A method and apparatus of estimating at least one intracranial hemodynamic parameter in a subject is disclosed, the method comprising:obtaining data of changes in electrical impedance across a head of a subject as a function of timeanalyzing the data andestimating two or more intracranial hemodynamic parameters selected from the group consisting of: cerebral perfusion pressure and/or mean transit time of blood through cerebral capillaries, intracranial pressure, and total cerebral blood volume, and wherein the values of one or more of the parameters are used to improve the estimates of one or more of the other parameters.
