Current concepts on the pathophysiology of idiopathic chronic adult hydrocephalus: Are we facing another neurodegenerative disease? / Actualización en la fisiopatología de la hidrocefalia crónica del adulto idiopática: ¿nos enfrentamos a otra enfermedad neurodegenerativa?

INTRODUCTION: Since its description five decades ago, the pathophysiology of idiopathic chronic adult hydrocephalus (iCAH) has been traditionally related to the effect that ventricular dilatation exerts on the structures surrounding the ventricular system. However, altered cerebral blood flow, especially a reduction in the CSF turnover rate, are starting to be considered the main pathophysiological elements of this disease. DEVELOPMENT: Compression of the pyramidal tract, the frontostriatal and frontoreticular circuits, and the paraventricular fibres of the superior longitudinal fasciculus have all been reported in iCAH. At the level of the corpus callosum, gliosis replaces a number of commissural tracts. Cerebral blood flow is also altered, showing a periventricular watershed region limited by the subependymal arteries and the perforating branches of the major arteries of the anterior cerebral circulation. The CSF turnover rate is decreased by 75%, leading to the reduced clearance of neurotoxins and the interruption of neuroendocrine and paracrine signalling in the CSF. CONCLUSIONS: iCAH presents as a complex nosological entity, in which the effects of subcortical microangiopathy and reduced CSF turnover play a key role. According to its pathophysiology, it is simpler to think of iCAH more as a neurodegenerative disease, such as Alzheimer disease or Binswanger disease than as the classical concept of hydrocephalus.

[Fibromuscular dysplasia of the cervicocephalic arteries. Report of two cases and review of the literature (author's transl)]. / Displasia fibromuscular de arterias cérvico-cefálicas. Presentación de dos casos y revisión de la literatura.

Two typical cases of fibromuscular dysplasia of the cervicocephalic arteries in two women of 61 and 48 years of age are reported. The angiograms revealed bilateral affectation of the internal carotid artery and of the right vertebral artery in one case, and of both vertebral and renal arteries in the other. The patients presented neurological symptoms corresponding to ischemia of the vertebro-basilar territory. The first case was treated with anti-platelet aggregates with positive results. An extensive review of 70 similar published cases is presented. Several characteristics are studied such as: age, sex, localization, symptoms, clinical course and treatment. The quantitative evaluation of these factors agrees with those of other reviews carried out by some other authors. Fibromuscular dysplasia is an arteriopathy of unknown etiology which has a predominant incidence among middle age females (83 percent approximately). The disease usually involves the renal arteries and the cervical segment (adjacent to C1-C2 interspace) of the carotid arteries. There was an association with single or multiple intracranial aneurisms in 22.86 percent of the cases. Vertebral arteries were affected in 28.57 percent of the cases, although vertebral angiograms were not performed in 35.7 percent of them. Transient episodes of cerebral ischemia is the most frequent clinical manifestation (42.85 percent of the cases.).