[Intracranial pressure instability index as a new method of evaluating the capacity of intracranial volume compensation].

An index of intracranial pressure instability is calculated as a new way to evaluate the capacity of intracranial voluminal compensation in patients suffering from cranio-cerebral trauma. The value of the index is determined by mutual relations of intracranial pressure standard deviations measured during 3-minute periods before and after intracranial administration of 2 ml of 0.9% NaCl. Normal physiological range of the index was evaluated in controls without intracranial pathology.