The use of computer-assisted image analysis in measuring the histological structure of the human median nerve

The aim of this study was to assess the histological structure of the median nerve and its motor branch (number and arrangement of nerve bundles) and the cross-sectional area (CSA) of the median nerve (on the level of the carpal tunnel).

This study has been conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy of the Jagiellonian University Medical College and cadavers from the Department of Forensic Medicine of the Jagiellonian University Medical College. After dissection the median nerves were stained with haematoxylin and eosin and histological slides were prepared. These were later photographed (16 x magnification) and analysed using ImageJ software. The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/209/B/2002).

The studied group comprised 8 women and 22 men (age between 23-92 years), yielding a total of 60 median nerves (30 right vs. 30 left). In 4 (6.67%) cases an accessory motor branch was found. The mean CSA of the median nerve was 0.19 cm(2). The median nerves from the right hand had a statistically larger CSA (p = 0.017). The number of nerve bundles in the median nerve varied between 13 to 38 and in the motor branch of the median nerve between 4 to 14.

The nerve bundles of the median nerve, at the level of the carpal tunnel, display no particular type of arrangement. ImageJ software proved useful in the assessment of the histological structure of the human median nerve and its motor branch.