Abstract
The electro-olfactogram (EOG) is a generator potential of the olfactory receptor produced by an odorous stimulation. This potential has been extensively studied in the frog, but it was not measured in hyposmic human subjects. The EOGs were measured in 12 healthy human subjects and 32 hyposmic subjects.of various origins. Nasal mucosa was anesthetized with xylocaine spray. A silver-silver chloride wire electrode was placed on the olfactory epithelium. An odorous gas of Skatol was introduced into the nasal cavity and the potential in the olfactory mucosa was recorded with a pen oscillograph. Skatol odor produced a slow negative potential of a negative-on-type in the olfactory epithelium in 11 out of 12 healthy subjects. A small positive potential was recorded in a few cases with congenital anosmia and with hyposmia due to head trauma. No normal EOG was recorded in anosmic patients with fracture of the skull. Patients with anosmia following non-fractured head trauma and whiplash injury showed normal EOG, although they complained of complete loss of smell. These cases may be attributed to central olfactory lesions or simulation. The EOGs in patients with hyposmia following cold were small or nonexistent. A remarkable recovery was observed in the EOG of a hyposmic patient when his olfaction improved with a medical treatment. The EOG appeared to be a reliable indicator of the olfactory receptor function in man.
