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H J Steiger

Publications and source records attributed to H J Steiger.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1998

[Calculation of absolute cerebral blood volume and cerebral blood flow by means of electron-beam computed tomography (EBT) in acute ischemia].

The utility of electron beam computed tomography (EBT) to estimate cerebral blood volume (CBV) and cerebral blood flow (CBF) was evaluated. Eleven patients with suspected acute cerebral ischemia were investigated. The EBT was performed with an acquisition time of 50 ms per slice at eight parallel levels. To compare signal/noise and contrast/noise ratios the data from the EBT investigation were compared to a similar examination on a spiral CT. The signal/noise ratio with EBT was about 30%, the contrast/noise ratio 25% of that with spiral CT. The absolute values of CBV were 4.9 +/- 1.2 ml/100 g (EBT); CBF was 50.5 +/- 7.0 ml/100 g/min in normal contralateral brain tissue. In four patients with proven infarcts on follow-up, the ischemic areas had a CBV ranging from 1.7 to 3.8 ml/100 g, while CBF ranged from 9.4 to 24.5 ml/100 g/min. Using a bolus injection of contrast material, calculation of absolute CBV and CBF is feasible using EBT. Advantages of EBT are the absolute measurements possible and it's multislice capability. Disadvantages, however, are caused by the high image noise, limiting the demarcation of ischemic tissue.

Acute Disease↗
PubMed1998

MRI assessment of cerebral blood volume in patients with brain infarcts.

MRI perfusion studies have focussed mainly on acute ischaemia and characterisation in ischaemia. Our purpose was to analyse regional brain haemodynamic information in acute, subacute, and chronic ischaemia. We performed 16 examinations of 11 patients on a 1.5 T MR images. Conventional and dynamic contrast-enhanced imaging were employed in all examinations. For the dynamic susceptibility sequences, a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. Reconstructed regional relative cerebral blood volume (rCBV) maps, bolus maps, and conventional images were analysed by consensus reading. In all examinations decreases in rCBV were observed in the lesions. The distribution of regional rCBV in lesions was heterogeneous. The rCBV of the periphery of the lesions was higher than that at their center. There was a correlation between the time since onset and abnormalities on the rCBV map and T2-weighted images (T2WI). In the early stage of acute stroke, the abnormalities tended to be larger on the rCBV than on T2WI. Many patterns of bolus passage were observed in ischaemic regions. rCBV maps provide additional haemodynamic information in patients with brain infarcts.

Adult↗
PubMed1998

Neurobehavioural disturbances, rehabilitation outcome, and lesion site in patients after rupture and repair of anterior communicating artery aneurysm.

OBJECTIVE: To determine: (1) patterns of cognitive and psychiatric dysfunction; (2) those neurobehavioural parameters which mostly influence disability in activities of daily living (ADL) and handicap in occupational and psychosocial activities, and (3) underlying neuroanatomical pathology in patients after rupture and repair of anterior communicating artery (ACoA) aneurysm. METHODS: 30 patients were extensively examined by means of a comprehensive battery of neuropsychological tests, by rating of psychopathological symptoms, and by use of the functional independence measure (FIM), Glasgow outcome scale (GOS), and MRI. RESULTS AND CONCLUSIONS: (1) Three main groups were characterised by primary impairment of memory, executive functions, or of attentional performance. Within these main groups, specific patterns were identified relating to extent of primary dysfunction and associated disorders. The variety of neuropsychological disturbances is in contradiction to the existence of an "ACoA syndrome" as an entity. (2) Rehabilitation outcome proved to be mostly associated with both memory and attentional performance. (3) In neuropathological terms, lesions of the medial septum and nucleus of the diagonal band of Broca (MS/ndbB) were closely associated with memory deficits and prefrontal lesions were associated with attentional, executive, and psychopathological dysfunctions. At the same time, bilateral lesions were associated with severe disturbances. The type and severity of the above mentioned deficits were independent of the side of lesion in unilateral cases, of rectus gyrus resection, and of the Hunt and Hess grading system.

Activities of Daily Living↗
PubMed1998

Cervical vertebral and subclavian artery reconstructions.

At our institution, endovascular treatment of subclavian artery (SA) or vertebral artery (VA) occlusive disease has been used as the treatment of first choice during the last years. Open procedures were performed only in cases of failed or unfeasible endovascular treatment or total occlusion of the proximal VA or SA, respectively. Nineteen open procedures were performed between 1992 and 1996. Proximal reconstructions included SA to common carotid artery (CCA) transpositions or bypasses and VA to CCA transpositions. Distal reconstructions included transposition techniques or direct reconstruction in a few cases of traumatic lesions. The operative procedure used two-channel transcranial Doppler monitoring for cases involving simultaneous CCA and SA or VA cross clamping. There was one technical failure of a distal VA reconstruction. No surgical complications occurred. The recent pertinent literature with regard to indications and techniques of SA and VA reconstructions is discussed.

Angiography↗
PubMed1998

Terson's syndrome in subarachnoid hemorrhage and severe brain injury accompanied by acutely raised intracranial pressure.

OBJECT: The syndrome of retinal or vitreous hemorrhage in association with subarachnoid hemorrhage (SAH) is known as Terson's syndrome. The authors' purpose was to determine whether intraocular hemorrhage occurs with similar incidence when caused by severe brain injury accompanied by acutely raised intracranial pressure (ICP). METHODS: Prospective ophthalmological examination was performed in 22 consecutive patients with SAH or severe brain injury and elevated ICP. Thirteen patients were admitted for SAH (World Federation of Neurological Surgeons Grades II-IV) and nine for severe brain injury (Glasgow Coma Scale scores 3-10). Monitoring of ICP was performed at the time of admission via a ventricular catheter. Initial ICP exceeded 20 mm Hg in all patients. Indirect ophthalmoscopy without induced mydriasis was performed within the 1st week after the acute event. Retinal or vitreous hemorrhage was seen in six (46%) of 13 patients with SAH and in four (44%) of nine patients with severe brain injury. Ocular bleeding was found bilaterally in three patients with SAH and in one patient with severe brain injury (18%). Six of the 10 patients with Terson's syndrome died as a result of their acute event. CONCLUSIONS: The present results indicate that Terson's syndrome may be related to acute elevation of ICP, independent of its causes, and may occur with similar incidence in patients with severe brain injury and those with SAH. Because recognition and treatment of Terson's syndrome may prevent visual impairment and associated secondary damage to the eye, increased awareness of this entity in all patients with acute raised intracranial hypertension is recommended.

Acute Disease↗
PubMed1997

Dural arteriovenous fistulas including the transverse and sigmoid sinuses: results of treatment in 30 cases.

We report about the treatment and outcome of 30 patients with dural arteriovenous fistulas including the transverse and sigmoid sinuses treated between 1986 and 1995. All patients underwent panangiography for definitive diagnosis. The dAVF were supplied by the external carotid artery system alone (14 patients), both external and internal carotid systems (10 patients) or both anterior and posterior circulation (6 patients). Depending on the venous drainage the fistulas were classified following a modification of Djindjian's description with 18 patients revealing Type I (main sinus with antegrade flow), 5 Type II a (main sinus with reflux into the contralateral sinus). 5 Type II b (cortical veins), 1 Type II a+b (both) and 1 of Type III (direct cortical drainage). Bruit, pulsatile tinnitus and headaches were the most common symptoms. 6 patients presented with intracranial haemorrhage, 4 with progressive neurological deficit or seizures and 3 with dementia. Arterial embolization was performed in all cases except one, where a transvenous approach for balloon occlusion of the transverse sinus was performed. 21 patients were treated by single or repeated embolization alone. Only in 9/21 cases did arterial embolization result in complete occlusion of the fistula. In 12/21 patients incomplete occlusion was achieved. Following embolization 8 patients underwent additional surgery including coagulation of the feeding arteries and arterialized veins, sinus resection and reconstruction of the sinus. Overall, 18 patients were cured, 11 improved and 1 patient was unchanged. There was a total number of 5 complications including transient stroke, transient facial nerve palsy, and a small necrotic skin area following embolization. Venous infarction of the occipital lobe was induced by transvenous occlusion and surgical resection of the transverse sinus in one patient each, respectively. From our results we conclude that the endovascular therapy alone is the treatment of choice in case of Type I fistulas. In dAVF of Type II and III repeated endovascular treatment seems not to be sufficient and additional surgery is necessary.

Adolescent↗
PubMed1997

[Bleeding atheroma. A nuclear magnetic resonance tomography differential diagnosis of dissection of the carotid artery].

Improved methods of imaging the cerebral vascular system have increased the detection of traumatic or spontaneous dissection of the vertebral and carotid arteries. Especially MRI allows direct demonstration of intramural hematomas that are a sign of dissection of the vessel wall. We report on a patient who had an acute onset of dysarthria and monocular blurred vision, which recurred several times. Doppler ultrasound showed stenosis in both internal carotid arteries with reduced velocity of the flow; angiography confirmed the stenosis, showing a long stretch of stenosis (70%) of the right and a short stretch of stenosis (60%) of the left internal carotid arteries. MRI demonstrated a narrowing of the lumen by an intramural mass, whose signal characteristics were typical for blood. The MRI findings were thus consistent with the diagnosis of a spontaneous dissection of the carotid arteries. Since the Doppler ultrasound follow-up showed no change during the following 3 days, we interpreted the MRI findings as an indication of bleeding in an atheroma. The carotid disobliteration, performed first on the left side and later on the right side, confirmed this interpretation. Since stenosis due to a fissuring atheroma or bleeding in an atheroma requires different therapy than a dissection, it is thus important to consider the possible differential diagnosis in interpreting the MRI.

Arteriosclerosis↗
PubMed1997

[Spiral CT angiography in demonstration of cerebral aneurysms before and after treatment with titanium clips].

PURPOSE: To determine the suitability of spiral CT angiography (SCTA) in patients with intracerebral titanium aneurysm clips. MATERIAL AND METHOD: The section parameters were optimised using a phantom. 16 patients were examined preoperatively and 18 following treatment of aneurysms with clips. RESULTS: The resolution, sensitivity and specificity for demonstrating cerebral aneurysms measuring > or = 3 mm was 91.3% and 75% respectively. In 15 patients with intracerebral clips there were no or only minor artefacts; three examinations were of no value because of major metal artefacts. Amongst six aneurysms demonstrated angiographically, two, which measured more than 3 mm, could be shown by SCTA. CONCLUSION: SCTA was able to demonstrate intracerebral aneurysms measuring > or = 3 mm. Titanium clips did not usually affect image quality significantly.

Adolescent↗
PubMed1997

Primary intracranial metatypical basal cell carcinoma: case report.

OBJECTIVE AND IMPORTANCE: A case of primary intracranial metatypic basal cell carcinoma in a 20-year-old man is described. CLINICAL PRESENTATION: A 20-year-old man presented with palsies of the left cranial nerves VI through XII, including complete facial and vestibulocochlear nerve palsy and signs of cerebellar dysfunction, which included left-sided brachydiadochokinesis and nystagmus when looking to the left. There was no evidence of extracranial tumor manifestation. Imaging showed a tumor located in the left pyramidal bone, filling the left cerebellopontine cistern and compressing the brain stem with an extension into the middle cranial fossa as far as the internal carotid artery. INTERVENTION: Subtotal tumor removal was accomplished by a combined neurosurgical-otolaryngological procedure through a transpetrosal approach. A histopathological examination revealed a metatypical basal cell carcinoma. Postoperatively, a total dose of 60 Gy of radiation therapy was administered over a period of 6 weeks. CONCLUSION: Although it is rare, primary intracranial basal cell carcinoma should be considered in the differential diagnosis of tumors of the temporal bone.

Adult↗
PubMed1997

Postoperative spiral computed tomography and magnetic resonance angiography after aneurysm clipping with titanium clips.

OBJECTIVE: To reduce morbidity and mortality after subarachnoid hemorrhage, it is imperative to evaluate the results of the surgical treatment of cerebral aneurysms. We investigated the usefulness of spiral computed tomography (CT) and magnetic resonance angiography as postoperative control examinations after cerebral aneurysms were clipped with titanium clips. METHODS: Eleven patients with 13 treated aneurysms were studied prospectively with postoperative digital subtraction angiography, spiral CT, and magnetic resonance angiography. The occlusion of the dome of the aneurysm, the presence of a remnant of the neck, the patency of the parent vessels and other major vessels, and the presence of vasospasm were investigated. RESULTS: The different parameters could all be well evaluated by postoperative spiral CT. The artifacts caused by the titanium clips, although relatively small compared with artifacts from other clips, precluded evaluating the dome and the neck of the aneurysm with magnetic resonance angiography. CONCLUSION: In our opinion, spiral CT promises to become a valuable aid in in the postoperative evaluation of clipped aneurysms, and we recommend its routine performance. Postoperative digital subtraction angiography remains the gold standard and has to be performed when spiral CT reveals abnormalities, when the neck of the aneurysm cannot be evaluated because the clip overlays it, or when, intraoperatively, imperfect clipping is suspected and intraoperative angiography cannot be performed.

Adolescent↗
PubMed1997

Radical resection of meningiomas and arteriovenous fistulas involving critical dural sinus segments: experience with intraoperative sinus pressure monitoring and elective sinus reconstruction in 10 patients.

OBJECTIVE: Radical resection of meningiomas and dural arteriovenous fistulas involving functional major dural sinuses entails the risk of intracranial hypertension and venous infarction. Surgical reconstruction of dural sinuses and bridging veins increases the spectrum of dural sinus conditions that can be treated by complete resection, but indications for venous reconstructions and associated risks are still not well defined. We report our experience with sinus reconstruction based on the intraoperative assessment of collateral venous flow. METHODS: Radical resection of meningiomas (n = 5) or dural arteriovenous fistulas (n = 5) involving critical segments of dural sinuses was performed in 10 patients. All but two patients were suffering from recurrent disease after incomplete treatment. Tolerance of sinus occlusion was assessed intraoperatively by measuring stump pressure in the superior sagittal sinus during test clamping of the involved sinus segment. RESULTS: In five patients, the results of pressure monitoring suggested that occlusion of the sinus might not be tolerated. In two other patients, major bridging veins entered the diseased segment. In these patients, the resected sinus segment was reconstructed and bridging veins were reinserted as far as possible. Postoperative graft occlusion occurred in two patients. One patient who was managed without reconstruction sustained a transient postoperative neurological deficit resulting from venous congestion in the vein of Labbé. Postoperative imaging confirmed total elimination of the pathological process in all 10 patients. There was no recurrence of disease during follow-up periods of up to 8 years. CONCLUSION: The monitoring of sinus pressure, together with the possible reconstruction of the diseased sinus, allows complete surgical treatment of dural sinus abnormalities and involves acceptable risk.

Adolescent↗
PubMed1996

Keeping in mind the mind: mental functions, networks and neurosurgery.

The object of the neurosurgeons daily endeavour, the human brain, is less well understood in its overall organization than any other organ. This puts the neurosurgeon in a very difficult position. However, a substantial body of knowledge has been accumulated during recent years, and scientists from a variety of different disciplines have worked out theoretical frameworks to accomodate the available data. Here we present some of the evolving concepts on the organization of the substrate of the mind. Review of the literature shows that application of mathematical neural network models to the nervous system is very successful in explaining function. An implicit aspect of neural network models is that information storage is not localized in certain neurons but that the information is stored as the global pattern of activity in the network. Because networks of the brain involve often millions of neurons, exact identification and comparison with the theoretical models is not possible today.

Brain↗
PubMed1996

Evidence for peroxidative damage by nitric oxide in experimental chronic cerebral vasospasm.

Recent data has suggested a role for the nitric oxide metabolite peroxynitrite in peroxidative injury to endothelium associated with atherosclerosis. The present experiments were designed to elucidate whether such a mechanism might be involved in the morphological changes observed during chronic vasospasm after subarachnoid hemorrhage. For this purpose, chronic vasospasm was induced in male Wistar rats by an injection of autologous blood (100 microliters) in the cisterna magna followed by a second injection 24 hours later. Vasospasm was verified by pressure controlled internal carotid angiography after retrograde cannulation of the external carotid artery 7 days after the second injection. Animals were then perfusion fixed and the brains removed for immunohistochemical assessment of nitrotyrosine, the peroxidation product of peroxynitrite with tyrosine contained in tissue proteins. Staining for nitrotyrosine was quantified by microscopy in 40 microns coronal floating sections. The brains of rats with angiographic vasospasm revealed nitrotyrosine predominantly located with a perivascular distribution and in the pia. We conclude that peroxidation of membrane proteins by the nitric oxide metabolite peroxynitrite may contribute to the morphological damage evident in chronic vasospasm.

Animals↗
PubMed1996

The Neurosurgical Clinic at the Ludwig-Maximilians University in Munich.

ThE NEUROSURGICAL CLINIC at the Ludwig-Maximilians University in Munich began as a small unit of the university's surgical clinic. Eduard Weber, who in 1952 became the first surgeon fully trained in the specialty of neurosurgery to join the surgical clinic's faculty, worked, until his death in 1962, to advance the new specialty. Neurosurgery became an independent department of the university in 1965, and the neurosurgical clinic moved to a new location at Beethovenplatz. Further expansion led the neurosurgical clinic to move again, in 1975, to the newly constructed Klinikum Grosshadern at the periphery of Munich. Frank Marguth, chairman of the department of neurosurgery from 1964 to 1991, had superb skill as an organizer and greatly enhanced the reputation of the department of neurosurgery. Today, the faculty of the department consists of 10 full-time staff members, 10 joint appointment staff members, and 16 residents and fellows. Annually, 2200 to 2300 procedures are performed in the neurosurgical clinic. The current philosophy in the department places heavy emphasis on subspecialization and academic training. Political and economic changes in Germany during recent years have affected the nation's public health system and pose major challenges to the department of neurosurgery.

Academic Medical Centers↗
PubMed1996

Identification of posttraumatic ischemia and hyperperfusion by determination of the effect of induced arterial hypertension on carbon dioxide reactivity.

BACKGROUND AND PURPOSE: Both ischemia and hyperperfusion are known phenomena that follow traumatic brain injury. Cerebral carbon dioxide reactivity is diminished in both conditions. Differentiation is important because ischemia is thought to be a major factor of secondary neuronal loss and is potentially amenable to therapy by manipulation of cerebral perfusion pressure. METHODS: The response of transcranial Doppler-based carbon dioxide reactivity to pharmacologically induced hypertension was studied sequentially in 29 patients with severe to moderate head injury to identify ischemia and luxury perfusion. After simultaneous baseline registration of the carbon dioxide reactivity of both middle cerebral arteries by two-channel transcranial Doppler, systolic arterial pressure was raised approximately 20 mm Hg by means of phenylephrine (Neosynephrine) infusion, and the carbon dioxide reactivity test was repeated. RESULTS: A significant improvement of impaired (< 2%/mm Hg) carbon dioxide reactivity after arterial pressure was raised by 20 mm Hg (signaling ischemia) was found in 32 of 124 evaluated middle cerebral arteries. Further deterioration of impaired reactivity occurred in only four tested hemispheres. While ischemic conditions were identified during the entire study period, hyperperfusion was encountered only after day 3. CONCLUSIONS: Ischemia after traumatic brain injury is a frequent phenomenon, whereas hyperperfusion is rare. Whether therapeutic optimization of carbon dioxide reactivity can improve the outcome of head-injury patients needs to be evaluated in further studies.

Blood Pressure↗