Background
Acute carpal tunnel syndrome (ACTS) is a rare form of median nerve mononeuropathy at the wrist. ACTS generally results after acute trauma or fracture, however rare atraumatic cases do occur. Treatment requires emergency decompression preventing irreversible damage to the median nerve. Atraumatic causes may include infection, inflammatory, anatomic or tumour-related pathologies leading to direct pressure on the nerve.
Methods
A review of recent literature suggests ACTS accounts for <1% of CTS cases [1, 2]. Distal radius and carpal bone fractures, infection (tenosynovitis or localized abscess), persistent median artery or systemic inflammatory conditions (eg. rheumatoid arthritis) represent the most common causes. CTS affects 15-20% of diabetics and is theorized to represent many patients with an iatrogenic cause.
Findings
We report the case of a 39-year-old man with an atraumatic two-day history of severe pain and altered sensation to radial 4 digits of the left hand. He was an insulin-dependent diabetic with poor glycaemic control, and a truck driver of right-hand dominance. Pre-operative ultrasound and MRI demonstrated grossly enlarged nerve trunk 15mm in maximal diameter in distal forearm and severe median neuropathy on EMG. Autoimmune screening was negative for common systemic inflammatory pathologies. The patient underwent emergency carpal tunnel decompression to good effect enabling return to work 4 weeks postoperatively.
Conclusions
Atraumatic ACTS is a rare pathology representing a surgical emergency. We present a rare case of ACTS secondary to diabetic peripheral neuropathy in a young man. This diagnosis should be considered in cases of acute sensory disturbance in diabetic patients.