Detection of Mild TBI
Mild traumatic brain injury (mTBI) is frequently seen in general neurology practice.Any alteration in mental state at the time of the accident (eg. feeling dazed, disoriented or confused) indicates diagnosis of mTBI. In the United States approximately 1.4 million people sustain TBI each year. Most of these injuries are classified as mild, with 80% of patients treated in the emergency room without hospitalization. This syndrome occurs after even mild head trauma with or without loss of the consciousness and consists of symptoms of daily headaches, frequent dizziness, fatigue, and memory and concentration problems. In addition, depression, anxiety, insomnia and other behavioral problems may be associated with this condition. There is increasing evidence that even whiplash types of injuries may cause mTBI due to rapidly occurring acceleration/deceleration, which contributes to brain dysfunction. Unfortunately, there is no single test to confirm this diagnosis in the clinical setting. Results from imaging techniques including magnetic resonance (MRI) and computed tomography (CT) are completely normal unless major head injury occurs where intracranial bleeding can be found. Another MRI modality called diffusion tensor imaging (DTI) is more sensitive in detection of diffuse axonal injury seen after head trauma; however these findings are also not usually seen after minor brain injuries. The introduction of quantitative EEG, which utilizes direct recording of electrical activity from the scalp is an application also used in mTBI cases. After injury, the distressed neurons can be identified by observing specific TBI patterns of neuronal electrical activity. Therefore the application of quantitative EEG (QEEG) seems to be a very promising tool in evaluation of patients suffering from mTBI.
I would like to present a case of mTBI from my practice illustrating my approach to patients suffering from post-concussion syndrome.
A 20-year-old college student fell off her bike and sustained head injury with possible short lasting loss of the consciousness and subsequent symptoms of frequent daily headaches, short term memory and concentration problems. Also she reported being confused for 2 hours after the accident and complained of subsequent sleeping problems. The patient indicated that her CT of the brain completed at the local ER was unremarkable. Her neurological examination in my office was normal; however computerized neurocognitive testing (NeuroTrax, WHERE IS THIS COMPANY?)) showed impairment of memory function (Fig.1). Memory score was 60.2 (expected mean score-100 where 1 SD-15) which was below 2 standard deviations (SD). Subsequent QEEG analysis (Neuroguide, Inc. St. Petersberg, FL) showed increased bilateral temporal theta power (Fig 2), specifically in the 6 Hz range,
indicative of temporal lobes dysfunction. Low resolution electromagnetic tomography (LORETA) analysis confirmed bilateral temporal localization of theta activity (Fig 3.) Additional traumatic brain injury discriminant analysis (Neuroguide, Inc.) was also consistent with TBI findings (Fig 4.) Patient was treated with 25 mg of Amityrptyline at night, however shortly thereafter patient’s symptoms diminished and after several months since the accident she reported normalization of her cognitive performance and resolution of headaches. This case illustrates the clinical benefit of QEEG utilization in neurological practice where mTBI patients are frequently evaluated and gives evidence of objective functional neuronal dysfunction related to prior head injury. QEEG complements well neuropsychological testing and is consistent with patient’s history of the accident and presenting subjective symptoms.
Dr. Koberda is the director of the Tallahassee Neuro-Balance Center and Clinical Assistant Professor at Florida State University-College of Medicine, Tallahassee