[Features of volume and pressure pulsations during changes in "reserve space" within the cranial cavity].
Changes in the amplitude and phase characteristics of pulse variations of volumes and pressures in response to an increase in the intracranial pressure are discussed. The study of 60 neurosurgical patients has shown that as the intracranial (subdural) pressure grows the amplitude of pulse variations of subdural pressure increase to 30 mm Hg and then decreases, the phase characteristics of the pulse waves changing accordingly. The changes in the amplitudes of pulse variations produced by mechanical displacement of the walls of cerebral lateral ventricles measured with the aid of the noninvasive ultrasonic method suggest that an increase in the CSF pressure above 200 mm H2O makes the intracranial cavity too "tight", which depletes the reserve spaces of the cerebrospinal system. If the above changes develop consistently, then it can be assumed that each of the pressure ranges isolated can be characterized by amplitude-phase parameters of pulse waves that form a specific pattern. Taking into consideration the potentials of noninvasive measurements of amplitude-phase characteristics of the intracranial pulse wave by means of ultrasonic echolocation, it deems possible to develop noninvasive techniques for measuring compensatory abilities of the cerebrospinal system.
D001696:Biomechanical Phenomena; D001794:Blood Pressure; D001921:Brain / Q000098:blood supply; D004453:Echoencephalography; D006801:Humans; D007427:Intracranial Pressure; D011674:Pulse; D013355:Subdural Space; D014690:Venous Pressure
Osobennosti pul'satsii ob'emov i davlenii pri izmenenii "rezervnykh prostranstv" v polosti cherepa.