Microanatomical and immunohistochemical study of the human anterior branch of the medial antebrachial cutaneous nerve of forearm at the antecubital fossa and its clinical implications.

PURPOSE: Poor prognosis of nerve repair in patients may be due to changes in intraneural anatomy with age. Also, chances of Complex Regional Pain Syndrome-Type I (CRPS-I) secondary to peripheral nerve injury are comparatively high. The present study is to find the fascicular pattern of the anterior branch of the medial antebrachial cutaneous nerve of forearm (MACN) (at antecubital fossa), microanatomic morphometric characteristics of its connective tissue components (adipose tissue) and changes with age and study of intraneural sympathetic fiber content. MATERIAL AND METHODS: Sixty six human (37-88-year-old) cadaveric anterior branch of MACN have been collected from antecubital fossa and the study has been performed at magnifications (5x, 10x, 20x, and 40x objective) after routine histological (Hematoxylin & Eosin stain, Masson's trichrome stain) processing was done for morphometric analysis (total cross-sectional, fascicular and non-fascicular area) and immunohistochemical (tyrosine hydroxylase) processing for sympathetic fibers. RESULTS AND CONCLUSIONS: The anterior branch of the MACN's average total cross section area was 1.150 mm(2) on right side and 1.156 mm(2) on left side. There was significant increase in non-fascicular connective tissue area. In non-fascicular area, there was very less amount of adipose tissue in 86.37% of cases and more adipose tissue in 13.63% (elderly) cases. The average sympathetic fiber area is 0.0109 mm(2) without definite relationship with age. Our study makes an attempt to build a normal data base for MACN which might be helpful during the application of diagnostic and surgical nerve graft procedures.

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.

Anthropometric analysis of the infraorbital foramen in a South Indian population.

INTRODUCTION: The aim of this study was to document the morphological and topographical anatomy of the infraorbital foramen (IOF) in relation to the infraorbital rim (IOR), which is necessary in clinical situations that require regional nerve blocks. METHODS: A total of 80 dry South Indian adult human skulls of unknown age and gender were studied. In each skull, the IOF on both sides was measured using a metal casing digital vernier caliper, with the IOR as the reference point. The IOF's location and its transverse and vertical diameters were measured. The shape, size, orientation and accessory foramens of the IOF were also documented. RESULTS: The majority of IOF among the skulls were oval-shaped on both the right (55 percent) and left (51.25 percent) sides. The majority were directed inferomedially on both the right (55 percent) and left (52.50 percent) sides. The overall combined distance between the IOR and IOF was 4.1 to 11.5 (6.57 +/- 1.28) mm. The overall combined vertical diameter was 1.2 to 4.7 (2.82 +/- 0.79) mm. The overall combined transverse diameter was 1 to 5.1 (2.87 +/- 0.78) mm. Accessory foramens of IOF were found in 13 (16.25 percent) skulls. CONCLUSION: Knowledge of the anatomical characteristics of IOF locations, diameters, shapes, directions and its accessory foramens may have important implications on blocking the infraorbital nerve for surgical and local anaesthetic planning. Information on the shape of the foramens obtained from this study may provide additional guidance to surgeons when introducing needles in anaesthetic procedures.

Microanatomical and immunohistochemical study of the human radial nerve at the antecubital fossa.

BACKGROUND: Poor prognosis of radial nerve repair in elderly patients may be due to changes in intraneural anatomy with age. Also, chances of Complex Regional Pain Syndrome-Type I (CRPS-I) following radial nerve injury are comparatively high. The present study is to find the fascicular pattern of radial nerve (at antecubital fossa), microanatomic morphometric characteristics of its connective tissue components and changes with age and study of intraneural sympathetic fiber content. METHODS: Twenty human (21-87 years) cadaveric radial nerves have been collected from antecubital fossa and the study has been performed at magnifications (10x, 20x and 40x objective) after routine histological (hematoxylin & eosin stain) processing was done for morphometric analysis (total cross-sectional, fascicular and non-fascicular area) and immunohistochemical (tyrosine hydroxylase) processing for sympathetic fibers. RESULTS: The radial nerve is of a polyfascicular type with a grouped pattern of nerve fascicular distribution. The number of fascicles range from 9 to 17, whereas the number of fascicles per square millimeter of a cross-sectional area is 1.95. In elderly cases, there is significant increase in total radial nerve cross-sectional area due to an increase in its non-fascicular connective tissue area and excessive adipose tissue deposition in interfascicular domains. The average sympathetic fiber area is 0.046 mm(2) without definite relationship to age. CONCLUSION: There is an increase in total nerve cross-sectional area of the radial nerve in elderly cases. There is no relationship of sympathetic content to age. Our study makes an attempt to build a normal data base for radial nerve which might be helpful during the application of diagnostic procedures.