J.D. Bartleston
Cynthia J. Chelf
Dietlind L. Wahner-Roedler
Rochester, Minnesota, United States

Functional neurological disorders are difficult to diagnose and treat, in large part because there are no objective physical, laboratory, or pathological findings to confirm or exclude the diagnosis. This brief communication describes the Rosenbach eyelid sign (RES) and its association with hyperthyroidism and possibly with functional neurological disorders and symptom susceptibility.

Ottomar Rosenbach (1851–1907) was a prominent German physician who contributed to multiple medical fields. He published around 278 books, monographs, treatises, and papers.¹ His legacy endures, in part, because of three physical signs that bear his name: palpable hepatic pulsation due to aortic regurgitation,² loss of the superficial abdominal reflexes contralateral to “apoplectic hemiplegia” (cerebral stroke),³ and eyelid fluttering or batting on gentle eye closure in Graves’ disease (hyperthyroidism)⁴ and likely in patients with conversion disorder and other non-volitional symptoms.

Probably Rosenbach’s most notable eponym, RES was reported over 100 years ago. RES consists of a fine, rapid eyelid tremor when the patient’s eyes are lightly closed. There is no weakness or involuntary movement aside from the eyelid tremor and no blepharospasm. The tremor causes no symptoms and no discomfort. The eyelid tremor or batting is not easily feigned. In general, the eyelids are still when the eyes are open.

It is not clear when the association between eyelid tremor and symptom inflation was first observed or reported. Dr. Russell N. DeJong, in his four comprehensive textbooks describing the neurological examination, repeatedly links RES to functional neurological disorders (previously called conversion disorder and hysteria) and symptom exaggeration.^5-8 The term functional neurological disorder is currently favored over conversion disorder.⁹

We conducted a literature review to look for documentation of the association of RES with hyperthyroidism or with a functional neurological or related disorder. This was difficult because most references were from the nineteenth century, and most were written in German. We found no medical literature documentation of an association of RES with hyperthyroidism or of an association with functional neurological disorder. It is possible that Rosenbach spoke about an association at a conference or less formal meeting with his peers, and it was not actually published.

The lack of a literature-reported association between RES and physical and functional neurological disorders suggests that there is no connection. However, RES is a common physical finding (author’s observation), is not thought to have clinical significance, and is therefore not looked for on physical examination. It has been observed, if not formally reported, for over 100 years and likely has some diagnostic clinical value in the examination of patients, especially in the presence of functional neurological disorder, exaggerated symptoms or signs, and possibly hyperthyroidism.

RES can be present without any underlying or associated symptoms or signs. It is also true that patients may have a functional neurological disorder without RES. Given the multiple reports of a possible relationship, it is possible if not probable that there is an increased incidence of functional neurological related disorders in patients with RES; conversely, there may be a lower incidence in patients without RES. This possible correlation could influence patient care. For example, if a patient with symptoms of a functional neurological disorder has RES, investigation (except perhaps for thyroid function testing) could be reduced or delayed. Alternatively, in the same setting, absence of RES could prompt an earlier or more aggressive approach.

References

1. Rastogi V, Singh D, Tekiner H, et al. Abdominal Physical Signs and Medical Eponyms: Physical Examination of Palpation Part 1, 1876-1907. Clin Med Res. Dec 2018;16:83-9110.3121/cmr.2018.1423.
2. Ashrafian H. Pulsatile pseudo-proptosis, aortic regurgitation and 31 eponyms. Int J Cardiol. Mar 8 2006;107:421-310.1016/j.ijcard.2005.01.060.
3. Rosenbach O. Beitrag zur Symptomatologie Cerebraler Hemiplegieen. Archiv fur Psychiatre und Nervenkrankheiten. 1876;6:845-51.
4. Kumar J, Batham S. Ocular Manifestations in Thyroid Eye Disorder: A Cross-Sectional Study. IOSR Journal of Dental and Medical Sciences 20, Issue 6 Ser.7 (June. 2021): 12-18.
5. DeJong R, Magee K. The Neurologic Examination. Harper & Row; 1979.
6. DeJong RN. The Neurologic Examination: Incorporating the Fundamentals of Neuroanatomy and Neurophysiology. 1st ed. Hoeber; 1950.
7. DeJong RN. The Neurologic Examination: Incorporating the Fundamentals of Neuroanatomy and Neurophysiology. 2nd ed. Hoeber; 1958.
8. DeJong RN. The Neurologic Examination: Incorporating the Fundamentals of Neuroanatomy and Neurophysiology. 3rd ed. Hoeber Medical Division, Harper & Row; 1967. 9. Diagnostic and statistical manual of mental disorders, DSM-5. Arlington, VA: American Psychiatric Association; 2022:1142.
9. Diagnostic and statistical manual of mental disorders, DSM-5. Arlington, VA: American Psychiatric Association; 2022:1142.