Something analogous to this epileptogenic zone has been noticed among hystero-epileptics, and has been pointed out by several writers. Richer gives the particulars of a number of cases. In one patient the hyperæsthetic zone was between the two shoulder-blades. Simply touching this region was sufficient to provoke an attack, and this was more easily done if near the time of a spontaneous seizure. After the grave attacks the excitability would seem to be exhausted, and pressure in the zone indicated would not cause any convulsive phenomena. A second case presented a similar condition. If touched over the dorsal spine between the shoulders, she felt a violent pain in the belly, then a sense of suffocation, which brought on at once loss of consciousness. In a third patient the hysterogenic zone was different. It was double. It was necessary to touch two symmetrical points situated to the outside and a little below the breasts in order to bring on the hystero-epileptic convulsions. Touching one of these points did not produce any result. Other cases are given in detail, but a glance at the two figures (22 and 23) will show some of the principal hysterogenic zones both for the anterior and posterior surfaces of the body. A zone of ovarian hyperæsthesia was common to all the patients. It did not differ essentially from the other hysterogenic zones. If the ovarian hyperæsthesia existed along with other hysterogenic points, the excitation of the ovarian region was always the most efficacious. The hysterogenic zones always occupy the same place in the same case. They are found on the trunk exclusively; they are more frequently in front than behind; in front they occupy lateral positions, and are often double and symmetrical; behind they are more often single and median; they exist more frequently to the left than to the right, and the unilateral zones have always been met with on the left side.
FIG. 22.
Principal Hysterogenic Zones, anterior surface of the body: a, a′, supramammary zones; b, mammary zones; c, c′, infra-axillary zones; d, d′, e, inframammary zones; f, f′, costal zones; g, g′, iliac zones; h, h′, ovarian zones (after Richer).
FIG. 23.
Principal Hysterogenic Zones, posterior surface of the body: a, superior dorsal zone; b, inferior dorsal zone; c, posterior lateral zone (after Richer).
The hysterogenic zones bear no constant relation to the hemianæsthesia. It is true that the ovarian pain is most often seated on the hemianæsthetic side, but sometimes it is present on the opposite side. They are not at all times equally excitable. They are more so when the convulsive attack is imminent.