Traumatic brain injuries (TBIs) irrevocably change the path of a human life. The brain, just as much a mystery to us as the deep space our planet spins through, is our most complex organ, and when it gets injured, those incredibly complex processes break down. Flattening out the many nuances and three-dimensional definitions of consciousness and mind vs. brain, in essence, brains create perceived reality. After fracturing an arm and recovering in the hospital, a patient will still retain their cognitive function and be able to converse with family members and enjoy a television show they enjoyed pre-injury. After suffering a TBI, in contrast, a patient may lose the ability to converse, or recognition of those closest to them, or even lack consciousness. According to Flint Rehab, there are four main types of TBI, categorized by a point score on the 15-point, 3-category GCS (Glasgow Coma Scale) (Maher, 2021). A patient is assessed on processes such as eye-opening and verbal response. The higher their score, the less effect the TBI has had on their cognitive functioning. A score of 13-15 points is qualified as a mild TBI, 9-12 is qualified as moderate, 4-8 is severe, and receiving 3 points is deemed as a vegetative state. All levels of TBI constitute brain damage, but as the amount of damage increases, the likelihood of recovery and regaining the characteristics of a normal life goes down exponentially. However, this does not mean all hope is lost, as we see in Dr. Theresa Pape's work with neuromodulation as a form of neurorehabilitation.
In the November/December issue of The Journal of Head Trauma Rehabilitation, Dr. Pape, a research professor at Northwestern University with a background in speech pathology, published a synthesis report of the psychological field's prior work with rTMS as a method of neurological recovery that also included projections for where she determined the field was headed. rTMS has been used in the past for "motor function and mood rehabilitation" (Pape et al., 2020), and this inspired investigation into its potential as a rehabilitative technology. rTMS can be used to deliver sub- and supra-threshold stimuli to the neurons of the injured brain—this encourages plastic behavior in the brain at both the synaptic and meta levels. The brain's plasticity is its greatest strength and strongest hope in recovery from a TBI. Different neuronal networks can repair or restructure themselves to restore cognitive function. Pape points out that the definition of neuromodulation does not lend itself especially well to the treatment of TBIs because of this role of plasticity in recovery. Neuromodulation's definition is focused exclusively on the area of abnormality, while Pape advocates for a whole-network rehabilitation and stimulation to better encourage plasticity to do its work. She cites the example of right lateralized network reorganization playing a large role in recovering language after a stroke. Beyond synthesizing the present information on rTMS as a treatment for TBI, Pape has also participated in numerous experiments that directly tested rTMS's effectiveness as a treatment. In her lecture to NEUR 300, she described an experiment she did with a double-blind randomized placebo-control clinical trial that took a population of TBI patients either in vegetative or minimally conscious states and intervened with rTMS treatments (Pape et al., 2006). For the experimental group with severe TBIs, localized in the left dlPFC, Pape utilized 30 rTMS sessions, with 300 trains per session. There was a significant neurobehavioral effect between the experimental group and the placebo group, which is promising for the future of rTMS as a treatment.
A related study that also discusses rTMS as treatment for brain injury comes from a meta-analysis that looks at rTMS as a method to promote "post-stroke clinical recovery and functional independence" (Fisicaro, 2019). Pape studies rTMS as a neuromodulatory treatment for traumatic brain injuries, while Fisicaro et al. looked at rTMS as treatment for strokes, which are non-traumatic (meaning that they come from within the body as opposed to a consequence from an external force). This synthesis looked at the effect of rTMS on motor function, dexterity, walking and balance, and other areas of function negatively impacted by stroke. Overall, all areas of function were improved by the rTMS intervention, excepting cognitive impairment and spasticity in a significant manner. This is interesting, because with a TBI, people were shown to regain their cognitive function with rTMS, and also mostly lack the symptom of spasticity.
As the usage of rTMS as a feasible, FDA-approved treatment in widespread cognitive settings takes off, I think it would be very interesting to compare and contrast the effect that rTMS has on a traumatic brain injury vs. a non-traumatic brain injury. What are these differences due to? Is it because of the localized nature of the damage in TBI compared to the often more-widespread damage of a stroke? These questions and more are important to address as we attempt to get to the point as a society where we can use our technological advancements to bring patients back to full function after brain injury.
REFERENCES:
Bender Pape, T. L., Herrold, A. A., Guernon, A., Aaronson, A., & Rosenow, J. M. (2020). Neuromodulatory interventions for traumatic brain injury. Journal of Head Trauma Rehabilitation, 35(6), 365–370. https://doi.org/10.1097/htr.0000000000000643
Fisicaro F, Lanza G, Grasso AA, Pennisi G, Bella R, Paulus W, Pennisi M. Repetitive transcranial magnetic stimulation in stroke rehabilitation: review of the current evidence and pitfalls. Ther Adv Neurol Disord. 2019 Sep 25;12:1756286419878317. doi: 10.1177/1756286419878317. PMID: 31598137; PMCID: PMC6763938.
Maher, Courtney. “Types of Traumatic Brain Injury: Understanding the 8 Levels.” Flint Rehabilitation Center, 14 Dec. 2021, www.flintrehab.com/types-of-traumatic-brain-injury/#:~:text=The%20four%20possible%20severity%20levels,%3A%20GCS%20score%20%3D%203%20pts.
Pape, Theresa Louise-Bender DrPH, MA, CCC-SLP/L; Rosenow, Joshua MD; Lewis, Gwyn PhD. Transcranial Magnetic Stimulation: A Possible Treatment for TBI. Journal of Head Trauma Rehabilitation 21(5):p 437-451, September 2006.
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