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Correlation between "hourglass-like fascicular constriction" and idiopathic anterior interosseous nerve palsy
Toru Sunagawa1,2, Yuko Nakashima1, Rikuo Shinomiya1
1Department of Orthopedic Surgery, Hiroshima University Hospital, 1-2-3 Kasumi, Hiroshima, 734-8551, Japan.
Introduction:
In recent operative cases of anterior interosseous nerve palsy (AINP), hourglass-like fascicular constrictions have been reported. We prospectively investigated the ultrasonographic history of these lesions to better understand the role of this lesion in AINP.
Methods:
Seven patients who were diagnosed with idiopathic AINP based on classic clinical findings and had hourglass-like fascicular constrictions found on ultrasonography were included. All but 1 patient selected surgery, and we followed up all patients clinically and with ultrasonography.
Results:
In the 5 patients treated surgically in whom paralysis recovered to a level greater than M4, postoperative ultrasonography revealed less constriction. The other patient experienced little recovery after surgery, and the severe constriction remained. In a conservatively treated patient, the paralysis recovered completely, and upon ultrasonography, the constriction had lessened.
Conclusions:
Although the mechanism is still unknown, hourglass-like fascicular constriction lessened with relief of motor weakness both in operatively and conservatively treated patients. Muscle Nerve 55: 508-512, 2017.
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