Abstract
The present study dealt with the relationship between the psychophysiological findings by means of Visual Evoked Response (VER) and psychic condition of patients with hyperventilation syndrome (HVS). There were 12 subjects al of whom were above 12 years of age (6 males and 6 females). Visual Evoked Potentials (VEPs) and Vertex-potentials (V-pot's) out of VERs were recorded simultaneously at rest and at 2 to 4 minute intervals during hyperventilation by means of a Digital Computer (ATAC-201). The amplitudes of VEP and V-pot were measured between the negative peaks (at about 100 msec) and the positive peaks (at about 200 msec). Thus the changes in amplitudes of VEPs and V-pot's under hyperventilation were examined for correlation with manifest anxiety in the patient with HVS.The results were as follows : 1. In the five patients with HVSs caused by anxiety neurosis, the amplitudes of VEPs on two (40%) and those of V-pot's on four (80%) increased during hyperventilation. An average amplitude of V-pot's during hyperventilation indicated a sgnificant increase (P<0.02) as did those of anxiety neurotic patients.2. In the five patients with HVSs caused by hysterical neurosis and two caused by nonneurosis, neither the amplides of VEPs nor those of V-pot's increase during hyperventilation as did those of hysteric and obsessive-compulsive neurotic patients or normal adults.3. These results suggest that V-pot's, which is dependent on a non-specific pathway, is affected by a psychic condition. The amplitudes of V-pot's in HVSs by anxiety neurosis may increase because manifest anxiety depending on anxiety neurosis becomes much stronger during hyperventilation. On the other hand, the amplitudes of HVSs by hysterical neurosis may not increase because manifest anxiety hardly becomes stronger during hyperventilation as the anxiety in hysterical neurosis is already converted into a physical symptom. These results also suggest that V-pot might afect VEP which is dependent on a specific visual pathway, and thus V-pot might cause correlated change in amplitude of the secondary component of VEP.4. We ponited out that the varied psychic conditions of HVS might be distinguished by means of VER, that is the recording of VEP and V-pot. We also indicated the psychophysiological methods dscribed above might be useful to clinical treatment for HVS.
