Cervicothoracic spinal cord and pontomedullary injury secondary to high-voltage electrocution: a case report
Abstract
High-voltage electrical injuries are uncommonly reported and may predispose to both immediate and delayed neurologic complications.
We report the case of a 43-year-old Caucasian man who experienced a high-voltage electrocution injury resulting in ischemic myelopathy and secondary paraparesis.
High-voltage electrocution injuries are a serious problem with potential for both immediate and delayed neurologic sequelae. The existing literature regarding effective treatment of neurologic complications is limited. Long-term follow-up and multidisciplinary management of these patients is required.
Introduction
High-voltage electrical injuries are uncommonly reported and may lead to serious neurologic sequelae. The true incidence and prevalence of these events are difficult to ascertain. This may be due to the fact that these cases are underreported in the literature, probably due to population unawareness and medically underserved communities. Children and young men are at the highest risk to receive an accidental electrical injury, with these subgroups being less likely to report the incident [1]. The extent of injury may be apparent immediately or it may take weeks to manifest. Clinicians need to be aware of the neurological consequences of electrocution.
Case presentation
A 43-year-old right-handed Caucasian man experienced an electrical burn after contact with a 440 volt line while working on a roof. Upon standing up from the squatted position, the right side of our patient’s head came into contact with an exposed wire, resulting in electrocution with a loss of consciousness. Witnesses called the emergency medical services, and our patient was intubated at the scene. He was transferred from a local community hospital to our institution’s burn unit for a higher level of care. Second and third degree burns covered 21% of his total body surface area. The entry wound was through his scalp, traversing through his neck and chest, into his groin, and exiting from his left foot. No spinal fractures were identified.
Initially, our patient was alert and able to move all four limbs. Over the ensuing days, he was observed to move his legs less than his arms. Two days after our patient received multiple skin grafts and a calvarial flap, sedation was held and he was noted to have absent limb movements during routine dressing changes. A neurological consultation was obtained on his 10th day of hospitalization because of his evolving weakness. On examination, our patient was intubated, and his head, chest, groin and bilateral lower extremities were covered by dressings. He was awake with eyes open, alert and able to follow simple commands. A cranial nerve examination revealed reactive pupils, intact extraocular movements and symmetrical facial movement to smile, eye closure and eyebrow elevation. Our patient indicated normal light touch sensation on his face with nodding. He was breathing over the ventilator and able to shrug his shoulders. A motor examination showed normal muscle bulk with flaccid tone and only intermittent, trace movement in his left fingers. Our patient acknowledged pain with nodding on light pressure to all limbs. His deep tendon reflexes were diminished and plantar responses were equivocal.
On admission, magnetic resonance imaging (MRI) of his cervical spine demonstrated changes suggestive of edema from C3 to T2 levels with an intact spinal cord. Given the changes noted on the neurological examination, a repeat MRI was suggested. Repeat imaging performed eight days after the first MRI revealed an interval development of cord swelling and acute ischemic infarction (Figure1A,B,C). MRI of his brain showed restricted diffusion in the bilateral medullary pyramids and pons, indicating infarction of the corticospinal tracts at the pontomedullary level (Figure2A,B).
Figure 1
Magnetic resonance imaging of the cervical spine repeated eight days after the initial magnetic resonance image performed on admission.Interval development of cord edema and infarction is seen from the C2 to T2 levels. (A) Sagittal T2 sequence. (B) Diffusion-weighted image. (C) Apparent diffusion coefficient image. The diffusion-weighted image and apparent diffusion coefficient image do not demonstrate the exact same level of involvement, with the apparent diffusion coefficient image showing signal changes slightly lower in the cervical spine than the diffusion-weighted image. Also, the diffusion-weighted image signal abnormality does affect somewhat the dorsal aspect of the cord. This reflects the often diffuse and collateral nature of electrical injuries.
Figure 2
Magnetic resonance imaging of the brain demonstrating restricted diffusion in the bilateral medullary pyramids and pons.(A) Diffusion-weighted image. (B) Apparent diffusion coefficient image. Repeat magnetic resonance imaging of the brain performed two months later demonstrates resolution of the diffusion restriction: (C) diffusion-weighted image; (D) apparent diffusion coefficient image.
Our patient was treated with fluid resuscitation, electrolyte replacement and nutritional support as well as wound care and pain control. Intravenous steroids were considered however not pursued due to the risk of infection and imaging findings of ischemia. A tracheostomy and percutaneous gastrostomy tube were placed. Our patient’s hospital course was complicated by pneumonia and the development of pulmonary emboli, requiring placement of an inferior vena cava filter. Over the next two months, our patient showed minimal improvement in motor function. Repeat imaging was obtained. MRI of his brain revealed near complete resolution of the ischemic changes (Figure2C,D). A cervical spine MRI suggested a persistent, abnormal signal posteriorly from the cervicomedullary junction to the C6 level with an interval decrease in cord edema (Figure3A,B). His course showed an ability to hold his head up with more movement in his left arm against gravity; some flexion of his right elbow and wrist was also noted. No improvement was observed in his lower extremities. Our patient was subsequently transferred to an inpatient rehabilitation facility, and unfortunately was lost to follow-up thereafter.
Figure 3
Magnetic resonance imaging of the cervical spine two months after the image in Figure1was taken.(A) T2 sequence. (B) T1 post-contrast image.
Discussion
In electrocution injuries, the overall mortality may reach 5%. Electrical injuries have been reported to occur in low-voltage settings, such as with household use, and high-voltage exposures from occupational hazards and lightning strikes [1]. Given the nature of these injuries, most of the literature has been reported as case studies with limited data regarding the evaluation and treatment of neurological complications.
Several pathophysiological mechanisms of injury to the nervous system have been proposed, including thermal injury, electroporation, and vascular damage through direct injury as well as indirect injury.
Electrical current flows from an area of low resistance to high resistance. Low areas of resistance include muscle, nerve and blood vessels. High-resistance tissue includes skin, connective tissue and bone, which suffer greater heat injury, typically at entry and exit sites but damage may be caused in any structure along the path of the current [2–4]. Nervous tissue provides a low-resistance route for electrical current. As the electrical current travels through tissue, neurons with larger surface area are more likely to be damaged by electroporation, in which the increase in cellular permeability and conductivity caused by permanent conformational change to membrane proteins ultimately leads to cell death [5]. The heat loss that occurs as current flows through tissues of increasing resistance causes damage to the intima and adventitia of the vasculature, such as thrombosis, necrosis of the vascular wall, vasospasm and spread into nearby tissue [3,4]. Most patients survive the initial insult, limiting the pathological work-up, with few postmortem studies available for review [1]. Morbidity of electrocution has been related to electrothermal injury causing direct tissue damage with secondary ischemi

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