Subarachnoid haemorrhage (SAH) often leads to subarachnoid fibrosis and resultant normal pressure hydrocephalus; however, how subarachnoid fibrosis occurs is unknown. We examined the changes within arachnoid granulations (AGs) and the subarachnoid space (SAS) chronologically at the parasagittal region obtained from patients with SAH at autopsy and made comparison with controls by immunostaining for cytokeratin, specific marker for leptomeningeal cells and by the elastica Masson-Goldner methods. Within a week some AGs were torn, and many inflammatory cells filled the AGs and SAS. Cytokeratin positive cells were scarce. During the next two weeks cytokeratin positive cells increased. After three weeks, AGs and SAS were filled by dense deposits of extracellular matrices surrounded by multiple layers of leptomeningeal cells.
1181In all our patients, we discarded other causes of nonfocal cerebral dysfunction of a vascular origin such as syncopes, and we performed a CT scan to discard other causes of sudden focal neurological deficit. Stroke is clinically defined as the occurrence of symptoms and signs with sudden (within seconds) or at least rapid (within hours) onset, which corresponds to the affectation of vascular areas in the brain.2 All our patients met these conditions and displayed one-sided neurological signs, which strongly supports the clinical diagnosis of stroke.Having proposed in our article 3 that cerebral cysticercosis preferably affects the small vessels, it is not surprising that we do not have CT evidence of cerebral infarction in a high percentage of our patients. In other patients with lesions in small vessels, such as those with lacunar infarcts in routine CT scans, there is a positivity of between 30% and 50% of cases 4 ; even with repeat CT scans and magnetic resonance imaging, the positivity attains a rate of 89%.4 These facts and the angiographic evidence in one of our vasculitis patients, in whom the CT scan did not show infarct, 3 reassert our thesis.In two patients without risk factors and with cortical infarcts, we established that the vascular affectation mechanism could be caused by its proximity to cerebrospinal fluid reflecting meningeal inflammation. We do not know with certainty whether the damage from cerebral cysticercosis is directly on the cerebral blood vessels or if it is mediated by other mechanisms. The neurocysticercosis could be an associated or independent risk factor for stroke.3 The risk factor contributes to the susceptibility to stroke and may or may not be the cause of stroke. There is no doubt, however, that in some of our 31 patients, the cause of stroke was not established.Our major concern was to show that cerebral cysticercosis is a risk factor for stroke. We have studied patients with stroke in whom we have been unable to demonstrate vasculitis by angiography but have been able to do so with intracranial surgery or autopsy. On the other hand, we have studied patients with cerebral cysticercosis without stroke in whom we have found severe vasculitis by means of angiography and surgery. These patients undoubtedly have a potential risk for stroke.We agree that there are new, demonstrable causes of stroke among young patients, especially in a subgroup with no known risk factors for stroke, 5 and that some of the patients of our series could have one of these causes. In November 1988, we modified our standard protocol for stroke to improve research among young patients, and we have been able to establish that cerebral cysticercosis was the attributable cause of stroke in only 3% of them.There is a probable association between cerebral cysticercosis and susceptibility to stroke. It is, therefore, a possible risk factor for stroke that should be taken into account, particularly among young and middle-aged patients; and in some cases, it is the attributable cause of stroke.
A right-handed Japanese man with no personal or family history of left-handedness developed severe Wernicke's aphasia, a mild constructional disorder, and slight left hemiparesis. MRI revealed infarction in the territory of the righ middle cerebral artery, including areas homologous to Broca's and Wernicke's areas. The cerebral blood flow in these areas remained diminished even after language activation. The most likely explanation is that language production occurred in the left Broca's area, while language comprehension occurred in the right Wernicke's area (a dissociated aphasia).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.