In the Hohara area of Nansei-cho, one of the foci of motor neuron dise
ase (MND) on the Kii Peninsula, an inquiry was conducted to investigat
e whether cycad exposure is an etiological factor of MND in the wester
n Pacific. Although cycads were commonly used as medicine around World
War II all over Japan, the medicinal use of cycads was exceptional in
the Hohara area. A questionnaire study in the Hohara and the neighbor
ing four areas in Nansei-cho showed that cycad used as food, medicine,
toys, and garden trees had no relation to the incidence of MND in the
se areas. The result in the Hohara area does not support the hypothesi
s that cycad is an etiological factor of MND common to the western Pac
ific foci.