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  • Updated 05.28.2024
  • Released 08.01.2006
  • Expires For CME 05.28.2027

Electrical injuries: neurologic complications

Introduction

Overview

Electrical injury can affect any organ. Neurologic complications are well-recognized and cause a distinct increase in morbidity. The broad range of neurologic complications of electrical injuries are described, including peripheral neuropathy, central nervous system disorders, and seizures. Clinical features that are useful in evaluating patients after electrical injury are identified. Neurologic sequelae of electrical injuries may present years after electrical injury. Neuropsychological disorders may present as posttraumatic stress disorder. The management of late neurologic sequelae of electrical injury is described.

Note that a separate MedLink article addresses Lightning injuries: neurologic complications.

Key points

• Neurologic sequelae from electrical trauma can be immediate (transient or permanent), delayed and progressive, or linked to a secondary injury caused by electrical injury.

• There is an increase in the incidence of neuropsychiatric sequelae of electrical injury, such as posttraumatic stress disorder, the second most common type of sequelae after those related to burns.

• Neurologic sequelae include loss of consciousness, headache, memory disturbance, seizures, movement disorders, speech impediment and mutism, vertigo, cranial nerve dysfunction, meningitis, autonomic nervous system complications, and peripheral neuropathies.

• The diagnostic approach to the neurologic consequences of an electrical injury patient is like the neurologic evaluation of a multi-trauma patient.

• Indications for hospital admission include the following: exposure to an electrical source of more than 200 V and 200 mA; cardiac abnormalities; loss of consciousness; fall from a height; thermal injury to greater than 15% of the body surface area or burns to the hands, feet, face, or groin; respiratory distress; spine fractures; serum electrolyte derangements; and compartment syndromes.

Historical note and terminology

The scientific study of electricity developed in the 17th and, particularly, 18th centuries, as did the study of electrical effects on human and animal bodies.

A Leyden jar (or Leiden jar, from archaic Dutch, or sometimes Kleistian jar) is an electrical device that stores a high-voltage electric charge between electrical conductors on the inside and outside of a glass jar--the original form of the capacitor or condenser. It was invented, apparently independently, by German cleric Ewald Georg von Kleist (c. 1700-1748) in 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden), Netherlands c1745-1746 (06) and his student Andreas Cunaeus. Musschenbroek and Cunaeus each received strong shocks from the capacitance discharge when they attempted to "condense" electricity in a glass of water.

I hung a copper wire ... from the end of the iron tube, and ... I took a glass vase from which we are wont to drink beer. This [glass] was filled half with water. Then the wire was hung in the middle of the water. When the [glass] globe was rotated [to generate a static charge], such heavy sparks were drawn from the wire to the finger that the pain was unbearable, and even the vase itself got cracks. The water remained electric for a long time and gave repeated explosions to the finger ... (from Musschenbroek 1745, translated by Present in 2022, page 118) (62).

Ultimately, before other means were developed to provide electricity, banks of Leyden jars were employed to store large-voltage electric charge for such things as wireless communications (ie, the telegraph).

German wireless telegraphy station powered by charge stored in 360 Leyden jars, c1908

Spark-gap radio transmitter for a long-distance wireless telegraphy radio station built by Gesellshaft fur Drahtlose Telegraphie (Telefunken) at Nauen, Germany in 1907. Designed by German radio pioneer Georg von Arco (1869-1940...

American statesman and scientist Benjamin Franklin (1706-1790) was the first to point out the relation of lightning to electricity in 1752. Franklin later invented the lightning rod and, in an infamous episode, attempted to use electricity to electrocute a turkey.

Italian physician, anatomist, and physiologist Luigi Galvani (1737-1798) established the existence of what he called “animal electricity” (animalis electricitas) (26; 57; 58; 59; 13; 43).

Luigi Galvani (1737-1798)

Lithograph depicts Italian physician, anatomist, and physiologist Luigi Galvani (1737-1798). (Courtesy of the Wellcome Trust. Creative Commons Attribution 2.0 Generic [CC BY] license, crea tivecommons.org/licenses/by/2.0/deed.e...

After more than a decade of research, Galvani described his results in De Viribus Electricitatis in Motu Musculari Commentarius (Commentary on the Effects of Electricity on Muscular Motion) (29). This was reprinted at Modena, 1792, with a note and dissertation by Galvani's nephew, Giovanni Aldini (1762-1834), and with new plates (30).

Although various individuals had previously suggested that electricity played a role in nervous action, Galvani’s experimental results garnered international attention. Although some derided Galvani’s notions, many considered to have proven both the existence of animal electricity and the operation of this electricity through nerves to produce muscular contractions.

Italian physicist Alessandro Volta (1745-1827) was among the first scientists to repeat Galvani’s experiments.

Initially, Volta enthusiastically supported Galvani's work, but he soon began to doubt that the observed muscle contractions were due to intrinsic electricity in animals. Volta suggested instead that the muscle contractions were due to an extrinsic form of electricity that was simply put in motion through the conducting metals or created by dissimilar metals.

From 1792 to 1797, German polymath Alexander von Humboldt (1769-1859) replicated many of the experiments of Galvani and Volta.

Friedrich Heinrich Alexander von Humboldt (1769-1859)

German polymath Friedrich Heinrich Alexander von Humboldt. Lithograph by C. Wildt after C Begas, 1840. (Courtesy of the Wellcome Trust. Creative Commons Attribution 2.0 Generic [CC BY] license, creativecommons.org/licenses/by/2...

Humboldt concluded that although the interaction of dissimilar metals could be an effective stimulus for muscle contraction (as both Galvani and Volta agreed), Galvani was nevertheless correct in believing that this was not necessary for muscles to contract and, further, that the preponderance of evidence supported the existence of an intrinsic form of “animal electricity.” However, Humboldt was not convinced that Galvani’s “animal electricity” was equivalent with other forms of electricity.

By 1800, Volta had constructed electrical batteries consisting of two different metals in an electrolytic salt solution. In addition, Volta discovered that a much greater electrical effect could be produced by a series of alternating copper and zinc disks placed in a line, with each copper-zinc pair separated from the next pair by a cloth or cardboard disk soaked in brine. This device, which Volta called a “pile” and is consequently now referred to as a “voltaic pile,” was the first practical battery.

Throughout the scientific controversy, Galvani was unwilling to engage directly in arguments against the challenges of Volta and others. Consequently, Galvani's nephew Giovanni Aldini became the main defender and proponent of Galvani’s concept of animal electricity (53; 43; 09).

Aldini traveled across Europe, publicly electrifying human and animal bodies in theatrical performances. In 1802, Aldini went to London and elicited repeated, spasmodic movements of facial muscles on human heads, arms, and legs as well as the heads and trunks of oxen, cows, horses, sheep, and dogs. Aldini's most famous performance was for a large medical and general audience at the Royal College of Surgeons in London in 1803 on a hanged man named George Forster, who had been convicted of murdering his wife and child by drowning them in the Paddington Canal. Aldini took a pair of conducting rods linked to a powerful voltaic pile and touched the rods to various parts of the corpse. When the rods were applied to Forster’s mouth and ear, “the jaw began to quiver, the adjoining muscles were horribly contorted, and the left eye actually opened” (04). When one rod was moved to touch the rectum, the whole body convulsed, and the movements were “so much increased as almost to give an appearance of re-animation” (04).

Aldini's Essai théorique et expérimental sur le galvanisme: avec une série d'expériences faites en présence des commissaires de l'Institut National de France, et en divers amphithéâtres anatomiques de Londres ... [Theoretical and Experimental Essay on Galvanism: With a Series of Experiments Made in the Presence of the Commissioners of the National Institute of France, and in Various Anatomical Amphitheaters in London] contained a full account of his various “experiments” as well as numerous engravings (05). A decade later, Aldini's spectacles served as an inspiration for Mary Shelley's novel Frankenstein; or, The Modern Prometheus (1818) and for various political cartoons.

Electric motors were invented in the early part of the 19th century (1820s-1830s), and with the development of power stations and electrical lightning, electricity entered the industry and daily life of people. In 1882, Thomas Edison (1847–1931) formed the Edison Electric Illuminating Company of New York, bringing electric light to parts of Manhattan. Nevertheless, most Americans still lit their homes with gas lights and candles for another 50 years.

One bizarre electrocution event of an elephant in 1903 has erroneously been attributed to an anti-alternating current demonstration organized by Thomas A Edison (who favored direct current) during the so-called "war of the currents." Topsy (c 1875 – January 4, 1903) was a female Asian elephant who was electrocuted at Coney Island, New York, in January 1903. During her 25 years at the Forepaugh Circus, Topsy gained a reputation as a "bad" elephant and, after killing a spectator in 1902, was sold to Coney Island's Sea Lion Park. During the construction of the park that took its place, Luna Park, Topsy was used in publicity stunts. Luna Park's publicity-hungry owners, Frederic Thompson and Elmer "Skip" Dundy planned to advertise the opening of their new park by euthanizing Topsy in a public hanging and charging admission to see the spectacle, but this was prevented by the American Society for the Prevention of Cruelty to Animals. The event was instead limited to invited guests and press only. On January 4, 1903, in front of a small crowd of invited reporters and guests, Topsy was fed carrots laced with 460 grams of potassium cyanide, electrocuted and strangled, the electrocution being the final cause of death. Among the invited press that day was a crew from Edison Studios who filmed the event. Their film of the electrocution was released to be viewed in coin-operated kinetoscopes under the title "Electrocuting an Elephant." Although Edison Studios filmed the event, Edison himself was never at Luna Park, and the electrocution of Topsy took place 10 years after the war of currents.

Serbian-American inventor and electrical engineer Nikola Tesla (1856–1943) is known for his contributions to the design of the modern alternating current (AC) electricity supply system.

Tesla emigrated to the United States in 1884 and began working almost immediately at the overcrowded Edison Machine Works on Manhattan's Lower East Side. Tesla quit after 6 months. In late 1886, after several other failed endeavors, the Tesla Electric Company was formed in April 1887 with the assistance of venture capitalists. In 1887, Tesla developed an induction motor that ran on alternating current (AC), a power system format that was rapidly expanding in Europe and the United States because of its advantages in long-distance, high-voltage transmission. The motor used polyphase current, which generated a rotating magnetic field to turn the motor (a principle that Tesla claimed to have conceived in 1882). This innovative electric motor, patented in May 1888, was a simple self-starting design that did not need a commutator, thus, avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes.

Engineers working for the Westinghouse Electric & Manufacturing Company reported to George Westinghouse (1846-1914) that Tesla had a viable AC motor and related power system—something Westinghouse needed for the alternating current system he was already marketing.

In July 1888, a licensing deal was negotiated with George Westinghouse for Tesla's polyphase induction motor and transformer designs. Westinghouse also hired Tesla for to be a consultant at the Westinghouse Electric & Manufacturing Company's Pittsburgh labs 1 year.

It was not until 1925 that half of all homes in the United States had electric power. Most of the earliest knowledge of electrical injury in this period was based on anecdotal reports.

Scientific characterization of human response to electricity did not progress significantly until the last half of the 20th century and was first thoroughly documented in a special report (21). Injuries from exposure to electricity may be superficial, resulting in skin burns if no electrical current travels through the body. Nevertheless, a patient who presents initially with electrical burns and no neurologic signs may develop late neurologic sequelae. In true electrical injuries, the victim becomes part of the electrical circuit with an entrance and exit site for the current. This can involve damage to various organs, including the nervous system. Secondary injuries may be due to falls caused by contact with electrical energy.

Most electrical injuries occur in workers dealing with electric machinery or power lines. The incidence of electrical injuries has decreased with the regulation of occupational electrical safety standards. Electrical injuries can occur at home due to mishaps in handling electric appliances.

Fatal electrical shock is referred to as electrocution, although the term "electrocution" is often used erroneously to refer to nonfatal electrical injuries. The earliest electrocution occurred in a theater in 1879, whereas intentional electrical fatality as a form of capital punishment dates to the first electric chair execution in 1890 (81).