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Biomedical subjects

J E Knake

Publications and source records attributed to J E Knake.

44 records · Page 3Linked to original sources

Intraoperative sonography in the nonstereotaxic biopsy and aspiration of subcortical brain lesions.

Deep-seated brain lesions, especially small ones, present a neurosurgical challenge to achieve tissue diagnosis with minimal damage to intervening normal brain. Needle biopsy is often indicated but has been a relatively arduous procedure using stereotaxic frame methods. Tissue sampling is greatly simplified by the use of intraoperative real-time sonography for needle guidance. The technique is also applicable to cyst or abscess drainage and ventricular decompression. Of 37 cases in which intraoperative brain sonography was used, 19 included sonographic guidance of a needle, probe, or wire-stiffened catheter into the lesion. Sonography is an easy and accurate substitute for stereotaxic guidance procedures. It is also useful for reexamination of the brain after interventions such as biopsy, resection, and drainage.

Adult↗

Cerebral CT findings in methylmalonic acid propionic acidemias.

The cerebral computed tomographic findings in two infants with methylmalonic acidemia and one infant and one adult with propionic acidemia are presented. Pertinent metabolic, clinical, and pathologic features of these genetic disorders of vitamin B12 (cobalamin) and biotin metabolism are reviewed briefly. Computed tomographic abnormalities consist of focal or diffuse deep cerebral hemisphere lucencies and diffuse loss of brain substance. These findings correlated well with the clinical and pathologic findings. The leukoencephalopathy in these uncommon autosomal recessive conditions appears to be due to ketoacidosis, which in some cases may be managed by vitamin supplementation.

Adolescent↗

Intraoperative sonography of intraspinal tumors: initial experience.

Real-time sonography during surgery for intraspinal tumors is capable of demonstrating the extent of the tumor, its relation to the spinal cord, and the internal morphology of both the tumor and the cord. Such information is not obtainable intraoperatively by any other imaging method. It is especially valuable when all or a part of the tumor is anterior to the cord and therefore not visible to the surgeon without exploration and the attendant risk of spinal cord injury. Direct contact with the spinal cord is not necessary for sonographic imaging.

Cauda Equina↗

Effect of head turning on blood flow in lateral sinuses of nonhuman primates.

The pattern of blood flow leaving the cranium via the lateral sinuses and internal jugular veins is significantly altered by head rotation. This effect is documented in the baboon and macaque monkey by Doppler flow recording and by angiography. This phenomenon may affect the validity of cerebral blood flow data determined by venous sampling and may have significance in angiographic interpretation and in the clinical course of patients with a hypoplastic or occluded lateral sinus or internal jugular vein.

Animals↗