Biomedical subjects

A Aschoff

Publications and source records attributed to A Aschoff.

At least 19 recordsLinked to original sources

PubMed2006

DNA fragmentation in chronic glomerulonephritis: an immunohistological analysis.

BACKGROUND: Experimental data suggest that apoptosis plays an important pathophysiological role in glomerulonephritis by restoring tissue structure after proliferation of intrinsic renal cells and infiltration of leukocytes. Relatively little is known of apoptosis in human glomerulonephritis, particularly in predicting renal function during follow-up. METHODS: In order to colocalize different markers for cell damage in renal tissue from patients with different forms of glomerulonephritis (GN), a series of semithin sections from 34 kidney biopsies were studied retrospectively. Normal kidney from a nephrectomy specimen with a small renal adenocarcinoma served as a control. DNA fragmentation, expression of tissue transglutaminase II, BAX and BCL-2 were visualized immunohistochemically. In some renal biopsies, immunohistochemical staining for activated caspase 3 was performed. Proinflammatory markers (C-reactive protein, leukocytes), serum creatinine, creatinine clearance, total proteinuria, albuminuria, alpha(1)-microglobulin and IgG excretion were determined at the time of biopsy. Serum creatinine and total proteinuria were assessed 6 and 12 months after renal biopsy. RESULTS: Nuclei with different degrees of DNA fragmentation were mainly found in epithelial cells of tubules, but also in glomerular cells, regardless of the form of GN studied. Transglutaminase II expression was found only in cells with a strong staining for DNA fragmentation. DNA fragmentation localized to glomerular cells was more pronounced in proliferative than in non-proliferative forms of GN, being most abundant in patients with rapid progressive GN. Staining for activated caspase 3 in selected biopsies confirmed the presence of apoptosis. BAX and BCL-2 staining was detected within the same cells, but exhibited a different intracellular distribution. In proliferative GN, the extent of DNA damage in tubular epithelial cells significantly corresponds with the concentration of serum creatinine (p < 0.04) and with urinary excretion of alpha(1)-microglobulin (p < 0.01) at the time of biopsy. A significant correlation (p < 0.01) was seen between glomerular DNA fragmentation and follow-up total proteinuria 12 months after biopsy for proliferative forms of GN. The damaged glomerular area (e.g. mesangial sclerosis) significantly correlated with DNA fragmentation in proliferative, but not in nonproliferative GN at the time of biopsy. Furthermore, glomerular damaged showed a significant correlation with tubular DNA damage in proliferative GN. CONCLUSION: In glomerular cells, apoptosis may be important for the clearance of proliferating cells whereas in tubules, cell damage showed dependence on the degree of tubular injury mediated by inflammation and/or proteinuria. Although the degree of apoptosis in tubular cells correlates with serum creatinine in proliferative GN at the time of biopsy, it is of limited use to predict future renal function.

Adult↗

PubMed2005

3D ultrasound navigation in syrinx surgery - a feasibility study.

BACKGROUND: The prototype of a 3D ultrasound navigation system, with a trackable 4- to 8-MHz phased-array ultrasound probe was used in syrinx-surgery. The aim of this study was to evaluate the advantages offered by 3D ultrasound and navigation in syringomyelial surgery. METHODS AND MATERIALS: After laminectomy, with a free-handed tilt of the ultrasound probe, the 3D volume of the target area is acquired within 15 seconds. The data are visualized after reconstruction in an axial, coronal, and sagittal view, offering the possibility of ultrasound-based guided surgery. RESULTS: Based on the intraoperative volume information, it was possible to navigate with the 3D ultrasound images in all cases. The orientation and image quality with respect to resolution, spatial information, and the identification of anatomical structures facilitated the surgery in all seven cases. The navigation tool, with a length of 12 cm and a tip diameter of 1 mm, was simple to place into the surgical site. The availability of an up-to-date 3D-image resulted in less interruption of the surgical procedure, with no need to repeatedly fill the cavity with sterile saline for new ultrasound acquisitions. New ultrasound images were only required if shift occurred. The coronal and "trajectory-plane" views, offer additional information about the syrinx cavity. The target borders are easier to determine and orientation in separated cavities was possible. Particularly in syringomyelial surgery it was helpful to determine the surface point of the syrinx to place the myelotomy or insert a catheter. CONCLUSION: 3D ultrasound offers the advantages of visualizing the third dimension of the target. For orientation and border determination navigation within the 3D ultrasound volume is very helpful and can take place with the ultrasound probe out of the way. Any disruption in the surgical procedure is minimized by not having to repeatedly fill the cavity with a sterile saline solution, there are fewer difficulties with image orientation because of new image adjustments.

Cervical Vertebrae↗

PubMed2004

[Spontaneous intracerebral hemorrhages].

Spontaneous intracerebral hemorrhage (ICH) accounts for 8-15% of all cases of stroke and among patients receiving oral anticoagulants this number increases up to 40%. Mortality and morbidity are considerably higher in patients with ICH compared to patients with ischemic stroke. Large randomized controlled trials provide only little evidence for therapeutic strategies in patients with spontaneous ICH. In this review we summarize the available data and give recommendations on the management of spontaneous ICH.

Administration, Oral↗

PubMed2004

Visually evoked changes of blood flow velocity and pulsatility index in the posterior cerebral arteries: a transcranial Doppler study.

OBJECTIVE: Transcranial Doppler sonography (TCD) can detect visual evoked blood flow responses non-invasively and continuously with high temporal resolution. While the mean flow velocity response to visual stimuli is well documented, the response of the pulsatile characteristics of the waveform is less well known. METHOD: We examined the changes of blood flow velocity and pulsatility index (PI) in the posterior cerebral artery (PCA) in 50 healthy volunteers. TCD responses were measured in response to metabolic activation of the visual cortex by visual stimulation. RESULTS: A specific, stimulus-related increase of the mean flow velocity (MFV) in the PCA was found. The intensity of the blood flow response was significantly influenced by the complexity of the stimulus. During complex visual stimulation we found a mean flow velocity (MFV) increase of 29.4 % from the baseline in the subjects. However, a stimulus-related decrease was observed in the pulsatility index (PI); although the mean PI with closed eyes during baseline measurement was 1.18 (SD 0.27), on average, it fell significantly to 0.95 (SD 0.23) with the alternating chessboard and 0.82 (SD 0.22) during the complex stimulus condition. The relative decrement of the pulsatility index with increasing complexity of the visual stimulus is highly significant, with values of -19.5 % and -30.5 % compared to the baseline. CONCLUSION: These findings demonstrate the inverse correlation between MFV response and pulsatility index in the PCA. We assume that this decrease of the PI in the PCA may reflect the reduced regional vascular resistance in the visual cortex during visual stimulation.

Adult↗

PubMed2002

[Current concepts of intensive care of space-occupying middle cerebral artery infarct].

The aim of this paper is to review new developments in the intensive care of patients with space-occupying middle cerebral artery infarctions. Elevated blood pressure should not be treated; however, there is no scientific basis to induce arterial hypertension in these patients. It is not recommended generally to nurse the patients in a position with the head elevated. If therapy is targeted for an optimum cerebral perfusion pressure, the patients should be nursed in a flat position. Decompressive surgery is associated with a marked reduction in an otherwise high mortality. The functional outcome after surgery is similar to the outcome of the survivors after conventional treatment alone. Treatment options for an acutely raised intracranial pressure are mannitol or hypertonic saline solutions, although the long-term effects have not been ascertained yet. There is not enough evidence supporting a prophylactic standard therapy with hypertonic solutions. Patients who require artificial ventilation can be safely ventilated using PEEP or an inverse inspiration/expiration ratio, if the blood pressure is monitored and a possible drop of the arterial blood pressure is treated. Corticoids and hemodilution are obsolete therapies in these patients.

Blood Pressure↗

PubMed2002

Hemicraniectomy and moderate hypothermia in patients with severe ischemic stroke.

BACKGROUND AND PURPOSE: We compared the clinical course of 36 consecutive patients with severe acute ischemic stroke (more than two thirds of the middle cerebral artery territory) treated with hemicraniectomy (CE; n=17) or moderate hypothermia (MH; n=19) in terms of intracranial pressure control, mortality, and specific treatment parameters. METHODS: Over a period of 18 months, patients with severe ischemic stroke were treated with CE when the nondominant hemisphere was affected and with MH when the dominant hemisphere was affected. MH (33 degrees C) was induced with either cold blankets and fans (n=11) or endovascular cooling (n=8). Intracranial pressure was monitored invasively in all cases. RESULTS: Age, sex, cranial CT findings, level of consciousness, and time to treatment were similar between the 2 groups; significant differences were noted in National Institute of Health Stroke Scale (NIHSS) score (20 [range, 18 to 22] and 17 [range, 16 to 18] for MH and CE, respectively) but were not present when NIHSS score was corrected for aphasia (17 [range, 15 to 19] and 17 [range, 16 to 18] for MH and CE, respectively). Mortality was 12% for CE and 47% for MH; 1 patient treated with MH died as a result of treatment complications (sepsis) and 3 of intracranial pressure crises that occurred during rewarming. Duration of mechanical ventilation and of neurological intensive care unit stay did not significantly differ, but duration of catecholamine application and maximal catecholamine dosage were significantly higher in the MH group. CONCLUSIONS: In patients with severe ischemic stroke, CE results in lower mortality and lower complication rates compared with MH. Both treatment modalities, however, are associated with intensive medical treatment and a prolonged stay in the neurological intensive care unit.

Adult↗

PubMed2001

Effect and feasibility of controlled rewarming after moderate hypothermia in stroke patients with malignant infarction of the middle cerebral artery.

BACKGROUND AND PURPOSE: Moderate hypothermia has been found to reduce intracranial pressure (ICP) significantly in patients who have severe middle cerebral artery infarction. However, during passive rewarming, ICP continuously rises and some patients suffer transtentorial herniation. METHODS: We investigated the question of whether slower rewarming leads to slower increase in ICP and slower decrease in cerebral perfusion pressure (CPP). Furthermore, we studied feasibility of slow, controlled rewarming. ICP, CPP, and core body temperature were monitored continuously. Achievement of rewarming protocol was assessed by hit rate of temperature target intervals. Side effects of hypothermia were assessed. RESULTS: Rates of change of both ICP and CPP were correlated significantly with increase in temperature (ICP r=0.62, P=0.002; CPP r=-0.50, P=0.017). In feasibility analysis of 13 controlled rewarmed patients, hit rate of temperature target intervals was 63% (median; range 48% to 81%); hit rate within the target interval or below was 79% (median; range 62% to 94%). CONCLUSIONS: Slow, controlled rewarming is feasible and may be used for ICP and CPP control after moderate hypothermia for space-occupying infarction.

Body Temperature↗

PubMed2001

Damaged myocytes as detected by the colocalization of DNA fragmentation and tissue transglutaminase and their prognostic significance in enterovirus-associated dilated cardiomyopathy.

BACKGROUND: Apoptotic cardiac myocytes have been described in chronic heart failure, but no data exist on the relationship between these 'damaged' myocytes and myocardial detection of enterovirus RNA often associated with dilated cardiomyopathy (DCM). DESIGN: In patients with idiopathic DCM, endomyocardial biopsy samples were studied for enteroviral RNA by one step reverse transcription-polymerase chain reaction (PCR) and a subsequent hybridization of the PCR product using a Southern blot technique. The endomyocardial biopsies were further investigated for markers of cell damage and apoptosis: DNA fragmentation and expression of tissue-transglutaminase (TTG) in the myocytes using the in-situ endlabelling method or an anti-TTG-staining, respectively. To assess the prognostic significance of these two markers the correlation between the percentage of myocytes positive both for DNA fragmentation and TTG (the index of damaged myocytes) and the hemodynamic course of the patients during a mean follow-up period of 15.9 +/- 6.2 months was investigated prospectively by echocardiography. RESULTS: In 14 (45%) of the 31 patients with idiopathic DCM, enteroviral RNA was found in the endomyocardial biopsy samples, while 17 patients (55%) were enterovirus-negative. In enterovirus-positive patients, the index of 'damaged' myocytes was significantly lower (10.7 +/- 4.9% vs. 19.2 +/- 8.8%, P = 0.002) and the left ventricular ejection fraction (LVEF) improved significantly (P = 0.00017 vs. P = 0.13) during long-term follow-up. In addition, a weak negative correlation was seen between the index of damaged myocytes and the changes in LVEF in all patients during long-term follow-up (r = - 0.48, P = 0.004). CONCLUSION: Our results favour the view that enterovirus-positive patients with DCM have less damaged myocytes and a better haemodynamic course than enterovirus-negative patients.

Adult↗

PubMed2001

Neurometabolic changes during treatment with moderate hypothermia in a patient suffering from severe middle cerebral artery infarction.

Microdialysis is a means of measuring neurochemical changes in the extracellular space and has been applied in acute brain trauma, subarachnoid hemorrhage and stroke patients. In this study, we monitored neurochemical changes in the extracellular space using microdialysis in a patient with left-sided hemispheric infarction treated with moderate hypothermia (33 degrees C). Microdialysis probes were obtained from the infarcted and noninfarcted hemisphere during hypothermia and rewarming. Concentrations of extracellular substances in the infarcted hemisphere (glutamate, glycerine, lactate/pyruvate) decreased with hypothermia and remained stable (glutamate) or increased (glycerine, lactate/pyruvate) during rewarming. Concentrations of these substances in the noninfarcted hemisphere remained at normal levels. Microdialysis monitoring of therapeutic hypothermia in severe hemispheric infarction might be a useful additional monitoring tool to assess the status of the brain and to predict further deterioration.

Adult↗

PubMed2001

Multimodal online monitoring in middle cerebral artery territory stroke.

BACKGROUND AND PURPOSE: Patients with large middle cerebral artery infarction and elevated intracranial pressure (ICP) who are undergoing invasive intensive care therapy require technical monitoring. However, the effectiveness of the current gold standard, measurement of ICP, is limited. Furthermore, the effects of what is considered to be standard antiedema medical treatment are not fully understood. We studied whether multimodal monitoring can help to overcome this problem. METHODS: ICP, cerebral perfusion pressure (CPP), and partial brain tissue oxygen pressure (PbrO(2)) were continuously measured within the white matter of the frontal lobe unilaterally or bilaterally. We analyzed the effects of antiedema drugs and looked for pattern changes in the PbrO(2) before transtentorial herniation in patients in whom this could not be prevented. Furthermore, complications were registered. RESULTS: We performed 27 measurements in 21 patients. A total of 297 antiedema drug administrations were analyzed in 11 patients. Hyper-HAES and mannitol were most often associated with an increase in CPP and PbrO(2), whereas the use of thiopental and tromethamine led to negative or contrary effects, although ICP was decreased in every case. Pattern changes in the PbrO(2) curve could be observed between 6 to 18 hours before transtentorial herniation. No bleeding complication or infections were observed. CONCLUSIONS: Multimodal monitoring can be used to monitor antiedema drug effects. Our data suggest that with multimodal monitoring, pathophysiological changes could be predicted considerably in advance. ICP alone is of questionable use. Furthermore, this method might help to optimize the timing of invasive therapy in space-occupying infarction.

Brain Edema↗

PubMed2001

Suboptimum hemicraniectomy as a cause of additional cerebral lesions in patients with malignant infarction of the middle cerebral artery.

OBJECT: The goal of this study was to determine the frequency of hemicraniectomy-associated lesions and their potential effect on the risk of mortality in patients suffering from malignant infarction of the middle cerebral artery MCA). METHODS: The authors evaluated serial computerized tomography scans obtained in 60 patients with complete infarction of the right MCA who were treated using hemicraniectomy. The maximum diameter of the hemicraniectomy was determined and the hemicraniectomy-associated lesions were classified as ischemic lesions or hemorrhages. The category of hemorrhages was composed of parenchymal, subdural, or epidural/subgaleal hematomas. Parenchymal hemorrhages and infarcts associated with hemicraniectomy occurred with frequency rates of 41.6% and 28.4%, respectively. The occurrence of hemicraniectomy-associated bleeding was related to the size of the hemicraniectomy performed; that is, the smaller the hemicraniectomy, the more often lesions occurred (p < 0.05). Hemicraniectomy-associated bleeding was also related to an increased risk of mortality. CONCLUSIONS: Hemicraniectomy is an effective therapy in patients with malignant infarction of the MCA. However, a hemicraniectomy that is too small in diameter may cause the formation of additional lesions and adversely affect the risk of mortality and the quality of survival. In addition, the size and shape of the edges of the bone defect are important factors relating to its efficacy.

Adult↗

PubMed2000

Incidence and prognostic significance of fever following intracerebral hemorrhage.

OBJECTIVE: To investigate the incidence and prognostic significance of fever on presentation and during the subsequent 72 hours in patients with spontaneous supratentorial intracerebral hemorrhage (ICH). METHODS: We analyzed 251 patients. On admission, body temperature, Glasgow Coma Scale (GCS) score, age, sex, blood pressure, blood glucose level, and presumed origin of hemorrhage were analyzed. From the initial CT scan, hematoma volume, location, and presence of intraventricular hemorrhage were determined. From the first 72 hours, hematoma enlargement, duration of increased temperatures, blood pressure, and blood glucose level were determined. Outcome was classified on discharge with the Glasgow Outcome Scale (GOS) score. RESULTS: Outcomes included no symptoms in 23 (9%), moderate disability in 64 (26%), severe disability in 104 (41%), vegetative state in 5 (2%), and death in 55 (22%) patients. Prognostic factors retained from a logistic regression model with a dichotomized GOS scale (GOS score of 1 or 2 versus GOS score of 3 to 5) as response variables were GCS score of 7 or less, age older than 75 years, hematoma volume of more than 60 cm3, ventricular hemorrhage, and presence of a coagulation disorder (p < 0.05). Fever was associated with intraventricular hemorrhage. From 196 patients, data from the first 72 hours were analyzed. A total of 18 patients (9%) had normal temperatures throughout the study. The duration of fever (> or =37.5 degrees C) was less than 24 hours in 66 (34%), 24 to 48 hours in 70 (36%), and more than 48 hours in 42 patients (21%). Independent prognostic factors during the first 72 hours were duration of fever, secondary hemorrhage, GCS score of 7 or less, ventricular hemorrhage, hematoma volume of more than 60 cm3, duration of increased blood pressure of more than 48 hours, and duration of increased blood glucose of more than 48 hours. CONCLUSIONS: The incidence of fever after supratentorial ICH is high, especially in patients with ventricular hemorrhage. In patients surviving the first 72 hours after hospital admission, the duration of fever is associated with poor outcome and seems to be an independent prognostic factor in these patients.

Adult↗

PubMed2000

MRI in the diagnosis of small bowel disease: use of positive and negative oral contrast media in combination with enteroclysis.

The aim of the study was to evaluate the additional findings of MRI following small bowel enteroclysis and to compare the efficacy of negative and positive intraluminal contrast agents. Fifty patients with inflammatory or tumorous small bowel disease were investigated by small bowel enteroclysis and consecutive MRI using breathhold protocol (T1-weighted fast low-angle shot, T2-weighted turbo spin echo). Patients were randomly assigned to either receiving a positive oral (Magnevist, Schering, Berlin, Germany) or a negative oral MR contrast media (Abdoscan, Nycomed, Oslo, Norway). The pattern of contrast distribution, the contrast effect, presence of artifacts, as well as bowel wall and extraluminal changes, were determined and compared between the contrast type using Fischer's exact test. Sensitivity, specificity, and diagnostic accuracy for MRI and enteroclysis were calculated. Twenty-seven patients had clinically proven Crohn's disease and two patients surgically proven small bowel tumours. Magnetic resonance imaging had important additional findings as abscesses and fistulae in 20 patients. Surgically compared sensitivities were 100 and 0% for MRI and enteroclysis, for the detection of abscesses, and 83.3 and 17 % for the diagnosis of fistulae, respectively. Bowel wall thickening was more reliably detected with use of positive oral contrast media without intravenous enhancement (p < 0.001), whereas postcontrast negative oral contrast media allow for a superior detection (p < 0.001). T2-weighted sequences were necessary with use of negative oral contrast media, because loop abscesses may be masked. Magnetic resonance imaging should be performed in all patients with suspicion of extraintestinal complications, because the complications are more reliably detected by MRI. Negative oral contrast media show advantages with the use of intravenous contrast but can mask loop abscesses using only T1-weighted imaging.

Abscess↗

PubMed2000

Use of scanning electron microscopy to investigate the prophylactic efficacy of rifampin-impregnated CSF shunt catheters.

Infection continues to be one of the major complications of cerebrospinal fluid (CSF) shunting procedures, and is caused mainly by skin-derived bacteria. Production of an extracellular biofilm plays an important role in the pathogenesis of shunt-associated infections by protecting bacteria from immune mechanisms and antibiotics. So far, removal of the original shunt and implantation of a new shunting device has been the only successful treatment for most patients. As an alternative strategy to prevent CSF infections, a rifampin-impregnated silicone catheter was designed to provide high initial and long-lasting (>60 days) release of bactericidal drug. To investigate the pathophysiological mechanism of its function, this new device was investigated both in vitro and in a rodent model of CSF infection by scanning electron microscopy (SEM) and bacterial culture. Staphylococcus epidermidis (10(8) cfu/ml) and S. aureus (10(4) cfu/ml) served as test strains. SEM demonstrated that, in contrast to the unloaded catheters, initial bacterial adherence on the catheter surface could be reduced to a few single cells, which did not show visible signs of proliferation. Bacterial cultures obtained simultaneously were all sterile, showing that adherent bacteria were killed immediately by the rifampin released from the catheter. Although rifampin incorporation into silicone polymers was not able to prevent initial bacterial adhesion completely, subsequent colonisation could be prevented.

Animals↗

PubMed1999

The scientific history of hydrocephalus and its treatment.

Hydrocephalus cases were regularly described by Hippocrates, Galen, and early and medieval Arabian physicians, who believed that this disease was caused by an extracerebral accumulation of water. Operative procedures used in ancient times are neither proven by skull findings today nor clearly reported in the literature. Evacuation of superficial intracranial fluid in hydrocephalic children was first described in detail in the tenth century by Abulkassim Al Zahrawi. In 1744, LeCat published findings on a ventricular puncture. Effective therapy required aseptic surgery as well as pathophysiological knowledge--both unavailable before the late nineteenth century. In 1881, a few years after the landmark study of Key and Retzius, Wernicke inaugurated sterile ventricular puncture and external CSF drainage. These were followed in 1891 by serial lumbar punctures (Quincke) and, in 1893, by the first permanent ventriculo-subarachnoid-subgaleal shunt (Mikulicz), which was simultaneously a ventriculostomy and a drainage into an extrathecal low pressure compartment. Between 1898 and 1925, lumboperitoneal, and ventriculoperitoneal, -venous, -pleural, and -ureteral shunts were invented, but these had a high failure rate due to insufficient implant materials in most cases. Ventriculostomy without implants (Anton 1908), with implants, and plexus coagulation initially had a very high operative mortality and were seldom successful in the long term, but gradually improved over the next decades. In 1949, Nulsen and Spitz implanted a shunt successfully into the caval vein with a ball valve. Between 1955 and 1960, four independent groups invented distal slit, proximal slit, and diaphragm valves almost simultaneously. Around 1960, the combined invention of artificial valves and silicone led to a worldwide therapeutic breakthrough. After the first generation of simple differential pressure valves, which are unable to drain physiologically in all body positions, a second generation of adjustable, autoregulating, antisiphon, and gravitational valves was developed, but their use is limited due to economical restrictions and still unsolved technical problems. At the moment, at least 127 different designs are available, with historical models and prototypes bringing the number to 190 valves, but most of these are only clones. In the 1990s, there has been a renaissance of endoscopic ventriculostomy, which is widely accepted as the method of first choice in adult patients with aquired or late-onset, occlusive hydrocephalus; in other cases the preference remains controversial. Both new methods, the second generation of valves as well as ventriculostomy, show massive deficits in evaluation. There is only one randomized study and no long-term evaluation.

Animals↗

PubMed1999

[Posttraumatic syringomyelia].

The improvement of preclinical emergency medicine, better surgical and conservative therapies, and the development of intensive care units and specialized centers have improved the survival rate for patients with serious spinal cord injuries. Therefore, more sequelae of chronic spinal cord injuries such as post-traumatic spinal cord cavitations also occur. The first such case was described by Bastian in 1867. Generally, these cavitations were diagnosed from 2 months up to 32 years after the trauma. The overall prevalence of post-traumatic syringomyelia (PTS) is not known; however, with the increasing use of magnetic resonance imaging (MRI), its diagnosis has increased, ranging from 2.3% of paraplegic and tetraplegic patients in 1976 and 3.2% in 1985, to nearly 50% in a selected group of patients in 1991 and 1993. In 1995, a 4.45% incidence was reported. In our clinic we are currently treating 440 cases of syringomyelia, 140 of which are PTS. Several observations suggest more than one potential mechanism for the evolution of a post-traumatic cyst or PTS. Various factors, such as hemorrhage or, in particular, ischemia within the spinal cord, blockage of the cerebrospinal fluid (CSF) pathways around the cord or localized meningeal fibrosis either alone or in combination with other factors, may be involved. Clinically, sensory disturbances, loss of motor function, pain, and modification of the deep tendon reflexes are observed in most patients. On MRI, PTS is seen as a longitudinal, cystic cavity within the spinal cord, giving a hypointense signal on T1-weighted images and a hyperintense signal on T2-weighted images. For treatment planning it is mandatory to identify the lower and upper end of the PTS on the MRI.

Humans↗

PubMed1999

New valves--new dangers? 22 valves (38 probes) designed in the 'nineties in ultralong-term tests (365 days)'.

UNLABELLED: In the nineties, more than 30 valves have been launched, most are "clones", but some introduce new concepts (Diamond, SiphonGuard, PaediGAV). Of the 22 designs we tested, 20 have no previous tests and 3 are low-cost valves from Mexico (Dewimed), Zimbabwe (Harare-shunt) and England (Nottingham Shunt). 27 were tested using non-stop-perfusions for 365 days, 8 for 168-294 and 3 for 2 days. RESULTS: Ranking of the mean relative deviation: adjustable valves 19%, gravitational 34%, simple ball 51%, diaphragm 73%, distal slit 74% and autoregulating valves 121%. Ranking of physiological flow properties: gravitational > Equiflow > autoregulating > adjustable > ball > diaphragm > distal slit. SAFETY: The Equiflow were highly susceptible to external pressure. CONCLUSION: Most valves designed in the nineties showed inaccuracy, long-term-drifts, safety deficits and hydraulic mismanagement similar to more than 400 previously tested probes. With regard to accuracy and drift the ball designs were superior, but simple and adjustable ball valves are at risk of overdrainage. The gravitational ball valves (Cordis GCA, Miethke valves) showed the closest relation to physiological flow requirements.

Cerebrospinal Fluid Shunts↗

PubMed1999

Favorable recovery from bilateral loss of somatosensory evoked potentials.

OBJECTIVES: Bilateral loss of the cortical somatosensory evoked potentials (SEP) is usually regarded as a strong predictor for a very poor clinical outcome. We present four patients with a favorable recovery from bilaterally absent cortical SEP. DESIGN: Case series. SETTING: Neurocritical care unit at the University of Heidelberg. PATIENTS: Four patients with viral encephalitis, carbamazepine intoxication, head trauma, and left-side, space-occupying hemispheric infarction, respectively. INTERVENTIONS: Serial recording of somatosensory and auditory evoked potentials, therapy of increased intracranial pressure, including decompressive surgery, hypothermia, and barbiturate coma. MEASUREMENTS AND MAIN RESULTS: Three patients had an excellent outcome (Glasgow Outcome Scale 4 and 5). In those three patients, the SEP became completely normal during the clinical course. In one patient who remained severely disabled, the SEP became detectable again over the contralateral hemisphere, but remained abnormal. Possible influencing factors were sedative and analgetic drugs in all patients, and hypothermia and barbiturate coma in one of the patients. CONCLUSIONS: The absence of cortical SEP does not invariably imply an unfavorable prognosis. Absent cortical SEP indicates a severe neuronal dysfunction, which may be completely reversible if the underlying disease does not lead to permanent structural damage.

Acute Disease↗