Background Carpal tunnel syndrome (CTS) is the most common type of peripheral nerves entrapment; It has a great socioeconomic impact. CTS may be idiopathic or secondary to many causes, especially diabetes mellitus. Insulin has anti-inflammatory effects1 and the effectiveness of local insulin Injection in diabetic patients with CTS has been previously evaluated 2. Local insulin Injection in idiopathic CTS has not been studied.
Objectives To evaluate the effectiveness of local insulin injection as a therapeutic tool in management of idiopathic CTS.
Methods Twenty eight consecutive hands of mild & moderate idiopathic CTS (diagnosed clinically & electrophysiologically and classified according to American association of neuromuscular diagnostic medicine monograph) received two local injections of 10 IU NPH insulin into the affected carpal tunnel 2 weeks intervals after informed consent. Patients with severe or secondary type of CTS were excluded from this study. Evaluation of the patients at baseline, then at 1 & 3 months after 2nd insulin injection was done clinically [by measuring visual analogue scale (VAS), paraesthesia, Phallen and compression tests] and electrophysiologically (by measuring motor and sensory nerve conduction studies of the median and ulnar nerves using a standardized technique).
Results Clinically; there was statistically significant improvement in VAS, paraesthesis, Phallen and compression tests at 1 & 3 months after 2nd insulin injection (p<0.01). Electrophysiologically; there was statistically significant improvement in distal motor latency (DML) and distal sensory velocity of median nerve 1 and 3 months after treatment (p<0.01), but the improvement was not statistically significant as regards median distal motor and sensory amplitudes (p>0.05).
Conclusions Local insulin injection is a promising effective treatment for idiopathic CTS. This is the first study to detect the effect of local insulin injection in idiopathic CTS.
Sun Q, Li J, Gao F. New insights into insulin: The anti-inflammatory effect and its clinical relevance. World J Diabetes. 2014 Apr 15; 5(2): 89–96.
Ashraf A, Yazdani A, Mirshams S. Evaluation of the effectiveness of local insulin injection in type 2 diabetic patients with CTS. Electromyogr Clin Neurophysiol. 2009 May-Jun;49(4):161–6.
Acknowledgement Thanks a lot to Dr. Samar Abd Alhamed for her great efforts in completing statistical analysis in this study.
Disclosure of Interest None declared