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Biomedical subjects

H J Steiger

Publications and source records attributed to H J Steiger.

100 records · Page 6Linked to original sources
PubMed1985

[Diagnosis and therapy of cerebral angiomas].

Cerebral angiomas are rare, congenital malformations of the cerebral blood vessels. Approximately 60 new cases are diagnosed in Switzerland each year. These malformations become symptomatic most often with cerebral hemorrhage, epilepsy or intractable headache. Total excision is the only curative therapy. Alternative treatments are embolization with isobutyl-cyanoacrylate or high energy radiotherapy, although these latter procedures rarely achieve complete obliteration. Indications for the different therapeutic modalities are discussed.

Arteriovenous Malformations↗
PubMed1985

[The significance of distal obstructions and stenoses of the vertebral artery].

3 patients with intracranial infarctions as consequence of obstructive lesions of the distal vertebral artery are presented. The first patient, with a unilateral occlusion of the distal intracranial portion of the vertebral artery and contralateral high grade stenosis at the same site, suffered bilateral cerebellar infarctions. Predominantly occipital infarction occurred in the second patient, with unilateral occlusion of the vertebral artery, the infarction being probably caused by embolization from the distal stump. In the third patient traumatic injury of the vertebral artery at the C1/C2 level was followed by embolic occipital lobe infarction. The discussion covers pathogenetic significance of hemodynamic and thromboembolic factors for cerebellar and occipital infarctions and the possible therapeutic options.

Adult↗
PubMed1984

Hemorrhage and epilepsy in cryptic cerebrovascular malformations.

A series of 15 angiographically cryptic, histologically proved, cerebrovascular malformations occurred. Nine patients were admitted to the hospital with evidence of recent neurological deterioration or onset of headache. Six patients had convulsions. Computed tomographic scan and surgical exploration disclosed a substantial cerebral hematoma in eight instances. The pathological diagnosis was arteriovenous malformation in 11 cases, cavernous angioma in three, and venous angioma in one. Histological evidence of previous microhemorrhage was present in the majority of the specimens, including the patients who had seizures. A change in neurological status or onset of seizures probably indicates recent hemorrhage in cryptic cerebrovascular malformations.

Adolescent↗
PubMed1982

The sensory representation of the dura mater in the trigeminal ganglion of the cat.

The representation of the dura mater in the trigeminal ganglion was examined in the cat using the horseradish peroxidase (HRP) method. Following craniotomy a 50% solution of HRP was applied to various areas of the cranial dura and after a survival time of 48 h the trigeminal ganglion was processed. Cells in the first division gave rise to fibers innervating the medial aspect of the anterior fossa as well as the tentorium cerebelli. Labeled cells associated with the orbital roof were located predominantly in the dorsal and intermediate layers of the second division while the middle fossa was found to be represented mainly in the more dorsal strata of the third division. Labeled cells were smaller than the average ganglion cell.

Animals↗
PubMed1981

Carotid Doppler hemodynamics in posttraumatic intracranial hypertension.

Repeated Doppler sonograms were performed on the common carotid arteries of patients with severe brain injury. The evolution of the flow-wave shape in 9 patients who developed massive intracranial hypertension and finally died with cerebral circulatory arrest demonstrated that, with increasing peripheral vascular resistance, the diastolic flow diminished while the peak systolic flow was not significantly affected. Thus, the so-called pulsatility index, a measure of the pulsatile characteristic of the sonogram, can be used as a semiquantitative measure of intracranial perfusion. Measurements on healthy control subjects provided pulsatility indexes between 1.5 and 2.0. In cases of posttraumatic brain edema, these values increased gradually. These data suggest that values higher than 3 are associated with severe intracranial hypertension and the decerebrate state. In angiographically demonstrated cerebral circulatory arrest, the pulsatility index was found to range between 6 and 8.

Brain Injuries↗
PubMed1979

Oculomotor nucleus afferents in the monkey demonstrated with horseradish peroxidase.

The afferents to the oculomotor nucleus were examined in the macaque monkey by means of horseradish peroxidase. The demonstration of afferents from the contralateral interstitial nucleus of Cajal, and from the nearby rostral interstitial nucleus of the medial longitudinal fasciculus, predominantly ipsilateral to the injection site, confirms the significant role of these two regions as premotor structures. HRP label in the pretectal area was strictly confined to the olivary nucleus and the corresponding pathway seems to concern the Edinger-Westphal nucleus in particular. A purely crossed internuclear pathway emanating from the abducens nucleus could be established, and evidence for the presence of intranuclear connections within the oculomotor complex itself was found. Ipsilateral afferents from the superior vestibular nucleus and bilateral connections from the medial vestibular nucleus and the y-group were prominent. A projection, showing some rostrocaudal organization within the oculomotor nucleus, arises from the ipsilateral perihypoglossal complex, and other afferents originated from the underlying medullary reticular formation. No evidence was found for the existence of afferents from the paramedian pontine reticular formation, the nucleus Darkschewitsch, the nuclei of the posterior commissure, the lateral tegmentum and the dentate nucleus.

Abducens Nerve↗
PubMedDate not supplied

Regional relative blood volume MR maps of meningiomas before and after partial embolization.

PURPOSE: Our goal was to evaluate the role of relative blood volume (rBV) measurements in monitoring the embolization effect in meningiomas by using maps of susceptibility-weighted first pass MR data. METHOD: Eighteen examinations of nine patients before and following partial embolization were performed on a 1.5 T scanner. Embolization was achieved by injection of particles (45-150 microns). During dynamic imaging a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. RESULTS: The tumor rBV/gray matter rBV ratio was 3.11 +/- 1.40 for untreated tumors and 0.12 +/- 0.09 for successfully embolized tumors. The regional rBV in embolized meningiomas was significantly lower than that in untreated meningiomas (t test, p < 0.001). Vital tumor tissue showed positive enhancement in T1 and high rBV; nonvital tissue lacked T1 enhancement and bolus effect in the first pass, thus leading to low or missing rBV values. However, we also observed lack of bolus formation despite T1 enhancement (6/9 postembolization regions), possibly due to slow collateral flow. One of the patients treated with embolization bled during surgery. CONCLUSION: Maps of relative regional cerebral BV provide hemodynamic information in meningiomas and monitor the treatment effect of embolization in meningiomas more precisely than T1-weighted contrast-enhanced imaging.

Blood Loss, Surgical↗