To the Editor:— The pregnant patients with upper extremity paresthesias described in the Aug 17 Questions and Answers section have the typical symptom complex now recognized as the result of median nerve compression in the carpal tunnel. Pain and numbness, often nocturnal, sometimes spreading proximally to the elbow and shoulder, precede thenar muscle weakness, which may rarely progress to severe atrophy. Phalen's sign (exacerbation of symptoms produced by hyperflexing the wrist for two or three minutes with the elbow extended) is helpful in differentiating carpal tunnel syndrome from other entrapment neuropathies. Most patients benefit from injection of 1 or 2 cc of corticosteroid suspension (hydrocortisone acetate or prednisolone tertiary-butylacetate) into the carpal tunnel, just medial to the palmaris longus at the level of the proximal wrist crease. In more severe or stubborn cases, surgical division of the deep transverse carpal ligament produces uniformly gratifying results. The pathological cause is still