Using a brain electrical activity biomarker could aid in the objective identification of mild Traumatic Brain Injury patients

Using Single-Photon Emission Computerized Tomography on Patients With Positive Quantitative Electroencephalogram to Evaluate Chronic Mild Traumatic Brain Injury With Persistent Symptoms

Background

Following mild traumatic brain injury (mTBI), also known as concussion, many patients with chronic symptoms (>3 months post injury) receive conventional imaging such as computed tomography (CT) or magnetic resonance imaging (MRI). However, these modalities often do not show changes after mTBI. We studied the benefit of triaging patients with ongoing symptoms >3 months post injury by quantitative electroencephalography (qEEG) and then completing a brain single positron emission computed tomography (SPECT) to aid in diagnosis and early detection of brain changes.

Methods

We conducted a retrospective case review of 30 outpatients with mTBI. The patients were assessed by a neurologist, consented, and received a qEEG, and if the qEEG was positive, they consented and received a brain SPECT scan. The cases and diagnostic tools were collectively reviewed by a multidisciplinary group of physicians in biweekly team meetings including neurology, nuclear medicine, psychiatry, neuropsychiatry, general practice psychotherapy, neuro-ophthalmology, and chiropractic providers. The team noted the cause of injury, post injury symptoms, relevant past medical history, physical examination findings, and diagnoses, and commented on patients' SPECT scans. We then analyzed the SPECT scans quantitatively using the 3D-SSP software.

Results

All the patients had cerebral perfusion abnormalities demonstrated by SPECT that were mostly undetectable by conventional imaging (CT/MRI). Perfusion changes were localized primarily in the cerebral cortex, basal ganglia, and cingulate cortex, and correlated with the patients' symptoms and examination findings. Qualitative and quantitative analyses yielded similar results. Most commonly, the patients experienced persistent headache, memory loss, concentration difficulties, depression, and cognitive impairment post mTBI. Because of their symptoms, most of the patients were unable to return to their previous employment and activity level.

Conclusion

Our findings outline the physical basis of neurological and psychiatric symptoms experienced by patients with mTBI. Increased detection of mTBI can lead to development of improved targeted treatments for mTBI and its various sequelae.

Assessment of Correlation Between Brain Function Index and Three Common Sedation Scales in Intensive Care Unit Patients

Objectives: This study aimed to evaluate the correlation of the Brain Function Index (BFI) with three criteria of consciousness (Glasgow, Richmond, and FOUR score) in the intensive care unit. Methods: We enrolled patients aged over 15 years who required no muscle relaxants and had no hearing and visual impairment, mental retardation, mental disorder, hemodynamic instability (MAP < 60 mmHg), and hypoxia (SpO2 < 90%), as well as patients with no brain electrical activity disorders such as epilepsy and focal brain disease, and those who had not undergone anesthesia and surgery for the past 24 hours. Results: All ICU patients were enrolled in the study in the autumn and winter based on inclusion and exclusion criteria (n = 85). During 24 hours, BFI and three clinical criteria of sedation and consciousness including RASS, GCS, and FOUR score were assessed three times with a minimum of four-hour intervals. Among the patients, 45 (52.9%) were males, and 40 (47.1%) were females; 24 (28.2%) patients were under 40 years of age, 13 (15.3%) patients were between 41 and 60 years old, and 48 (56.5%) patients were over 61 years old. There was a significant positive relationship between the BFI score of ICU patients and the score of patient consciousness based on RASS, FOUR score, and GCS. The correlation of BFI with the FOUR score was higher than those with the other two criteria. Conclusions: Objective criteria for assessing the consciousness level such as BFI are sufficiently accurate and can be used instead of clinical criteria to assess the level of consciousness in special wards.

Electrophysiological testing in concussion: A guide to clinical applications

The diagnosis of mild traumatic brain injury in concussion is difficult since it is often unwitnessed, the patient’s recall is unreliable and initial clinical examination is often unrevealing, correlating poorly with the extent of brain injury. At present, there are no objective biomarkers of mild traumatic brain injury in concussion. Thus, a sensitive gold standard test is required to enable the effective and safe triage of patients who present to the acute services. As well as triage, objective monitoring of patients’ recovery over time and separate from clinical features that patients may develop following the injury (e.g. depression and migraine) is also needed. In contrast to neuroimaging, which is widely used to investigate traumatic brain injury patients, electrophysiology is readily available, is cheap and there are internationally recognized standardised methodologies. Herein, we review the existing literature on electrophysiological testing in concussion and mild traumatic brain injury; specifically, electroencephalogram, polysomnography, brainstem auditory evoked potentials, electro- and videonystagmography, vestibular evoked myogenic potentials, visually evoked potentials, somatosensory evoked potentials and transcranial magnetic stimulation.