High Resolution Ultrasound as a Neuroimaging Tool in Traumatic Peripheral Nerve Injuries

Abstract

Traumatic peripheral nerve injury (TPNI) is quite common in various types of acral trauma. It mostly passes unnoticed at the time of the initial trauma. The patients are usually sent for an ultrasound (US) assessment about 4 weeks following the trauma, after the electrophysiological changes are established. This paper presents a 5-year experience of US findings of TPNI through 60 cases, who were examined as an outpatient with clinical and electrodiagnostic (EDX) tests suggesting nerve injury. The study population includes 40 males, 20 females, and mean age 34.4 ± 16.3. Upper limb nerves were more affected than the lower ones, with no significant difference between the right and left sides. Mechanisms of injury include laceration in 53.4% of cases, 38.3% had history of traction injury and only 8.3% had history of compression/contusion injury. Regarding the severity grading of the injuries, long segments of thickened separate or matted fascicles (Grades I and II) was found in 27 (40.9%) nerves; partial disruption with interstitial neuroma (Grade III) in 15 (22.7%) nerves; complete disruption (neurotmesis) (Grade IV) in 24 (36.4%) case. The integrity of six repaired nerves was also assessed. Muscle states within the territory of the motor nerve were always assessed, 62.9% of cases had decreased muscle bulk, 28.6% had muscle atrophy, and the remaining was normal. EDX testing results of 44 out of 60 patients was severe in 14 cases (31.8%), moderate in 15 cases (34.1%), mild in 11 case (25%), and normal in four cases (9.1%). The purpose of this study is to demonstrate that the US is a convenient neuroimaging tool by which we can accurately determine the level and the degree of peripheral nerve damage to plan the appropriate treatment.