[Multilevel segmental interbody fusion versus vertebral body replacement: comparison of two operative methods]. / Mehrsegmentale interkorporelle Fusion vs. Wirbelkörperersatz: Vergleich zweier operativer Methoden.

BACKGROUND: The surgical techniques of interbody fusion and vertebral body replacement represent two concurrent options for multilevel anterior decompression and arthrodesis of the cervical spine. PATIENTS AND METHODS: In a retrospective study the data from 61 patients who received either interbody fusion (n = 38) as anterior cervical discectomy and fusion (ACDF) or vertebral body replacement (n = 23) (as anterior cervical corpectomy and fusion (ACCF) because of degenerative disc disease of the cervical spine were collected. RESULTS: The clinical outcome was better at all time points in the patient group with ACDF than in those with ACCF but with no statistically significant differences. The operated segments showed a more rapid fusion progress after ACDF during the time course in comparison to ACCF; however, there was no relationship between the grade of fusion and the clinical result. CONCLUSION: In direct comparison multisegmental interbody fusion showed better results with respect to the clinical outcome and bony fusion with a lower rate of complications than vertebral body replacement. However, the differences did not reach statistical significance.

First manifestation of lambda positive plasmacytoma in the orbital apex with acute unilateral loss of vision.

INTRODUCTION: An intracranial plasmacytoma is a rare form, which can involve the calvarium, dura or the cranial base. Only few case reports describe the manifestation of plasmacytoma of the skull base with affection of visual acuity. CASE REPORT: We describe the case of a 43-year-old woman, presenting with an acute unilateral loss of vision. The presumption diagnosis was retrobulbar neuritis as first manifestation of multiple sclerosis. MR imaging disclosed a tumour in the left orbital region and a meningioma was suspected. After complete resection with decompression of the optic nerve, the neuropathological examination revealed a lambda positive plasmacytoma. Additional work-up disclosed an involvement of multiple vertebral bodies. Due to the diagnosis of multiple myeloma, oncological therapy had been initiated. CONCLUSION: Skull base plasmacytoma is a rare disease. Solitary lesions causing neurological deficits should be treated aggressively including surgery for histological diagnosis and decompression of neural structures. Prognosis and further therapy depends on the systemic stage of disease, which has to be defined by diagnostic work-up.

Somatosensory evoked potential monitoring during positioning of the patient for posterior fossa surgery in the semisitting position.

OBJECTIVE: Midcervical flexion myelopathy is a rare but well-known complication of posterior fossa surgery. To reduce the risk, we routinely used somatosensory evoked potential (SSEP) monitoring during positioning of the patient. METHODS: Fifty-five consecutive patients were operated on for posterior fossa lesions in the semisitting position via a median (5 patients) or a lateral (50 patients) suboccipital approach. During positioning, monitoring of SSEPs by stimulation of the tibial nerve (T-SSEP) as well as by stimulation of the median nerve (M-SSEP) was established. In the case of pronounced SSEP changes, the head was repositioned. Surgery was started after SSEP recordings were unchanged as compared to the baseline investigation. RESULTS: Effective monitoring was possible in all cases. Whereas M-SSEP recordings showed no changes while placing patients in the sitting position, T-SSEP recordings were altered in 14 cases (25%). In cases using the midline approach, SSEP changes were never so pronounced to require repositioning of the head. Head flexion and rotation resulted in significant changes of T-SSEP recordings in eight patients (14.5%), requiring repositioning. In two cases, an amplitude loss was noted. In only two of these eight patients were M-SSEP recordings markedly changed. SSEP recordings after repositioning disclosed recovery of spinal cord function. In no patient were clinical signs of myelopathy observed postoperatively. CONCLUSION: We observed a high incidence of pronounced changes of T-SSEP recordings when the patient's head was flexed and rotated for lateral suboccipital craniotomy in the semisitting position. Despite the low specificity monitoring of T-SSEPs during positioning of the patient for posterior fossa surgery, the semisitting position is strongly recommended.

Meningeal melanocytoma of the C8 nerve root: case report.

A case of a meningeal melanocytoma involving the C8 nerve root is presented. The clinical symptoms and the radiological investigations resembled a neurinoma of the spinal nerve root. Intraoperatively the tumor was seen to be firmly attached to the dural covering of the dorsal nerve root. By using microsurgical technique, complete removal of the tumor with preservation of the ventral nerve root was accomplished. Histological examination revealed a typical meningeal melanocytoma as described by Limas and Tio in 1972. Ten additional cases of previously reported spinal meningeal melanocytomas are reviewed. The importance of differentiating this benign lesion from meningeal malignant pigmented tumors is stressed.

Long term EEG analytical and neurological follow-up study in completed stroke patients after extra-intracranial vascular anastomosis.

In 33 chronic stroke patients, who had internal carotid or middle cerebral artery occlusion that resulted in neurological deficit persisting for an average of more than 10 weeks, it was possible to perform a postoperative follow-up study for a period of six to eight years after extra-intracranial vascular anastomosis. Serial neurological examinations with grading of motor deficit and EEG analyses were performed to assess the clinical course of the cerebral lesion. These long term examinations showed a postoperative continuing improvement of electrical brain activity in nearly two thirds of the patients, nine patients showed no significant changes and three worsened. The EEG analytical findings correlated well to the neurological findings. An increase of electrical brain activity was bilateral with accentuation over the affected hemisphere, a phenomenon known from follow-up nrCBF measurements after anastomosis. During the follow-up one patient died five years, one six years following stroke under signs of cardiovascular disease, and one after six years suffering from a recurrent stroke opposite to the side of anastomosis. In conclusion the findings indicate that EEG analysis is of value for assessment of long term follow-up of cerebral ischaemic lesions, chronic ischaemic alterations of the brain can be improved by anastomosis, and especially in comparison to a non-operated group of stroke patients, the course of the operated one seemed to be more advantageous, as the five-year survival rate of the Framingham study for stroke victims is 69%.

Experimental intracerebral hemorrhage: description of a double injection model in rats.

For experimental purposes, the most common technique of producing an intracerebral hematoma in rats is the injection of unclotted autologous blood. All modifications of this model share the problem that size and extension of the hematoma are not reproducible, because the injected blood either ruptures into the ventricular system or it extends to the subarachnoid or subdural space. Therefore a double injection model of experimental intracerebral hemorrhage in rats has been developed using 19 male Sprague-Dawley rats. After inducing anesthesia a cannula was stereotactically placed into the caudate nucleus and an intracerebral hematoma was produced with the double injection method in which first a small amount of fresh autologous blood is injected which is allowed to clot (preclotting) in order to block the way back along the needle track; the actual hematoma is produced in a second step of the injection. The clot volume was measured on stained serial sections. A total injection volume of 50 microliters of autologous blood produced intracerebral hematomas of 41.1 +/- 10.0 microliters and of similar shapes. The double injection method allows to generate reproducible hematomas in rats. This new model of intracerebral hemorrhage will allow further investigation of fibrinolytic and cytoprotective therapies.

Fibrinolysis and aspiration of experimental intracerebral hematoma reduces the volume of ischemic brain in rats.

The hypothesis was tested in rats that brain ischemia by an intracerebral hematoma can be ameliorated by fibrinolysis and aspiration of the hematoma. Intraparenchymal blood clots were generated by the injection of 50 microliters of autologous blood into the right caudate nucleus in two portions seven minutes apart. Thirty or 120 min later 12 microliters recombinant tissue plasminogen activator (rtPA) or 0.9% NaCl were injected and after 30 min the resolved hematoma was aspirated. Six hours later cerebral blood flow (CBF) was determined by 14C-iodoantipyrine autoradiography. Tissue volumes of CBF < 10 ml 100 g-1 min-1 and CBF < 30 ml g-1 min-1 were determined. Clot and lesion volume were quantified histologically from serial sections stained for succinate-dehydrogenase (SDH) activity. In rtPA-treated rats the major part of the hematoma could be evacuated 30 min as well as 120 min after production of the clot. The volume of ischemic brain (CBF < 10) was significantly reduced (p < 0.05) in the rtPA group compared to saline-treated and control groups irrespective of the time of treatment. In contrast, no difference was found between the control group and the experimental groups when the volumes of brain tissue surrounding the lesion were compared which had values of CBF < 30 ml 100 g-1 min-1. In a rat model of intracerebral hemorrhage, treatment by local fibrinolysis followed by aspiration of the hematoma is effective in reducing the volume of ischemic brain tissue and of the remaining clot volume.

Local fibrinolysis and aspiration of intracerebral hematomas in rats. An experimental study using MR monitoring.

Serial magnetic resonance (MR) imaging has not yet been validated in the therapy of experimental intracerebral hematomas in a rat model. It is possible to test the effect of local fibrinolysis and aspiration on the clot volume using serial magnetic resonance imaging and different MR-sequences. Experiments were carried out in 22 male Sprague-Dawley rats. Intracerebral hematoma was produced by injection of fresh autologous blood into the caudate nucleus using a double injection technique. Thirty minutes later 10 rats were treated by injecting 12 microliters of recombinant tissue plasminogen activator. MR-imaging was performed immediately after generation of the hematoma and after clot lysis. The clot volume measured in the magnetic resonance images was compared with that obtained in stained histological serial sections at the end of the experiment. Serial MR scanning demonstrated a significant reduction (p < 0.01) of hematoma volume after fibrinolysis followed by aspiration of the blood clot. The best correlation between MR- and histological volumetry was found on RF-spoiled FLASH 2D-images. This study documents the efficacy of MRI in detecting and delineating the size of acute intracerebral hematomas and its time course. Local fibrinolysis and aspiration can be simulated in an experimental rat model.

Lymphocytic infiltration in human intracranial tumors--morphologic evidence for a host-immune reaction and comparison with the leukocyte migration inhibition (LMI) test.

Lymphocytic infiltration in and around malignant tumors is generally considered to be an expression of immunologic defence reactions. The extent of such infiltrations correlates with an increase in survival rate. This paper tries to correlate results obtained from leukocyte migration inhibition tests (in vitro) with the presence and the extent of mononuclear infiltrations detected in 67 cases with intracranial tumors of different histologic classification. In the majority of cases there was a close correlation of the results. Possible reasons for discrepant findings are discussed.

Immunohistochemical demonstration of immunoglobulins and albumin in human brain tumors.

Routinely processed biopsy material, including 56 gliomas of varying malignancy, 10 meningiomas, 10 brain metastases and 12 brain abscesses, was examined for the presence and distribution of IgG, IgA, IgM, IgD and albumin using the unlabeled antibody peroxidase-antiperoxidase technique. In all specimens the deposition of stained immunoglobulins (Ig) was strictly associated with that of albumin even on cell surfaces. Thus there was no evidence for specific membrane binding or cytotoxicity. The interstitial proteins demonstrated are most likely derived from the plasma by blood-brain barrier breakdown which occurs in nearly all tumors and abscesses. Obvious intracellular staining for Ig and albumin was seen in glioma cells and astrocytes only. This is suggested to be due to active protein uptake as a specific feature of astrocyte differentiation which decreases with malignancy and is lost in glioblastomas. Evidence for local Ig production was found in 8 out of 10 metastases with striking IgG- and IgA-positive plasma cells within lymphocytic infiltrations and in one meningioma showing conspicuous plasma cells components. No glioma contained Ig-bearing plasma cells, though round cell infiltrations were present in 64% of the unselected cases. The significance of these findings regarding the immunological situation in brain tumors is briefly discussed.

Localized hypertrophic neuropathy--a rare, clinically almost unknown syndrome.

Localized hypertrophic neuropathy is a rare disease, which predominantly affects the radial nerve. The pathogenesis of this alteration is not yet clearly understood. We report a case with an unusually long history, discuss the relevant treatment briefly, and review the literature.

Mononuclear infiltrates in human intracranial tumors as a prognostic factor. Influence of preoperative steroid treatment. I. Glioblastoma.

One hundred ninety-nine glioblastomas were investigated for the presence of mononuclear infiltrates in the light of preoperative steroid treatment and in regard to their prognostic influence. Preoperative steroid treatment does not seem to severely influence the frequency of lymphocytic infiltration in the doses routinely administered by us. The presence of infiltrates corresponds with a better prognosis for the disease, and with a mean postoperative survival time of 8.1 months as compared to 5.6 months in the group without infiltrates, irrespective of adjuvant treatment. As a prognostic factor, infiltrates may be of relevance for a statistical evaluation, but not a reliable indicator in the individual case.

Immunohistochemical demonstration of the KI-67-antigen in paraffin-embedded tumor biopsies.

10 tumor specimens were processed according to a modification of the AMeX method, which allows for paraffin embedding plus immunostaining of the slices. We used this method to determine the growth fraction of tumors using the monoclonal antibody KI-67. Results were essentially the same as those obtained when studying frozen sections. The quality of the histological slices is equal to frozen sections, but greater areas of tumor can be examined. Furthermore, this method allows for compilation of a stock of tumor specimens which can be used for further immunohistochemical studies whenever needed.

[Motor aphasia after cervical myelography with metrizamide (author's transl)]. / Motorische Aphasie nach zervikaler Myelographie mit Metrizamid.

Two cases of transient motor aphasia after cervical myelography with Metrizamide are described. A possible mechanism is thought to be prolonged contact of contrast with a brain already damaged by a pre-existing vascular abnormality.

Recurring intracranial meningiomas. Evaluation of some factors predisposing for tumor recurrence.

60 cases of recurring meningiomas are analyzed in respect to factors influencing the risk of tumor recurrence. In our series of meningiomas operated on between 1970 and 1980 the recurrence rate was 9.5%. Recurrence rate was highest in tumors of the medial sphenoid. Incomplete tumor resection according to Simpson's grade III and IV lead to a higher recurrence rate than in grade I and II resection, but the difference is statistically not significant. Presence of mitoses, brain invasion and focal necrosis also is linked to a higher tumor recurrence rate. Tumors exhibiting all these three characteristics recurred in every case. Absence of lymphocytic tumor infiltration as a factor of risk is statistically not significant.

Injuries to the large abdominal vessels during lumbar nucleotomy.

The rare complication of iatrogenic damage to the large abdominal blood vessels during lumbar intervertebral disc operations is demonstrated by three case reports. A sudden decrease in blood pressure and tachycardia are major signs of such vessel lacerations. Due to a valve mechanism which prevents a dorsal blood leakage through the intervertebral space, early detection of this problem by the surgeon or anesthesiologist may prove to be difficult. Myocardial infarction, pulmonary embolism, abnormal volume distribution after positioning, dysfunction of circulatory regulation due to anesthesia or faulty positioning, obstruction of the subclavian artery due to false placement of chest padding, all occur more frequently and therefore must be considered and excluded. A wrong interpretation of this acute occurrence carries a mortality of 70%. Even immediate intervention by vascular surgery shows a mortality rate of 50% for this uncommon emergency. In order to prevent the disastrous sequelae to this complication, blood vessel injury should be suspected for every unexplained intraoperative decrease in blood pressure during lumbar nucleotomy. Only a rapid termination of the operation and appropriate preparation for vascular surgery can lower the mortality of this rare occurrence.

Paragangliomas of the spinal canal.

Paragangliomas are tumors arising in the paraganglia and rarely occur in the spinal canal. In the literature, 11 such cases have been reported. We present 7 additional cases, 3 of which were epidural in location in contrast to previously described intradural cases. The problems of histological diagnosis of these tumors are discussed. The value of determination of biogenic amines in the tumor tissue or the urine has been pointed out.

Multiple spinal hemangioblastomas in a case of Lindau's disease.

A 32-year-old man with Lindau's syndrome is presented. After an initial operation for cerebellar hemangioblastoma and laser coagulation of retinal tumors, other retinal tumors, a second cerebellar tumor, and four spinal hemangioblastomas occurred 10 years later; cystic lesions of both kidneys and of the pancreas could also be shown. There is no family history. Consequences for further diagnostic procedures in patients with hemangioblastomas are discussed.