UNDERSTANDING THE CONNECTION BETWEEN ELECTRICAL SHOCK AND SUBSEQUENT NEUROMUSCULAR DISORDERS
As electrical power finds increased use in many fields, the possibility of experiencing an electric shock does too. While the majority of electrical shocks are minor and go unnoticed, there is a subset of cases where these shocks manifest long-term disability with peripheral pain, loss of strength and coordination, and a variety of other problems that interfere with daily activities. Injuries from lightning cause similar long-term effects. One of CETRI's primary research goals is to understand the connection between electrical shock injury and the delayed onset of specific symptoms. These manifestations are typically related to neuromuscular pain and/or disability. CETRI's research priority is understanding the preinjury factors that predispose someone to neuromuscular problems and determining effective therapies to mitigate this.
NEUROPSYCHOLOGICAL SEQUELAE OF ELECTRICAL SHOCK INJURY
Some survivors of electrical shock injury frequently present with clinical signs and symptoms of stress disorders, depression, cognitive changes, and emotional disorders with no pre-injury history of these problems. In many cases, these symptoms do not manifest immediately following the injury. Over the past 26 years, CETRI has performed multidisciplinary clinical evaluations on many hundreds of electrical shock survivors that contacted CETRI because of clinical complaints after surviving electrical shock. CETRI is working to parameterize and analyze the factors linking electrical shock and neuropsychological disorders.
OPTIMAL PHYSICAL THERAPY APPROACHES TO RECOVERING FROM ELECTRICAL SHOCK INJURY
Neuromuscular retraining is an important aspect of successfully recovering from all forms of physical trauma, especially those that damage nerves and skeletal muscle. Proper healing and neuromuscular adaptation are important for a successful recovery. A fundamental priority for CETRI is to learn how best to maximize functional sensory and motor recovery following electrical shock injury.
Electrical shock ranks among the most devastating of all injuries: outright electrocution is a leading cause of death in some jobs. In contrast, survivors of severe electrical burns may undergo progressive tissue loss, preventing them from returning to work. Historically, it was believed that the main cause of injury in electrical burns was the heating of tissue by the passage of current. CETRI researchers first challenged this assumption by demonstrating that much of the damage resulted from the opening and enlargement of pores in cell membranes due to high-intensity electric fields.
This electroporation process allows important ions to flow freely through the membrane, eventually resulting in cell death. A paper presenting evidence that this can occur even in the absence of thermal damage won the 1995 Lindberg Award of the American Burn Association.
Based on this understanding of electrical burns, CETRI researchers postulated a new type of treatment in which a surfactant already used for medical purposes, Poloxamer 188 (P-188), is administered to injured tissue to seal the membrane pores. The effectiveness of P-188 in this application has now been confirmed in both cell-culture and animal studies, and the U.S. Food and Drug Administration has given approval to begin clinical trials of the treatment.
PAIN INFLUENCES NEUROPSYCHOLOGICAL PERFORMANCE FOLLOWING ELECTRICAL INJURY: A CROSS-SECTIONAL STUDY
DOROCIAK KE, SOBLE JR, RUPERT PA, FINK JW, LEE RC, ANITESCU M, WEISS D, COOKE G, RESCH ZJ, PLISKIN NH.;
Journal of the International Neuropsychological Society
Objective. Electrical injury (EI) is a significant, multifaceted trauma often with multi-domain cognitive sequelae, even when the expected current path does not pass through the brain. Chronic pain (CP) research suggests pain may affect cognition directly and indirectly by influencing emotional distress which then impacts cognitive functioning. As chronic pain may be critical to understanding EI-related cognitive difficulties, the aims of the current study were: examine the direct and indirect effects of pain on cognition following EI and compare the relationship between pain and cognition in EI and CP populations.
Method. This cross-sectional study used data from a clinical sample of 50 patients with EI (84.0% male; Mage = 43.7 years) administered standardized measures of pain (Pain Patient Profile), depression, and neurocognitive functioning. A CP comparison sample of 93 patients was also included.
Results. Higher pain levels were associated with poorer attention/processing speed and executive functioning performance among patients with EI. Depression was significantly correlated with pain and mediated the relationship between pain and attention/processing speed in patients with EI. When comparing the patients with EI and CP, the relationship between pain and cognition was similar for both clinical groups.
Conclusion. Findings indicate that pain impacts mood and cognition in patients with EI, and the influence of pain and its effect on cognition should be considered in the assessment and treatment of patients who have experienced an electrical injury.
AMPHIPHILIC BLOCK COPOLYMER-CATALYZED CELL MEMBRANE SEALING IS LINKED TO DECREASED MEMBRANE TENSION
AATOUK, C., LING, M.X., TITUSHKIN, I.A., CHO, M.R., MCFAUL, C.A., & LEE, R.C. ;
Regenerative Engineering and Translational Medicine
Abstract. The cell plasma membrane suffers structural disruptions from both daily environmental stresses and trauma. Rapid loss of cell viability occurs if membrane integrity is not rapidly restored. Physiological membrane sealing involves alteration of local intermolecular thermodynamics that is manifested by changes in membrane tension which precede reassembly of the membrane planar bilayer structure. Certain block copolymer surfactants, including poloxamer 188 (P188), have been proven to seal-disrupted cell membranes. However, the specific molecular mechanics of poloxamer-mediated membrane sealing remains a target of investigation. A decrease in membrane tension precedes membrane sealing by natural intrinsic cell sealing processes. The effect of P188 on the quasistatic membrane tension of Madin-Darby canine kidney (MDCK) and Swiss 3T3 fibroblasts cells under normal and saponin-permeabilized conditions was measured using laser optical tweezer (LOT)-extracted membrane tethers. The tether trap length of saponin-permeabilized MDCK cell membranes decreased from an uninjured control of 11.28 ± 1.1 μm to 6.43 ± 0.67 μm. Treatment with P188 (0.2 mM) significantly increased the tether trap length to 9.69 ± 1.0 μm (p < 0.05) while the control polymer, polyethylene glycol (0.2 mM) resulted in tether trap length of 7.02 ± 0.73 μm that was not significantly different. Similar observations were made in the saponin-permeabilized fibroblasts. Corresponding fluorescence cell viability assays revealed that P188-treated cells had a higher survival rate. Thus, surfactant copolymer membrane sealing restores the membrane integrity by decreasing the membrane tension.
PHYSICAL MECHANISMS OF TISSUE INJURY IN ELECTRICAL TRAUMA
LEE, R.C. ;
IEEE TRANSACTIONS ON EDUCATION. Vol 34(3); 223-230, 1991
Progress towards an effective therapeutic strategy for victims of electrical trauma depends on advancing knowledge of the physical mechanisms of tissue injury activated by strong electric fields. It is well recognized that rupture of skeletal muscle cell membranes is a prominent clinical feature manifested by victims of electrical trauma. Exposure to either supraphysiologic temperatures or supraphysiologic transmembrane potentials can cause cell membrane disruption. The strong electric fields characteristically established in high-voltage electrical trauma victims generate rapid heating as well as impose destructively large transmembrane potentials in skeletal muscle and nerve tissues. The relative importance of heat versus electrical stress as mechanisms of cellular damage is uncertain in the majority
of victims. This is an active and important arena of bioengineering research. The salient biophysical aspects of this frequently crippling and often fatal injury is reviewed.
HIDDEN REALITIES OF ELECTRICAL INJURIES
McCollum, Kyle BS; Gowrishankar, T.R. PhD; Lee, Raphael C. MD, ScD;
Abstract. The clinical spectrum of electrical injury ranges from the absence of any external physical signs to severe and life-threatening trauma. This article discusses the fundamental concepts and misunderstandings surrounding electrical injuries and the best practices for evaluation and treatment.
A FOLLOW-UP STUDY OF A LARGE GROUP OF CHILDREN STRUCK BY LIGHTNING
L M A SILVA, PHD; M A COOPER, MD; R BLUMENTHAL, MD; N PLISKIN, PHD;
South African Medical Journal 2016
Background. On 11 November 1994, 26 preadolescent girls, 2 adult supervisors, and 7 dogs were sleeping in a tent in rural South Africa when the tent was struck by lightning. Four of the girls and four of the dogs were killed. The 2 adults were unharmed, but all but 3 of the children suffered significant injuries. An article in 2002 detailed the event and examined the medical and psychological changes in the surviving girls.
Objective. To understand the medical and psychological changes secondary to lightning strike years after injury.
Methods. An online questionnaire was prepared that included a checklist of physical and psychological symptoms. Participants were asked to report on both initial and current symptoms. Eleven of the 22 survivors were contacted, and 10 completed the survey.
Results. Participants reported that initial physical symptoms generally resolved over time, with ~10 - 20% continuing to experience physical symptoms. Vision problems persisted in 50% of respondents. Psychological symptoms, overall, had a later onset and were more likely to be chronic or currently experienced. Depression and anxiety, specifically, were higher among the survivors than the reported incidence in South Africa.
Conclusions. Initial and current/chronic physical and psychological symptoms following a lightning strike are reported found, adding to the body of literature on the long-term after-effects of a lightning strike on survivors. A brief discussion on post-traumatic stress disorder symptomatology and post-lightning shock syndrome is provided.
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Cell Injury: Mechanisms, Responses & Repair
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