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Biomedical subjects

V L McAllister

Publications and source records attributed to V L McAllister.

17 recordsLinked to original sources

White matter lesions and season of birth of patients with bipolar affective disorder.

OBJECTIVE: It is established that patients with bipolar disorder have an excess of births in winter or early spring. The authors investigated a link between season of birth and white matter lesions with magnetic resonance imaging (MRI). METHOD: T(2)-weighted and proton density MRI scans were examined for 79 patients with bipolar disorder (DSM-IV) for the presence of deep subcortical and periventricular white matter lesions. The birth seasons of patients with white matter lesions were compared with those of the general population. RESULTS: Thirteen subjects exhibited deep subcortical white matter lesions, of whom nine (69.2%) were born in the winter months (January to March). Seven of these patients remained symptomatic, despite adequate treatment for more than 2 years. CONCLUSIONS: Birth season, illness outcome, and deep subcortical white matter lesions appear to be closely linked. Deep subcortical white matter lesions may be a marker of a toxic or infective insult in utero.

Adult↗

Cerebral white matter lesions in bipolar affective disorder: relationship to outcome.

BACKGROUND: Twenty per cent of patients with bipolar affective disorder suffer an illness that responds inadequately to treatment and has a poor outcome. Many patients, but not all, with bipolar disorder show white matter abnormalities on T(2)-weighted magnetic resonance imaging (MRI). AIMS: To explore the hypothesis that white matter abnormalities on MRI are seen more frequently in subjects whose illness has a poor outcome compared with those with a good outcome or controls. METHOD: Two groups of age- and gender-matched patients with bipolar disorder (14 with a good outcome and 15 with a poor outcome) and 15 controls, aged 20-65 years, were studied. Axial T(2)-weighted MRI scans were examined for the presence and severity of white matter abnormalities. RESULTS: Significantly more poor outcome group members had deep subcortical punctate, but not periventricular, white matter hyperintensities than the good outcome group (P:=0.035) or controls (P:=0.003) and these abnormalities were of greater severity (P:=0.030 and P:<0.014, respectively). CONCLUSIONS: Subcortical white matter lesions are associated with poor outcome bipolar disorder.

Adult↗

Cerebrotendinous xanthomatosis in two sisters: case reports and MR imaging.

Cerebrotendinous xanthomatosis is a rare inherited disorder of bile acid metabolism producing xanthomata and severe, progressive neurological deficits. In spite of the rarity of the condition it is important because it is treatable: the neurological deterioration can be halted and in some cases reversed.

Adult↗

Subarachnoid hemorrhage in childhood and adolescence.

The authors have reviewed 167 cases of subarachnoid hemorrhage (SAH) occurring in patients aged 20 years and younger in a 23-year period. The modes of presentation and etiology of SAH are similar in childhood and adolescence and in the adult population, but there was a different incidence of the specific pathology producing the bleeding in this series. Twenty-six percent of cases were due to bleeding arteriovenous malformations, 52% were due to ruptured aneurysms, and in 19% no cause was found. Aneurysms in this young age group differed in several important respects from those in the adult population: there was a male predominance, a higher incidence of internal carotid bifurcation aneurysms was seen, and multiple aneurysms were encountered less commonly.

Adolescent↗

Posterior circulation aneurysms. Results of direct operations.

Twenty-eight patients with aneurysms of the posterior circulation were managed by direct operations, 53.6% of these being done within 14 days of a subarachnoid hemorrhage. Transvenous cardiac pacing was used in 4 of the 13 patients with aneurysms of the basilar bifurcation in order to produce a short period of profound hypotension while final dissection and clip application was performed. There were nine patients with posterior-inferior cerebellar artery/vertebral-junction aneurysms, the only one dying having a large aneurysm. The operative technique used in the majority of the 13 patients with basilar bifurcation aneurysms involved subtotal temporal lobectomy, and the operative exposure so obtained was excellent. Five patients died, one of whom rebled from an aneurysm of the basilar artery origin that could only be wrapped, the total mortality being 17.9%. Seventeen (74%) of the 23 survivors were assessed as showing good results; 5 (22%) as showing fair results, and only 1 (4%) as showing a poor result.

Adult↗

Intracranial calcification in survivors of childhood medulloblastoma.

Computerised tomography scans of the brain have been performed on 5 children who have survived at least 5 years after treatment with surgery and radiotherapy for medulloblastoma. Intracranial calcification of varying degrees of the basal ganglia and of the frontal and parietal cortex was detected in the 3 children who were irradiated under age 5 years.

Age Factors↗

Metrizamide cisternography in pituitary and juxtapituitary lesions.

Seventy-five suprasellar metrizamide cisternograms were obtained, 25 in normal individuals who had had cervical myelography and 50 in patients with pituitary or juxtapituitary lesions. The technique accurately delineates a suprasellar extension of a small or moderate-sized pituitary lesion and usually shows its relationship to the optic chiasm. Large suprasellar masses, however, are not well visualized. 'Empty sellae' are readily demonstrated and have a high incidence in both normal individuals and those with pituitary tumors. This procedure can be supplemented by metrizamide CT cisternography and is simpler to perform and often better tolerated by patients than is pneumoencephalography.

Acromegaly↗

Myelography with metrizamide in occult spinal dysraphism.

The initial experiences with metrizamide (Amipaque) in cases of spinal dysraphism are described. The technique, myelographic appearance and adverse reactions are discussed. The results have been promising and it is believed that this contrast medium will provide more accurate diagnostic information. However, further experience is necessary and in particular correlation with surgical findings.

Adolescent↗

The radiology of thoracic disc protrusion.

The radiological features of 20 surgically proven thoracic disc protrusions are reviewed. In 15 (75%), characteristic plain film changes were found to be very helpful in making the correct diagnosis. Calcified disc material in the spinal canal was clearly demonstrated in 11 (55%) cases, and this, in association with linear calcification in the adjacent disc space, has been shown to be diagnostic of the condition. At myelography, central protrusions (55%) were found to be predominant, while lateral protrusions were uncommon. The differential diagnosis of a calcified lesion in the spinal canal includes thoracic disc protrusion, osteochondroma and meningioma.

Calcinosis↗

Cerebral blood flow in dementia.

Twenty-four patients of comparable age, blood pressure, and degree of dementia were classified by an "Ischemic Score" based on clinical features into "multi-infarct" and "primary degenerative" dementia. Regional cerebral blood flow (CBF) was measured by the intracarotid xenon 133 method. Both groups showed a decreased proportion of rapidly clearing brain tissue (largely gray matter). Cerebral blood flow per 100 gm brain per minute was normal in the primary degenerative group but low in the multi-infarct group. This suggests the blood flow is adequate for metabolic needs of the brain in patients with primary degenerative dementia but inadequate for those with multi-infarct dementia. There was no correlation between degree of dementia and CBF in the primary degenerative group but an inverse relationship existed in the multi-infarct group. Reactivity of blood vessels to reduction of arterial carbon dioxide pressure was normal in both groups.

Aged↗

Symptomatic vertebral haemangiomas.

Eight cases of vertebral haemangioma causing spinal cord or nerve root compression are described, together with one other which was not causing organic signs or symptoms. The compression was due to extradural tumour in 5 cases, bony expansion encroaching on the neural canal in 2 cases, and a combination of bony expansion and extradural tumour in one case. When present the classical radiological appearance of accentuated vertical striation or honeycomb pattern is easily recognized, but atypical features, such as apparent pedicular erosion, paravertebral soft tissue mass and bony expansion, may occur, making diagnosis more diffcult. In 2 cases the correct diagnosis was not made before surgery. In one of these there were no plain film changes and in the other a metastasis was considered the more likely diagnosis. In the asymptomatic case the absence of extra-osseous extension was an important factor in excluding any possible clinical significance of the haemangioma. The great importance of pre-operative spinal angiography is stressed.

Adult↗

Tolosa-Hunt syndrome. The dangers of an eponym.

Two cases of painful ophthalmoplegia are described which were initially thought to be examples of the Tolosa-Hunt syndrome. Both were partially responsive to steroid treatment. Subsequent investigations showed that in one case the condition was due to an aneurysm and in the other to a malignant lymphoma.

Aneurysm↗

Radiology in the diagnosis of colloid cysts of the third ventricle.

A series of 38 cases of colloid cyst of the 3rd ventricle is described in most of whom the diagnosis, important for curative surgery, was made radiologically. The most useful investigative technique was pneumography, by which the tumour was outlined in almost all cases. The lateral "hanging head" projection generally demonstrated the lesion most satisfactorily. Care in manipulating air introduced at ventriculography through the foramina of Monro into the 3rd ventricle was frequently rewarded by clear definition of the tumour. In more than one-third of the cases, the lateral plain skull radiograph showed truncation of the dorsum sellae indicative of chronic obstructive hydrocephalus, and, in the large majority of these, pneumography confirmed that the 3rd ventricle, rather than the interventricular foramen, was the site of obstruction to the drainage of cerebrospinal fluid. Carotid angiography, showing hydrocephalus, and in the same cases elevation and lateral displacement of the anterior portion of the internal cerebral veins yielded strong supportive evidence. Vertebral angiography was less specific, and isotope scanning was quite unhelpful.

Adult↗

Effect of changes in cerebral blood flow on proportion of high and low flow tissue in the brain.

Regional cerebral blood flow was measured by injection of (133)Xenon into the internal carotid artery in 11 patients with cerebrovascular disease. All patients were studied under general anaesthesia, first at normocapnia and then at hypocapnia. The 15 minute isotope clearance curves were analysed by computer by two-compartmental analysis and regional changes in flow and the proportions of fast and slow clearing tissue obtained at two levels of arterial CO(2) tension. Hypocapnia caused a fall in blood flow which was consistently accompanied by a decrease in the proportion of fast clearing tissue. Regional changes were not significantly different from the hemisphere mean changes. There was no correlation between changes in blood flow through grey matter and the proportion of fast clearing tissue on a hemisphere mean basis, but on regional analysis the data from 10 out of the 11 patients showed that in areas where blood flow through grey matter changed most the proportion of fast clearing tissue changed least and vice versa. A hypothesis has been proposed to explain this phenomenon.

Adult↗