An Elderly Woman With Muscle Spasms

An 81-year-old woman with a history of thyroidectomy for thyroid carcinoma presented 2 years later with recurrent muscle spasms, muscle pain, and weakness.

Her serum calcium levels were consistently in the range of 4.3–4.5 mEq/L (normal, 4.3–5.3 mEq/L), despite aggressive therapy with calcium (Os-Cal 1500 mg three times a day) and vitamin D (50,000 IU three times a week). She had carpopedal spasms that persisted, with weakness in the lower extremities, and she also developed difficulty swallowing.

Examination revealed a clinically ill-appearing woman. Cranial nerves and mentation were normal. She had mild leg weakness and stiffness. Reflexes were 2+ to 3+ symmetrical; there were no Babinski signs. Sensation was normal. There was no myotonia or fasciculations. She had positive Chvostek and Trousseau signs. The rest of the examination was normal.

What is the Differential Diagnosis?

This woman had weakness and neuromuscular irritability of recent onset; for this the differential diagnosis is very limited. There was no history to suggest myotonia nor was this seen clinically. Muscle rigidity and spasms occur in hypothyroidism, but these are usually not accompanied by carpopedal spasms. Acquired neuromyotonia, such as Isaacs syndrome, is a consideration and should be thought of in the differential diagnosis, but although generalized stiffness is seen in Isaacs syndrome, there are no carpopedal spasms. The most likely possibility is tetany due to her hypocalcemia.

It was determined that this patient developed hypoparathyroidism due to the removal of the parathyroid glands, which caused recurrent hypocalcemia and tetany.

An EMG Test was Performed

Motor Nerve Studies

This case was reported as Puniani TS, Bertorini TE. Tocainide therapy in muscle cramps and spasms due to neuromuscular disease. Muscle Nerve . 1991;14:382–385.