Carpal Tunnel Syndrome, ABOS Oral Boards Preparation

This is a 48-year-old right-hand-dominant female dental hygienist with an 18-month history of progressive numbness and tingling in her right hand. The symptoms are worst at night, they wake her from sleep and she shakes her hand for relief. That is the classic Flick sign. Over the past three months, she has noticed difficulty with fine motor tasks, buttoning shirts and gripping her dental instruments at work.

She tried night splinting for eight weeks with some improvement but the symptoms returned when she stopped. She received a corticosteroid injection into the carpal tunnel four months ago, which helped for about six weeks and then wore off. No history of wrist trauma, thyroid disease, diabetes, or inflammatory arthritis.

On exam, two-point discrimination was 8 millimeters in the index and middle fingers, normal is less than 6. There was visible thenar atrophy compared to the left hand. Tinel sign was positive at the carpal tunnel. Phalen test reproduced symptoms at 15 seconds. Durkan compression test was positive. Grip strength was 18 kilograms on the right versus 28 on the left. Sensation in the dorsal hand and small finger was normal, that helps distinguish median neuropathy from ulnar neuropathy or a C6-C7 radiculopathy.

Electrodiagnostic studies confirmed severe carpal tunnel syndrome with prolonged distal motor and sensory latencies and reduced thenar motor amplitudes. No evidence of cervical radiculopathy or ulnar neuropathy on the study.

Given the failed conservative management, splinting and injection, the progressive motor deficit with thenar atrophy, and the impact on her livelihood, surgical release was indicated. The presence of thenar atrophy is particularly important because it means there is axonal loss, and delay risks incomplete recovery. We discussed surgery and she agreed.

I performed a mini-open carpal tunnel release. The median nerve appeared flattened with a visible hourglass deformity, confirming severe compression.

She was placed in a soft dressing with immediate finger and wrist motion encouraged. At two weeks, her night symptoms had resolved completely. At six weeks, her numbness in the index and middle fingers had improved significantly. Grip strength was recovering. I counseled her that the thenar atrophy may not fully recover given the severity and duration of the compression, that is an important informed consent point. At three months, she was back to work without limitations, two-point discrimination had improved to 5 millimeters, and grip strength was 24 kilograms. At six months, the thenar eminence showed some recovery but remained slightly flatter than the contralateral side.

She was satisfied with the outcome, the night symptoms were gone, she was working without significant limitations, and her grip strength had improved substantially. In retrospect, I wish I had seen her sooner. The thenar atrophy at presentation told me there had been significant axonal loss, and earlier intervention, before the atrophy developed, would have given her a better chance at thenar recovery. That is a conversation I now have more proactively with referring providers. I monitored for recurrent symptoms and pillar pain, and she remained well at her final follow-up.