.g. a tissue adhesive. Observations indicate that this is the best isolation material of those used so far in MVD procedures.

[Qualification of patients with CPA tumors to translabyrinthine approach based on own experiences]. / Wlasne doswiadczenia dotyczace kwalifikacji chorych z guzami kata mostowo-mózdzkowego do operacji z dostepem przezblednikowym.

On the basis of the presented clinical material, the authors present their own observations concerning qualification of the patients with cerebello-pontine angle tumors for surgery utilizing the translabyrinthine approach. The clinical material includes 15 cases of stage II, III and IV cerebello-pontine angle tumors removed through translabyrinthine approach. In view of the fact that there are different opinions concerning the selection of appropriate surgical approach and of a conviction that translabyrinthine approach should be used in case of stage II, relatively small tumors, and that larger, stage III and IV ones should be operated on using the retromastoid approach, we are presenting our views concerning the qualification of patients. In our opinion, the translabyrinthine approach can be used for larger tumors--also for stage IV ones. The translabyrinthine approach was considered only in the cases with total hearing loss and not useful hearing. Of course, in the cases when the tumor penetrates into the middle cranial fossa or into the foramen magnum, the approach may prove rather difficult. As it has been known, the dimensions of the access route are determined by three main anatomical structures: altitude of the bulb of the internal jugular vein, location of the sigmoid sinus and the diameter of the internal auditory meatus. The fundamental advantages of the approach include: no cerebellum retraction required in the case of classic retromastoid approach, easy anatomical and neurophysiological identification of the course of the facial nerve and maintaining its continuity. An approach involving damage of internal ear structures can be performed only if the patient is deaf.

[Indication to translabyrinthine approach to remove of the cerebello-pontine angle tumors--anatomical aspects]. / Wskazania i planowanie dostepu przezblednikowego w operacjach guzów kata mostowo--mózdzkowego przy uwzglednieniu ograniczen anatomicznych.

Indication to translabyrinthine approach to removing of the cerebello-pontine angle tumors--anatomical aspects. Translabyrinthine approach was used in surgical procedures performed for stage II, III and IV tumors of the cerebello-pontine angle of various sizes in 15 cases. In order to ensure a correct course of the procedure and successful removal of the tumor, translabyrinthine approach should be carefully planned on the basis of radiological criteria (CT, NMR). Anatomical limitations of the approach are connected with the localization of the sigmoid sinus, the bulb of the internal jugular vein, pneumatization of the mastoid process and the location of the superior petrosal sinus. In approach planning it should be considered whether the bulb of the internal jugular vein is not located high in relation to the internal auditory meatus, what is the meatus diameter (IAC), location of the sigmoid sinus--its shift to the front is a serious limitation for the approach. The pneumatization state of the mastoid process is also important because of the duration of petrosectomy. Taking into consideration the aforementioned conditions allows to plan precisely and perform the approach appropriate for the tumor size.

[Revascularisation after encephalo-duro-arterio-synangiosis. Case report]. / Rewaskularyzacja mózgowia u chorych po wykonaniu encephalo-duro-arterio-synangiosis. Opis przypadku.

In surgical treatment was performed of patients after cerebral ischaemic stroke and cerebral ischaemia. The authors applied the surgical technique of indirect anastomosis (EDAS-encephalo-duro-arterio synangiosis). The Japanese authors described this method first as a treatment for moya-moya disease. The acetazolamid (Diamox) test and clinical symptoms were the main criteria to perform this surgical procedure. All patient with abnormal Diamox test were treated surgically. After 6 months control angiography was performed to visualize a new network of vessels near the main vessel (superficial temporal artery).

[Embolitic material (coils) dislocation inside a giant and cerebral aneurysm and morphological aneurysm changes after coiling. Case report]. / Przemieszczenie materialu zatorowego (spirali) wprowadzonych do wnetrza olbrzymiego tetniaka oraz zmiany morfologiczne tetniaka. Opis przypadku.

The placement of tungsten coils into aneurysm sack in patient after SAH is a method of treatment used in many neurosurgical departments. The main indications for coiling procedures are severe neurological status (IV i V according to WFNS) and posterior circulation aneurysms. Coiling can be offered to a patient who does not agree to clipping procedure. The presented case is a patient with a giant MCA aneurysm who did not agree to clipping procedure and, therefore, was subjected to coiling. During the follow-up of 2 months; control skull X-rays and after them control angiography were performed to monitor coils arrangement in the aneurysm sack and their possible dislocation. The control angiography after 6 months showed significant enlargement of the aneurysm. The aneurysm was clipped, totally excised and subjected to histopathological examination. It was found that the material inside the aneurysm sack can change its shape due to the impact of the flowing blood (change in the coil shape, resorption and the recanalization of the clot) similarly to the natural process of aneurysm development. Morphological changes of the aneurysm appear to be also possible in spite of the thrombus formation in the aneurysm sack.

Immune abnormalities in aneurysmal subarachnoid haemorrhage patients: relation to delayed cerebral vasospasm.

Peripheral blood CD3+, CD19+, CD4+, CD8+ and CD45RO+ mononuclear cell subsets, T-cell proliferative responses to combinations of coimmobilized OKT3 antibody and an ECM protein (collagen I, collagen IV, fibronectin or elastin), and T-cell adhesion to collagen IV, fibronectin and elastin were studied in patients with aneurysmal subarachnoid haemorrhage. No significant difference was found in the major lymphocyte subsets between subarachnoid haemorrhage patients receiving no dexamethasone for brain oedema treatment and healthy blood donors. Compared with the latter, both the dexamethasone-untreated and -treated subarachnoid haemorrhage patients showed decreased relative proliferative responses of circulating T cells to OKT3 combinations with collagen IV and fibronectin, and an increased PHA-activated T-cell adhesion to elastin. CD45RO+, CD4+ and CD19+ peripheral blood cell subsets, CD4+/CD8+ cell ratio, PHA-activated T-cell adhesion to fibronectin and collagen IV, and OKT3-triggered T-cell costimulatory responses to elastin, collagen IV and fibronectin were significantly higher in subarachnoid haemorrhage patients presenting with delayed cerebral vasospasm (DCV) than in their DCV-free counterparts. The DCV-related differences in circulating lymphocyte subsets showed no apparent relationship to the glucocorticoid treatment, whereas the differences in the other indices were confined to the dexamethasone-untreated subarachnoid haemorrhage patients. The above results suggest that the CD4+/CD8+ ratio and T cell-ECM interactions play a role in the emergence of subarachnoid haemorrhage/DCV and may represent potential targets for subarachnoid haemorrhage therapy.

Combined treatment of cerebral aneurysms with utilization of clipping and coiling techniques.

Cerebral aneurysm clipping is a widely used and accepted treatment option. However, in some patients in severe condition (IV and V WFNS grade), with aneurysms of basilar and vertebral part of the arterial circulation and with high general surgical risk, direct aneurysm surgery can be a real technical and clinical problem. Therefore, low risk of coiling procedures gain more and more support. Out of 218 patients with diagnosed aneurysms, 60 were selected for coiling treatment, and 15 patients with multiple aneurysms were treated with both procedures. Special attention has to be addressed to the selection of patients for coiling procedures, especially in the cases when aneurysmal neck is directed accordingly to the main blood stream. The follow-up of the treatment effects is necessary. In the cases with growing aneurysms clipping is recommended. In the cases with stable size of the aneurysmal sack and visible coils compression, the coiling procedure is repeated. The coiling procedures can offer a valuable treatment option for selected patients. However, the maintenance of permanent occlusion of the aneurysm sack after coiling gives rise to some controversy.

[Occipital nerve neuralgia as postoperative complication. Views on etiology and treatment]. / Neuralgia potyliczna jako powiklanie pooperacyjne. Poglady na etiologie i leczenie.

Occipital neuralgia might have a various etiology but the most common cause is hypertrophic fibrosis of subcutaneous tissue following trauma to the occipital region, surrounding the occipital nerve. The other important cause of neuralgia is spondylosis of the upper part of the cervical spine (C1-C2). Rare causes are-diabetes, gout and neoplasm. In the presented material we point out the possibility of the occipital neuralgia after surgery in the treatment of the tumours of ponto-cerebellar region and trigeminal neuralgia. We observed the symptoms in two groups of patients and used pharmacological treatment, local blockade and cutting (neuronectomy) of the occipital nerves trunk when the conservative treatment was unsuccessful. We also present the present concepts of occipital neuralgia treatment. In case of severe symptoms, unsuccessful conservative therapy and poor results of the neuronectomy the most indicated therapy is selective posterior rhizotomy.

Experience with intraoperative high frequency Doppler sonography in neurosurgical practice.

The method of blood flow velocity (BFV) evaluation by intraoperative application of the high frequency Doppler is presented. The device is used to estimate BFV changes in small caliber arteries by direct placement of the probe upon the examined vessel. BFV examinations were performed on the site during aneurysm operations, during transsphenoidal approaches to identify the intracavernous portion of ICA embedded in the tumor mass and in patients after encephalodurosynangiosis evaluated on the outpatient basis. Technical characteristics of the flowmeter used are described and examples of the BFV pictures in cerebral arteries are presented. The device allows a precise BFV evaluation in the selected vessel and detection of changes in BFV patterns particularly useful during aneurysms surgery. This method of identifying cerebral vessels may become applicable in other types of neurosurgical operations.

[The usefulness of intraoperative high-frequency doppler flowmetry in surgeries for intracranial aneurysms]. / Przydatnosc sródoperacyjnego aparatu dopplerowskiego wysokiej czestotliwosci w operacjach tetniaków tetnic mózgowych.

The flowmeter enables estimation of blood flow velocity changes in small calibre arteries. The authors examined blood flow velocity patterns in the vessels during aneurysm operations and blood flow velocity and its disturbances inside aneurysm. Evaluation technique, technical data of the flowmeter use are described and the characteristics of the blood flow velocity picture in cerebral arteries obtained by this method is presented. The presented method enables a very precise estimation of blood flow velocity and detection of changes in flow patterns. The method may become very helpful in identification of the vessels in other types of cerebral surgery.

[The examination of the blood flow velocity in arterial vessel during and after encephalo-dura-arterio-synangiosis. Preliminary results]. / Badania przeplywu krwi w naczyniu tetniczym uzytym do rewaskularyzacji. Encephalo-duro-arterio-synangiosis. (non bypass anastomosis). Doniesienie wstepne.

The Japanese authors first described encephalo-duro-arterio-synangiosis, a new treatment for moya-moya disease, 17 years ago. The other authors used this method (EDAS, indirect anastomosis) in surgical treatment of patients suffered cerebral transient ischaemic attack and cerebral ischaemia. In our department this method was applied in 5 patients with cerebral ischaemia. All patients had internal carotid artery occlusion. After angiography, to localize carotid artery occlusion, acetazolamid (Diamox) test was performed. The patients with negative Diamox test were treated surgically (EDAS). The authors used the intraoperative microdoppler device to monitor blood flow velocity of the prepared vessel (temporal superficial artery) at every stage of surgery. The device was also useful in controlling the patency of encephalo-duro-arterio-synangiosis percutaneously after the surgery. The proximal and the distal part of the non-bypass anastomosis was examined in the follow up during 5-8 months before angiography.

Survival and maturation of heterotopic fetal brain stem xenografts after treatment with 2-chlorodeoxyadenosine and cyclosporine A.

Brain stem halves from fetal rabbits were transplanted to the caudate nucleus area of adult rats. The animals were treated postoperatively with cyclosporine A (CsA) and 2-chlorodeoxyadenosine (CdA) for three days, and with CdA alone for the next 13 days. The treatment started at the day of implantation, and in some animals it was repeated starting at day 36 after grafting (at the time when signs of a light inflammatory reaction appeared in some grafts). Grafts survived and matured histologically, and no signs of acute rejection were observed up to the 90th day. In some grafts we recorded phasic neuronal activities similar to the respiratory-related neural activities characteristic for the adult brain stem. Immunosuppressive with CdA and CsA deserves further evaluation in fetal brain grafting.

Multiple cerebral cavernous angiomas. Case report.

This 26-year-old woman was admitted to Neurosurgery Department in 1972 for the first time due to increased intracranial pressure and since observed and treated by ventriculo-peritoneal shunt during next twenty years. First symptoms such as visual disturbances, hemiparesis and hemianesthesia appeared 8 years earlier followed 4 years later by epileptic fits. Ventriculography revealed hydrocephalus and the tumor in the region of the third ventricle. CT scan visualized multiple hyperdense foci. Ventriculo-peritoneal shunt provided good improvement. During the next twenty years condition of the patient gradually worsened. Diagnosis of multiple cavernous angiomas was established only at autopsy.

2-Chloro-2'-deoxyadenosine (2-CdA) combined with cyclosporine A successfully prevents rejection of fetal brain stem allograft in rabbits.

Allografts of brain stem from 20-day-old fetuses to nucleus caudatus of adult rabbits were performed. To prevent graft rejection immunosuppression with 2-CdA and cyclosporine A was transiently induced. Graft survival were assessed by histological and electrophysiological techniques. Both morphological (synaptogenesis, myelinization) and functional (generation of rhythmic neuronal activity) signs of graft maturation were found after nine weeks. The data suggest that transient immunosuppression used is sufficient to induce tolerance to neural graft, and no interference with maturation of implanted fetal tissue occurs.

Modulation of lymphocyte-fibroblast interactions by 2-chloro-2'-deoxyadenosine (2-CdA) in subarachnoid hemorrhage.

The adherence to monolayers of human fibroblasts of chromium-51 labelled peripheral blood mononuclear cells (PBMC) from normal subjects, and from patients after single or multiple subarachnoid hemorrhage (SAH), and the effect of 2-CdA on cell adhesion have been quantified. The fraction of cells adhering to fibroblasts were the lowest for multiple SAH patients and the highest for normal subjects, which can be explained by depletion of activated lymphocytes from peripheral blood of SAH patients. 2-CdA decreased the fraction of adhering cells isolated from normal subjects, did not change the adherence of cells from single SAH patients and increased the fraction of adhering cells isolated from multiple SAH patients. We conclude that the influence of 2-CdA on the adherence of PBMC to fibroblasts is inversely related to the degree of immune system activation.

A strategy for analyzing multiple parameters with application to aneurysmal SAH patients all of them clipped but treated with and without cyclosporine.

The study evaluated the effectiveness of the combination of nimodipine and cyclosporine A vs nimodipine alone in the prevention of delayed neurologic deficit in 82 (31 plus 51) patients in whom intracranial aneurysms were clipped within 72 h after subarachnoid haemorrhage. The tests performed included examination of the neurological condition before and after operation, angiography of cerebral arteries to visualize vasospasm, and analysis of the distribution and amount of blood in the brain fluids and/or tissue according to Fisher's scale. Inclusion of cyclosporine A in the treatment was clearly beneficial for the neurological condition. While cyclosporine A did not appear to produce a statistically significant improvement as evaluated by the chi-square test, a positive result was obtained following analysis of the correlation coefficients after Pearson in combination with the logistic log-linear regression analysis. The results argue against the utility of the chi-square test for verifying clinical data obtained in a limited number of patients.

Impaired in vitro proliferative response of suppressor lymphocytes in patients with subarachnoid haemorrhage from ruptured intracranial aneurysm.

Proliferative response to mitogens concanavalin A, phytohemagglutinin and pokeweed mitogen, and other chosen indicators of the activity of the immune system were assayed in peripheral blood mononuclear cells isolated from blood of patients with subarachnoid haemorrhage from ruptured aneurysm. Healthy blood donors served as control group. The SAH group displayed impaired response to concanavalin A, which is a mitogen specific for suppressor cells. It is suggested that the impaired activity of suppressor cells pre-existed in patients with subarachnoid haemorrhage, and after intracranial bleeding it might have contributed to the development of late neurological deficits.

Successful prevention of neurological deficit in SAH patients with 2-chlorodeoxyadenosine.

Twenty patients suffering from subarachnoid haemorrhage due to ruptured intracranial aneurysm and operated on within 72 h after SAH were treated with an experimental immunosuppressive drug 2-chlorodeoxyadenosine (2-CDA), dose 0.05 mg/kg/day i.v. for 7 days. The 2-CDA treatment was started immediately after angiographic confirmation of ruptured aneurysm, and the standard pharmacological treatment (nimodipine and steroids) was also given. 50% of patients were severely threatened by "delayed vasospasm" or late neurological deficit (Fisher's score 3 or 4). The neurological outcome (assessed 8-12 weeks after SAH) was good (GOS = 1) in 70%, and fair (moderate disability, GOS = 2) in 25%. A single case of severe disability (GOS = 3), as well as two cases of less than perfect outcome (GOS = 2), were related to unusual pre- or intraoperative complications. We conclude that the low doses of 2-CDA can be considered as a valuable adjunct to the standard pharmacotherapy of SAH patients operated on early.