Distribution of sympathetic fiber areas in the sensory nerves of forearm: an immunohistochemical study in cadavers.

Purpose: Secondary to peripheral nerve injuries, involvement of sympathetic fibers complications such as Complex Regional Pain Syndrome (CRPS) have been reported. There are no reports available in the distribution of the sympathetic fibers/areas of sensory nerves in the forearm.
Materials and Methods: The present study aim is an attempt to find the distribution of sympathetic fibers in the anterior branch of medial antebrachial cutaneous nerve of forearm (AMACN), lateral antebrachial cutaneous nerve of forearm (LACN) and superficial branch of radial nerve (SBRN) at cubital fossae. We have studied on 17 fresh human cadaveric AMACN, LACN and SRBN samples. Frozen sections of these nerves were processed by immunohistochemical (tyrosine hydroxylase) method for sympathetic fibers.
Results: Sympathetic fibers area (Asym) was found to be more in SBRN when compared to AMACN and LACN. The comparison of the sympathetic index (SI = sympathetic fibers area / total fascicular area of the nerve) between AMACN and LACN (p-value < 0.001), AMACN and SBRN (p-value <0.001), LACN and SBRN (p-value < 0.001) were statistically significant. Sympathetic index (SI) for SBRN was more when compared to AMACN and LACN. SBRN had maximum percentage (5.16%) of Asym when compared with LACN and AMACN.
Conclusions: Sympathetic fibers area (Asym), sympathetic index (SI) and percentage of sympathetic fibers area (Asym %) were found to be more in SBRN when compared with AMACN and LACN. These results of the study might help to explain sympathetic system-related diseases in the area of distribution of AMACN, LACN and SBRN.