A Case Report of Spinal Cord Injury Patient From a High Velocity Gunshot Wound to the Lumbar Spine
A 40-year-old man became paraplegic after a gunshot wound to the lumbar spine. The injury occurred when he came under fire during a shooting rampage while he was abroad. The perpetrator had fired an AR-15 rifle ArmaLite Model 15 (Colt Inc., Hartford, CT, USA), and the bullet went through the victim's back. After the incident, his bilateral lower limbs showed no muscle contraction with sensory loss. The patient underwent explorative laparotomy and was diagnosed with injuries to the spinal cord and aorta. He was transferred to our hospital on the second post-traumatic day. A computed tomography (CT) scan revealed a burst fracture of the first lumbar vertebra, resulting from penetration by a bullet from the gunshot through the right paraspinal muscles and L1-2 intervertebral disc (). The bullet was fragmented, and one of the largest fragments was lodged in the T12-L1 disc. Another large fragment was located between the right vertebral body and aorta at the level of the renal arteries (). Apart from bowel contusion, there was no evidence of intra-abdominal trauma such as active bleeding or bowel perforation on the patient's CT images.\nThe patient underwent L1 decompressive laminectomy, partial corpectomy, removal of the bullet and T11-L3 posterior fixation. The dura in the level of the first lumbar vertebra was severely damaged, and most parts of the cauda equina were severed from the conus medullaris. A 0.8-cm bullet fragment at the T12-L1 disc level was removed (). Subsequently, a rupture of the abdominal aorta was treated by a vascular surgeon. A 1.0-cm bullet fragment just anterior to the first lumbar vertebral body was also removed. However, massive bleeding occurred following removal, so aorta graft interposition with polytetrafluoroethylene was performed after resection of the aorta between the renal artery and the superior mesenteric artery. A possibility of a second insult to the spinal cord due to infarction caused by massive bleeding was considered, although it could not be confirmed. A postoperative spinal CT scan revealed multiple bone remnants and bullet fragments in the L1-2 intervertebral disc and spinal canal space ().\nThe patient subsequently began range of motion exercise at bedside on the 13th post-traumatic day and tilting table exercise in the gym on the 18th day.\nOn the 39th post-traumatic day, the patient was transferred to the Department of Rehabilitation. His neurological level of injury was determined as T12 according to the American Spinal Injury Association Impairment Scale (AIS)-A. Sensory examination revealed sensory loss in L2 and below. The manual muscle test showed grade 0 in all the muscles of the bilateral lower limbs. Deep tendon reflexes of the bilateral knees and ankle joints were decreased and muscle tones of bilateral lower extremities were flaccid. The bulbocavernosus reflex was absent. His bladder and bowel sense decreased, and urodynamic examination revealed detrusor areflexia with coordinated sphincter.\nOn the 53th post-traumatic day, the patient underwent an electromyographic study. No responses were observed in motor nerve conduction study, H reflex, F wave, somatosensory evoked potential and bulbocavernosus reflex. The sensory nerve conduction study showed a normal value. Needle electromyography of all the muscles of the bilateral lower extremities showed severe to profound abnormal spontaneous activities with no motor unit action potential. The results were compatible with polyradiculopathy or the anterior horn cell lesion below L1, and there was no evidence of reinnervation.\nThe patient complained of severe neuropathic pain in the bilateral lower extremities (visual analogue scale [VAS], 7 to 8). Neuropathic pain was characterized by tingling and squeezing, which were aggravated at night. Although transcutaneous electrical nerve stimulation (TENS) and many kinds of analgesics including gabapentin (900 mg/day), pregabalin (450 mg/day), amitriptyline (25 mg/day), clonazepam (1 mg/day), oxycodone (20 mg/day), and fentanyl patch (50 µg/hr) were tried simultaneously and alternatively, he continued to suffer from pain that waxed and waned in the range of 4 to 8 on the VAS.\nOn the 55th post-traumatic day, he performed parallelbar (p-bar) gait with both knee-ankle-foot orthosis (KAFO), in parallel with the Walking Index for Spinal Cord Injury (WISCI) level 1. On the 90th post-traumatic day, he managed axillary crutch gait with both KAFO in the p-bar. Seven months after the trauma, however, there was no recovery in the neurological level of his injury according to neurologic examinations including the manual muscle test and sensory exam compared with the initial evaluation. Moreover, the patient's endurance and stability of gait function remained poor to the point that he could only manage the p-bar gait for 2 cycles and crutch gait for one quarter of a cycle in the p-bar (WISCI level 3). He showed no significant improvement in the activities of daily living, measured by the Korean Spinal Cord Independence Measure (KSCIM) score over the course from the 39th to the 81st post-traumatic day (from 32 to 35 points). Improvement was shown in bathing, dressing and motion in bed.