Natural course and treatment efficacy: one-year observation in diabetic and idiopathic carpal tunnel syndrome.

Our aims were to observe the effects of rehabilitation and surgery on idiopathic and diabetic carpal tunnel syndrome (CTS) and compare them with the natural course of the disease. Forty-two patients aged 33 to 74 years with clinically diagnosed, electrophysiologically confirmed, and laboratory screened hands with CTS (46 idiopathic and 34 diabetic) were enrolled in the study. Improvement of symptom severity and functional status after treatment using the Boston questionnaire (scales), changes of nerve conduction parameters (NCPs), and correlations between NCP and Boston questionnaires were outcome measures. Follow-up periods were 3 to 5 months and 6 to 12 months. In idiopathic CTS, surgery was effective according to scales and NCP. Rehabilitation was also effective according to scales but only in the late period. Nontreatment did not improve scales at a later period. In diabetic CTS, rehabilitation was not effective according to scales. Baseline and follow-up correlations between scales and NCP were weak and limited to sensory amplitudes (baseline), sensory amplitudes-velocity, and median motor distal latency (follow-up). Regression analysis also did not reveal any associations between scales and NCP. A repeated nerve conduction study was not meaningful if the diagnosis was definite. Treatment of CTS was definitely superior to spontaneous improvements. Rehabilitation was ineffective in diabetic CTS.