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Biomedical subjects

H Zeumer

Publications and source records attributed to H Zeumer.

At least 19 recordsLinked to original sources
PubMed1992

99mTc-HMPAO-SPECT with acetazolamide challenge to detect hemodynamic compromise in occlusive cerebrovascular disease.

BACKGROUND AND PURPOSE: Insufficiency of collateral supply may lead to low-flow infarcts in severe occlusive cerebrovascular disease. The aim of this study was to evaluate the feasibility of technetium-99m-labeled hexamethylpropyleneamine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) to assess hemodynamic compromise in the anterior circulation. METHODS: Cerebral blood flow before and after 1 g acetazolamide was analyzed by 99mTc-HMPAO-SPECT in 21 symptomatic patients with documented extracranial obstructions. SPECT findings were correlated with the results of angiography, transcranial Doppler sonography, and computed tomographic scan. RESULTS: The acetazolamide-induced increase of cerebral blood flow could be reliably monitored by increase of cerebral 99mTc-HMPAO uptake, which varied between 11.4% and 47.6% in the less-affected hemisphere. Increment of hemispheric side-to-side asymmetry of tracer uptake after drug challenge revealed significant restriction of regional vasoreactivity in 11 patients. Agreement in assessing hemodynamic compromise was reached in 81% of patients with ophthalmic artery collaterals on angiography (p < 0.001), in 76% with low-flow infarcts on computed tomographic scan (p < 0.01), and in 91% with markedly reduced flow velocities on transcranial Doppler (p < 0.0001). One patient developed a low-flow infarct in the area predicted by SPECT during follow up. CONCLUSIONS: We conclude that 99mTc-HMPAO-SPECT with acetazolamide challenge is a useful method for assessment of the adequacy of hemispheric collateral pathways in patients with severe occlusive cerebrovascular disease.

Acetazolamide↗
PubMed1992

[Vertebrobasilar ischemia. Value of Doppler ultrasound in the acute phase].

We prospectively studied patients with acute vertebrobasilar ischaemia to assess the value of Doppler ultrasound compared to cerebral angiography during initial evaluation. Doppler ultrasound was diagnostic in 11 of 14 patients (79%). Transcranial ultrasonic examination yielded important information in addition to extracranial findings in 8 of 11 patients. Depending on the underlying vascular pathology, Doppler ultrasound proved to be a useful screening instrument to support acute management of vertebrobasilar ischaemia. With regard to clinical symptoms and ultrasonic findings, practical consequences for diagnostic evaluation are proposed.

Blood Flow Velocity↗
PubMed1991

[Indications for interventional neuroradiology. Arterial lysis, angioplasty and embolizing procedures].

Interventional neuroradiology (INR) includes such occlusive procedures as, for example, pre-operative embolization of cerebral and spinal arteriovenous malformation (AVM) and extracerebral head and neck tumors (meningioma, angiofibromas, etc.). In addition to this combined neuroradiological/surgical treatment, cranial and spinal dural fistulas, and traumatic arteriovenous fistulas as well as certain aneurysms at the base of the skull, may also be indications for transvascular embolization treatment alone. Recanalizing procedures (local fibrinolysis, percutaneous transluminal angioplasty (PTA] are employed for the most part in the vertebrobasilar and, with reservations, also in the carotid territories.

Angioplasty, Balloon↗
PubMed1991

[Association of arteriovenous and cavernous angioma of the head and neck area].

A 20-year-old man complained of pulse-synchronous noise in the ear and recurrent bleedings in the nose and throat region. From birth he had had an extensive haemangioma, black-blue with dark-red parts. It had been diagnosed as a cavernous haemangioma, part of a Sturge-Weber syndrome. An angiogram was performed before intended dermatological treatment of the disfiguring venous angioma. It demonstrated the capillary venous angioma (slow-flow angioma) in the lateral triangle of the neck, extending up to the skull base. In addition there was an arteriovenous angioma (high flow angioma) in the region of the clivus, which was supplied bilaterally largely by the ascending pharyngeal artery. The arteriovenous angioma also had connections to the outflow area of the capillary venous angioma. These findings and absence of ocular changes excluded Sturge-Weber syndrome. Because of the risk of life-threatening bleedings, the arteriovenous malformation was superselectively embolized by multiple injections of nonresorbable polyvinyl-alcohol particles via a microcatheter. This brought about the collapse of the cutaneous angiomatous spaces. This case demonstrates that external appearance indicating a capillary venous angioma is not reliable. Before treatment of this malformation a neuroradiological diagnosis should be undertaken.

Adult↗
PubMed1991

Local thrombolysis in the management of acute cerebral ischemia.

Local intraarterial fibrinolytic therapy (LIF) in patients with acute vertebrobasilar occlusion (AVBO) is a rational and, if successful, life saving treatment. The recent progress in this field is determined by the use of microcatheters for superselective basilar artery catheterisation and a "short-time, high-dose" regimen using 750,000 IU urokinase in not more than 2 h. Two out of 7 patients died and 1 did not improve to a better than a locked-in-state. Four patients, however, survived with excellent outcome.

Cerebral Angiography↗
PubMed1990

Selective cerebral intraarterial DSA. Complication rate and control of risk factors.

In 1095 patients 2770 brain supplying arteries have been studied by i.a.-DSA. Definitive neurological deficits occurred in 0.09%, transient deficits were observed in 0.45%. The reduced complication rate in comparison to former studies seems to be a continued effect of technical progress (DSA) and the use of new isoosmotic contrast media. In order to reduce the "training hospital effect" as to complication rate careful supervision of trainees is necessary. The average fluoroscopy time per vessel is proposed as an objective measure of the investigational skill of a neuroradiologist.

Adult↗
PubMed1990

Intramedullary vascular lesions in the high cervical region: transoral and dorsal surgical approach. Two case reports.

Intramedullary vascular malformations in the high cervical region are extremely rare. Two young adult patients with vascular lesions at the level C 2 and 3, and C 2-4 are reported. In one patient selective spinal angiography revealed a combined malformation with a ventral intramedullary arteriovenous angioma and a premedullary aneurysm. This malformation was approached and removed transorally after spondylectomy of C 2. In the second patient MRI and selective angiography showed an intramedullary hemangioblastoma extending from C 2-C 4. After embolization, this lesion was surgically removed via a dorsal approach. Both patients suffered from severe neurological deficits preoperatively. MRI and selective angiography showed the exact locations of the tumors within the spinal cord and indicated a transoral approach in one case and a dorsal approach in the other. After complete obliteration and removal of the lesions, the patients showed no neurological deficits and returned to their previous professions.

Adult↗
PubMed1989

Local intraarterial fibrinolysis in acute vertebrobasilar occlusion. Technical developments and recent results.

Local intraarterial fibrinolytic therapy (LIF) in patients with acute vertebrobasilar occlusion (AVBO) is a rational and if successful a life saving treatment. The recent progress in this field is determined by the use of microcatheters for superselective basilar artery catheterisation and a "short time, highdose" regimen using 750.000 IU Urokinase in not more than two h. Two out of 7 patients died and 1 did not improve to a better than a locked-in-state. Four patients however survived with excellent outcome.

Acute Disease↗
PubMed1989

The use of the "cross over technique" in the management of a traumatic vertebro-vertebral fistula.

A case of dissecting stab wound injury to the right vertebral artery with a vertebro-vertebral fistula is reported. Since a complete occlusion of a VV-fistula was not possible from a proximal approach with detachable balloons only retrograde catheterisation of the right vertebral artery via the left vertebral artery was undertaken (cross over technique). The introduction of thrombogenic platinum-coils led to a successful and complete occlusion of the fistula.

Adult↗
PubMed1989

[Chlorhexidine in the treatment of root canal infection and its sequels].

The plaque inhibitor chlorhexidine digluconate was used for intra- and transcanal irrigation in the endodontic treatment triad for periapical lesions (circumscribed, diffuse, fistulating, cystic, suspected cystic lesions). 50 patients were followed up by clinical and standardized radiologic studies. In another 18 patients microbiologic criteria were also used. 16 root canals showed pretreatment infection with mixed aerobic and anaerobic organisms. Mechanical preparation of the root canals with or without extension of the foramen and triple irrigation with 0.5% chlorhexidine digluconate produced clinical relief of symptoms (49 pts.), sterility (14 of 18 pts.) and reduction of the size of periapical lesions (12 pts.). At a mean follow-up of 24 months 30 patients have so far shown complete restitution of periapical bone.

Adolescent↗
PubMed1989

[Clinical and MRT follow-up of carotid aneurysm following balloon embolization].

Percutaneous embolization using detachable balloons was successfully performed in a series of nine patients with intracranial carotid aneurysms. The clinical progress and the results of MR examination are reported. Up to 4 months after treatment, MR imaging did not show any significant change in size of the artificially thrombosed aneurysms. Complete resorption cannot be expected in less than 6-8 months, but resorption does eventually occur. The intensity pattern observed in the evolution of the thrombus was similar to that of intra- and extra-cranial hematomas.

Adult↗
PubMed1988

Evoked potentials in basilar artery thrombosis: correlation with clinical and angiographic findings.

In 28 patients with vertebro-basilar or basilar artery thrombosis brain-stem auditory evoked potentials (BAEPs) and somatosensory evoked potentials (SEPs) have been recorded. Visual evoked potentials (VEPs) were recorded in 7 of these 28 patients. In 24 patients the diagnosis was angiographically proven and in 4 patients Doppler sonography and computerized tomography suggested this diagnosis. The BAEP and SEP findings were correlated to clinical and angiographical signs. BAEPs could be classified into 6 different patterns. In more than half of the patients different BAEP patterns from the two ears could be found. A pathological IV/V complex was most often found in comatose patients and in patients with a basilar artery occlusion distal to the anterior inferior cerebellar artery. Prolonged interpeak latency of I-III was mainly found in alert or drowsy patients with caudal occlusions. The frequent occurrence of a BAEP with only wave I preserved, or with no waves preserved, in patients with brain-stem functions suggests that BAEPs are not useful in the diagnosis of brain death when basilar artery thrombosis is suspected. SEPs were either absent bilaterally or else severely altered on one side in all comatose patients. In alert patients, including those with 'locked-in' syndrome, SEPs were never absent bilaterally. Increased N13-N20 interpeak latency was an uncommon finding in this series. There was no correlation between the SEP and the angiographically proven location of the occlusion. In the 'locked-in' syndrome both SEP and BAEP findings were non-uniform. Normal SEPs were sometimes found in combination with severely altered BAEPs, suggesting partial deafferentation. Since basilar artery thrombosis is now a treatable condition, early diagnosis and documentation of functional deficits moves into a more important clinical area than heretofore.

Adult↗
PubMed1988

Intra-arterial thrombolytic therapy improves outcome in patients with acute vertebrobasilar occlusive disease.

In this retrospective analysis we report our treatment experience in 65 consecutive patients with clinical signs of severe brainstem ischemia with angiographically demonstrated thrombotic vertebrobasilar artery occlusions who received either local intra-arterial thrombolytic therapy (urokinase or streptokinase) (43 patients) or conventional therapy (antiplatelet agents or anticoagulants) (22 patients). We analyzed the data with respect to cerebral artery occlusion patterns, posttreatment arterial recanalization, and the clinical categories of favorable/unfavorable outcome and survival/death. In subgroup analyses, recanalization in patients who received thrombolytic therapy correlated significantly with clinical outcome; in 19 of 43 patients, recanalization was demonstrated angiographically, while in 24 patients the occlusion persisted. All patients without recanalization died, but 14 of the 19 patients displaying recanalization survived (p = 0.000007), 10 with a favorable clinical outcome. Only three of the 22 patients who received conventional therapy survived, all with a moderate clinical deficit. When we compared the treatment groups, highly significant differences in both outcome quality (p = 0.017) and survival (p = 0.0005) were found to depend on establishing recanalization. Our data support the concept that technically successful thrombolysis of vertebrobasilar artery occlusions is associated with beneficial clinical outcome.

Acute Disease↗
PubMed1988

Local intra-arterial fibrinolytic therapy in acute carotid territory stroke. A pilot study.

The possibility that intra-arterial local infusion of fibrinolytic agents may achieve recanalization of previously occluded carotid territory arteries in acute stroke was tested in a prospective angiography-based open pilot study at two centers. Fifteen of 20 patients with acute symptoms (mean treatment-onset interval 7.6 hours) demonstrated complete recanalization; 10 of the 15 patients exhibited clinical improvement of varying degree by the time of hospital discharge. Four of the 20 patients suffered hemorrhagic transformation of the infarcted territory without clinical deterioration or demise. Because of the study format and the limited number of patients, dose responses for recanalization and risk relations were not established. We conclude that local intra-arterial fibrinolytic therapy may lead to cerebral arterial recanalization in acute carotid territory thrombotic stroke. The particular implications and limitations of this approach are discussed.

Acute Disease↗
PubMed1987

The role of plasma hyperviscosity in subcortical arteriosclerotic encephalopathy (Binswanger's disease).

Five haemorheological variables (haematocrit, plasma viscosity, red cell aggregation, red cell deformability and yield shear stress) and the plasma fibrinogen concentration were determined in blood samples from 21 untreated patients with subcortical arteriosclerotic encephalopathy (SAE, Binswanger's disease). The results were compared with those obtained in blood samples from 40 untreated patients with lacunar infarcts and from 275 healthy control subjects without vascular risk factors. Pathological ("solid body") flow behaviour was detected in the blood of both groups of patients (SAE and lacunar infarcts). However, highly elevated plasma viscosity was a consistent feature only of SAE. The authors present the hypothesis that the high plasma viscosity in patients with SAE may account for the progressive degeneration of cerebral white matter. It is postulated that microcirculatory abnormalities due to microrheological changes may be one of the many missing links in the pathophysiology of SAE.

Blood Viscosity↗
PubMed1987

Carotid endarterectomy: factors influencing perioperative complications.

Early carotid surgery has been suggested to be an important cause of perioperative deterioration due to secondary haemorrhage into a recent brain infarction. It has also been suggested that the existence of preoperative neurological deficits may worsen the prognosis of surgical treatment in carotid disease. Neither of these observations could be confirmed; severe perioperative complications (5%) in this study of carotid endarterectomy were strongly related to the degree of carotid stenosis. This aspect of carotid surgery has not been previously studied. Even though technical difficulties may play an exaggerated role in a training hospital system, it is nevertheless necessary to assess the impact of surgical procedures of different extent when the "acceptable risk" for carotid surgery is calculated.

Adult↗