Erben's Symptom

ERBEN'S SYMPTOM (Erben), a sharp, suddenly occurring transient slowing of the pulse when squatting on one's haunches with simultaneous forward bending of the trunk until the chin touches the knees. This slowing does not occur immediately, but after 4-15 normal heart contractions; after 3-6 slowed heartbeats, the subject, even while remaining in the specified position, returns to the previous, and sometimes accelerated, rhythm. Erben explains this phenomenon as central irritation of the vagus nerve resulting from blood congestion in the brain that occurs in the above-mentioned position; according to his data, the presence of this symptom indicates mild excitability of the parasympathetic division of the autonomic nervous system. The practical and scientific use of E. s. encounters great difficulties due to the complexity of interpreting the mechanism of its occurrence (the completely unnatural position of the subject, disturbance of cerebral circulation). Therefore, and also due to the development in recent years of the physiological significance of the sinus plexus (Hering's carotid sinus reflex), E. s. is little applied. Similar to E. s. in character and apparently in origin is Ortner's symptom (the same changes in the rhythm of heart contractions as in E. s., occurring when squatting with the head thrown back). Its use encounters the same difficulties as the use of E. s.