Haenel's Symptom

HAENEL'S SYMPTOM (Haenel), consists in the decreased sensitivity to pressure on the eye, which Haenel described as a symptom characteristic of tabes. In the most recent time, this symptom has been subjected to thorough examination by Herzberg. Physiologically, the sensitivity of the eye to pressure begins with a load of 150 to 350 grams. The appearance of sensitivity only at 400 grams should already be considered a positive Haenel's symptom, the cause of which probably lies in a lesion of the cervical sympathetic nerve. Based on extensive material, Herzberg came to the conclusions: 1) a single Haenel's symptom already makes the patient suspicious of neurosyphilis and, particularly, tabes, of course, if there is no other obvious cause of suffering of the sympathetic nerve; 2) in the presence of spinal syphilis or tabes, Haenel's symptom gives grounds to think about a relatively high localization of the process; 3) in isolated cases, this symptom may indicate hidden diseases of the lungs and heart; 4) in pronounced cases, examination by finger is sufficient, in doubtful cases a special apparatus is needed. However, some authors are skeptical about the diagnostic value of Haenel's symptom.