Graves' disease complicating myelopathy

Exophthalmos, supraventricular arrhythmias, and myxedema have been noticed among patients chronically paralysed due to myelopathy. A survey was conducted to document and explain the observation.

A long term care population of 77 male myelopathy patients aged 59 +/- 14 years (mean +/- 1 standard deviation), paralysed 19 +/- 11 years, were compared by exophthalmometry (Hertel instrument) with 53 male non myelopathy patients and hospital employees, aged 57 +/- 15 years, by review of electrocardiograms (EKGs) of record with 91 male non myelopathy hospital patients, aged 59 +/- 13 years, and by thyroid function tests with standard values.

Abnormal ocular protrusion (greater than 22 mm) was found in 9 myelopathy patients (12%) and in none of the controls. Exophthalmos was bilateral in 7. The mean ocular protrusion was 17.2 +/- 3.6 mm for myelopathy patients and 14.9 +/- 3.9 mm for controls (p less than 0.001). Three exophthalmic patients had atrial fibrillation. Arrhythmias had been recorded in 186 of 1390 EKGs in 34 myelopathy subjects and in 63 of 377 EKGs in 25 controls. The ratios of supraventricular to ventricular arrhythmias were 2.8 for myelopathy patients and 0.7 for controls (p less than 0.02). Hypothyroidism was found in 2 of 74 patients tested, 2.7%.

Exophthalmos, supraventricular arrhythmias, and myxedema are unusually common among chronic myelopathy patients. Preceding Graves' disease with residual effects can be suggested as the explanation.