An Unusual Case of Acute Carpal Tunnel Syndrome.

Acute atraumatic carpal tunnel syndrome (CTS) that results from a hematoma as a complication of oral anticoagulation use is a highly uncommon presentation. CTS is a common type of peripheral compression neuropathy, with CTS's acute presentation being less common than chronic. The acute type is commonly caused either by recent trauma, including fractures of the distal radius and carpal dislocations, atraumatic etiologies like infections, or inflammatory conditions that increase the pressure in the carpal tunnel. Timely diagnosis of acute CTS is essential, as often surgical decompression is required if symptoms do not improve within hours. A 79-year-old female presented to the ED with a past medical history significant for stroke, paroxysmal atrial fibrillation on rivaroxaban, and hypertension. She complained of a one-day history of left wrist pain, swelling, and restricted range of motion, associated with numbness in the median nerve distribution and weakening of the handgrip. The patient denied any trauma or unusual physical activity. CCT imaging of the left upper extremity showed soft tissue expansion around the flexor pollicis longus proximal to and just distal to the carpal tunnel consistent with dissecting hematoma within the flexor compartment. The orthopedics hand team evaluated the patient. Her rivaroxaban was held, and she was monitored for 24 hours in the hospital. The next day, she almost had a complete resolution of her symptoms. She was discharged home with a close follow-up. There are various atraumatic causes of acute CTS. Spontaneous atraumatic hematoma occurring in the forearm's flexor compartment and resulting in acute CTS is extremely uncommon. In contrast to chronic CTS, acute CTS requires urgent carpal tunnel release to prevent irreversible median nerve damage. Anticoagulants in such cases increase the bleeding risk. This case highlights the importance of considering CTS into the differential diagnosis of someone on an anticoagulant and presenting with acute wrist swelling and pain. Despite the absence of any direct trauma, timely diagnosis of this condition is prudent and greatly affects the outcomes.