Ultrasound as a Diagnostic Modality for Wrist Pain in a Nonverbal Patient with Autism Spectrum Disorder: A Case Report

Case Diagnosis: 19-year-old female with Autism Spectrum Disorder (ASD) with carpal tunnel syndrome (CTS) secondary to persistent median artery (PMA).

Case Description or Program Description: A 19-year-old nonverbal female was brought to clinic by her mother after noticing one month of guarding both hands, more apparent on the right. Mother reported noting hand weakness and difficulty performing fine motor tasks. Prior wrist x-rays were unremarkable. Physical exam was limited due to patient cooperation but on inspection the patient’s hands were freely moving, with antigravity strength grossly. Recommendation was made to treat pain with Tylenol, improving symptoms in two weeks. For the second appointment, Xanax 0.5 mg, 30 minutes prior and immediately before evaluation was administered. Again, patient deferred physical examination but limited diagnostic ultrasound of the volar wrists was obtained.

Setting: Outpatient Musculoskeletal clinic

Assessment/Results: Adjacent to the entire course of the median nerve was an anechoic, pulsating structure with internal doppler flow that was slightly compressible. The median nerve appeared with normal echotexture and size. Diagnosis of CTS was given and she was treated with nighttime wrist splinting, improving over the next few weeks.

Discussion (relevance): Electrodiagnostics are the gold standard for the diagnosis of CTS. However, the invasive nature of this test makes it difficult for patients with heightened sensory perception. In this case, ASD was severe and proper physical examination could not be conducted despite multiple attempts by numerous providers. Using ultrasound to gamify the examination allowed the providers to obtain a likely diagnosis considering an anatomical risk factor that crowds the carpal tunnel predisposing to median neuropathy. This novel use of ultrasound provides clinicians with another tool for diagnosing CTS in a challenging patient population.

Conclusions: Point-of-care ultrasound may be used more readily in patients with ASD or other neurodevelopmental abnormalities as a safe, non-invasive, and tolerable diagnostic modality in cases of CTS.