Occult vascular malformations of the brain - abstract

Intracranial vascular malformations have been classically divided into four groups: arterio-venous malformations (AVMs), cavernous angiomas, venous angiomas and capillary telangiectasias. The AVMs are the best documented of these lesions and are readily characterized with cerebral angiography. The other malformations have previously been rarely diagnosed during life as they are usually not seen on cerebral angiograms. Recently, however, with the use of advanced neuro-imaging techniques these lesions have been increasingly recognized in association with intracranial haemorrhage and epilepsy. Cavernous angiomas, in particular, have a characteristic appearance on MRI scans. This paper will define these "occult" vascular malformations of the brain, their incidence, clinical presentation, natural history and issues related to management. The experience of the Department of Neurosurgery and the Division of Neuro-Radiology at the Victoria General Hospital in Halifax during 1990 will be summarized. Of over 1,200 consecutive cranial MRI scans, 18 cases of cavernous angiomas were encountered. Some of these caused intracerebral haemorrhage and others were seen in patients with complex countered. Some of these caused intracerebral haemorrhage and others were seen in patients with complex partial seizures. A surprising number were multiple and familial in occurrence. These lesions can present in the brain stem or spinal cord thus mimicking multiple sclerosis. The majority of them are asymptomatic and are incidental findings. Venous angiomas are, in fact, hamartomas and rarely lead to symptoms; because they drain normal neural tissue they cannot be sacrificed without risk of significant neurological sequelae. The emerging literature on angiographically occult vascular malformations of the brain will be reviewed (AU)

Ocular findings in hemoglobin SC disease in Jamaica

In order to structure a series without bias, the retinal and chorioretinal lesions were recorded in a series of 70 Jamaicans with hemoglobin SC disease who were consecutive patients at a sickle cell clinic during a one-month period. By avoiding selective inclusion of cases with ocular pathology, a direct comparison with 76 SS cases studied earlier was possible. An analysis of both series, together indicated that peripheral retinal whitening was associated with mild grades of peripheral retinal vessel disease in 84.3 percent and with severe grades in 47.4 percent, giving rise to the postulation that peripheral whitening reflects an anoxic change, possibly edema, whereas a reddish brown appearance characterizes retinal atrophy associated with more severe vessel disease. Proliferative sickle retinopathy occurred in 63 percent SC paients compared with 26 percent SS patients. The incidence of retinitis proliferans in SC patients was related to hemoglobin level and occurred in 73 percent of patients with hemoglobin levels above 12.5 percent compared to 15 percent of those with hemoglobin below this level. This suggests that an increased blood viscosity may contribute to the development of retinitis proliferans. (Summary)