Carpal tunnel syndrome. Diagnosis and treatment

Sammanfattning: Carpal Tunnel Syndrome (CTS) is the most common compression neuropathy causing pain, impaired hand function and sick leave. CTS is usually diagnosed based on patient history and clinical tests. In some patients an additional ENeG is done to support the diagnosis. However, ENeG can show pathology in healthy people and show normal values in patients with overwhelming clinical signs of CTS. Traditionally CTS is treated with CTR, however it is well known that a number of patients do not improve after surgery. The understanding of the human nervous system has increased dramatically during the last few decades. This has made it possible to better understand symptoms seen in patients with nerve injuries and to design treatment strategies where the dynamic capacity of the brain, i.e. brain plasticity is guided for therapeutic purposes. The aim of this thesis was to assess cerebral changes following CTS, and evaluate treatment using guided plasticity for patients with CTS. A further aim was to evaluate whether analysis of vibration perception thresholds at multiple frequencies can detect CTS, and if ENeG results are important for post-operative outcome following CTR.The first two studies evaluated the clinical and cerebral effects of treatment using guided plasticity in the form of cutaneous forearm anesthesia over 8 weeks. The results show that cutaneous stimulation of the hand with CTS causes activation of fewer neurons in the S1 compared to stimulation of a healthy hand. The concept of guided plasticity works, and treatment using guided plasticity results in recruitment of more neurons in the S1. However, it does not result in improved sensory function in the affected hand. Study III shows that patients with clinical and ENeG-verified CTS have increased vibration perception thresholds at multiple frequencies in all fingers. This suggests that analysis of vibration perception thresholds using multi-frequency vibrometry can serve as a diagnostic tool for CTS. Study IV showed that the outcome after endoscopic CTR is beneficial. This study also shows that the subjective outcome after endoscopic CTR is better if the patient, in addition to a typical history and positive diagnostic tests also has an ENeG indicating CTS as compared to a normal ENeG.