Time axis calibration in human CNS organization for judging dysfunction.

Abstract

Based on measurements of relative phase and frequency coordination between the firings of neurons in the human central nervous system (CNS) with the single-nerve fibre action potential recording method a coordination dynamic recording method could be developed with which it is possible to measure the coordination dynamics between arms, legs and trunk non-invasively when exercising on a special coordination dynamic therapy device. To analyze integrative functions when the human CNS is generating different coordinated movements of arms and legs, a time axis calibration is needed, which catches relevant CNS organization. Repeatedly occurring characteristic movement states are found in the pace and trot gait coordination when exercising continuously on the special coordination dynamic therapy device. CNS organization dynamics is thus projected onto the changing coordination dynamics of arm and leg movement. The collective variable for measuring the coordination dynamics of a physiologically and pathologically functioning CNS, when performing coordinated arm and leg movements with changing coordination between arms and legs including pace and trot gait coordination and all intermediate coordination, is the amplitude of variation of the frequency of turning (delta f) and of its time derivative (delta df/dt). When a volunteer exercises on the special coordination dynamic therapy and recording device, it was found that the healthy CNS can generate all possible coordinations between arms and legs with small turning frequency variation (small delta f and delta df/dt). But the lesioned CNS cannot any more generate all coordinations with small frequency variation, that means easily. Often the easy pace and trot gait coordinations can be performed by the patient with small frequency variation but not the difficult intermediate coordinations or, depending on the CNS lesion, the patient can only perform pace or trot gait coordination easily or the change from the pace to the trot gait and not from trot to pace gait coordinations can be performed easily. In the most severe cases the arrhythmicity is so large that the patient starts to stop turning or cannot turn the levers any more. Also time drifting CNS organizations can be identified with this time axis calibration; the easy coordinations appear at different coordinations with ongoing time. Improvements of the coordination dynamics and deterioration of the coordination dynamics with stress were measured in the short-term memory. It is discussed that stress deteriorates relearned CNS organization in the short-term memory apart from relearned automatisms.