Intracranial Hydrodynamics

Cerebrospinal fluid outflow and intracranial pressure in hydrocephalic patients with external ventricular drainage

“…A vicarious mechanism may reasonably be suspected in a patient exhibiting a combination of low daily Q¢ext csf -mainly dependent on manoeuvres increasing intrathoracic pressure with little basal outflow (Fig. Yet the respective Q¢ext csf in these subjects was respectively 12.1 and 8.6 ml ⁄ h, about half the 21 ml ⁄ h standard rate of production (12)(13)(14)(15)(16)(17). patient 2).…”

“…In patients 1 and 11, the elevation of the drip chamber was 5 cm above the external auditory meatus and the resulting hydrostatic pressure was assumedly lower than the sagittal sinus pressure, therefore likely to bypass any significant absorption. Yet the respective Q¢ext csf in these subjects was respectively 12.1 and 8.6 ml ⁄ h, about half the 21 ml ⁄ h standard rate of production (12)(13)(14)(15)(16)(17). This rate has been estimated from the time interval necessary to restore ICP following depletive lumbar puncture (13,14) or tracer dilution technique with infusion into the ventricles and sampling at the lumbar subarachnoid space (12,15).…”

“…3B) -normal ICP and favourable long range clinical outcome (e.g. This rate has been estimated from the time interval necessary to restore ICP following depletive lumbar puncture (13,14) or tracer dilution technique with infusion into the ventricles and sampling at the lumbar subarachnoid space (12,15). On the other hand, the process of absorption is supposed to be markedly impaired in severe acute hydrocephalus, in which case Q¢ext csf would be closer to the production rate, particularly with a continuous flow pattern.…”

Manuel Balado y las diferencias de presión craneales y espinales

“…A nuestro mejor entender no fueron muchos los autores que reportaron sobre diferencias de presión ventrículolumbares, y con unas pocas excepciones, 2,34 no hemos hallado ilustraciones sobre tales diferencias de presiones en la literatura de la época. A pesar de que la neumoventriculografía requería en algunos casos de la punción de ambos ventrículos laterales, tampoco hallamos descripciones sobre diferencias de presión entre ambos ventrículos laterales (como sí Balado hizo en su EB #8), ni entre lesio-nes (quísticas) y las cavidades ventriculares (como aparecen en el EB #12).…”

“…culos laterales y las cisternas magna y lumbar permanece libre, cualquiera fuera la presión generada en el sistema. 34 El EB #4 (Figura 4, izquierda) es el única dedicado a diferencias de presión por lesiones espinales. Se describe igura 5: izquierda (EB #6): tumor cerebeloso que cierra el cuarto ventrículo.…”