Ultrasound of the Month – Case 111
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Ultrasound of the Month – Case 111
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Ultrasound of the Month – Case 111
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Diagnosis: Hourglass Constriction of the Deep Branch of the Radial Nerve Discussion Hourglass constriction is an uncommon entity which has become increasingly recognized as a cause of acute spontaneous peripheral nerve palsy. It has been described in various nerves of the upper extremity, mainly at the level of the elbow and forearm. There is some disagreement in the published literature about the relationship of hourglass constriction to idiopathic neuralgic amyotrophy (ParsonageTurner syndrome), with some researchers differentiating the two entities and some considering the two as the same entity. Both ultrasound and MRI can be useful for assessing patients presenting with acute nerve palsy. Advantages of ultrasound over MRI include greater anatomic detail especially for smaller nerves; faster, less expensive, and more tolerable exam; and the ability to compare to the contralateral limb. Focal constricted appearance of the nerve in the background of a diffusely enlarged segment of the nerve is the hallmark of hourglass constriction on both ultrasound and MRI. Treatment is also variable, but surgical neurolysis may be indicated. Ultrasound of the Month – Case 111
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