Specific evaluating method and therapeutic approach for chronic dizzy sensation

摘要

Objective: Paroxysmal dizziness or vertigo is very common symptom with various neurological and psychological disorders, and continuous and chronic dizzy or floating sensation (chronic dizziness, CD) is also popular symptom. However, effective treatment of such chronic dizziness is not determined because of the lack of objective method for evaluating this sensation. We had found the specific evaluating method and therapeutic approach to the chronic dizzy sensation. Method: On the basis of assumption that CD may be attributable partly to cortical functional abnormality, we attempted to estimate the cortical vestibular function by measurements of auditory-evoked magnetic fields (AEFs). Magnetic field signals in the parieto-temporal cortex were evoked by 1,000Hz tone-burst with 90dB normal hearing level (nHL) sounds in using magnetoencephalography (MEG), which are known to stimulate the vestibular system, and 100-msec (N100m) waveforms were analysed as electrical current arrows in normal subjects (n=9) and patients with CD patients (n=14). Results: In normal subjects, the currents direction of N100m always headed toward one direction on the superior temporal lobe, on the other, in the patients with CD, the currents direction of N100m always appeared rotational pattern over the temporoparietal lobe. Such spinning current-arrows pattern disappeared in four of our patients with amelioration of dizzy sensation following an anti-epileptic drug. Conclusions: We successfully detected the spinning electrical currents of the N100m in AEFs on the patients with CD in MEG. This method is useful for evaluating dizzy sensation and anti-epileptic medication is effective to the amelioration of CD.