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Biomedical subjects

H Zeumer

Publications and source records attributed to H Zeumer.

At least 37 records · Page 2Linked to original sources
PubMed1987

"Distal stump" of the internal carotid artery with ascending pharyngeal artery collateralisation. A potential source for further embolic ischemia.

In 2 patients, clinically exhibiting recent amaurosis fugax and small cortical infarction, carotid occlusion had been shown by means of doppler ultrasound. IA-DSA showed a collateral circulation within the distal carotid artery in the base of the skull via the ascending pharyngeal artery. The slowly perfused stump of a distal carotid artery is supposed to be a potential source of emboli into the retinal or intracranial territories.

Carotid Artery Diseases↗
PubMed1987

Vascular recanalizing techniques in the hind brain circulation.

Percutaneous transluminal angioplasty (PTA) was performed in 45 patients with a manifest subclavian steal syndrome. Thirty-five of those patients were subjected to follow up examinations over a period of 6 to 18 months. Five patients suffered from severe restenosis and were treated again. Two thirds of the patients benefited from the treatment. PTA of the proximal vertebral artery was performed in 15 patients with bilateral occlusive lesions of the extracranial vertebral arteries. In 13 of these cases the neurological and the vascular states of the patients were regularly reexamined, 8 showed a marked improvement. During the 2 to 25 month observation period (average 15 months post-PTA) reocclusion was observed in only two cases. These showed no recurrent neurological sequelae. Forty-three consecutive patients with acute vertebro-basilar or basilar occlusion received intraarterial fibrinolytic therapy with streptokinase or urokinase. Twenty-three of these had presented severe deficits at the beginning of therapy (e.g. complete tetraplegia, comatous state for more than 6 hours). None of this group survived. By contrast the 20 other patients in this group presented with incomplete fluctuating or progressive motor deficits. None was comatous for more than 6 hours. Fourteen patients (33% in this group) survived. Local intraarterial fibrinolytic therapy is the only therapy successful in the treatment of progressive stroke from vertebro-basilar thrombosis.

Aged↗
PubMed1987

[Significance of vertebral angiography for the diagnosis and therapy of vertebrobasilar occlusive disorders with special reference to vascular recanalizing procedures].

Between 1980 and 1985 a total of 912 vertebral angiographies were performed in 793 patients, 198 of whom had ischemic symptoms attributable to the hindbrain circulation. The complication rate was 6%. With due consideration for the clinical findings and those recorded by Doppler ultrasound and computed tomography, vertebral angiography is indicated in vertebrobasilar occlusive disease if anticoagulation, percutaneous transluminal angioplasty (PTA) or local intraarterial fibrinolytic therapy (LIF) of the hindbrain circulation is intended, and also if there is a discrepancy between the clinical findings and the results of computed tomography or Doppler ultrasound examination. With today's sophisticated angiographic techniques (e.g. DSA) and the possibilities opened up by modern interventional neuroradiological techniques, the complication rate of vertebral angiography now seems to be lower than previously.

Angioplasty, Balloon↗
PubMed1986

Percutaneous transluminal angioplasty of the vertebral artery. A therapeutic alternative to operative reconstruction of proximal vertebral artery stenoses.

Percutaneous transluminal angioplasty (PTA) of the proximal vertebral artery was performed in 13 patients with stenosis of the proximal vertebral arteries. All of these patients had symptoms indicating vertebrobasilar insufficiency. PTA was performed only if an extreme reduction of the total diameter of both vertebral arteries was present. Only 13 patients have fulfilled the strict selection criteria in the last 3 years. All patients were monitored during the procedure by means of continuous-wave Doppler ultrasound and electrophysiological techniques. After PTA their neurological and vascular conditions were serially examined. Of the 13 patients, 8 showed marked improvement of both subjective and objective clinical symptoms. During an observation period of 2-25 months (average: 15 months) reocclusion of the angioplasty was observed in only 2 cases, without any additional neurological sequelae. Electrophysiological and Doppler sonographic monitoring during PTA helped to minimize the risk of angioplasty.

Angioplasty, Balloon↗
PubMed1986

[Atraumatic diagnosis and semi-invasive therapy of subclavian steal syndrome using percutaneous transluminal angioplasty. A current concept].

Percutaneous transluminal angioplasty (PTA) is a semiinvasive, non-operative transvascular technique for dilatation of stenosed vessel segments by help of balloon catheters. This technique was applied to 30 out of 42 patients with a subclavian steal mechanism due to highgrade proximal subclavian artery (PSA) lesions. The transfemoral, transaxillary or both approaches were used. A staging of the severity of the subclavian steal mechanism on the basis of the pre-interventional Doppler ultrasound findings (Grade I-IV) was proposed for adequate selection of patients for angioplasty. During balloon dilatation of the subclavian artery permanent CW Doppler monitoring of the ipsilateral vertebral blood flow velocity was performed at the mastoid. Balloon dilatation failed to be effective in 4 patients with complete subclavian artery occlusions (Stage IV). In 26 patients with high-grade stenoses of the proximal subclavian artery (Stage II/III), angioplasty led to recanalisation of the vessel and abolishment of the steal mechanism. However, relief or improvement of the concomitant subclavian steal syndrome could not be achieved except in one-third or two-thirds of the patients, respectively. Long term follow-up with repeat Doppler sonography indicated a complete removal of the subclavian lesions in 50% of the cases, whereas the remaining patients produced some kind of re-stenosis. However, repeat angioplasty became necessary in only 5 cases and was permanently successful in two of them. If patients with complete subclavian artery occlusions were excluded, the complication rate due to angioplasty was very low. Embolism into the finger arteries could only be observed once. In another case, accidental dissection and complete occlusion of the distal subclavia artery occurred but underwent spontaneous recanalisation. Doppler monitoring of vertebral flow velocity was very useful for both control of the effectiveness of the dilatation procedure and deeper insight into the pathophysiology of the subclavian steal mechanism. An unexpected delay phenomenon concerning the re-establishment of cephalad vertebral flow direction was observed immediately after recanalisation of the subclavian artery and was thought to protect the posterior circulation against early embolism due to mobilisation of plaque debris within the proximal subclavian segment. From an angiological point of view, the outcome of percutaneous transluminal angioplasty does not yet meet the success rates of various modern extra-thoracic surgical procedures for operative treatment of subclavian steal mechanism. However, the rate of improvement of clinical signs and symptoms is equal with both methods.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

Acute vertebral-basilar thrombosis. Angiologic-clinical comparison and therapeutic implications.

The clinical-angiologic data and the clinical outcome in 66 patients with acute vertebro-basilar thrombosis treated with antiplatelet agents, anticoagulants, or fibrinolytic agents are presented. Forty-three patients were treated with local intraarterial infusion of streptokinase or urokinase proximal to the thrombotic occlusion; 14 patients in this group (33%) survived, only one of whom was in deep coma when therapy was started. Twenty-three patients did not receive fibrinolytic therapy; 4 of these patients (17%) who exhibited mild brainstem-related symptoms survived. This study implies that early diagnosis and treatment in vertebrobasilar stroke in progression may achieve improved survival.

Acute Disease↗
PubMed1986

[Neuroradiologic and surgical treatment of a recurrent angiofibroma supplied by the internal carotid artery].

If blood supply to the brain hemisphere is disturbed following closure of internal homolateral carotid artery tumors of the skull base with involvement of this artery should not be operated on radically. The authors describe the electrophysiological monitoring of cortical evoked somato-sensory potentials. If there is no alteration of the evoked potentials after preliminary reversible blockade of the internal carotid artery this vessel can be definitely closed using a detachable balloon. Thereafter the whole tumor including the carotid artery can be removed. The authors describe a case of juvenile angiofibroma operated on in this way. The combined interventional-neuroradiological and surgical management widens the range of skull base surgery.

Adult↗
PubMed1986

[Electrophysiologic findings in lacunar infarcts].

Lacunar lesions are small infarctions in the territory of small penetrating arteries of the brain. Because of their small size these lesions can only in part be detected by CT. Clinical symptoms do not always correspond with the lesions visible in the CT. We studied the somatosensory evoked potentials (SEP), the visual evoked potentials (VEP) and the electrically elicited blink reflex in 50 patients with lacunes to determine if there are any other lesions which are not detectable by clinical examination or CT alone. While VEP and the blink reflex showed pathological results in only a few of these patients the SEP were pathological in about 75%. The multiplicity of the lesions may be documented by means of these investigations.

Aged↗
PubMed1986

[Validity of early acoustically-evoked potentials in the diagnosis of brain death].

Brainstem acoustic evoked potentials (BAEP) in clinically proven brain death are already described in the literature. In most cases there were no reproducable BAEP or only wave I ipsilateral. In a few cases, shortly after the onset of brain death, wave I and a wave II ipsilateral have been detected. 40 Patients were examined during developing brain death and in brain death. Using an ipsilateral and contralateral montage (mastoid/vertex) four different patterns of BAEP in brain death could be distinguished: Wave I ipsilateral and wave II ipsilateral, reduced in amplitude and delayed in latency and a wave I-contralateral, Wave I ipsilateral and wave I-contralateral, Only wave I ipsilateral, No reproducable BAEP. In clinically not brain dead patients, three different patterns of BAEP are recorded which should be known in order to comment on the validity of the method in the diagnosis of brain death: Only wave I and a flat and late wave, only recordable using several reproductions and with a low rate of artefacts. Only wave I recordable while the patient is still breathing spontaneously (false positive results). Reversible loss of wave I. Ignoring the results, the BAEP may lead to false positive results in the diagnosis of brain death.

Brain Death↗
PubMed1985

Vascular recanalizing techniques in interventional neuroradiology.

Vascular recanalizing techniques only recently became methods of some clinical importance. Angioplasty of the subclavian artery in cases with subclavian steal syndrome has now been performed in so many instances that it can be judged safe. Angioplasty at the origin of the vertebral artery has not yet been performed in as many cases. However, even there this method is obviously less hazardous than surgery. Local intraarterial fibrinolytic therapy is the only therapy providing some success in progressive stroke from vertebrobasilar thrombosis. In contrast to the vertebrobasilar territory local fibrinolytic therapy within the carotid territory has to be strictly limited to some special indications.

Angioplasty, Balloon↗
PubMed1985

The haemorheological features of lacunar strokes.

Clinical and haemorheological data were recorded in 40 patients with lacunar strokes confirmed clinically and by computed tomography. The following haemorheological variables were monitored: haematocrit, erythrocyte aggregation, erythrocyte deformability, plasma viscosity, fibrinogen concentration and yield shear stress. Clinically, most patients had case histories and features according to the description of Fisher. All haemorheological parameters with the exception of the haematocrit were pathological when compared with values obtained from a normal control group. In descending order of frequency the pathological changes were in erythrocyte aggregation, plasma viscosity and erythrocyte deformability.

Aged↗
PubMed1985

Surgical treatment of cerebral arteriovenous malformations. Follow-up study of 43 cases.

In 43 patients with arterio-venous malformations and one patient with a cavernous haemangioma, whose angiomas were completely removed by the same Surgeon, pre- and postoperative angiograms were reviewed and the clinical results documented in a follow-up study. Mortality rate (7%) and severe disability (7%) are significantly lower than in untreated patients. A poor outcome strongly depends on the number of feeding arteries, on localization (midline) and size.

Adolescent↗
PubMed1985

Balloon embolization in the treatment of basilar aneurysms.

Some vertebro-basilar aneurysm may not be treatable at a reasonable risk by direct clipping. A possible alternative is transvascular obliteration, using the means of modern interventional neuroradiology in combination with neurophysiological monitoring. These possibilities and related difficulties are outlined and discussed and the example of two cases with different types of vertebrobasilar aneurysms (top of the basilar artery and basilar trunk aneurysm) which have been treated by balloon embolization.

Adult↗
PubMed1985

[Contribution of computer tomography of the brain to differential typology and differential therapy of ischemic cerebral infarct].

In order to provide a pathogenetically oriented differentiation of brain infarctions on the basis of CT-morphological criteria, the CTs of 422 patients with visible brain infarctions were analysed. All of the supratentorial lesions were classified according to topographical features and were associated with the underlying cardio-vascular and other general diseases. This concept lead to a typology of brain infarctions which allowed for a differentiation of ischaemic lesions due to cerebral microangiopathy on the one hand (i.e. lacunar infarctions, subcortical arteriosclerotic encephalopathy), and lesions due to cerebral macroangiopathy on the other. The latter were hemodynamically induced terminal supply area infarctions and watershed infarctions or territorial infarctions due to thromboembolism. A third group of symmetrical subcortical lesions were associated with hypoxia. The frequencies of cerebral lesions within the whole cohort were as follows: 34% cerebral microangiopathy, 45% macroangiopathy, 1% generalised hypoxia, 10% miscellaneous lesions and 10% non-classifiable infarctions. Stenosing lesions of the extracranial brain supplying arteries were found in 22% of the microangiopathy group but in 71% of the macroangiopathy group. Patients with territorial infarctions presented with embolising extracranial vascular lesions in 42% and with embolising heart disease in 21% of the cases. Local thrombosis of the intracranial large arteries was a rare event. Hypoxia occurred due to haemorrhagic shock, carbon monoxide poisoning, air embolism and strangulation. The following conclusions were drawn: In patients with cerebral microangiopathy any procedures aimed at the diagnosis and therapy of major vessel disease are not useful. Therapy should follow the principles of internal medicine. If haemodynamically induced infarctions are present, the clinician's primary task is to look for high grade extracranial vessel lesions. Recanalizing techniques (endarterectomy and ECIC-bypass) are the main therapeutical strategies. In territorial infarctions the embolising extracranial vessel lesions may be haemodynamically non-significant. An intra-arterial source of emboli should be removed by the vascular surgeon. In younger patients, however, and in patients with normal Doppler findings and/or multiple territorial infarctions, a cardiac source of emboli is highly probable and its diagnosis should be pursued consistently. Bilateral symmetrical ganglionic infarctions are indicative of hypoxia and help to exlude other causes of the severe neurological disturbances associated with this condition.(ABSTRACT TRUNCATED AT 400 WORDS)

Brain Ischemia↗
PubMed1985

Transcranial Doppler sonography as a non-invasive guide for the transvascular treatment of an inoperable basilar-artery aneurysm.

This report deals with the successful treatment of a giant aneurysm located at the caudal basilar trunk in a 19-yr old boy. The aneurysm had been declared to be inoperable by several authorities in the field of neurosurgery. A series of neuroradiological interventions was performed in order to block the aneurysm with the help of a detachable balloon or, at least, to induce spontaneous thrombosis of the aneurysm sac by reducing blood flow within the caudal basilar artery. Transcranial Doppler sonography proved to be a helpful guide for therapeutic decision-making from one interventional step to the next in this adventurous field of treatment. The changing sonographic findings of the vertebrobasilar system during the course of the treatment and during the functional tests, as well as the favourable outcome, have made this case worth reporting.

Adult↗
PubMed1985

[Monitoring of therapeutic neuroradiologic examination and therapeutic procedures using evoked potentials].

Interventional neuroradiology makes use of different diagnostic and therapeutic catheterization techniques. Treatments performed are local intraarterial thrombolytic therapy, embolization and occlusion of brain supplying arteries, percutaneous transluminal angioplasty and intraarterial application of drugs. These treatments make it most important to check the patients neurological state during the procedure. Intraoperative monitoring of evoked potentials offers the opportunity to get objective information about changes in certain central nervous system functions even in anaesthesized patients. Usually intraoperative monitoring is performed to obtain information whether the function of structures at risk remains stable or is altered by the operation. This represents a more passive, observing way of monitoring. During interventional neuroradiology one is enabled to take additionally a more active and experimental way of monitoring by using the advantages of special catheter techniques like series of reversible balloon occlusion or intraarterial drug application. This leads to a dialogue between the radiologist and the neurophysiologist about the safety or the risk of the next step during a procedure. There are mainly two types of new information that can be achieved by active monitoring: the identification of functional territories of single or multiple feeding vessels and new insights into hemodynamics and the establishing of new sufficient collaterals. We have used intraoperative neuromonitoring in 35 patients during interventional neuroradiology. Our findings will be summarized and the usefulness of the different monitoring methods will be discussed.

Amobarbital↗