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Biomedical subjects

T M Markwalder

Publications and source records attributed to T M Markwalder.

46 records · Page 3Linked to original sources
PubMed1982

Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries.

In this report the authors describe a noninvasive transcranial method of determining the flow velocities in the basal cerebral arteries. Placement of the probe of a range-gated ultrasound Doppler instrument in the temporal area just above the zygomatic arch allowed the velocities in the middle cerebral artery (MCA) to be determined from the Doppler signals. The flow velocities in the proximal anterior (ACA) and posterior (PCA) cerebral arteries were also recorded at steady state and during test compression of the common carotid arteries. An investigation of 50 healthy subjects by this transcranial Doppler method revealed that the velocity in the MCA, ACA, and PCA was 62 +/- 12, 51 +/0 12, and 44 +/- 11 cm/sec, respectively. This method is of particular value for the detection of vasospasm following subarachnoid hemorrhage and for evaluating the cerebral circulation in occlusive disease of the carotid and vertebral arteries.

Adult↗
PubMed1981

The course of chronic subdural hematomas after burr-hole craniostomy and closed-system drainage.

A consecutive series of 32 adult patients with chronic subdural hematoma was studied in respect to postoperative cerebral reexpansion (reduction in diameter of the subdural space) after burr-hole craniostomy and closed-system drainage. Patients with high subdural pressure showed the most rapid brain expansion and clinical improvement during the first 2 days. Nevertheless, a computerized tomography (CT) scan performed on the 10th day after surgery demonstrated persisting subdural fluid in 78% of cases. After 40 days, the CT scan was normal in 27 of the 32 patients. There was no mortality and no significant morbidity. Our study suggests that well developed subdural neomembranes are the crucial factors for cerebral reexpansion, a phenomenon that takes at least 10 to 20 days. However, blood vessel dysfunction and impairment of cerebral blood flow may participate in delay of brain reexpansion. It may be argued that additional surgical procedures, such as repeated tapping of the subdural fluid, craniotomy, and membranectomy or even craniectomy, should not be evaluated earlier than 20 days after the initial surgical procedure unless the patient has deteriorated markedly.

Adult↗
PubMed1979

Primary intraventricular oligodendrogliomas.

Two cases of primary intraventricular oligodendrogliomas which were successfully removed by a transventricular approach using microtechniques are presented. Oligodendrogliomas in this location are very rare. The literature is reviewed.

Adolescent↗
PubMed1979

Intracerebral ciliated epithelial cyst.

The authors describe a case of hemispheric brain cyst of possible neuroectodermal origin, presenting as a frontotemporoparietal mass lesion. The etiologic aspects of intracranial neuroepithelial cysts are discussed.

Adult↗
PubMed1979

Metastatic chordoma.

The authors present two cases of vertebral chordomas with widespread metastases. The literature is reviewed and the metastatic potential of chordomas is analysed.

Adult↗
PubMedDate not supplied

Spontaneous bilateral recanalization in bilateral internal carotid artery occlusion.

The authors report a young woman with bilateral internal carotid artery occlusion shown by carotid angiography. There was spontaneous bilateral recanalization demonstrated radiographically. The possible causes, e.g. the intake of oral contraceptive drugs, a spontaneous intimal dissection and other etiological features are discussed and the literature is reviewed.

Adult↗