Head Position and Posturography: A Novel Biomarker to Identify Concussion Sufferers.

Balance control systems involve complex systems directing muscle activity to prevent internal and external influences that destabilize posture, especially when body positions change. The computerized dynamic posturography stability score has been established to be the most repeatable posturographic measure using variations of the modified Clinical Test of Sensory Integration in Balance (mCTSIB). However, the mCTSIB is a standard group of tests relying largely on eyes-open and -closed standing positions with the head in a neutral position, associated with probability of missing postural instabilities associated with head positions off the neutral plane. Postural stability scores are compromised with changes in head positions after concussion. The position of the head and neck induced by statically maintained head turns is associated with significantly lower stability scores than the standardized head neutral position of the mCTSIB in Post-Concussion Syndrome (PCS) subjects but not in normal healthy controls. This phenomenon may serve as a diagnostic biomarker to differentiate PCS subjects from normal ones as well as serving as a measurement with which to quantify function or the success or failure of a treatment. Head positions off the neutral plane provide novel biomarkers that identify and differentiate subjects suffering from PCS from healthy normal subjects

The Pupillary Light Reflex as a Biomarker of Concussion.

The size of our pupils changes continuously in response to variations in ambient light levels, a process known as the pupillary light reflex (PLR). The PLR is not a simple reflex as its function is modulated by cognitive brain function and any long-term changes in brain function secondary to injury should cause a change in the parameters of the PLR. We performed a retrospective clinical review of the PLR of our patients using the BrightLamp Reflex iPhone app. The PLR variables of latency, maximum pupil diameter (MaxPD), minimum pupil diameter (MinPD), maximum constriction velocity (MCV), and the 75% recovery time (75% PRT) were associated with significant differences between subjects who had suffered a concussion and those that had not. There were also significant differences in PLR metrics over the life span and between genders and those subjects with and without symptoms. The differences in PLR metrics are modulated not only by concussion history but also by gender and whether or not the person has symptoms associated with a head injury. A concussive injury to the brain is associated with changes in the PLR that persist over the life span, representing biomarkers that might be used in clinical diagnosis, treatment, and decision making

Brain Vital Signs in Elite Ice Hockey: Towards Characterizing Objective and Specific Neurophysiological Reference Values for Concussion Management.

Background: Prior concussion studies have shown that objective neurophysiological measures are sensitive to detecting concussive and subconcussive impairments in youth ice-hockey. These studies monitored brain vital signs at rink-side using a within-subjects design to demonstrate significant changes from pre-season baseline scans. However, practical clinical implementation must overcome inherent challenges related to any dependence on a baseline. This requires establishing the start of normative reference data sets. Methods: The current study collected specific reference data for N = 58 elite, youth, male ice-hockey players and compared these with a general reference dataset from N = 135 of males and females across the lifespan. The elite hockey players were recruited to a select training camp through CAA Hockey, a management agency for players drafted to leagues such as the National Hockey League (NHL). The statistical analysis included a test-retest comparison to establish reliability, and a multivariate analysis of covariance to evaluate differences in brain vital signs between groups with age as a covariate. Findings: Test-retest assessments for brain vital signs evoked potentials showed moderate-to-good reliability (Cronbach's Alpha > 0.7, Intraclass correlation coefficient > 0.5) in five out of six measures. The multivariate analysis of covariance showed no overall effect for group (p = 0.105), and a significant effect of age as a covariate was observed (p < 0.001). Adjusting for the effect of age, a significant difference was observed in the measure of N100 latency (p = 0.022) between elite hockey players and the heterogeneous control group. Interpretation: The findings support the concept that normative physiological data can be used in brain vital signs evaluation in athletes, and should additionally be stratified for age, skill level, and experience. These can be combined with general norms and/or individual baseline assessments where appropriate and/or possible. The current results allow for brain vital sign evaluation independent of baseline assessment, therefore enabling objective neurophysiological evaluation of concussion management and cognitive performance optimization in ice-hockey

THE PREVALENCE OF LYME DISEASE AND ASSOCIATED CO-INFECTIONS IN PEOPLE WITH A CHRONIC POST-CONCUSSIVE SYNDROME

Introduction: There is increasing awareness that Lyme borreliosis (LB) and traumatic brain injury (TBI) may cause mental health symptoms. TBI and Lyme disease compromise the health and activities of millions of patients per year. The chronic symptoms and disability of TBI and Lyme disease share a similar clinical presentation. We have identified an alarming number of individuals suffering from post-concussion syndrome (PCS) that are refractory to care and that have serologically tested positive for Lyme disease. Subject and methods: A single-center retrospective review of patient charts that were symptomatic a minimum of one year after a TBI that were tested for Lyme disease to ascertain if there was a relationship. Results: 217 PCS patient records (93 females with a mean age of 34 years, 120 males with a mean age of 40 years and 4 individuals with unknown gender) were included in the review. 38% had a positive Western Blot Igenex IgM. There was a statistically significant relationship of a positive Western Blot Igenex IGM predicting chronic PCS Pearson χ2(1)=6.8866, P=0.009, Fisher’s exact score p=0.015 and φ=0.2813 representing a moderate effect size. Conclusions: Long term PCS over one year’s duration is associated with undiagnosed Lyme disease. There was statistical and substantive significance between individuals with chronic PCS having a positive Western Blot Igenex IgM. Males were more likely to have a positive Western Blot Igenex IgM than females

IMPROVEMENT OF SACCADIC EYE MOVEMENTS AFTER HEAD-EYE VESTIBULAR MOTION (HEVM) THERAPY AND NEURO-PSYCHIATRIC CONSIDERATIONS

Introduction: Eye movement pathology can assist in the identification, diagnosis and treatment of mental health disorders. Eyetracking paradigms have been utilized to provide greater ecological validity, and directly capture the detailed sequence of processes in perception and attention, while quantifying classifiers in mood, anxiety, and psychotic disorders. Saccadic eye movements serve as an endophenotype for various mental health disorders. Subjects and methods: Patients suffering from post-concussive syndrome and mental health concerns performed saccadic eye movements that were quantified for amplitude, velocity, latency and accuracy before and after Head-Eye Vestibular Motion therapy (HEVM). Results: HEVM therapy is associated with statistical and substantive significant improvements in mental health and in saccadic metrics. Conclusions: Oculomotor dysfunction is related to the symptom dimensions of mental health disorders that may be treated with physical rehabilitation modalities. We feel it reasonable to suggest that psychiatrists and others involved in the treatment of mental health disorders quantify eye movements and use them as biomarkers in the evaluation of the outcomes of varied therapies