To the Editor: Myelopathy is not listed among the several well established neurologic syndromes associated with thyrotoxicosis. We have recently encountered a patient in whom thyrotoxicosis was closely associated with subacute posterolateral myelopathy. We have not been able to find a similar case in the literature available to us. The patient, a 48-year-old woman, began to experience excitability, excessive sweating, palpitation, frequent diarrhea, tremor and hair loss six months before admission. Weakness of the upper and lower extremities and instability of gait developed at the same time. All symptoms were rapidly progressive and accompanied by severe weight loss. On admission,….