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Biomedical subjects

N B Rewcastle

Publications and source records attributed to N B Rewcastle.

44 records · Page 3Linked to original sources
PubMed1967

Shear injuries of the brain.

A blow to the head will impart rotational velocity to the brain and, depending on its magnitude, will produce effects ranging from concussion to profound neurological dysfunction. Resultant shear strains distort and rupture axons, blood vessels and major fibre tracts. Thirty-seven patients with head injury that was not complicated by significant hemorrhage or superficial laceration of the brain had coma or severe dementia, spastic quadriparesis, incontinence and autonomic dysfunction. These patients survived 24 hours to 243 days. Gross pathological examination revealed little, but there was microscopic evidence of axonal and small vessel injury in all; this was localized to the basal and midsagittal areas of the diencephalon and mesencephalon, particularly in those less severely injured. Such changes represent the basic pathology of all head injury. Data from this study suggest that concussion depends upon varying degrees of damage to the axon as well as the neuron. The current definition of concussion-immediate loss of consciousness with rapid and complete recovery of cerebral function-should not exclude the fact that a small number of neurons may have been permanently disconnected or have perished.

Axons↗
PubMedDate not supplied

Recurrent stenosis at site of carotid endarterectomy.

Five patients studied by the authors and 28 mentioned in the literature indicate that recurrent stenosis occurs in no less than 0.6% of patients after carotid endarterectomy. The pathology of the recurrent stenosis was stated in only 10 cases indicating atherosclerotic disease in various stages of development in 7 and a fibrous intimal hyperplasia in 3. Correlation between risk factors for the development of atherosclerosis and the pathology of the recurrent disease was poor. Six patients developed recurrent disease despite postoperative prophylactic oral anticoagulation. Surgical technique appeared to have contributed to re-stenosis in 8 patients (1) by failure to remove the distal tongue of plaque or (2) narrowing of the lumen by the arteriotomy suture or (3) damage by a vascular clamp. In 18 symptomatic patients, 44% had symptoms by 3 years, 67% by 5 years, and 83% by 7 years after operation. The 8 patients with possible errors in surgical technique did not develop symptoms earlier than the other patients. Seventeen symptomatic patients had surgical correction of the re-stenosis (endarterectomy 9, vein patch 6, arterial homograft 1, not detailed 1). The incidence of recurrent stenosis after carotid endarterectomy is low and usually the operation provides a patent artery for life.

Adult↗
PubMedDate not supplied

Tomographic abnormalities simulating pituitary microadenomas.

False-positive and false-negative interpretations of sellar tomography were found in about one-fifth of cases in a recent autopsy study correlating the presence of pituitary microadenomas with abnormal sellar tomograms. An analysis of minor variations in the bony configuration of the sella disclosed variations due to posterior lobe asymmetry, intercavernous venous channels, bony asymmetry, and an empty sella in 27 of the 120 sellas examined. In some instances, the asymmetry resulted from a combination of these causes. A further study of 50 pituitary glands in situ showed posterior lobe asymmetry to be a common anomaly (76%) that can produce an obvious disparity between the two halves of the sella. Thus, the minor radiologic criteria of local thinning of the anterior wall or floor, slant of the floor, or asymmetry of the two halves of the sella must be interpreted with caution as being indicative of the presence of pituitary microadenoma. In the absence of clinical or biochemical dysfunction, the changes more likely result from explainable anatomic causes.

Adenoma↗