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Letters to the Editor  |   June 2014
Response
Author Affiliations
  • Laura A. Harmon, MD
    Department of Internal Medicine and the Center for Diabetes and Metabolic Disorders, Texas Tech University Health Center-Permian Basin, Odessa
Article Information
Neuromusculoskeletal Disorders
Letters to the Editor   |   June 2014
Response
The Journal of the American Osteopathic Association, June 2014, Vol. 114, 426-427. doi:10.7556/jaoa.2014.093
The Journal of the American Osteopathic Association, June 2014, Vol. 114, 426-427. doi:10.7556/jaoa.2014.093
I appreciate the comments of Reeves and Ladner1 and Wiwanitkit.2 The use of electroencephalography (EEG) has been widely debated throughout the literature. In our investigation,3 which was limited to standard inpatient EEG, 96% of the EEGs performed did not change or contribute to clinical decision making. At this time, there are no national guidelines for EEG use, and EEGs are being employed for a wide spectrum of conditions, including altered mental status, epilepsy, seizure rule-out, syncope, cerebrovascular accident, and traumatic brain injury. 
The shortfall of EEG is its low diagnostic sensitivity (25%-56%) and slightly higher specificity (78%-98%).4 Even in the presence of a normal EEG, patients can have a multitude of seizure disorders failing detection,4 while an abnormal EEG can correlate with specific underlying brain pathologies, such as Creutzfeldt-Jakob disease5 or burst suppression patterns.6 Although burst suppression patterns often correlate with poor prognoses, they do not point to any specific disease pathology and can be seen in traumatic brain injury and metabolic encephalopathy alike.6 
The utility of EEG has, however, been demonstrated in intraoperative monitoring during carotid endarterectomy.7 Additionally, there have been evidence-based reviews published on its benefit in the evaluation of pediatric neurologic disorders8 and the management of newly diagnosed epilepsy.9 
In the 2013 clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit (ICU), put forth by the American College of Critical Care Medicine, EEG was recommended (+1A; high quality, strong recommendation in favor of the intervention) to monitor nonconvulsive ICU patients with known or patients suspected of having seizure disorders or to titrate electrosuppresive medications in patients with elevated intracranial pressures.10 At our institution, in accordance with these guidelines, continuous EEG is used most commonly in patients with traumatic brain injuries, intracerebral hemorrhages, and cerebrovascular accidents to guide treatment. 
Our study3 was limited to standard 23-channel, 30-minute recordings and cannot be extrapolated to include the utility of video EEG, 24-hour continuous EEG, or quantitative EEG. Regarding standard 23-channel, 30-minute EEG recordings, my coauthors and I believe that the level of utility is reflected in the appropriateness of ordering. In our study3 there were 8 cases (4%) in which EEG was performed that supported clinical decision making. In each of the EEGs with abnormal findings, indication for ordering EEG was consistent with the clinical practice guideline recommendations10 for use in ICU patients. 
Unfortunately, 24% of our population had EEG performed for syncope, whereas previous studies11,12 have clearly shown that EEG was not valuable in treating patients with syncope. Smith et al13 examined appropriate use of EEG in comparison to the United Kingdom national guidelines for the use of EEG and found up to 40% of EEGs had been ordered inappropriately. 
In the current political climate, I believe now more than ever, we as physicians are going to be asked to justify our health care expenditures. With a paucity of guidelines for EEG use, the responsibility falls to the physician to determine clinical utility. The goal of our study3 was to bring to light the common indications at our institution for ordering EEGs and the relatively small impact they had on clinical judgment in these cases. 
References
Reeves RR, Ladner ME. Effect of inpatient electroencephalography on clinical decision making: EEG is more valuable than findings suggest [letter]. J Am Osteopath Assoc. 2014;114(6):425-426. doi:10.7556/jaoa.2014.091. [CrossRef] [PubMed]
Wiwanitkit V. Effect of inpatient electroencephalography on clinical decision making: EEG is more valuable than findings suggest [letter]. J Am Osteopath Assoc. 2014;114(6):426. doi:10.7556/jaoa.2014.092. [CrossRef] [PubMed]
Harmon LA, Craddock M, Jones EG, Spellman CW, Loveman DM. Effect of inpatient electroencephalography on clinical decision making. J Am Osteopath Assoc. 2013;113(12):891-896. doi:10.7556/jaoa.2013.067. [CrossRef] [PubMed]
Smith SJM. EEG in the diagnosis, classification, and management of patients with epilepsy. J Neurol Neurosurg Psychiatry. 2005;76 (suppl 2):ii2-ii7. doi:10.1136/jnnp.2005.069245. [PubMed]
Brown P. EEG findings in Creutzfeldt-Jakob disease. JAMA. 1993;269(24):3168. doi:10.1001/jama.1993.03500240112046. [CrossRef] [PubMed]
van Putten MJ, van Putten MH. Uncommon EEG burst-suppression in severe post-anoxic encephalopathy [published online April 2, 2010]. Clin Neurophysiol. 2010;121(8):1213-1219. doi:10.1016/j.clinph.2010.02.162. [CrossRef] [PubMed]
Blume WT, Furguson GG, McNeill DK. Significance of EEG changes at carotid endarterectomy. Stroke. 1986;17(5):891-897. [CrossRef] [PubMed]
Kwong KL, Chak WK, So KT. Evaluation of paediatric epilepsy care. HK J Paediatr. 2002;7(3):169-172.
Ross SD, Estok R, Chopra S, French J. Management of Newly Diagnosed Patients With Epilepsy: A Systematic Review of the Literature. Rockville, MD: Agency for Health Care Research and Quality; 2001. Evidence Reports/Technology Assessments, No 39. Report No. 01-E038.
Barr J, Fraser GL, Puntillo Ket al; American College of Critical Care Medicine. Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med. 2013;41(1):263-306. doi:10.1097/CCM.0b013e3182783b72. [CrossRef] [PubMed]
Davis TL, Freemon FR. Electroencephalography should not be routine in the evaluation of syncope in adults. Arch Int Med. 1990;150(10):2027-2029. doi:10.1001/archinte.1990.00390210029008. [CrossRef]
Abubakr A, Wambacq I. The diagnostic value of EEGs in patients with syncope. Epilepsy Behav. 2005;6(3):433-434. [CrossRef] [PubMed]
Smith D, Bartolo R, Pickles RM, Tedman BM. Requests for electroencephalography in a district general hospital: retrospective and prospective audit. BMJ. 2001;332(7292):954-957. [CrossRef]