Lhermitte's Sign Research Articles

Lesions About the Junction of Medulla and Spinal Cord

TO ERR in the diagnosis of a relievable disorder is a tragedy. A readily missed and usually eminently relievable lesion of the nervous system is one about the junction of the medulla and spinal cord (a junction lesion). Here, the arrangement of nervous structures and their blood supply 1 is such as to result in a multiplicity and variance of symptoms and signs from patient to patient, signs that may come and go. A recent leading article in The Lancet' 2 called attention to missed foramen magnum tumors. Aneurysms and subarachnoid cysts in this locale, characterized by remission and exacerbation, test diagnostic acumen. The most common mistake in diagnosis has been to call these troubles and perhaps next most common, cervical spondylosis. A sign of multiple sclerosis, the tingling shock that occurs on first flexing the neck (Lhermitte sign) has been found in junction lesions. Also, horizontal

Lhermitte sign following head injury.

Lhermitte sign, an electric-like sensation in limbs and trunk elicited by neck flexion, often can be an omen of chronic progressive neurological disease. Three patients are reported in whom this symptom was benign and transient. These patients, and some reported by others, met all of the following criteria: (1) history of recent cranial trauma; (2) delay of weeks to months between trauma and onset of the symptom; (3) normal neurological examination results; (4) no history of neurological symptoms prior to trauma; (5) normal cervical spine x-ray films, including flexion and extension views; (6) disappearance of symptoms within a few months. We suggest that these patients should be treated conservatively and spared cervical myelography.

Lhermitte's sign in subacute combined degeneration of the cord.

Lhermitte's sign is a common early symptom of subacute combined degeneration of the cord occurring in 11 out of 44 patients admitted to the National Hospitals for Nervous Diseases during the decade 1962-71 with this diagnosis. Two patients, in both of whom it was the presenting complaint, are described in detail. It is concluded that, in these cases, Lhermitte's sign is due to stretching of demyelinated fibres in the posterior columns in the cervical cord, produced by neck flexion. The symptoms disappear after treatment with vitamin B(12). The clinical importance of this symptom is emphasized.

A localizing symptom in thoracic myelopathy. A variation of Lhermitte's sign.

The sensation of an electric shock described by Lhermitte has become accepted as an indication of cervical cord lesions and is described in most texts as elicited by neck flexion. This sensation may also occur in the presence of a thoracic cord lesion with trunk flexion. A patient had this symptom during trunk flexion, caused by documented extradural compression of the thoracic cord. After surgical decompression, the electrical shocks were no longer felt. The clinician is alerted to this symptom as an indication of a spinal cord lesion. More specifically it suggests a thoracic cord lesion if it is elicited by flexion of the trunk and not by flexion of the neck.

Carbamazepine, a new symptomatic treatment for the paraesthesiae associated with Lhermitte's sign.

Carbamazepine (Tegretol®) was found to have an immediate and reproducible symptomatic effect on the paraesthesiae associated with Lhermitte's sign in 3 patients. The preparation was administered in a dose of 400–600 mg/day and resulted in the disappearance of the paraesthesiae within 24 hrs. When carbamazepine was withdrawn there was a recurrence of the paraesthesiae in 2 of the 3 patients. The favourable effect of the preparation was confirmed by a series of several short treatments in 2 of the patients.

Eponyms

<h3>To the Editor:—</h3> It would enhance the value ofThe Journalgreatly if short descriptions of the signs and symptoms of rarer diseases, as well as of eponyms, were to be included immediately after their first use in an article or an abstract. I have felt the deficiency for some time, and it was forcefully called to my attention on page 1737 of the Sept 15 issue, in which an article on Lhermitte's sign is abstracted, with no description of the sign. Neither Merritt nor Wechsler describes this sign. It is described in Dorland's dictionary, but Collins' "Neurologic Diagnosis" gives a different definition. I suspect that I am not alone in not keeping track of some of the rarer diseases as well as eponyms.

TRANSIENT RADIATION MYELOPATHY (WITH REFERENCE TO LHERMITTE'S SIGN OF ELECTRICAL PARAESTHESIA).

Radiation myelopathy of the cervical cord may be revealed by Lhermitte's sign of electrical paraesthesia on neck flexion. A transient syndrome is described, occurring some three to four months after therapeutic irradiation, with electrical paraesthesia as the sole manifestation. This is contrasted with the features of progressive radiation myelopathy which usually appears after a longer latent period of one to two years. Transient radiation myelopathy does not (unless the evocative dose is above the accepted tolerance level) herald later and progressive cord degeneration. The pathogenesis of the condition is discussed in relation to the radiosensitivity of oligodendroglia, together with its significance in clinical neurology and radiotherapeutics.

SENSATION OF ELECTRIC SHOCK FOLLOWING HEAD INJURY

RECENT observation of many cases of the sensation of electric shock on flexion of the neck as a result of war injuries has reawakened interest in this phenomenon, which was first noted and described during World War I. Heretofore it has been regarded as an interesting medical curiosity, chiefly because of its occurrence as a subjective symptom in cases of multiple sclerosis. Its appearance with this disease was described by Lhermitte, and the phenomenon is frequently referred to in the literature as Lhermitte's sign. It is the purpose of this paper to report these recently observed cases, together with details of the variations of the symptom, for it is believed that this sign may be indicative of concomitant damage to the cord in cases of head injury and that it is of more than academic interest. In an excellent brief review of the literature, Salmon 1 noted that in Babinski's