The Diagnostic Value of Intraoperative Measurement of Choline Acetyltransferase Activity During Brachial Plexus Surgery

We used the measurement of choline acetyltransferase (CAT) activity to distinguish between preganglionic and postganglionic injuries of the spinal roots during brachial plexus surgery. This study includes ten spinal roots in six patients with traumatic brachial plexus injuries. The results of CAT activity were compared with myelographic findings, the operative findings and the intraoperative evoked spinal cord potentials. The results of CAT activity and the operative findings were consistent in all roots. Whereas CAT activity in fascicles in preganglionic injured roots was below 500 cpm, it was above 2000 cpm in postganglionic injured roots. This study shows that intraoperative measurement of CAT activity can provide useful information on the site and severity of brachial plexus injuries and the assessment of the motor function status of the injured spinal root, both directly and quantitatively.