Published in IJCP March 2020
Short communication
Brain Activation In Unresponsive Patients With Acute Brain Injury: Words Of Caution
March 17, 2020 | Amit Agrawal, Luis Rafael Moscote-Salazar, Ravish Keni
     


Functional and structural integrity of severely injured brain remains a challenge for clinicians and neuroscientists.1 New studies2 are further expanding our understanding on noninvasive methods to evaluate the structural integrity of brain functions.1,3 Apparently, it has been presumed that the patients have normal hearing; however, auditory response has been shown to be reduced after brain injury in many clinical studies.4,5 There is a need to identify the presence or absence of pre-existing hearing impairment to find out its impact on brain activation. It needs to be further clarified whether evoked potential can help us to confirm the integrity of hearing. It is also important to note that apparently global insult due to systemic factors (cardiac arrest) causes more damage than more focal insult (TBI > SAH). There is a further need to understand the severity of injury, e.g., imaging evidence of global versus focal injuries, dominant versus non-dominant side lesions. Studies have shown promising results as majority of the patients at follow-up though dependent were alive. How to interpret and apply these findings on individualized basis is the next challenge.

References

  1. Bodart O, Amico E, Gomez F, Casali AG, Wannez S, Heine L, et al. Global structural integrity and effective connectivity in patients with disorders of consciousness. Brain Stimul. 2018;11(2):358-65.
  2. Claassen J, Doyle K, Matory A, Couch C, Burger KM, Velazquez A, et al. Detection of brain activation in unresponsive patients with acute brain injury. New Engl J Med. 2019;380(26):2497-505.
  3. Hinterberger T, Wilhelm B, Mellinger J, Kotchoubey B, Birbaumer N. A device for the detection of cognitive brain functions in completely paralyzed or unresponsive patients. IEEE Trans Biomed Eng. 2005;52(2):211-20.
  4. Bamiou DE, Werring D, Cox K, Stevens J, Musiek FE, Brown MM, et al. Patient-reported auditory functions after stroke of the central auditory pathway. Stroke. 2012;43(5):1285-9.

Lew HL, Jerger JF, Guillory SB, Henry JA. Auditory dysfunction in traumatic brain injury. J Rehabil Res Dev. 2007;44(7):921-8.