Search PubMed⌕ Search

Biomedical subjects

H Zeumer

Publications and source records attributed to H Zeumer.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Transcranial sonographic monitoring of the blood flow of the middle cerebral artery in recanalizing operations of the extracranial internal carotid artery].

During endarterectomy of the internal carotid artery (ICA) blood flow velocity of the ipsilateral medial cerebral artery (MCA) was continuously monitored in twelve patients with the help of a new transcranial pulsed Doppler system. Additionally, the basal cerebral arteries where examined pre- und postoperatively in order to evaluate criteria for selective intraoperative shunting and to document flow improvement following ICA reconstruction. All patients had symptoms, either of TIA or of minor stroke. Five of them had in addition a contralateral ICA occlusion. During intraoperative carotid cross-clamping on the patients with unilateral ICA lesions, MCA blood flow dropped to zero in only one of them. In the other cases, a 20 to 60% flow reduction occurred indicating cross-filling or/and collateral blood supply via the posterior circulation. More severe MCA flow reductions were found in patients with contralateral ICA occlusion, with the occurrence of a no-flow state in two of them. All patients were operated on with an indwelling shunt. Its effect on MCA blood flow varied considerably. Apparently, the shunt was necessary in some patients but was superfluous in the majority of them. Transcranial Doppler meets the basic criteria of an examination technique to be recommended for monitoring. The method is noninvasive. The parameter, i.e. MCA flow velocity, can be evaluated on-line. It is representative and highly sensitive for cerebral circulatory disturbances and impending ischemia in the carotid territory. Transcranial MCA flow monitoring does not affect the course of the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

[Ectopic internal carotid artery in the tympanic cavity. Intraoperative complications and their treatment. A case report].

Ectopy of the internal carotid artery involving the middle ear occurs only rarely. In this case, middle ear surgery will almost always result in severe haemorrhage. After package of the external auditory canal and the epipharynx, immediate closure or ligation of the internal carotid artery is mandatory. The authors describe the interventional neuroradiological treatment as an alternative way to the known neurosurgical methods like cervical and intracranial ligation of the artery. Intravasal blocking of the leakage was done by using a detachable balloon filled with contrast medium. During this procedure cortical evoked potentials were measured showing no decrease of the homolateral haemispheric blood flow. Although this procedure cannot maintain the continuity of the internal carotid artery, it preserves a maximum of collateral vessels. The cortical evoked potentials simultaneously show the brain function during blockage of the artery.

Carotid Artery, Internal↗
PubMed1984

Local intraarterial fibrinolytic therapy in inaccessible internal carotid occlusion.

Two exemplary cases of upper carotid occlusion and successful local intraarterial fibrinolytic therapy are described. To achieve a positive result one has to perform a balloon occlusion of the affected internal carotid artery while applying the fibrinolytic agent. Possible time limits of instigating therapy are discussed especially if the lenticulostriatal arteries are additionally affected.

Adult↗
PubMed1984

Delayed reversal of vertebral artery blood flow following percutaneous transluminal angioplasty for subclavian steal syndrome.

Twelve patients suffering from subclavian steal syndrome of various severity due to either proximal subclavian stenoses (10 cases) or subclavian occlusion (2 cases) were treated with percutaneous transluminal angioplasty (PTA). Olbert's dilatation catheters were used. The occlusions could neither be recanalized by the transfemoral nor transaxillary approach. In one right-sided subclavian stenosis an additional distal subclavian occlusion prevented proper placement of the catheter. All the other patients were treated successfully with no re-occlusion during a follow-up period of 1 to 7 months. In one patient, a transient embolic occlusion of the finger arteries was seen following post-interventional repeat angiography. Before, during and after PTA, continuous ultrasound monitoring of the homolateral vertebral flow patterns revealed an unexpected "delay" phenomenon. Despite sufficient recanalization of the proximal subclavian artery, the flow direction within the vertebral artery did not immediately change to antegrade but rather did so gradually within 20 s up to several minutes. This delay of flow-reversal is thought to serve as a protective mechanism against cerebral embolism during, and shortly after PTA of the subclavian artery. Relying on Doppler ultrasound findings, a staging of the subclavian steal is proposed in order to allow adequate selection of patients for PTA.

Adult↗
PubMed1983

[Angiologic and prognostic evaluation of brain stem injuries. Clinical, doppler-sonographic and neuroradiological findings].

Due to suspect vascular occlusion characterized by disorders of brainstem function 183 patients were investigated using Doppler sonography of the vertebrobasilary vascular system. Extracranial vascular lesions were diagnosed in 32 patients (basilary steal syndrome, vertebral artery branching stenosis), 11 patients showed bilateral vertebral artery occlusion or basilary thrombosis, nine unilateral intracranial vertebral artery occlusion and 131 patients showed no abnormal findings. The prognostically worse intracranial lesions were all confirmed by angiography. Twenty-five patients with normal Doppler findings were also controlled. Of these, three patients showed macroangiopathy presenting as megadolichobasilary artery and haemodynamically ineffective stenosis of the basilary artery (one patient). In the majority of cases neurological disorders associated with normal Doppler sonography findings were however considered as representative of cerebral microangiopathy, characterized by a favourable prognosis.

Adult↗
PubMed1983

Evoked potential monitoring during acute occlusion of the basilar artery and selective local thrombolytic therapy.

Neurophysiological examinations of brainstem functions before, during and after selective interventional neuroradiology i.e. selective intraarterial thrombolytic therapy of an acute occlusion of the basilar artery are reported. The success of the therapy was demonstrated by the reappearance of normal somatosensory potentials and of the blink reflex immediately after the thrombolysis. The BAEPs were continuously recorded during the thrombolysis. Normalization of the latencies and of the interpeak latencies at a very early stage of the therapy indicated the improvement of brainstem functions.

Adult↗
PubMed1983

The so-called atheromatous pseudoocclusion of the internal carotid artery. A diagnostic and therapeutical challenge.

The term "atheromatous pseudoocclusion" of the internal carotid artery (ICA) describes an extreme type of stenosing lesion which, during non-invasive procedure and conventional angiography is easily misdiagnosed as complete occlusion. Its recognition requires special sonographic and angiographic techniques. Nine subjects with pseudoocclusion could be observed during the last 12 months, most of them presenting minor strokes. Infarction suggesting a haemodynamic pathogenesis were demonstrated in seven of the cases by computed tomography. In seven of the eight subjects that were operated on, ICA reconstruction was successful. Since pseudoocclusion of the ICA is likely to progress rapidly to definite occlusion, the patient is severely jeopardized from periocclusive embolism into the major brain arteries. Immediate diagnostic clarification and emergency endarterectomy are mandatory.

Aged↗
PubMed1983

[Orbicularis oculi reflex in computerized tomography verified lesions of the posterior cranial fossa].

The blink reflex elicited by electrical stimulation was studied in 60 patients with lesions of the brainstem and cerebellum (ischemic lesions, non-traumatic bleedings or tumors), which were diagnosed by computertomography. The relationship between localized morphological changes in computertomography and changes in blink reflex has been studied. 46 patients (77%) had a pathologic blink reflex. Usually the blink reflex was normal in patients with a tumor of cerebellum. In bleedings or tumors of the brainstem a good relationship existed between localization and extension of the lesion and the pathological pattern of the blink reflex. In patients with thrombosis of the basilar artery no responses or single delayed responses to the electrical stimulation were found. A less good relationship was observed in ischemic lesions of the brainstem. This is interpreted as indicating possible multilocalization of vascular lesions in the brainstem. Nearly half of the patients with ischemic lesions also had supratentorial lesions. The influence of these lesions on the pattern of the blink reflex will be discussed.

Adolescent↗
PubMed1983

[Arterial retinal circulatory disorders: an urgent indication for Doppler sonographic study of the carotid flow system].

Nineteen subjects with retinal strokes of different degrees of severity (amaurosis fugax, occlusion of individual retinal arteries or of the central retinal artery) were examined by continuous-wave Doppler sonography. Evaluation of periorbital Doppler flow and direct examination of the major neck vessels were performed. Twelve subjects presented with homolateral arteriosclerotic lesions at the carotid bifurcation. The ultrasonographic findings were confirmed by carotid arteriography. High-grade stenosis or occlusion of the internal carotid artery were found in approximately 50% of the patients; the remainder turned out to have low-grade stenoses or nonstenosing plaques. These findings emphasize the role of emboli from the major neck arteries in the pathogenesis of retinal and cerebral insults. Hemodynamic effects seem to be of minor significance. Continuous-wave Doppler sonography is a completely non invasive, but nevertheless reliable method for the detection of clinically relevant carotid lesions. Especially patients suffering from retinal insults should be examined by Doppler sonography, since they are at high risk for further cerebral stroke.

Aged↗
PubMed1983

[Vascular recanalization procedure in interventional neuroradiology].

Thirty-two patients are described. Sixteen patients were treated by local intra-arterial fibrinolysis (LIF) for lesions of the intracranial vessels. In nine patients there was a vertebrobasilar thrombosis, in four patients an occlusion of the middle cerebral artery and in three patients a sinus thrombosis. The results of percutaneous transluminal angioplasty (PTA) in fourteen patients are reported; they included dilatation of the subclavian artery in 12 and the vertebral artery in two of them. Dilatation of post-operative fibrous stenosis of the internal carotid artery in two patients is described. The technique for local intra-arterial fibrinolysis and recommended doses for streptokinase are given. The use of Doppler sonographic monitoring during PTA is recommended, particularly as for delayed return to normal flow in the vertebral artery.

Angioplasty, Balloon↗
PubMed1983

[EDP-adapted grid model of the brain for topographic analysis of lesions on the cranial computer tomogram].

A method for the recording and statistical evaluation of computer tomographic morphological data is described. The lesions demonstrated by computer tomography are transferred to a sectional model of the brain on which a grid is superimposed. The sections and grid are then transferred to the Evaluscope (Siemens) and the original CT lesion is recorded with a light-pen and then stored. Statistical evaluation of the data can be carried out centrally and can be combined with the results of other clinical studies.

Aphasia, Broca↗