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H J Steiger

Publications and source records attributed to H J Steiger.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Surgical therapy of intracerebral hemorrhages].

Level of consciousness and focal neurological deficits following spontaneous intracerebral hemorrhage are a consequence of tissue destruction and compression. Surgical indications are given, if compression is the principal factor. Accepted indications are superficial cerebral hemorrhages of more than 50 to 100 ml and cerebellar hemorrhages of more than 20 to 30 ml. If basal ganglia hematomas should be surgically evacuated is still a matter of discussion. Arterial aneurysms and arteriovenous malformations associated with some spontaneous hematomas require special treatment strategies.

Cerebral Hemorrhage↗
PubMed1995

Carotid endarterectomy--when to do it, how to do it?

With the completion of the major carotid endarterectomy trials the indications for this procedure can be defined. The procedure, if done by experienced teams, has been shown to improve the chance of stroke free survival in symptomatic and asymptomatic patients with a high-grade stenosis of the internal carotid artery. In asymptomatic patients the risk reduction gained by prophylactic carotid endarterectomy may be small in relation to the risk of coincident factors particularly coronary artery disease. The benefit gained by carotid endarterectomy depends closely on the risk of the procedure itself, and a single little flaw during the management can annulate the benefit of the operation in asymptomatic patients. There are still considerable controversies with regard to peri-operative management and surgical technique, e.g., the necessity of routine pre-operative arteriography has recently been questioned. Quality control programmes become a requirement with the publication of performance standards for carotid endarterectomy. According to a consensus of the American Heart Association, the surgical morbidity/mortality must be less than 6% for symptomatic carotid lesions and less than 3% for asymptomatic lesions. The present review discusses the steps of the pre-operative work-up, the procedure itself and the post-operative management with the aim to identify accepted safety standards as well as areas of uncertainty.

Carotid Artery, Internal↗
PubMed1995

Determination of cognitive hemispheric dominance by "stereo" transcranial Doppler sonography.

BACKGROUND AND PURPOSE: Transcranial Doppler sonography (TCD) can assess blood flow velocity changes induced by focal brain activation. Therefore, TCD may have the potential to identify hemispheric dominance for cognitive tasks. METHODS: Using a system with two TCD probes ("stereo" TCD), we monitored simultaneously both middle cerebral arteries (MCAs) of 14 healthy right-handed volunteers while they performed cognitive tasks. The averaged blood flow velocity ratio of the two MCAs and the hemispheric blood flow velocity shift induced by the cognitive task were calculated. RESULTS: In every subject, language tasks resulted in blood flow velocity shift to the left compared with visuospatial tasks. Mean MCA blood flow velocity shift to the left was 1.67%, 2.01%, and 2.31% in three language tasks. Mean blood flow velocity shift to the right was 1.67% and 2.31% in two visuospatial tasks. CONCLUSIONS: Bilateral simultaneous MCA blood flow velocity monitoring and averaging during cognitive tasks can help to identify hemispheric dominance for cognitive tasks in individuals.

Adult↗
PubMed1994

Current pattern of in-hospital aneurysmal rebleeds. Analysis of a series treated with individually timed surgery and intravenous nimodipine.

The management of aneurysmal subarachnoid haemorrhage has recently changed considerably. Emergency admission to specialized centres and early surgery have become common practice. In addition, the use of nimodipine has gained widespread acceptance. Little data are available concerning the frequency and temporal profile of reruptures under the current policies. The case histories of 387 patients treated for aneurysmal subarachnoid haemorrhage between January 1984 and March 1992 were reviewed with regard to the incidence of in-hospital reruptures. All patients were managed according to the same protocol including a policy of individually timed early surgery and intravenous nimodipine. A total of 44 first in-hospital rebleeds were observed during the waiting period. Two percent of the patients admitted on the day of haemorrhage had a rebleed on the same day after admission to the hospital. No rebleeds were observed on the day after subarachnoid haemorrhage. Rebleed rates on day 2 and 3 were also low with 0.6 and 0.8% of the population with an unclipped aneurysm. For the following 10 days, the daily rate of rerupture increased. A further peak was observed during the 4th week. Using life-table methods, the cumulative rate of rebleeds was calculated as 23% within 2 weeks and 42% within 4 weeks. Although patients suffering rebleeds differed in several respects from patients without rebleeds, most of the differences could be identified to be a consequence of a selection bias resulting in a longer period of exposure to the risk of rerupture for certain subgroups. Only patients suffering a loss of consciousness after the initial subarachnoid haemorrhage were definitively exposed to a higher daily risk of rerupture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Transcranial Doppler monitoring in head injury: relations between type of injury, flow velocities, vasoreactivity, and outcome.

Eighty-six patients with head injuries with an admission Glasgow Coma Scale score between 3 and 12 were studied sequentially by transcranial and cervical Doppler sonography. On a subset of 26 patients, sequential autoregulation and CO2 reactivity testing was also performed. Patient characteristics and hemodynamic data were correlated and analyzed with respect to the final outcome. The internal carotid artery (ICA) and middle cerebral artery flow velocities followed a typical pattern. Both were depressed during the first 3 days after the trauma and then increased to a maximum between Days 5 and 7. The increase of the middle cerebral artery flow velocities was more pronounced than the increase of the ICA flow velocities, thus indicating some degree of vasospasm. The amount of subarachnoid hemorrhage on the initial computed tomography correlated with the average middle cerebral artery/ICA flow velocity ratio (r = 0.5). Subarachnoid hemorrhages on computed tomography and, to a lesser degree, subdural and intracerebral hematomas were correlated with an unfavorable outcome. Vasospasm remained subcritical, and no negative relationship to outcome could be identified. Hyperperfusion, as based on ICA flow velocities, and vasospasm were correlated with diminished vasoreactivity. However, disturbed vasoreactivities, particularly during the first days, were common and did not necessarily predict an unfavorable outcome.

Adolescent↗
PubMed1993

[Surgical prevention and therapy of cerebral ischemia].

Surgery for cerebral ischemias has three main purposes: (1) prevention of cerebral infarctions, (2) functional improvement in patients with chronic ischemia, and (3) reduction of morbidity and mortality after complete infarction. The preventive efficiency of carotid endarterectomy has been documented in cases of high-grade symptomatic carotid artery stenosis. Several multicentric randomized studies are still under way whose aim is to define the benefit of surgery in cases of low and medium-grade symptomatic carotid stenosis as well as asymptomatic carotid stenosis. Little data is at present available on the value of prophylactic surgery in the vertebro-basilar system. In contrast to prophylactic surgery, several procedures are used for treatment of chronic hypoperfusion syndromes. In addition to carotid endarterectomy, extra-/intracranial bypass surgery, percutaneous balloon dilatation and transposition of the vertebral artery may improve perfusion. The indication for surgery with the goal of functional improvement is based on the typical symptomatology of a fluctuating neurological deficit and on tests of cerebro-vascular reactivity. In the treatment of established infarctions, neurosurgery may help non-geriatric patients to recover to the greatest possible extent by offering the methods of monitoring and management of intracranial pressure that have been used in neurotraumatology for the last twenty years.

Brain Ischemia↗
PubMed1993

Dynamic computed tomographic imaging of regional cerebral blood flow and blood volume. A clinical pilot study.

BACKGROUND AND PURPOSE: The advent of faster computed tomography scanners has evoked considerable interest in using this technology as a more practical method of regional cerebral hemodynamic evaluation than the currently available positron emission and single-photon emission computed tomography. The theoretical concepts have been worked out and validated in the laboratory by several groups. The aim of the present study was the development of a clinically useful system. METHODS: Software was developed for dynamic computed tomography-based calculation and color-coded representation of regional cerebral blood flow and blood volume. Normal values, reproducibility, and sensitivity to acetazolamide challenge were established in 13 volunteers. The method was applied to an additional three patients with internal carotid artery occlusion and known decreased vascular reserve capacity as diagnosed by transcranial Doppler ultrasonography. RESULTS: Normal regional cerebral blood flow was determined as 50 +/- 13 ml/100 ml per minute and normal fractional cerebral blood volume as 58 +/- 12 ml/1,000 ml (mean +/- SD). In five volunteers, two examinations were performed within 15 minutes for determination of reproducibility. Intermeasurement variability of hemispheric blood flow and blood volume was determined as +/- 23% and +/- 16%, respectively. Intravenous administration of 1 g acetazolamide resulted on the average in a 75% increase of blood flow and a 65% increase of fractional blood volume. In the patients with decreased cerebrovascular reserve capacity, baseline fractional blood volume in the ischemic hemispheres was significantly increased. Baseline regional cerebral blood flow in the ischemic territories was overestimated. Reactivity to acetazolamide of both regional blood flow and fractional blood volume was clearly reduced in the ischemic hemispheres. CONCLUSIONS: The present results demonstrate that the method is a simple and effective means of determining regional cerebral blood volume. Spatial resolution is superior to that of the radioactive tracer methods. Hemodynamic evaluation of ischemic conditions can be performed on the basis of increased resting cerebral blood volume and a diminished increase after acetazolamide. Accuracy of cerebral blood flow measurements, on the other hand, is affected by abnormal cerebral blood volume, and corresponding adjustments need to be made in pathological conditions.

Acetazolamide↗
PubMed1992

[Assessment and treatment of minor cranio-cerebral injuries].

Despite the usually uncomplicated course, minor head injury has a major economic impact because of its high frequency. The traditional evaluation and management using plain skull x-rays and subsequent surveillance has recently been questioned due to the wide-spread availability of CT and MRI. Indication and value of these diagnostic methods, however, are still ill-defined. The resulting uncertainty leads to increasing pressure on the smaller hospitals to transfer patients with minor head injury to specialized centres. This trend causes further financial escalation and the capacity of the specialized centres is not large enough to admit all minor injuries. The present review is focused on the initial risk estimation after minor head injury with the aim to derive guidelines for safe and efficient patient management. Adequately communicating patients without history of loss of consciousness have only a minimum risk of an intracranial haemorrhage and need not routinely be submitted to x-ray studies or in-hospital surveillance. Patients with a history of change of consciousness carry a risk of a few percent to develop intracranial haemorrhage and need therefore be admitted for 24 hours. A skull fracture increases the risk of haemorrhage to approximately 10%. An initially unsuspicious CT-scan is no absolute guarantee against subsequent intracranial haemorrhage. Patients who are disoriented and/or somnolent upon emergency room admission or who display a focal neurological deficit have a high risk of intracranial haemorrhage and emergency CT-scan is therefore recommended. The expensive MRI technique is not justified for initial diagnostic work up of head injuries. However, this technique represents a sensitive means to define organic lesions in cases of persistent neurological or neuropsychological deficits.

Brain Injuries↗
PubMed1992

[Results of percutaneous chemonucleolysis in lumbar disk hernia].

The percutaneous interventions have gained widespread acceptance for operative treatment of certain lumbar disc herniations. During recent years, percutaneous nucleotomy and laser discolysis replaced more and more the older technique of chemonucleolysis. Reports of anaphylactic shocks and severe neurological complications as well as unsatisfaction with the results of chemonucleolysis were responsible for this change. The basic mechanical concept of reduction of the intradiscal pressure remains the same with the newer methods. At the Inselspital percutaneous nucleotomy replaced chemonucleolysis in 1990. The results of chemonucleolysis were analysed with the aim of quantifying the efficiency of the percutaneous approach among our patient population. A total of 111 patients underwent chemonucleolysis between 1984 and 1989. The indication for the intervention was based on a several month history of lumbosciatica and a correlating radiological finding of disc protrusion or limited herniation. One case of anaphylaxis was the only serious perioperative complication. Upon follow-up examination approximately 2 months later, 54% of the patients were satisfied with the result, 27% reported an unchanged condition, and 19% had more pain than prior to the intervention. These results appear insufficient for an intervention associated with a non-negligible risk. Reduction of the nucleus pulposus appears often not to be an efficient mechanical concept for the treatment of disc protrusions and herniations.

Adult↗
PubMed1991

Outcome of acute supratentorial cerebral infarction in patients under 60. Development of a prognostic grading system.

Thirty-five patients under the age of 60 were admitted to the Neurosurgical Department of the Inselspital with acute supratentorial ischaemic strokes between February 1985 and June 1990. The mean delay from the onset of the symptoms until emergency room admission was 10 hours. CT scan, Doppler sonography, and angiography were done routinely at the time of admission and CT was repeated 24 hours later. Initial treatment consisted of mannitol, low-molecular dextran and prednisolone. Intravenous nimodipine was added to the protocol in 1987. Intensive care including hyperventilation and intracranial pressure monitoring was instituted in cases of deteriorating level of consciousness and considerable oedema as visualized on the primary or repeat CT scan. Eight patients developing severe intracranial hypertension and/or unilateral mydriasis despite hyperventilation and osmotherapy underwent decompressive craniectomy. A total of 9 patients died in the acute stage, all but one due to a cerebral cause. At 6 months, only 6 patients were without significant neurological or neuropsychological deficits. Fourteen patients were moderately disabled and 6 were severely disabled. There were no vegetative survivors. A number of demographic, clinical and radiological variables were investigated for a possible prognostic significance. A grading scale was developed for each variable. Of the initial neurological deficits, degree of motor paralysis, gaze deviation, and decreased level of consciousness correlated with an unfavourable result. While the prognostic significance of each of these individual variables was only moderate, the combined score of these 3 variables correlated better with outcome (r = 0.62). More advanced age was found to correlate with a less favourable prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Prognostic factors in the treatment of trigeminal neuralgia. Analysis of a differential therapeutic approach.

144 patients operated on for trigeminal neuralgia between June 1982 and May 1990 were followed for up to 8 years. 122 patients were treated by retrogasserian glycerol rhizolysis and 22 by posterior fossa exploration. The average age was 65 years. 89 patients were women and 55 men. The 1st branch was principally involved in 9 patients, the 2nd in 92 and the 3rd in 43. 32 patients had prior procedures. 102 of the 122 patients submitted to glycerol injection were rendered pain-free (84%). An additional 7 patients were relieved by a supplemental radiofrequency procedure, thus achieving an 89% success rate with the percutaneous approach. All 22 posterior fossa explorations were initially successful. 65 patients of the group treated percutaneously had some new postoperative objective and/or subjective sensory deficit as well as 13 of the patients operated on by posterior fossa exploration. Corneal sensation was decreased after 19 glycerol procedures including 3 who had a supplemental radiofrequency coagulation. No corneal hypaesthesia was seen after posterior fossa explorations. Kaplan-Meier analysis showed that at 5 years 59% of the percutaneous rhizolysis group were free of neuralgia and 68% of the patients treated by posterior fossa exploration. A number of patient characteristics and surgical factors were analysed for a possible correlation with outcome. Intact preoperative facial sensation was the most important prognostic factor for an initially successful operative result. Some degree of postoperative sensory deficit was the most important factor for long-term remission of neuralgia. However, of the 54 patients with a postoperative new sensory deficit who were available for long-term follow-up, 13 complained of persistent disturbing disaesthesias.

Aged↗
PubMed1990

Early prognosis of supratentorial grade 2 astrocytomas in adult patients after resection or stereotactic biopsy. An analysis of 50 cases operated on between 1984 and 1988.

50 adult supratentorial low-grade astrocytomas operated upon between 1984 and 1988 were analysed retrospectively with respect to postoperative condition and progression-free survival. Pilocytic lesions were excluded. In 32 instances the tumour was macroscopically completely removed and partially in 4. In 14 cases a stereotactic biopsy was performed only. 10 patients received postoperative radiotherapy with 55 to 65 Gy. 1 patient died perioperatively from pulmonary embolism. 39 patients could resume their previous activities after discharge from the hospital, 10 were significantly disabled by neurological deficit, reduced neuropsychological performance or medically intractable epilepsy. Postoperatively, most patients required continuous anti-epileptic medication, 10 recurrences or tumour progressions of incompletely removed or merely biopsied lesions were observed within the mean follow-up period of 22 months. All recurrences after gross total removal, that were reoperated, had progressed to a malignant glioma. Of the prognostic tumour characteristics analysed, a histologically well-delineated tumour demarcation was most clearly associated with a favourable prognosis. Concerning treatment modalities, gross total resection was associated with a favourable prognosis. Radiotherapy was associated with an unfavourable outcome but this is probably due to selection of otherwise unfavourable cases.

Adolescent↗
PubMed1990

[Anemia-induced focal cerebral symptoms in carotid stenoses. Observations of pathophysiology].

Four patients with cerebral ischemic events related to anemia or therapeutic hemodilution were observed within a 10-month period. Upper gastro-intestinal hemorrhage was responsible in 2 patients. The 3rd suffered from chronic polyarthritis and erosive gastritis, and in the 4th instance, the decrease of hematocrit was the result of a therapeutic hemodilution for polycythemia. A significant carotid stenosis corresponding to the symptoms was diagnosed in all patients. Passage of emboli in the middle cerebral or ophthalmic artery respectively was detected in two patients during the transcranial Doppler exam. Analysis of the effect of a decrease of hematocrit on arterial stenoses suggests that cerebral ischemic events related to blood loss are partially due to induced embolism.

Aged↗
PubMed1990

[Stereotaxic brain puncture. Indications and results].

228 stereotactic biopsies for the diagnosis of brain lesions were evaluated. In 98.2% a diagnosis could be established. The diagnosis was made of brain tumor in 79.3%, of brain abscess in 7.5% and of encephalitis in 3.5% of cases. In 2.2% of the patients a pathological finding was obtained without a clear histological definition. No histological diagnosis could be made in 1.8% of the patients. A severe complication of brain biopsy occurred in 2.2% of the patients (1 death, 1 abscess, 3 increased impairments). The stereotactic procedure appears to have a low mortality and morbidity, and to be highly accurate.

AIDS Dementia Complex↗
PubMed1989

[Results in microsurgical carotid artery endarterectomy].

100 consecutive carotid endarterectomies were performed by a microscopic technique with monitoring of cerebral perfusion by transcranial Doppler sonography and EEG. No additional cerebral deficits occurred in this series. Perioperative mortality due to medical complications occurred in 2 instances. During the average follow-up period of 15 months, 1 patient suffered a lethal cerebral infarction ipsilateral to the operated carotid artery and 1 patient a contralateral minor stroke. 2 patients died from unrelated causes during follow-up.

Aged↗