Hormonal influence on water permeability across the blood-brain barrier.

We have shown that steroid manipulations may influence the rate of flux of water across the blood-brain barrier. Such changes are regionally variable and are best seen in the cerebral cortex. Administration of dexamethasone produced decreased water permeability while withdrawal of dexamethasone and ethinyloestradiol resulted in increased permeability.

Management of traumatic intracranial haematoma.

Deciding which head-injured patients should be transferred to a neurosurgical unit can be difficult. Traditional criteria emphasise the development of deteriorating responsiveness but lead to delayed diagnosis and to avoidable mortality and morbidity. To discover if a more liberal admission policy improved results a study was conducted analysing data collected prospectively from 683 patients who had a traumatic intracranial haematoma evacuated in the Glasgow neurosurgical unit between 1974 and 1980.

Autoradiographic assessment of choroid plexus blood flow and glucose utilization in the unanesthetized rat.

Choroid plexus blood flow (CPBF) and glucose utilization (CPGU) were measured in two groups, each of seven identically prepared, unanesthetized rats, using complementary quantitative autoradiographic techniques. Both CPBF and CPGU were lowest in the lateral ventricles (0.83 +/- 0.

Intra-arterial histamine increases blood-brain transport in rats.

The neurotransmitter histamine is located in multiple compartments in the brain and may influence cerebral vessels during some conditions. We made measurements of cerebrovascular transport of labeled sucrose, alpha-aminoisobutyric acid (AIB), and horseradish peroxidase during sustained infusion of histamine into the internal carotid artery of anesthetized rats. Histamine increased the rates of transport of sucrose and AIB up to 237% in several brain regions and in different areas of cerebral cortex.

Cerebrovascular permeability following MCA occlusion in the rat. The effect of halothane-induced hypotension.

A quantitative autoradiographic technique that utilizes carbon-14-aminoisobutyric acid (14C-AIB) as a tracer was used to study alterations in cerebral microvascular permeability in 15 rats. Five were "sham-operated" controls and 10 underwent microsurgical, unilateral occlusion of the proximal middle cerebral artery (MCA). Histological changes indicative of focal cerebral ischemia were observed in only the latter 10 animals.

Observer variability in grading patients with subarachnoid hemorrhage.

The management of individual patients with subarachnoid hemorrhage depends greatly on assessment of the patient's clinical condition. Difficulty in applying current grading systems prompted the authors to conduct studies of observer variability and to attempt to identify sources of inconsistency. Observers graded 15 patients by both the Hunt and Hess and Nishioka systems.

Cryosurgery or microsurgery in the management of acromegaly.

Fifty-six patients with growth hormone-secreting pituitary adenomas, 28 treated by cryoablation and 28 by microsurgery, have been followed up from three to eight years. Mean serum growth hormone concentrations were less than 10 mU/L in 19 patients (68%) after microsurgery as compared with seven (25%) after cryosurgery. Hypopituitarism and operative complications were more frequent after cryosurgery.

Regional effect of mepyramine on cerebral glucose utilization in conscious rats.

We examined effects of the antihistamine, mepyramine, which occupies cerebral H1-receptors, on regional brain metabolism of glucose in conscious rats. Although glucose utilization by most structures was not significantly affected, in high doses, mepyramine did cause modest, localized reductions in brain areas with both high (ventromedial nucleus of hypothalamus) and low (medial forebrain bundle) densities of histamine H1-receptors.

Assessment of the consequences of subarachnoid haemorrhage.

The management of patients with subarachnoid haemorrhage depends greatly on assessment of the patient's clinical condition. Difficulty in applying currently used grading systems prompted us to conduct studies of observer variability and to attempt to identify sources of inconsistency. Observers graded 15 patients from the Hunt and Hess and Nishioka systems.

Forehead reconstruction using a bi-pedicled bone flap.

The forehead can be reconstructed using a bi-pedicled bone flap based on the temporalis muscles. The technique is illustrated by the description of a patient in whom post-operative radio-isotope scanning was used to demonstrate the viability of the transposed bone. The technique is useful when there has been previous infection.

Evoked potentials in severe head injury--analysis and relation to outcome.

Somatosensory, visual and auditory cortical and brainstem evoked responses were obtained from 32 patients with severe head injury. A simple count of the number of waves present in the various responses provided the optimum method of analysing the data. The results of each cortical response, but not of the brainstem response, correlated with outcome, and a combined assessment gave the highest correlation.

Impromidine, a potent dilator of cat pial arterioles.

Impromidine (SKF 92676) has been demonstrated to have highly potent and selective activity at histamine H2-receptors in a variety of physiological systems. We compared responses produced by perivascular microapplication of histamine and impromidine in cat pial arterioles in situ. Impromidine caused twice as much maximal dilation as histamine, and was ten times more potent.

The reliability of radiology in detecting prolactin-secreting pituitary microadenomas.

Radiological findings in 30 patients with proven prolactin-secreting pituitary adenomas, originally diagnosed exclusively by endocrine criteria, have been reviewed. Conventional tomography was the examination most often abnormal (50%), and changes or lack of changes corresponded to the state of the pituitary fossa as noted at operation in 93%. Tomographic abnormalities indicated the site of the tumour in 86%.

Predicting the need for operation in the patient with an occult traumatic intracranial hematoma.

Computerized tomography scanning has shown that acute traumatic intracranial hematomas are more common than was previously realized, but whether all hematomas must be removed remains controversial. About half of this series of 26 patients who were not clinically deteriorating and who were initially managed without operation had to undergo hematoma removal because they subsequently deteriorated. Features present at the time of diagnosis (age, type and site of hematoma, presence of focal signs, level of responsiveness, and degree of midline shift) were not helpful in predicting that operation would be needed.

Serial ventricular volume measurements: further insights into the aetiology and pathogenesis of benign intracranial hypertension.

Ventricular volumes have been measured from CT scans of patients with benign intracranial hypertension both at initial presentation and at a later date. Volumes initially were smaller than normal, but at review five patients showed a significant increase in ventricular size. Persisting small ventricular volume correlated with persisting symptoms and signs and with persisting obesity.

Vasoconstrictive effects of human post-hemorrhagic cerebrospinal fluid on cat pial arterioles in situ.

Cat cortical arterioles were exposed in vivo to cerebrospinal fluid (CSF) from four patients with subarachnoid hemorrhage (SAH) due to a ruptured intracranial aneurysm. Pial arteriolar caliber was measured by the television image-splitting technique. There was a consistent vasoconstrictive response to CSF.

Focal cerebral ischaemia in the rat: 2. Regional cerebral blood flow determined by [14C]iodoantipyrine autoradiography following middle cerebral artery occlusion.

Local cerebral blood flow has been measured by quantitative autoradiography, employing [14C]iodoantipyrine as tracer, in rats killed half an hour after occlusion of the middle cerebral artery. The results were compared with pattern of local cerebral blood flow (CBF) in sham-operated rats and with neuropathological findings. In every animal there was a profound reduction (to 13% of control levels)in blood flow in the neocortex previously by the occluded artery.