Electrical Injury and Mild Traumatic Brain Injury

It's time once again for an edition of SLPs Blogging About Research! For information about this, or if you want to participate, you can find out more here.

Acute care speech pathology is a world all its own. Interestingly, it is not an environment conducive to therapy. Rather, I like to think of it more as a place for a lot of assessment, followed by maintenance and, naturally, more assessment. Most of the time, patients are too ill, or their injuries too recent, to begin to establish meaningful change in a therapeutic way.

This isn't to say that we don't have our own goals. Quite the opposite, actually. I remain a big believer that getting started early is the best way to begin on the road to recovery. Where I feel I can make a difference is to get in early and establishing some baselines for function. At the acute stage, there is often concern for evolving infarcts, or even the possibility of new ones. If a stroke is hemorrhagic, it doesn't make sense to push much for therapy because it's changing. Recovery, in general, requires medical stability, and at the acute stage stability is tepid at best.

An additional challenge of acute care is being able to recognize mild traumatic brain injuries. In the midst of the more severe cases, it's easy to encounter patients with mild TBI and feel like they're in relatively good shape. After working extensively with trauma patients, I've found that medical teams are often quick to dismiss head injuries if visible clots or bleeds are not seen on scans. Ask any neurologist or neurosurgeon, and they'll readily confirm that a clean MRI or CT does not necessarily indicate a lack of head injury. This is where SLPs come in handy on a multidisciplinary team.

The hospital where I work also happens to house a Burn Unit, which, as its name suggests, specializes in the care and treatment of burns. Several months ago, I evaluated a patient who was status post electrical shock injury with resulting brief pulseless electrical activity. Though the patient was what we affectionately like to call a "walkie talkie", I requested a consult out of concern for possible anoxic brain injury. I noticed some cognitive deficits in my initial evaluation, most prominent of which were attention and memory. When I brought this up to the team, a psychiatry fellow introduced me to a new world of mild traumatic brain injury, and one that did not necessarily involve any physical trauma to the head or brain.

The Neuropsychological Effects of Electrical Injury: New Insights By Pliskin et al.

The authors of this study note that, despite evidence, the following four assumptions remain common (as of the writing of the article) about patients with electrical injury:

1. a more visible burn will indicate greater psychological difficulties
2. low voltage exposures will not cause significant neuropsychological problems
3. electrical injury patients who experience changes are not premorbidly psychologically stable
4. electrically injured patients are faking their difficulties for secondary gain (i.e. workers' compensation)

The study focused on electrical injury peripheral to the head (no direct electrical contact to the head) and the source of electrical injury was a power source only (no lightning strike patients were included). Also, none of the patients studied had sustained a known head injury. They were separated into two groups: acute (seen within 3 months post-injury) and postacute (seen after 3 months post-injury). A control sample of electricians was used, and none had a history of prior electrical injury, neurological disease or lesion, head injury, or psychiatric illness.

The study was then split into three groups.

Study 1: Symptom Profiles

The participants and the control group were administered two assessments: the Neuropsychological Symptom Checklist (NSC) and the Beck Depression Inventory (BDI), and "[r]esults indicated that the EI (electrical injury) group had a much higher self-reported rate of phsyical, cognitive, and emotional symptoms" (143). In addition to physical complaints such as paresthesias (tingling), EI patients indicated cognitive difficulties such as difficulty with concentration, word-finding in conversation, memory, attention (feeling distracted), and "slower thinking".

Also of note, the authors point out that findings "were not statistically related to severitry of physical injury, voltage exposure, involvement in litigation, or previous psychiatric history" (143). What's more, they found that patients who were further post-injury actually reported more symptoms than the more newly injuried. "[T]he high frequency of specific cognitive complaints in the EI sample may be surprising, especially considering that no patient sustained a direct mechanical electrical contact to the head" (144). What's more telling, for me is their comment that "little is known about the pathway that electricity takes once it enters the body after perifpheral contact despite apparent hand to hand or hand to foot injuries" (144).

Study 2: Neuropsychological Function

The next step of the study was to determine if any objective data could be found to support the cognitive complaints noted in the first part of the study. They tested the following:

1. intelligence (Wechsler Adult Intelligence Scale - Revised)
2. learning and memory (Logical Memory and Visual Reporduction subtests of Wechsler as well as California Verbal Learning Test (CVLT))
3. attention and concentration (Paced Auditory Serial Addition Test (PASAT), Stroop test, and trailmaking test)
4. motor function (grooved pegboard)
5. depression screening (Beck Depression Inventory)

The study found significant differences, with "poor performances on measures of attention and concentration, motor speed/dexterity, and memory performance... [and] visual memory performance in particular was worse in the EI group, especially in initial acquisition of new information" (145). Once again, the study also found that postacute patients had even lower scores than acute patients.

Study 3: Longitudinal Outcome

The study found that these symptoms and functional deficits could be present for years after an accident, with an average report of 3.9 years. Further study is indicated to better understand these long-term implications.

The study concludes almost more questions than it started with. The biggest one: "why are patients who were seen postacutely up to five years after injury apparently worse from a psychological and nueropsychological standpoint than patients who were evaluated acutely?" (147). The authors question if it takes time for effects to truly become apparent, or if these patients represent only a small subset of electrical injury patients. Further studies are indicated.

The Takeaway

I have to thank my psychiatrist colleague for sending me this article. Even though the focus is from a psychological perspective, I found the information immensely helpful and a definite asset to my clinical foundation. I appreciate more than ever how vital it is to be part of a multidisciplinary team.

Though electrical injury is thankfully a relatively rare diagnosis in my practice, I feel more prepared to work with patients and having this information will go a long way for patient and family education. For example, with the patient that sparked this discussion earlier this year, I was able to provide the patient and family with information and resources in the event that difficulty might arise following discharge.

Article Citation

Pliskin, Neil H., et al. (November 1999.) The Neuropsychological Effects of Electrical Injury: New Insights. Annals of the New York Academy of Sciences, vol. 888, pp. 140-149.