Matthias Preuss

Updated physiology and pathophysiology of CSF circulation—the pulsatile vector theory

IntroductionHydrocephalus is still a not well-understood diagnostic and a therapeutic dilemma because of the lack of sufficient and comprehensive model of cerebrospinal fluid circulation and pathological alterations.ConclusionsBased on current studies, reviews, and knowledge of cerebrospinal fluid dynamics, brain water dynamics, intracranial pressure, and cerebral perfusion physiology, a new concept is deducted that can describe normal and pathological changes of cerebrospinal fluid circulation and pathophysiology of idiopathic intracranial hypertension.

Spontaneous Intracerebral Hemorrhage With Ventricular Extension and the Grading of Obstructive Hydrocephalus: The Prediction of Outcome of a Special Life-Threatening Entity

BACKGROUND:Primary spontaneous intracerebral hemorrhage (SICH) with secondary intraventricular hemorrhage (IVH) accounts for the highest in-hospital mortality after stroke. OBJECTIVE:To analyze predictors and the role of acute hydrocephalus in outcome, especially 30-day mortality or an unfavorable outcome at 6 months. In addition, a new risk stratification tool for SICH- IVH was developed. METHODS:Hospital charts of 104 of 110 SICH-IVH patients were retrospectively analyzed. All patients underwent at least 1 external ventricular drainage. Multivariate logistic regression analysis was used to identify independent prognostic predictors for 30-day mortality and outcome. Outcome was determined by the modified Rankin Scale. On the basis of the independent predictors, we developed an IVH scoring system. The IVH score was tested with prospective data from 51 patients and was compared with established intracerebral hemorrhage scoring systems. RESULTS:An initial SICH volume of 60 cm3 or greater, severe hydrocephalus, Glasgow Coma Scale score of 8 or less, and age 70 years and older were independent outcome predictors. Different cutoff values for the prediction of 30-day mortality and functional outcome were defined. The IVH score was best for the prediction of 30-day mortality. CONCLUSION:Severe hydrocephalus is an independent predictor of 30-day mortality in SICH with ventricular extension. The IVH score is a simple and reliable tool for predicting 30-day mortality.

Diffusion-weighted MRI reflects proliferative activity in primary CNS lymphoma

Purpose To investigate if apparent diffusion coefficient (ADC) values within primary central nervous system lymphoma correlate with cellularity and proliferative activity in corresponding histological samples. Materials and Methods Echo-planar diffusion-weighted magnetic resonance images obtained from 21 patients with primary central nervous system lymphoma were reviewed retrospectively. Regions of interest were drawn on ADC maps corresponding to the contrast enhancing parts of the tumors. Biopsies from all 21 patients were histologically analyzed. Nuclei count, total nuclei area and average nuclei area were measured. The proliferation index was estimated as Ki-67 positive nuclei divided by total number of nuclei. Correlations of ADC values and histopathologic parameters were determined statistically. Results Ki-67 staining revealed a statistically significant correlation with ADCmin (r = -0.454, p = 0.038), ADCmean (r = -0.546, p = 0.010) and ADCmax (r = -0.515, p = 0.017). Furthermore, ADCmean correlated in a statistically significant manner with total nucleic area (r = -0.500, p = 0.021). Conclusion Low ADCmin, ADCmean and ADCmax values reflect a high proliferative activity of primary cental nervous system lymphoma. Low ADCmean values—in concordance with several previously published studies—indicate an increased cellularity within the tumor.

Adult long-term health-related quality of life of congenital hydrocephalus patients.

OBJECT Congenital hydrocephalus has a major impact on the lives of patients and their relatives, as well as their long-term neurological development and social integration. The aim of this study was to assess the self-reported health-related quality of life (HRQOL) of patients after reaching adulthood. METHODS A total of 31 patients who required CSF shunt treatment for congenital hydrocephalus within the 1st year of life (between 1963 and 1987) agreed to undergo a structured SF-36 self-assessment. An age-matched German standard cohort was used as control. Additional parameters of surgical, social, and global neurological outcome were analyzed. The mean patient age was 35 years (range 26-51 years, 13 females and 18 males). Hydrocephalus etiologies were posthemorrhagic hydrocephalus (n = 9), postinfectious hydrocephalus (n = 5), aqueductal stenosis (n = 10), myelomeningocele (n = 2), and unknown cause (n = 5). RESULTS The mean modified Rankin Scale score was 1.6 (range 0-4). Hydrocephalic patients achieved lower scores for the SF-36 items physical functioning (70.5 vs. 93.5, p < 0.05), physical role functioning (74.2 vs. 88.3, p < 0.05), and general health perceptions (64.5 vs. 72.3, p < 0.05). Emotional, social role functioning, and mental health items did not differ between the groups. Assessment of vitality and pain resulted in a trend to worse values. Whereas the Physical Component Summary score was lower (46.1 vs. 54.3, p < 0.05), the Mental Component Summary score was not significantly different (50.2 vs. 48.7, p = 0.3). There was neither a statistically significant difference between subgroups of different etiologies nor an association with the number of subsequent hydrocephalus-related surgeries. CONCLUSIONS Adult HRQOL for patients with congenital hydrocephalus appears to be similar to that for healthy con with regard to mental health and social functioning aspects. Physical impairment is a predominant factor of compro quality of life.

Operative management of idiopathic spinal intradural arachnoid cysts in children: a systematic review.

BackgroundSpinal intradural arachnoid cysts are rare with only a few patients reported so far. Idiopathic, traumatic, posthemorrhagic, and postinflammatory causes have been reported in the literature. Especially, idiopathic lesions, in which other possible etiological factors have been ruled out, seem to be rare.Patients and MethodsWe systematically reviewed the literature in regards to localization within the spinal canal, treatment options, complications, and outcome. Additionally, we present management strategies in two progressively symptomatic children less than 3 years of age with idiopathic intradural arachnoid cysts.ResultsIn total, 21 pediatric cases including the presented cases have been analyzed. Anterior idiopathic spinal arachnoid cysts are predominantly located in the cervical spine in 87.5 % of all cases, whereas posterior cysts can be found at thoracic and thoracolumbar segments in 84.6 % of the patients. Most children presented with motor deficits (76.2 %). Twenty-five percent of anterior spinal arachnoid cysts caused back pain as the only presenting symptom. Open fenestration by a dorsal approach has been used in the vast majority of cases. No major surgical complications have been reported. Ninety-four percent of all patients did improve or showed no neurological deficits. Recurrence rate after successful surgical treatment was low (9.5 %).ConclusionIdiopathic spinal intradural arachnoid cysts can present with neurological deficits in children. Pathologies are predominantly located in the cervical spine anteriorly and in thoracic and thoracolumbar segments posteriorly to the spinal cord. In symptomatic cases, microsurgical excision and cyst wall fenestration via laminotomy are recommended. Our radiological, intraoperative, and pathological findings support the cerebrospinal fluid obstruction and vent mechanism theory of arachnoid cysts.

Assessment of parameters influencing the blood flow velocities in cerebral arteries of the rat using ultrasonographic examination

Abstract Objectives: Rat models of cerebrovascular diseases are used for a variety of human pathologies comprising ischemic stroke or subarachnoid hemorrhage. Whereas in neuro-intensive care, Doppler ultrasonographic examination of major cerebral arteries is a common diagnostic tool, only few data exist concerning the animal model. We therefore studied cerebral blood flow velocities in the rat by ultrasonographic triplex mode. Methods: Female Wistar rats underwent a large craniectomy and baseline values for blood flow velocities were obtained by 399 examinations in 52 animals. Vessel diameters were assessed by 301 examinations in 39 animals. Finally, in 26 animals, continuous measurements of blood flow velocities were performed. For a duration of more than 30 minutes, values in the anterior trunk, the left carotid artery and the basilar artery were obtained every 60-90 seconds with simultaneous detection of heart rate. Results: Blood flow velocities in the anterior part of cerebral circulation were faster than those in the posterior part and showed higher standard deviation. Flow velocities in arteries belonging to the anterior circulation changed in relation to carotid flow velocity and heart rate, whereas the velocity in the basilar artery showed much lower correlation to carotid flow velocity or heart rate. Discussion: Ultrasonographic triplex mode examination of cerebral vessels offers a reproducible method to study rat cerebral blood flow velocities and vessel diameters. In combination with monitoring of systemic hemodynamic parameters, it can provide a detailed description of the vascular response to drugs, experimental stroke or subarachnoid hemorrhage.

Metastatic tumours mimicking vestibular schwannoma

In this review of the literature we discuss the rare occurrence of metastatic tumours mimicking bilateral vestibular schwannoma and present an own case with pancreatic signet-ring cell carcinoma as primary tumour.

The Prediction of 30-Day Mortality and Functional Outcome in Spontaneous Intracerebral Hemorrhage with Secondary Ventricular Hemorrhage: A Score Comparison

The original ICH (oICH) score was tested in different populations and showed good accuracy in the prediction of outcome and 30-day mortality after spontaneous ICH. The oICH was developed to stratify patients with all types of spontaneous intracerebral hemorrhage (SICH). Several modifications of the oICH score exist in the literature.In the current study, we tested the oICH score, two modified ICH scores, and the IVH score on a cohort of 171 patients with SICH and mandatory secondary intraventricular hemorrhage (IVH). Receiver-operating characteristic (ROC) curves were plotted, and the areas under the curves (AUC) were calculated for each score.The calculated AUCs for the prediction of 30-day mortality in the cohort were 0.736, 0.816, 0.805, and 0.836 for the original ICH, the mICH-A, the mICH-B, and the new IVH score, respectively. The best AUC for functional outcome was observed for the mICH-B score (0.823). For the mICH-A and the IVH score, an AUC of 0.811 was calculated.The scores that include the quantification of IVH or the grading of hydrocephalus show good accuracy in the prediction of 30-day mortality and functional outcome at 6 months in SICH with secondary IVH.

Cerebrospinal Fluid Lactate Concentration After Withdrawal of Metabolic Suppressive Therapy in Subarachnoid Hemorrhage

Hyperglycolysis is a known phenomenon after severe subarachnoid hemorrhage (SAH) and after brain injury. It is characterized by decreased oxidative metabolism and relatively increased anaerobic glycolysis. Metabolic suppressive therapy reduces the cerebral metabolic rate of oxygen (CMRO(2)) and the cerebral metabolic rate of glucose (CMRGluc). If CMRO(2) is suppressed after SAH, withdrawal of metabolic suppressive therapy could lead to the accumulation of lactate. In this project, we assessed the relationship between the withdrawal of metabolic suppressive therapy and cerebrospinal fluid (CSF) lactate concentration. A prospective observational database containing 262 patients with SAH was retrospectively analyzed. CSF lactate levels were compared with the daily dose of metabolic suppressive therapy. Outcome was assessed with the Glasgow Outcome Scale (GOS). In 56% of patients an increase in CSF lactate (mean: 3.2 ± 0.9 mmol/L) after withdrawal of metabolic suppressive therapy was observed. Mean Glasgow Outcome Score (GOS) was lower in patients with an increase in CSF lactate concentration (>0.5 mmol/L) after withdrawal of metabolic suppressive therapy (p = 0.095). In 88% of patients who died during the first 30 days after SAH, a CSF lactate elevation of more than 0.5 mmol/L after withdrawal of metabolic suppressive therapy was found (p = 0.071).

Pathophysiology and Treatment Options in Trigeminal Meningoceles

Trigeminal meningoceles, lateral to the maxillary nerve (V2), have seldom been reported as underlying pathology for spontaneous rhinoliquorrhea. In contrast to sphenoid meningoceles arising from a persistent lateral craniopharyngeal canal (Sternberg–Cruveilhier, medial to V2), their occurrence seems to be generated by addition of erosive processes to the constitutively thin bony shell underneath the semilunar ganglion, lateral to the round foramen (and V2). The developmental and anatomical relationships of trigeminal meningoceles to the sphenoid bone are depicted, and in a review of the literature we present the different surgical approaches employed for sealing the dura leak. In view of these techniques we discuss an unusual case of therapy-resistant rhinoliquorrhea with left-sided trigeminal meningocele involving the Meckel cave at the lateral sphenoid and reaching the superior orbital fissure and the medial orbital space. In contrast to patients who have lateral sphenoidal meningoceles with a persistent lateral craniopharyngeal canal (Sternberg–Cruveilhier), who can be treated successfully using an endoscopic transsphenoidal approach (recurrence rate 13.7%), the recurrence rate of cerebrospinal fluid (CSF) efflux for trigeminal meningoceles lies much higher (endoscopically 66%, open craniotomy 33%). The surgical strategy thus has to be chosen individually, taking into account specific anatomical situations and eventually preceding operations.