Matthias Zumkeller

Computed Tomographic Criteria and Survival Rate for Patients with Acute Subdural Hematoma

OBJECTIVE Computed tomographic data from 174 patients with acute subdural hematoma were analyzed statistically to identify parameters that could be evaluated independently of clinical and neurological status to estimate outcome. METHODS This retrospective study was made necessary by the fact that the patients admitted usually had been treated with intubation, sedation, and artificial ventilation, which precludes neurological examination. RESULTS In surgically treated patients, the hematoma thickness ranged from 5 to 35 mm and the midline shift was 0 to 33 mm. In 81 patients (46.6%), the hematoma thickness was greater than the midline shift; in 24 patients (13.8%), the hematoma thickness equaled the midline shift; and in 69 patients (39.6%), the midline shift exceeded the hematoma thickness. Of the patients, 52% died after surgery, for 29% we obtained good or satisfying results, and 19% were in poor condition after therapy. The Kaplan-Meier survival analysis proved that the survival rate was only 50% for a hematoma thickness of approximately 18 mm and a midline shift of 20 mm. The survival function dropped markedly for midline shifts of more than 20 mm and converged to 0% for midline shifts of more than 25 mm. If the midline shift exceeded the hematoma thickness by 3 mm, the survival function was 50%; when the midline shift exceeded the hematoma thickness by 5 mm, the survival function was 25%. The Glasgow Outcome Scale scores were correlated significantly with these parameters. The parameters, which are the measured hematoma thickness, the midline shift, and the difference between the hematoma thickness and the midline shift, allow robust/adequate estimation of survival function and outcome for patients suffering from acute subdural hematoma. CONCLUSION Based on these data, indications for surgery could be assessed by means of video conferencing, i.e., without personal examination of the patients.

Intraspinal lipomas in infancy and childhood causing a tethered cord syndrome.

The authors report on a series of 26 children with spina bifida occulta in combination with intraspinal lipoma and clinical signs of tethered cord syndrome. The age of the children at presentation ranged from 1 month to 12 years. The typical signs and symptoms consisted of skin lesions in the lumbar-sacral region, neurogenic foot deformities, and bladder and bowel disturbances.The diagnosis was confirmed by neuroradiological investigations including lumbar myelography, computerized tomography, and only recently magnetic resonance imaging. Indications for surgery were based on the radiological evidence of intraspinal lipoma and tethered cord and especially on the clinical signs of neurological deterioration.The results of the operative treatment are presented and the role of surgery before onset of symptoms as well as during the symptom-free interval is discussed.

The results of surgery for intracerebral hematomas

Our retrospective study included 104 patients (28 female and 76 male) with intracerebral bleeding, treated between 1978 and 1988 in the Neurosurgical Clinic of the Medical University in Hannover. The average age was 43 years. 53 patients presented with traumatic intracerebral bleedings, and 51 with spontaneous hematomas. 31 patients with spontaneous hematomas were operated: among these a good or satisfactory result was obtained in 19 patients, and 12 died. Of the 20 non-operated patients, a good or satisfactory result was achieved in 10. 31 patients were operated in the group with traumatic hematoma, of these 22 had a good or satisfactory outcome and 9 patients died or had an unsatisfactory result. Of the 22 non-operated patients, 13 died and 9 achieved a good or satisfactory result. In the stratified Chit-Test the effects of the operation were not found to be significant, with 0.1 < p < 0.25 for spontaneous, and 0.25 < p < 0.05 for the traumatic hematomas. There is a trend in favor of the operation in certain cases.

The use of recombinant activated factor VII in neurosurgery

BACKGROUND Bleeding complications in neurosurgery often take alarming proportions without major hemodynamic effect or impairment of coagulation physiology because severe neurologic deficits are to be expected. Any measures used to stabilize or normalize coagulation are therefore of great interest. Administration of packed red cells, fresh frozen plasma, and platelet concentrates is associated with volume loading, which is suspected to multiply the secondary brain damage, for example, by the development of an edema. In this respect, the administration of rFVIIa may develop into a new option associated with low-volume administration. CASE DESCRIPTIONS We report on 5 neurosurgical patients to whom rFVIIa was given at doses of 51 to 202 microg/kg of body weight for the treatment of severe intraoperative bleeding (n = 3) or as prophylaxis of bleeding (n = 2). The operation was completed successfully in all patients after administration of rFVIIa, with stabilization of the coagulation status. CONCLUSION Therefore, reported cases constitute an approach in treatment and prophylaxis of bleeding complications in neurosurgery. There are reports of thromboembolic events in use of rFVIIa, particularly in unlabeled use. But according to our findings and current literature, there is no evidence of higher risk of thromboembolic adverse events in treatment with rFVIIa. However, the number of patients presented does not allow any final assessment to be made as to whether the properties of rFVIIa are of particular benefit for neurosurgical patients. Further studies with appropriate study design are required to verify effects observed in this investigation.

On the effect of calcium antagonists on cerebral blood flow in rats. A comparison of nimodipine and flunarizine

To assess the influence of nimodipine treatment in brain tissue at different levels of blood pressure, we estimated the cerebral blood flow using hydrogen clearance. Rats were treated with nimodipine (n = 8), its placebo (n = 10), flunarizine (n = 11) and its placebo (n = 10), and a group of controls (n =10). Cerebral blood flow was estimated during arterial normo-, hyper-and hypotension. The lowest cerebral blood flow estimates calculated for nimodipine were 43.8 ± 7.8, 90.9 ± 13.3, and 33.6 ± 6.1 ml/min/100 g for normo-, hyper- and hypotension, respectively. Cerebral blood flow in the nimodipine placebo group was 84.1 ±10.3,139.9 ± 19.9, and 55.2 ± 10.5 ml/min/100 g. In the flunarizine group, the blood flow was 77.3 ± 15.2,144.7 ± 15.0, and 43.8 ± 5.9 ml/min/100 g. In the control group, cerebral blood flow was 90.0 ± 29.1, 143.0 ± 42.1, and 75.5 ± 29.8 ml/min/100 g. The low blood flow in the nimodipine group might have been a consequence of brain edema caused by extravasates. Thus impaired blood flow reduces the usefulness of nimodipine in the prevention of vasospasm. Flunarizine is a potential alternative treatment of vasospasm treatment as well as for cerebral blood flow improvement, as shown in our experimental study.

Cerebral Blood Flow in Chronic Hydrocephalus A Parameter Indicating Shunt Failure — New Aspects

Prediction of outcome after shunt-therapy in chronic hydrocephalus syndrome is uncertain. Pathology reveals an impairment of cerebral blood flow (CBF). Based on this, we evaluated CBF and its significance for the assessment of prognosis. In 21 patients (mean age 69 years) selected for surgery, CBF was measured by PET (15O-H2O) before, about one week and 7 months (n = 14) after shunting. CBF was computed by a 1-compartmental model in the territories of the ACA, MCA and PCA. One PET slice in the height of the maximum projection of both cellae mediae was chosen. CBF data were standardized by cluster analysis. Three CBFClusters with significantly different CBF levels prior to shunting in the ACA, MCA and PCA territory, respectively, referred to the sample average (38.2 ml/100 ml/min) were found. These CBFClusters differed in clinical outcome: almost 50% and 90% of patients improved clinically in CBFCluster I, with a perfusion level lower than average, after one week and 7 months, respectively. In contrast, patients of CBFCluster II with an average perfusion did not improve. CBF changes 7 months after shunting related to global CBF before surgery showed a relationship with the clinical course. Clinical outcome corresponded with preoperative global CBF values. Cerebral blood flow lower than average forecasts clinical improvement. Our results suggest that measurement of CBF adds to the indication for surgery.

CT-Kriterien und Überlebensrate bei Patienten mit akutem Subduralhämatom

ZusammenfassugGrundlagenPatienten mit akutem Subduralhämatom (ASH) werden in der Regel intubiert und beatmet gleich nach dem Unfall in die Klinik eingeliefert. Die präklinische Versorgung läßt die klinisch-neurologische Untersuchung und somit eine Aussage über den postoperativen Verlauf nicht zu und erschwert das Stellen der Operationsindikation.MethodikDie CT-Daten von 164 operierten Patienten mit ASH wurden retrospektiv statistisch analysiert, um computertomographische Kriterien zu erhalten, die unabhängig von klinischneurologischem Befund eine Prognose über den weiteren Verlauf und den Operationserfolg zulassen. Analysiert wurden Hämatomdicke (HD), Mittellinienverlagerung (MLV) und die Differenz aus beiden.ErgebnisseDie HD war von 0,5 cm bis 3,5 cm, die MLV 0 cm bis 3,3 cm. Bei 81 Patienten (46,6%) war die HD größer als die MLV, bei 24 Patienten (13,8%) waren HD gleich MLV und bei 69 Patienten (39,6%) war die MLV größer als die HD. 52% der Patienten verstarben nach der Operation, 29% hatten gute bis befriedigende Resultate, 19% hatten ein schlechtes postoperatives Ergebnis. Die logistische Regression ergibt eine Überlebensrate von 50% für Patienten mit HD bis 1,23 cm und einer MLV von 1,13 cm. Ab einer MLV von 2 cm fällt die Überlebenswahrscheinlichkeit weiter ab und ist bei MLV größer 2,90 cm unter 25%. Bei einer HD, die größer als 0,45 cm als die zugehörige MLV ist, beträgt die Überlebensrate 50%. Der Glasgow Outcome Score korreliert signifikant mit diesen Parametern.SchlußfolgerungenDie Parameter HD, LV und die Differenz aus beiden erlauben somit eine gute Prognose für postoperativen Outcome und die Überlebensrate bei Patienten mit ASH. Dies erlaubt auch eine Einschätzung der Prognose dieser Patienten anhand der CT-Bilder an Bildübertragungssystemen, die Teil der neurochirurgischen konsiliarischen Tätigkeit sind.SummaryBackgroundThe necessity for this retrospective study was derived from the fact that the patients admitted were more often intubated, sedated, and artificially ventilated, which excludes neurological examination.MethodsFrom 164 patients after acute subdural hematoma (ASH) computer tomographic data were analysed statistically to extract parameters which could be evaluated independently from clinical and neurological status to estimate outcome. Hematoma thickness (HT), midline shift (MLS) and their difference were documented.ResultsIn operated patients HT ranges from 0.5 to 3.5 cm and the MLS was 0 to 3.3 cm. In 81 (46.6%) HT was greater than MLS, in 24 patients (13.8%) HT equals MLS, and in 69 patients (39.6%) MLS exceeds HT. 52% of the patients died after operation, in 29% we obtained good or satisfying results, 19% were in poor condition after therapy. Using logistic regression the outcome can be estimated if more than 70% the basal cisterns were demonstrable in CT. The logistic regression proved that survival is 50% only for HT about 1.23 cm and MLS at 1.13 cm. For MLS greater than 2 cm the survival function drops and is lower than 25% for MLS greater than 2.90 cm. If HT exceeds MLS by 0.45 cm survival is 50%. The Glasgow Outcome Scores correlate significantly with these parameters.ConclusionThe parameters, which are degree of representation of basal cisterns, HT, MLS and difference between HT and MLS allow robust/adequate estimation of survival function and outcome in patients suffering from ASH. Based upon these data, presumingly operation could be indicated by means of videoconferences i.e. without examination of the patients personally.

Assessment of Prognosis and Indication for Surgery on the Basis of Cluster Analysis in Intracerebral Hematomas

Although the surgical evacuation of intracerebral hematomas is rather common, there is still considerable controversy regarding the indications for this treatment [2, 4, 5, 7]. The clinical trial of McKissock et al. [3] more than 30 years ago suggested that conservative treatment is preferable in most cases. Their conclusion was mainly due to the rather poor surgical outcomes of that time and not attributable to particularly successful medical therapy. In the meantime, the diagnosis has been facilitated by the availability of the computed tomographic (CT) scan. This has led to the improvement of the operative treatment owing to the better assessment of size and location of the lesion by CT imaging. Less invasive techniques, such as small craniectomies combined with stereotaxic or ultrasonic retrieval necessitating only minimal cortical incisions, have been developed. It can be assumed that this progress has made the results of this early clinical trial obsolete. However, more recent randomized trials are not available. Therefore we performed a retrospective study to answer the question of when to operate and when to treat conservatively. Like all retrospective trials, our study has the inevitable deficiency that no randomization was performed. To compensate for this, we performed a cluster analysis. This statistical procedure allows for objective grouping of the patients on the basis of clinical data. Thus it is possible to compare the results of conservative and surgical treatment within homogeneous groups of patients.

The Effect of Nimodipine on Cerebral Blood Flow Autoregulation

Experimental and clinical investigations show that the cerebrovascular calcium antagonist, nimodipine, a dihydropyridine derivative, increases the cerebral blood flow (CBF) (5, 8, 11, 13). The effect is attributed to a loss of contractibility of the major vessels of the brain (16) and to a dilatation of the pial vessel (1). Cerebral autoregulation is an adaptive reaction which maintains the blood flow to the brain nearly constant in spite of variations in cerebral perfusion pressure (15). Autoregulation depends on the responsiveness of the cerebral arteries and the cerebral microvasculature to changes in the arterial blood pressure (9). With mean arterial blood pressures above the lower limit of autoregulation, the CBF is maintained by constriction of cerebral arteries and microvessels (9). Conceivably, an agent which inhibits smooth muscle contraction of the vessels by blocking the calcium influx might impair the cerebral autoregulation. Although important for clinical decisions, the effects of nimodipine on cerebral autoregulation have not been clarified up to now.