Search PubMed⌕ Search

Biomedical subjects

A C Klassen

Publications and source records attributed to A C Klassen.

At least 37 records · Page 2Linked to original sources

Altered cerebral inhibition of respiratory and cardiac responses to hypercapnia in acute stroke.

Ventilatory and heart-rate responses to hypercapnia were evaluated by a CO2 rebreathing technique in 56 patients with acute ischemic stroke and 14 normal controls. Both ventilatory and heart-rate responses were increased in patients with hemispheral lesions, but not in patients with brainstem lesions. In patients with hemispheral infarct, there was a decrease in CO2 sensitivity 1 to 3 weeks later. Acute hemisphere lesions may result in a transient decrease of cerebral inhibition of brainstem-mediated autonomic responses to a chemical stimulus.

Adolescent↗

Superficial temporal to middle cerebral artery anastomosis. Clinical outcome in patients with ischemia of infarction in internal carotid artery distribution.

The clinical outcome of our first 40 patients (six with transient ischemic attacks, 22 with mild ischemic infarctions, and 12 with moderate ischemic infarctions) treated with a superficial temporal artery-middle cerebral artery anastomosis was analyzed. All cerebral ischemias or infarctions occurred in the internal carotid artery distribution. An independent neurologist observer recorded the patients preoperative and postoperative medical and neurological histories and objective neurological findings. There was no operative mortality. During the period of observation (up to 36 months), four patients died of probable myocardial infarction. No patient suffered from recurrent cerebral infarction. Three patients experienced a single ischemic event postoperatively. Neurological deficits were either unchanged (21 patients) or improved (19 patients). Postoperative angiograms showed patency in 97% of the anastomoses.

Adult↗

Hypercapnic alteration of visual evoked responses in acute cerebral infarction.

To determine the effect of inhaled carbon dioxide on acute ischemic cerebral injury, we have compared occipital visual evoked responses (VER) at baseline and during hypercapnia in 20 patients with acute unilateral cerebral infarction (ten with and ten without homonymous hemianopsia) and in ten normal controls. Visual evoked responses were judged on the basis of interhemispheral symmetry. In eight of ten controls and six of 20 patients, baseline VERs were symmetrical and remained unchanged during hypercapnia. In 14 patients with asymmetrical baseline VERs, hypercapnia caused improvement of symmetry in five, worsening in three, and no change in six. Hypercapnic vasodilation may be either beneficial or deleterious to cerebral function in patients with acute cerebral infarction.

Acute Disease↗