Presentation
Tingling in fingers for the last few weeks.
Patient Data
There is the bifurcation of the median nerve proximal to the carpal tunnel. It is a normal variant and known as a bifid median nerve. There is no associated persistent median artery.
Combined Cross-sectional area of two branches - normal combined up to 11 mm2
Proximal to tunnel - ulnar division - 3 mm2 + radial division - 3 mm2 - Total 6 mm2
Distal to tunnel - ulnar division - 8 mm2 + radial division - 6 mm2 - Total 14 mm2
Edema followed by tapering distally to the carpal tunnel involves both ulnar and radial divisions which is known as an inverted notch sign.
No intratunnel mass lesion/ flexor tenosynovitis.
Case Discussion
Median nerve edema followed by tapering distally to tunnel involving both ulnar and radial divisions which is known as an inverted notch sign. Findings favor carpal tunnel syndrome.