Psychogenic sensory loss.

One hundred consecutive patients complaining of hemifacial numbness were tested for two features commonly thought to indicate psychogenic sensory loss: a) exact splitting of the midline to pinprick, and b) diminished vibratory sensation on the affected forehead. Twenty patients had purely psychogenic complaints, while 80 had organic lesions. Sensory loss split the midline in four patients (20%) with psychogenic complaints but also in six patients (7.5%) with structural lesions (p = NS). Vibration was diminished in 19 patients (95%) with psychiatric disease but also in 69 patients (86%) with organic lesions (p = NS). Contrary to popular beliefs, these "nonphysiologic" findings do not distinguish psychogenic from organic sensory loss.