Prevalence and distribution of peripheral nerve injuries in victims of Bam earthquake

In the early morning of Friday 25th Dec. 2003, the ancient and historical city of Bam in Southern East of Iran was vibrated by a big and horrible earthquake for 6.4 degree of Richter. About 30,000 people were died and about 30,000 victims and injured persons were the initial results of the earthquake. Almost all of the buildings were destroyed and all the people became houseless. In this study, 156 patients with peripheral nerve lesion (PNL) were assessed for their injuries.

In a cross sectional study since the second week after the quake until 6 months later, we examined 506 patients with the symptoms and signs of motor/sensory and performed the Electrodiagnostic study for all of the patients who had obvious or suspected lesion of peripheral nerves. There were 156 patients (31.2%) afflicted with peripheral nerve lesion. We performed NCS/EMG for upper limb and face at least 2 weeks and for lower limb, at least 3 weeks after injury in 156 of the victims that had PNL.

Of 156 patients, 75 (48%) were female and 81 (52%) were male. The average of age was 29.2 +/- 12.9 years, about 87.2% were between 15 to 50 yrs old. The frequency of injuries was 88 nerves, 53 neural plexuses and 5 cauda equina lesions. The most frequent injured nerve was sciatic nerve (24.8%) and the next was Radial nerve (15.5%) and the less frequent nerve was axillary which observed just in 1 patient. 21.6% of patients had the brachial plexus and/or lumbosacral plexus injuries. There were more involvements in lower limbs comparing upper limbs and face (p < 0.01).

Peripheral nerve injury is one of the most frequent injuries in earthquake victims. These lesions may cause temporary or lifelong disabilities in patients. In this study, the more frequent involvement of sciatic and radial nerve seems to be related to their anatomic location and also the position of victims when earthquake happened and the involvement of brachial and lumbosacral plexus could be due to inappropriate evacuation of the victims from the loads and also due to incorrect transportation.