Inclusion Criteria:  Adult age 18 years and up. Diagnosed with severe CTS based on EMG/NCS, meaning those with evidence of axonal loss (absent or low amplitude median sensory nerve action potential and/or absent or low amplitude median motor nerve action potential and/or evidence of abnormal spontaneous activity, reduced recruitment, or motor unit action potential changes on needle EMG of median innervated muscles).  Exclusion Criteria:  Younger than age 18 years (minor status). Diagnosed with concomitant peripheral neuropathy. Previous CTR on the affected side. Have contraindications to PRP (platelet dysfunction syndrome, critical thrombocytopenia, hemodynamic instability, septicemia, local infection at site of procedure, consistent use of NSAIDs within 48 hours of procedure, steroid injection at treatment site within 1 month, systemic use of steroids within 2 weeks, tobacco use, recent fever or illness, or cancer).