Abstract: Apparatus and method for diagnosing spinal disorders. Pairs, left and right, of symmetric dermatoms of a patient are individually excited by means of electrode pairs, and the "time of flight" is determined for impulses to arrive to the cortex. Due to noisy signals, it is necessary to register a substantial number of individual waveforms, control their integrity, exclude questionable waveforms and sum those not excluded. The invention makes possible the diagnosis of spinal disorders where prior art methods have failed although the patient is in pain.

Abstract: The invention relates to apparatus which includes stimulating electrodes (2,3) through which electrical signals are applied to an extremity of a patient (1). Detecting electrodes (30,40) are disposed along the patient's spine and on the crown of the patient'head. The apparatus also includes signal amplifiers (7,8), a loudspeaker (9) or the like to which an amplified signal is applied for physiological feedback purposes, an A/D-converter and a computer (20). Samples of signals are collected so as to obtain from the distributed electrodes means value curves from which the transport time of the nerve signals from respective extremities can be determined.