S. Turtas

Regional cerebral blood flow after omental transposition to the ischaemic brain in man. A five year follow-up study.

SummaryRegional cerebral blood flow, recorded by the133Xenon inhalation method, was measured preoperatively and over a five years postoperative period in six patients with completed stroke and stabilized neurological deficits, who had undergone omental transposition for revascularization of the ischaemic brain. Comparisons of the preoperative blood flow values with those recorded following surgery demonstrate a postoperative increase of blood flow in five patients, with a high statistical degree of significance in four of them at the final examination. The flow increase was noted over the infarcted areas of the brain, upon which the omentum had been placed, as well as areas of the ischaemic hemisphere without omental placement and the contralateral hemisphere. Out of the five patients who demonstrated preoperative flow values below the expected norm for age, four showed final postoperative cerebral blood flow within the normal limits for their age. The results are consistent with the assumption that the transposed omentum played a role in postoperative blood flow increase, by adding collateral circulation to the ischaemic brain.

Mobile neurinoma of the cauda equina. Case report.

SummaryA mobile neurinoma arising from a redundant nerve root of the cauda equina is reported. The abnormal length of the nerve root allowed the neoplasm to move in the cranio-caudal direction along two segments of the spine.

Effect of omental transposition to the brain on protein synthesis in experimental cerebral ischaemia.

SummaryOcclusion of the middle cerebral artery severely affects the uptake of labelled leucine into various subcellular fractions from rabbit brain. Previous transposition of pedicled omentum to the cerebral surface maintains to a large extent the protein synthetic activity of the brain following arterial occlusion. The role of the transposed omentum in providing an effective collateral circulation and minimizing the occurrence of irreversible ischaemic lesions is stressed.

Cerebral Water and Electrolytes in Experimental Ischaemia Following Omental Transposition to the Brain

SummaryOcclusion of the middle cerebral artery induces a local decrease in percentage of tissue dry weight in rabbit brain, associated with flux of sodium and potassium in reciprocal directions. Cortical swelling occurs also in remote non-ischaemic areas. Previous transposition of the omentum majus to the brain minimizes the onset of oedema consequent on occlusion of a major cerebral artery. Increasing experimental evidence points to the role of omental transposition in providing an effective source of collateral circulation, thus strongly affecting the threshold for infarction.

Omental transposition or transplantation to the brain and superficial temporal artery-middle cerebral artery anastomosis in preventing experimental cerebral ischaemia

SummaryTransposition of lengthened omentum to the brain surface, transplantation of an omental graft, or superficial temporal artery-middle cerebral artery anastomosis were performed in dogs prior to transcranial occlusion of the ipsilateral middle cerebral artery at its origin, including the bifurcation of the internal carotid artery. Both omentum and by-pass were able to reduce the changes in cerebral blood flow, somatosensory evoked responses, cerebral water and electrolyte content, consequent to the ischaemic insult. In the experimental conditions adopted in this study, the effect of omental transposition in maintaining high levels of flow throughout the entire occluded hemisphere was more marked compared to that resulting from the other methods, while the onset of ischaemic cerebral oedema was affected approximately at the same degree by all procedures. The results point to the role of the transposed omentum in providing an effective collateral circulation to the ischaemic brain.

Cerebral blood flow in minor cerebral contusion

Seventeen patients with minor cerebral contusion were selected from a series of patients with head injuries of various severity, who had undergone repeat evaluations of the regional cerebral blood flow. The mean global flow (expressed as mean global initial slope index) on early examination was found to be significantly lower, compared with that recorded in healthy volunteers. A tendency towards the recovery of higher flow values was apparent in repeat evaluations that were performed several weeks after the injury. Interhemispheric asymmetries of flow were a common occurrence, with lower perfusion and reduced attenuation values on computed tomography scans being, however, in good agreement only in approximately half of the cases.

Effect of Omental Transposition on to the Brain on the Cortical Content of Norepinephrine, Dopamine, 5-Hydroxytryptamine and 5-Hydroxyindoleacetic Acid in Experimental Cerebral Ischaemia

SummaryLocal cerebral ischaemia causes a significant decrease in norepinephrine, dopamine, 5-hydroxytryptamine in the cortical brain tissue of rabbits, associated with an increase in 5-hydroxyindoleacetic acid. Previous transposition of the omentum on to the brain surface maintains, to a large extent, physiological levels of these metabolites. This study stresses the role of the transposed omentum in reducing the effects of experimental occlusion of a major cerebral artery.

Parkinsonism in the presence of intracranial extracerebral haematomas

SummaryBilateral Parkinsonism has been observed in a 60-year-old female with a chronic subdural intracranial haematoma. Scattered, poorly marginated, hypodense areas within the ipsilateral pallidus and putamen were evident on the preoperative CT scans. The rapid neurological improvement following the surgical drainage of the subdural clot and the evolution of the densitometric features of the nuclear lesions, which became clear-cut, though smaller, in the following months, suggest a cause-and-effect relation between the haematoma and the clinical symptomatology. To the best of our knowledge this is the first case in which anatomical lesions within the basal ganglia could be detected neuroradiologically.

Surgical removal of a pontine haematoma associated with a cryptic angioma. Case report.

SummaryA further case of successful removal of an intrapontine haematoma related to a cryptic angioma is described. With a CT scan, the most accurate anatomical localization of the lesion may be obtained.

Unusual appearance of an acoustic neurinoma in CT scans

SummaryA large cystic neurinoma of the cerebellopontine angle is reported. This case is unusual in that the clinical history, CT patterns and plain radiological findings were rather misleading for the differential preoperative diagnosis.