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H J Reulen

Publications and source records attributed to H J Reulen.

At least 37 records · Page 2Linked to original sources
PubMed2001

The risk of haemorrhage after image guided stereotactic biopsy of intra-axial brain tumours--a prospective study.

OBJECTIVE: To analyze prospectively the frequency and the risk of symptomatic and asymptomatic haemorrhage after image guided stereotactic biopsy of intra-axial brain tumours. METHODS: The study was conducted within a time frame of 24 months (April 1998-April 2000). 326 patients (150 males, 176 females; mean age 56.8 years) were included and 345 computerized tomography (CT)-guided stereotactic biopsies were performed/supervised by a specialized stereotactic neurosurgeon. A modified Riechert Stereotaxy System and a workstation for multiplanar trajectory planning were used in all patients. Serial biopsies (median, 5 samples) were done with small forceps (diameter 1 mm), smear preparations of the biopsy specimens were intra-operatively examined. Frequency, size, and location of any detectable bleeding were analyzed by post-biopsy CT-scan investigation. For risk estimation, logistic regression analysis was performed. The chi-square statistic was used for comparative analysis of the study results with available data from the literature. RESULTS: A conclusive tissue diagnosis could be achieved in 98%. Overall treatment morbidity was 3.1%. There was no mortality. Haemorrhage related morbidity was 0.9%. Age, Karnofsky score, mass effect of the tumour, tumour histology, tumour location and the number of specimens taken did not have any prognostic significance. The clinically silent bleeding rate was 9.6% and more often seen in patients with high grade gliomas (p = 0.03). Both the silent and non-silent bleeding rate were significantly lower as compared to available prospective data in the literature (p < 0.01). CONCLUSION: Using multiplanar image guided trajectory planning, small biopsy forceps and intra-operative smear preparations the risk of major haemorrhage related morbidity after stereotactic brain tumour biopsy is extremely low (<1%) in experienced hands.

Adolescent↗
PubMed2000

Intracranial hypertension influences the resolution of vasogenic brain edema following intracerebral hemorrhage.

Aim of the current study was to investigate the influence of intracranial hypertension on the resolution of vasogenic brain edema following intracerebral hemorrhage. An intracerebral hematoma was induced by 500 microliters of blood injected into the left frontal lobe of rabbits (n = 25). Na(+)-fluorescein (MW376) and Texas-Red-albumin (MW67.000) were administered intravenously as edema markers. By using a closed cranial window for superfusion of the brain surface and a ventriculo-cisternal perfusion the clearance of both fluorescence markers was measured in the CSF-effluates up to 8 hours using spectrophotometry. ICP was adjusted between 2-6 mmHg (low pressure, n = 10), 8-12 mmHg (moderate pressure, n = 10) or 14-20 mmHg (high pressure, n = 5). In all groups Na(+)-fluorescein started to accumulate at 60 min after induction of the hematoma in the subarachnoid space, while at 90 min in the ventricular system. In the low intracranial pressure group Na(+)-fluorescein (mean +/- SEM) in the ventricular system amounted to 1.47 +/- 0.42 nmol as compared to 1.34 +/- 0.41 nmol in the moderate, or 0.38 +/- 0.11 nmol in the high intracranial pressure group. In the subarachnoid space the marker reached 1.96 +/- 0.57 nmol, 4.15 +/- 1.28 nmol, or 0.96 +/- 0.32 nmol, respectively. In conclusion, the data demonstrate that vasogenic edema induced by an intracerebral hematoma is cleared into both CSF compartments, albeit with delay into the ventricular system. Edema resorption occurred earlier and to a higher extent into the subarachnoid space as compared to the ventricular system. Further, edema resorption is influenced by the actual intracranial pressure, with marked inhibition by a high intracranial pressure.

Animals↗
PubMed2000

Neuroprotective effects of the novel brain-penetrating antioxidant U-101033E and the spin-trapping agent alpha-phenyl-N-tert-butyl nitrone (PBN).

Literature on the therapeutic efficacy of free radical scavengers suggests that drugs that are able to cross the blood-brain barrier are more effective in protecting the brain from ischemic damage. However, the exact mechanisms by which brain-penetrating antioxidants act have yet not been delineated. We compared the neuroprotective potential of the newly discovered pyrrolopyrimidine U-101033E with that of alpha-phenyl-N-tert-butyl nitrone (PBN) and investigated their influence on cerebral blood flow. Thirty male Sprague-Dawley rats were subjected to 90 min of middle cerebral artery (MCA) occlusion by an intraluminal filament. Local cerebral blood flow (LCBF) was bilaterally recorded by laser Doppler flowmetry. Neurological deficits were quantified daily. Infarct volume was assessed after 7 days. MCA occlusion reduced ipsilateral LCBF to 20-30% of baseline. After reperfusion, postischemic hyperemia was followed by a decrease in LCBF to about 70% of baseline. There was no difference in LCBF among groups. U-101033E improved neurological function and reduced infarct volume by 52% (P < 0.05). Improvement of neurological function and reduction of infarct volume (-25%) in animals treated with PBN was not significant. We conclude that U-101033E has superior neuroprotective properties compared with PBN. Neither drug improves blood flow during ischemia and 1 h of reperfusion. The mechanisms by which these brain-penetrating antioxidants act remain to be clarified.

Animals↗
PubMed2000

Accuracy and clinical applicability of a passive marker based frameless neuronavigation system.

A passive marker system permits the inclusion of an unlimited number of instruments and other devices during frameless stereotaxy. The aim of this study was to evaluate the accuracy and clinical applicability of a passive marker based frameless image guided system (VectorVision; BrainLab, Heimstetten, Germany) developed for surgical planning and intraoperative image guidance. The system was first applied to a plastic phantom to determine the accuracy of the system by measuring the difference between the actual probe position and its analogous position on the monitor screen. The navigational device was subsequently applied to 40 procedures for brain tumours and cavernomas. The mean error value between the image on the monitor screen and the real location in the phantom and the clinical study was 1.45 mm (+/-0.99) and 4.05 mm (+/-3.62), respectively. Many different instruments could be employed as pointing devices. It was helpful in minimising the size of the craniotomy. An average lengthening of the surgical procedure of 20 minutes was experienced. The neuronavigation system proved to be a useful surgical tool to approach and detect lesions larger than 5 mm in diameter. The passive marker technology is intuitive and enables the surgeon to use his or her own instruments at any time as a pointing device, thus avoiding further costs for specially designed surgical equipment.

Adult↗
PubMed2000

Transcallosal interforniceal-transforaminal approach for removing lesions occupying the third ventricular space: clinical and neuropsychological results.

OBJECTIVE: The present study was undertaken to describe the clinical and prospective neuropsychological results for our group of 30 patients who were treated using a transcallosal interforniceal-transforaminal microsurgical approach. METHODS: The transcallosal interforniceal and transcallosal-transforaminal approaches were used to treat 30 patients with space-occupying lesions located in the anterior part of the third ventricle. We used a modified anterior transcallosal microsurgical approach, as described recently. The patients underwent extensive, pre- and postoperative, prospective neuropsychological testing, using a specially designed test battery. RESULTS: Twenty-three of 30 patients (77%) experienced excellent clinical outcomes (Glasgow Outcome Scale Grade V). The surgical procedures described in this report did not themselves impair attentional function. In both the early and late postoperative neuropsychological testing sessions, deficits in verbal memory were only rarely observed and were not noted to be correlated with the surgical procedures. The most relevant neuropsychological results for individual patients are reported in detail. CONCLUSION: The approach described here can be successfully used for the resection of various space-occupying lesions in the anterior part of the third ventricle. The anatomic landmarks we recently defined and described (for example, the midline vessel on the trunk of the corpus callosum, to direct the callosotomy) guide the surgical path. Furthermore, we recommend the use of neuropsychological test batteries for both scientific and rehabilitative purposes.

Adolescent↗
PubMed2000

A keyhole approach for endoscopically assisted pedicle screw fixation in lumbar spine instability.

OBJECTIVE: The standard approach for dorsal transpedicular fixation in lumbar spine instability requires extensive exposure of the vertebral column. This increases the risk of potential complications and possibly destabilizes healthy neighboring segments because of the dissection and denervation of paravertebral muscles. The majority of spinal disorders are currently treated successfully via limited and tailored approaches. Accordingly, a keyhole approach for dorsal fusion of the lumbar spine was developed on the basis of an anatomic study. METHODS: The new endoscopic technique entails the transmuscular insertion of a pedicle screw-rod fixation device via a rigid operating sheath. As a prerequisite, the endoscopic microanatomy of the target area, as visible through the operating sheath, was first evaluated on lumbar bone specimens. To localize the exact screw entry point into the pedicle, we identified the bony and ligamentous landmarks on partly macerated specimens. To determine the course of the pedicle screws, we deduced the corresponding angles of convergence from transparent polyester casting models of average vertebrae from T12 to S1. These angles were transferred into the operative situation and measured on-line with an inclinometer. The approach was finally tested on 12 cadavers for clinical feasibility and accuracy of screw placement and then successfully implemented in patients. RESULTS: After extracutaneous localization of the pedicles at lateral fluoroscopy, paramedian skin incisions were made above the pedicles of the motion segment to be stabilized. The operative windows were exposed by use of a rigid operating sheath (length, 50 mm; diameter, 15 mm), which was inserted transmuscularly in the pedicle axis. The screw entry point into the pedicles was localized by endoscopic dissection of the mamilloaccessory ligament, bridging the mamilloaccessory notch. The pilot holes were created via insertion of a blunt-tipped pedicle probe. The adequate angles of convergence were constantly controlled during hollowing of the pedicles by an inclinometer mounted to the pedicle probe handle. The pedicle screws were then inserted through the operating sheaths. After removal of the operating sheaths, the connecting rods were inserted transmuscularly and anchored in the pedicle screw heads. Posterior bone grafting was performed after completion of the dorsal instrumentation. The dorsal fusion site was exposed by reinserting the operating sheath and tilting it medially. CONCLUSION: This new approach significantly reduces surgical traumatization and destabilization of adjacent motion segments. An endoscopic operating sheath, adopted from thoracoscopic surgery, creates space for visualization and surgical manipulations. The newly defined anatomic landmarks provide guidance to the screw entry point into the pedicle in the center of the exposure. Observation of the exact corresponding angles of convergence during screw insertion by an inclinometer facilitates correct screw placement. In accordance with the initial anatomic studies, this approach was successfully performed on 12 cadavers and then used in six patients. Two illustrative cases are presented.

Adult↗
PubMed2000

Fluorescence-guided resection of glioblastoma multiforme by using 5-aminolevulinic acid-induced porphyrins: a prospective study in 52 consecutive patients.

OBJECT: It has been established that 5-aminolevulinic acid (5-ALA) induces the accumulation of fluorescent porphyrins in glioblastoma multiforme (GBM), a phenomenon potentially exploitable to guide tumor resection. In this study the authors analyze the influence of fluorescence-guided resection on postoperative magnetic resonance (MR) imaging and survival in a series of patients who underwent surgery in the authors' department. METHODS: Fifty-two consecutive patients with GBM received oral doses of 5-ALA (20 mg/kg body weight) 3 hours before induction of anesthesia. Intraoperatively, tumor fluorescence was visualized using a modified operating microscope. Fluorescing tissue was removed whenever it was considered safely possible. Residual enhancement on early postoperative MR imaging was quantified and related to each patient's characteristics to determine which factors influenced resection. Survival was analyzed using the Kaplan-Meier method and multivariate analysis was performed in which the Karnofsky Performance Scale (KPS) score, residual fluorescence, patient age, and residual enhancement on MR images were considered. Intraoperatively, two fluorescence qualities were perceived: solid fluorescence generally reflected coalescent tumor, whereas vague fluorescence mostly corresponded to infiltrative tumor. Complete resection of contrast-enhancing tumor was accomplished in 33 patients (63%). Residual intraoperative tissue fluorescence left unresected for safety reasons predicted residual enhancement on MR images in 18 of the 19 remaining patients. Age, residual solid fluorescence, and absence of contrast enhancement in MR imaging were independent explanatory factors for survival, whereas the KPS score was significant only in univariate analysis. No perioperative deaths and one case of permanent morbidity were encountered. CONCLUSIONS: The observations in this study indicate the usefulness of 5-ALA-induced tumor fluorescence for guiding tumor resection. The completeness of resection, as determined intraoperatively from residual tissue fluorescence, was related to postoperative MR imaging findings and to survival in patients suffering from GBM.

Adult↗
PubMed1999

Neuroprotective efficacy of combination therapy with two different antioxidants in rats subjected to transient focal ischemia.

The vascular endothelium and parenchyma of the brain have both potential pathways to generate free radicals under pathological conditions. We evaluated the neuroprotective efficacy of two different antioxidants, a microvascularly acting 21-aminosteroid (U-74389G) and a brain-penetrating pyrrolopyrimidine (U-101033E) alone and in combination. Forty Sprague-Dawley rats were randomly assigned to one of four treatment groups: (1) vehicle-treated controls, (2) U-74389G, (3) U-101033E, (4) U-74389G+U-101033E. Drugs were administered in a dosage of 3x3 mg/kg i.v. before, during, and after ischemia. All animals were subjected to 90 min of middle cerebral artery occlusion. Local cortical blood flow (LCBF) was continuously recorded by bilateral laser Doppler flowmetry. Functional deficits were quantified by daily neurological examinations. Infarct volume was assessed after 7 days. There were no significant differences in LCBF among groups. U-101033E improved neurological function from postoperative day 4 to 7, while U-74389G did not improve neurological recovery. Animals treated with both drugs showed significantly less deficits from postoperative day 1 to 7. U-101033E and combination therapy reduced total infarct volume by 53% and 54% (P<0.05). U-74389G non-significantly reduced total infarct volume by 25%. Cortical infarct volume was significantly reduced in all treatment groups but only U-101033E and combination therapy protected the basal ganglia from infarction. In conclusion, brain-penetrating antioxidants have superior neuroprotective properties compared to microvascularly acting agents. Combination therapy, affording antioxidation plus radical scavenging in blood vessels and brain parenchyma, might yield the highest degree of neuronal protection from peroxidative damage. The neuroprotective efficacy seems to be independent of CBF.

Analysis of Variance↗
PubMed1999

EEG burst suppression is not necessary for maximum barbiturate protection in transient focal cerebral ischemia in the rat.

Barbiturates have been demonstrated to reduce the cerebral metabolic rate (CMR) in a dose-dependent manner but investigations of a dose-response relationship for their neuroprotective efficacy are scant. It has been suggested that barbiturates possess other mechanism of action that may be critical to their protective effect. If so, it is conceivable that the peak effect of such mechanisms does not parallel the reduction in CMR. Thus, maximal neuroprotection may be achieved with a substantially lower dose of the drug. Thirty Sprague-Dawley rats were subjected to 2 h of middle cerebral artery occlusion while either anesthetized with (1) halothane (control) or (2) intravenous thiopental titrated to cause mild EEG suppression or (3) thiopental titrated to maintain EEG burst suppression. Cortical blood flow was recorded by continuous bilateral laser Doppler flowmetry (LDF). Infarct volume was assessed after 3 h of reperfusion. Low-dose thiopental decreased blood flow to 80% of baseline and high-dose thiopental to 70% of baseline. LDF did not indicate improvement of blood flow by thiopental in the ischemic area. Compared to controls, low-dose thiopental significantly decreased infarct volume by 28% and high-dose thiopental by 29%. The results of this study and a review of literature indicate that barbiturates provide cerebral protection but that the magnitude of this effect has been overestimated. Other mechanisms than CMR reduction seem to contribute to their beneficial effects, and high doses administered to the point of burst suppression may not be required to obtain maximal protection.

Animals↗
PubMed1999

Technical note: a new model for quantitative analysis of brain oedema resolution into the ventricles and the subarachnoid space.

OBJECTIVE: The aim of the current study was to develop an experimental animal model for quantitative analysis of oedema resolution via the subarachnoid space and the ventricular system using fluorescent oedema markers. METHODS: Artificial cerebrospinal fluid (CSF) containing TRITC-albumin (MW 67.000D) and Na(+)-fluorescein (MW 376D) was continuously infused into the white matter of the left frontal lobe of New Zealand white rabbits (n = 6) at a rate of 100 microliters/h for 3 hrs. A closed cranial window for superfusion of the brain surface with artificial CSF fluid (3 ml/h) was implanted above the left parietal cortex for measurement of the fluorescence markers in the subarachnoid space. Uptake of the fluorescence indicators into the ventricles was quantified by ventriculo-cisternal perfusion (3 ml/h). The effluates were collected at 30 min intervals for 3 hrs after the start of infusion. Clearance of the oedema fluid into the perfusates was measured by fluorescence spectrophotometry. RESULTS: At an intracranial pressure of 15.0 +/- 1.7 mm Hg (mean +/- SEM) both indicators started to accumulate in the subarachnoid and ventricular perfusates at 90 min following onset of oedema fluid infusion. The concentrations of the indicators in the ventricular system increased to 7.7 +/- 5.1% of Na(+)-fluorescein and 16.1 +/- 13.0% of TRITC-albumin of the total amount infused were recovered in the ventricular system at 3 hours after start of the oedema infusion, while 3.4 +/- 3.2% of Na(+)-fluorescein and 3.7% +/- 3.2 of TRITC-albumin, respectively, were found in the effluates of the subarachnoid space. CONCLUSION: The present study demonstrates that resolution of vasogenic brain oedema into the cerebral ventricular system and the subarachnoid space following its entry into cerebral white matter can be quantitatively analysed using fluorescence markers, which serve as oedema fluid indicators. The results indicate that the oedema fluid is cleared not only into the ventricular system but also via the subarachnoid space.

Animals↗
PubMed1999

Cavernous haemangiomas of the spinal cord. A review of 117 cases.

Intramedullary spinal cord cavernous haemangiomas are rare lesions that can cause severe myelopathic symptoms. The purpose of the present study was to define the pattern of clinical presentation, part of natural history, prognostic factors and therapeutic strategies considering both our own experience and reports from the literature. The data of 48 studies (published between 1903 and 1996), presenting information of all together 107 patients (108 lesions) regarding pre-treatment clinical and radiological factors, treatment strategies, and the outcome, plus our own experience of nine patients were retrospectively re-analyzed. The prognostic influence of pretreatment factors was estimated with the chi-square statistics. Clinical evaluation before/after treatment was performed using the Frankel scale. The average bleeding rate was obtained from the ratio of percentage of first bleeding events in the population to the mean age of the population. There were 47 males and 69 females (aged from twelve to 88 years). Thirty nine percent of the lesions were found in the cervical, 54% in the thoracic (30% upper, 24% lower) and 7% in the lumbar cord. The peak age of presentation was in the fourth decade, the median duration of symptoms was 32 months. Clinical symptoms before treatment were progressive in all cases. Three patterns of clinical presentation could be identified: a) episodes of stepwise clinical deterioration (30%), b) slow progression of neurological decline (41%), c) acute onset with rapid or gradual decline over weeks or months (26%). 58% of the lesions showed clinical or radiological signs of haemorrhage. In 66% of surgical patients (91 efficiently documented cases), clinical improvement was achieved, 28% remained unchanged and 6% deteriorated. Whereas age, sex and lesion location had no influence on the results, duration of symptoms (< three years) correlated significantly to a better outcome (p < 0.02). Surgical management in symptomatic patients is recommended. Once clinical signs caused by the malformation have appeared, the patients tend to experience progressive neurological deterioration.

Adolescent↗
PubMed1999

Interdisciplinary management results in 100 patients with ruptured and unruptured posterior circulation aneurysms.

The authors report on a series of 100 posterior circulation aneurysms managed by surgical and endovascular procedures. The series consisted of 41 elective admissions more than 14 days after SAH or for unruptured aneurysms and 59 acute admissions after subarachnoid haemorrhage (SAH). In this first interdisciplinary series after the introduction of electrolytically detachable coils, surgical clipping was maintained as treatment of choice in good grade patients while endovascular therapy was primarily offered for patients in poor clinical grade or if the aneurysm was judged difficult to be accessed surgically. A total of 70 patients underwent aneurysm elimination, 54 surgically and 16 by the endovascular route. In 30 patients the aneurysm was not treated, either because of persisting grade 5 WFNS after SAH or because the risk of treatment appeared excessive with some complex unruptured aneurysms. A complication leading to permanent morbidity or mortality occurred after 5 surgical and 1 endovascular procedure (8.6%). Regarding overall management results after acute SAH, 14 of the total of 59 patients admitted with acute SAH died, corresponding to a management mortality of 24%. Although the present series cannot provide statistically firm conclusions, the authors believe from the actual experience and the accumulating literature, that the principal complementary aspect of the two treatment modalities is aneurysm location. Size and shape do not appear to be a primary factor to favour one or the other modality. The hope that endovascular therapy improves the prognosis of poor grade patients with posterior circulation aneurysms probably has been overstated. The good results of endovascular treatment with small narrow-necked aneurysms on proximal arteries of the posterior circulation, as seen in the present series and as reported in the accumulating literature, suggest that in future surgical and endovascular treatment should be considered as alternatives in these special cases while in large and broad-necked aneurysms surgery should be considered first.

Aneurysm, Ruptured↗
PubMed1999

Neuroprotective effects of combination therapy with tirilazad and magnesium in rats subjected to reversible focal cerebral ischemia.

OBJECTIVE: Cell death after cerebral ischemia is mediated by release of excitatory amino acids, calcium influx into cells, and generation of free radicals. We examined the hypothesis that concurrent administration of tirilazad, a well-known antioxidant, and magnesium, an antagonist of calcium and excitatory amino acids, would result in a synergistic neuroprotective effect. METHODS: Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion and assigned to one of four treatment arms (n = 10 in each): 1) vehicle, 2) tirilazad, 3) MgCl2, or 4) tirilazad and MgCl2. Cortical blood flow was recorded using laser Doppler flowmetry. Functional deficits were quantified by performing daily neurological examinations. Infarct volume was assessed after 7 days. RESULTS: There was no difference in cortical blood flow among groups. Animals that received tirilazad or MgCl2 monotherapy had significantly better neurological function compared with control animals only on postoperative Days 3 and 4, whereas animals treated with both drugs had significantly better neurological function than did control animals from postoperative Days 2 through 7. Magnesium reduced total infarct volume by 25% (nonsignificant), tirilazad by 48% (P<0.05), and combination therapy by 59% (P<0.05) compared with control data. CONCLUSION: Combined therapy with antagonists of excitatory amino acids and free radicals provides better neuroprotection from the effects of transient focal ischemia than does therapy with either antagonist alone. In contrast to many experimental agents, tirilazad and magnesium offer the advantage of being licensed for clinical use. This drug combination could be of great benefit when administered before temporary artery occlusion in patients undergoing cerebrovascular surgery.

Animals↗
PubMed1999

Transcallosal approach to the third ventricle: normative morphometric data based on magnetic resonance imaging scans, with special reference to the fornix and forniceal insertion.

OBJECTIVE: The ability to visualize median-sagittal brain structures by magnetic resonance imaging (MRI) improves the planning for surgical removal of lesions located in and around the third ventricle. The transcallosal approach is the most appropriate path to the anterior part of the third ventricle. The present study was undertaken to obtain normative morphometric data, derived from sagittal MRI scans, which are necessary for operation planning that takes into account the surgical microanatomy and landmarks encountered during this approach. METHODS: The morphometric evaluation was performed on 72 median-sagittal MRI scans. The surface landmarks for the corridor were the two points, P5 and P7, located 5 and 7 cm anterior to the central sulcus, respectively. With these two points on the cortical surface as references, a variety of measurements were made to provide quantitative information about distances between brain structures encountered during the surgical approach. In addition, various parameters were determined to characterize the different shapes of the fornix and the different types of forniceal insertion. RESULTS: The following measurements (means) were obtained: 1) the distance between P5/P7 and the cingulate sulcus was 25.76 mm (range, 17.113-42.73 mm) with reference to P5, and 25.41 mm (range, 12.91-36.29 mm) with reference to P7; 2) the distance between the cingulate sulcus and the corpus callosum was 12.91 mm (range, 7.19-22.60 mm) with reference to P5, and 12.92 mm (range, 6.75-23.37 mm) with reference to P7; 3) the height of the corpus callosum was 6.22 mm (range, 3.07-9.00 mm) with reference to P5, and 6.92 mm (range, 3.50-13.57 mm) with reference to P7; 4) the distance between the anterior commissure and the foramen of Monro was 6.78 mm (range, 1.86-14.57 mm), independent of P5 and P7; 5) the distance between the lower margin of the corpus callosum and the upper insertion point of the fornix was 12.44 mm (range, 2.71-26.13 mm) with reference to P5, and 13.34 mm (range, 3.74-27.58 mm) with reference to P7; 6) the distance between the lower margin of the corpus callosum and the lower insertion point of the fornix was 18.08 mm (range, 9.47-29.71 mm) with reference to P5, and 18.58 mm (range, 10.48-30.40 mm) with reference to P7; and 7) the distance between the lower margin of the corpus callosum and the anterior commissure was 23.46 mm (range, 11.98-32.70 mm) with reference to P5, and 22.89 mm (range, 11.05-33.04 mm) with reference to P7. Four different insertion types between the fornix and the corpus callosum were noted and classified. CONCLUSION: Morphometric data concerning the surrounding structures of the third ventricle have received very little attention in the literature. This morphometric study permitted definition of the surgical corridor to the third ventricle by preserving important anatomic structures such as the motor strip, genu of the corpus callosum, forniceal commissure (hippocampal commissure), anterior commissure, and forniceal columns. The detailed morphometric data obtained on median-sagittal MRI scans of the brain structures involved in the transcallosal interforniceal and/or transcallosal transforaminal approach allow for exact planning of the surgical approach.

Adult↗
PubMed1999

Combination drug therapy and mild hypothermia: a promising treatment strategy for reversible, focal cerebral ischemia.

BACKGROUND AND PURPOSE: Hypothermia has been suggested to be the most potent therapeutic approach to reduce experimental ischemic brain injury identified to date, and mild hypothermia is increasingly used for neuroprotection during neurovascular surgery. We have recently demonstrated that combined administration of tirilazad mesylate and magnesium provides for an overall enhanced neuroprotective effect. The present study was designed to determine whether the efficacy of mild hypothermia (33 degrees C) can be increased by combination pharmacotherapy with tirilazad and magnesium (MgCl(2)). METHODS: Forty Sprague-Dawley rats were subjected to transient, middle cerebral artery occlusion and were randomly assigned to 1 of 4 treatment arms (n=10 each): (1) normothermia+vehicle, (2) normothermia+tirilazad+MgCl(2), (3) hypothermia+vehicle, or (4) hypothermia+tirilazad+MgCl(2). Cortical blood flow was monitored by a bilateral laser-Doppler flowmeter, and the electroencephalogram was continuously recorded. Functional deficits were quantified by daily neurological examinations. Infarct volume was assessed after 7 days. RESULTS: Tirilazad+MgCl(2), hypothermia, and hypothermia+tirilazad+MgCl(2) reduced total infarct volume by 56%, 63%, and 77%, respectively, relative to controls. In animals treated with both hypothermia and combination pharmacotherapy, cortical infarction was almost completely abolished (-99%), and infarct volume in the basal ganglia was significantly reduced by 55%. In addition, this treatment provided for the best electrophysiological recovery and functional outcome. CONCLUSIONS: The neuroprotective efficacy of hypothermia can be increased by pharmacological antagonism of excitatory amino acids and free radicals by using clinically available drugs. This treatment strategy could be of great benefit when applied during temporary artery occlusion in cerebrovascular surgery.

Animals↗
PubMed1999

Surgery and radiotherapy compared with gamma knife radiosurgery in the treatment of solitary cerebral metastases of small diameter.

OBJECT: The aim of this retrospective study was to compare treatment results of surgery plus whole-brain radiation therapy (WBRT) with gamma knife radiosurgery alone as the primary treatment for solitary cerebral metastases suitable for radiosurgical treatment. METHODS: Patients who had a single circumscribed tumor that was 3.5 cm or smaller in diameter were included. Treatment results were compared between microsurgery plus WBRT (52 patients, median tumor dose 50 Gy) and radiosurgery alone (56 patients, median prescribed tumor dose 22 Gy). In case of local/distant tumor recurrence in the radiosurgery group, additional radiosurgical treatment was administered in patients with stable systemic disease. Survival time was analyzed using the Kaplan-Meier method, and prognostic factors were obtained from the Cox model. The patient groups did not differ in terms of age, gender, pretreatment Karnofsky Performance Scale (KPS) score, duration of symptoms, tumor location, histological findings, status of the primary tumor, time to metastasis, and cause of death. Patients who suffered from larger lesions underwent surgery (p < 0.01). The 1-year survival rate (median survival) was 53% (68 weeks) in the surgical group and 43% (35 weeks) in the radiosurgical group (p = 0.19). The 1-year local tumor control rates after surgery and radiosurgery were 75% and 83%, respectively (p = 0.49), and the 1-year neurological death rates in these groups were 37% and 39% (p = 0.8). Shorter overall survival time in the radiosurgery group was related to higher systemic death rates. A pretreatment KPS score of less than 70 was a predictor of unfavorable survival. Perioperative morbidity and mortality rates were 7.7% and 1.6% in the resection group, and 8.9% and 1.2% in the radiosurgery group, respectively. Four patients presented with transient radiogenic complications after radiosurgery. CONCLUSIONS: Radiosurgery alone can result in local tumor control rates as good as those for surgery plus WBRT in selected patients. Radiosurgery should not be routinely combined with radiotherapy.

Adolescent↗
PubMed1999

Evaluation of abstracts submitted for the annual meeting of the German Neurosurgical Society 1999--unravelling a mystery.

The evaluation for the abstracts submitted for the annual meeting of the German Neurosurgical Society together with the Swiss Neurosurgical Society in Munich 1999, is presented as it has developed during the meetings of the last years. 597 abstracts were reviewed by the 30 members of the review committee according to a 5 point grading system. Cut off for acceptance was a mean grading of 2.7 points. Abstracts better than 2.4 were accepted, abstracts worse than 2.7 were rejected. Experimental studies were judged slightly better than clinical studies: the mean grading of clinical and experimental studies was 2.55 +/- 0.5 vs. 2.72 +/- 0.6 (p < 0.02). All abstracts with a mean grading of 2.4-2.7 and a standard deviation > 1.0 were discussed in a meeting of the review committee. 353 abstracts were accepted. Some of the abstracts submitted for oral presentation had to be converted to poster presentations. Among others the decision was based on the grading of the abstract.

Abstracting and Indexing↗