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Concussion is a common brain injury. The American Academy of Neurology provides a definition of concussion: “Concussion is a traumatically, or biomechanically, induced alteration of brain function. Emphasis is placed on a pathophysiological process, or functional disruption, as opposed to anatomic, structural, or tissue injury.”. The incidence of mild traumatic brain injury (mTBI) is estimated at 200 per 100 000. The Centers for Disease Control and Prevention (CDC) estimates 3.8 million sport and recreational mTBIs occurring in the United States each year. A more recent CDC assessment estimates 2.5 million concussion injuries in high school sports alone. The controlled environment and opportunity for direct surveillance and observation has made the sports arena the scientific “wet lab” for the study of mTBI natural history, short- and long-term consequences and opportunities to intervene. Quantitative EEG methods have been utilized in the assessment and management of mTBI and lends to provide a cost-effective procedure that has the sensitivities needed to identify pathology where routine visual inspection of the EEG has failed.

A vital sign of the central nervous system, electroencephalographic (EEG) activity provides unique information on the function of the brain. Visual inspection of the EEG signals, graphically displayed in standardized formats, has been the cornerstone method used clinically. Since subtle variations in the EEG are important but not visually apparent, EEG has had somewhat limited clinical applications, primarily for seizure detection and severely altered mental status and coma assessment. Computer technology has brought enhanced sensitivity with objective, quantified, analysis methods into the field of EEG. New computer statistical analysis methods, not possible through archaic visual inspection have drastically enhanced EEG utilization as a biomarker for assessing traumatic brain injury (TBI). This chapter outlines various EEG techniques that have been used to assess TBI. Cutting edge techniques, which provide 3D characterization of brain activity derived from scalp EEG electrodes, are discussed. Therapeutic approaches using neurofeedback are introduced. These technologies hold promising potential for future contributions that will improved clinical outcomes.

ObjectiveTo evaluate correlations between sLORETA quantitative electroencephalogram (qEEG) analysis and a computerized symptom and neurocognitive performance assessment.BackgroundWe previously reported results of sLORETA qEEG deregulation in recently concussed high school athletes. Correlations between this deregulation and concussion symptoms and neurocognitive performance have not been described in this population.Design/MethodsEEGs were analyzed in 61 high school athletes shortly after concussion injury using sLORETA imaging compared to a normative database (NYU/BrainDx). Concussion related symptoms and neurocognitive performance were assessed (XLNTbrain). Peak Z-score variation (PZV), and %volume of grey matter activity falling outside Z = −2.5 to 2.5 were calculated for 5 EEG frequency bands. Pearson correlation coefficients were calculated between the qEEG findings and the cognitive performance testing. Statistical comparisons were made between athletes endorsing high symptom scores vs. low scores.ResultsStatistically significant positive correlations were observed between performance on verbal go/nogo, emotional recognition of happy and angry faces and volume and severity of sLORETA deregulation suggesting a pathological relationship. This deregulation consisted primarily of deficient activity in the delta, theta, beta, and beta-gamma bands. Significant negative correlations were observed between performance on nonverbal go/nogo, emotional recognition of angry faces, motor tapping, sentence completion, facial recognition, and word recognition and volume and severity of sLORETA deregulation suggesting compensatory mechanisms. This deregulation consisted primarily of excess activity in the alpha and theta bands. Elevated scores for migraine, worry, and mood were associated with increased severity and volume of increased activity in the beta and beta-gamma bands. Athletes with elevated vestibular symptoms had lower theta band deregulation.ConclusionsThis study demonstrates correlations between performance on computerized neurocognitive tasks and changes in sLORETA qEEG analysis shortly after concussion injury in high school athletes. The data suggest some of these changes are pathological, while others are compensatory.

BackgroundStudies have identified gender differences in the incidence, severity and recovery time from sport concussion injury, all increased in females. The objective of this investigation is to explore gender differences in volumetric QEEG analysis after sport concussion injury in high school athletes.MethodsStandard electroencephalograms (EEGs) were analyzed in 40 high school athletes (20 males) shortly after concussion injury using sLORETA imaging compared to a normative database (NYU/BrainDx). Peak Z-score variation (PZV), and %volume of grey matter activity that fell outside Z = −2.5 to 2.5 (PIGMV for increased activity, PRGMV for reduced) were calculated for each of 5 EEG frequency bands.ResultsPZV was increased in the Delta/Theta/Alpha, in both genders with no statistical gender difference (M/F averages: 3.82/3.16, 2.73/2.72, 2.52/2.72, respectively, p ≥ 0.05), Beta in females not males, Beta-Gamma in males and females which was significantly increased in females (M/F averages: 1.75/2.88, 3.64/5.02 respectively, p < 0.01). PZV was decreased in Beta in males not females (M/F averages: −2.83/−2.18, p = 0.05) there was a significant difference in reduced beta-gamma activity (M/F averages: −1.11/−0.49, p = 0.01). Greater than 1% grey matter volume of PIGMV was seen in Delta/Theta/Alpha/Beta activity with no gender difference (M/F averages: 20.94/11.71, 5.87/7.38, 5.62/7.93, 4.09/9.22 p ≥ 0.05). There was a significant difference in PIGMV in Beta-Gamma (M/F averages: 31.94/60.04, p = 0.01). Greater than 1% PRGMV in Alpha/Beta in both genders and Theta activity in females not males.ConclusionsSlower frequency (Delta, Theta, and Alpha) abnormal variations show no statistical gender differences. In the faster frequency bands (Beta and Beta-Gamma), females demonstrate a larger variation from the norm and larger percent grey matter volume affected by increased Beta and Beta-Gamma activity. Males, not females exhibit a deficiency in Beta activity after concussion. Further research to correlate these electrophysiologic changes with symptom severity and recovery time is needed.

In order to evaluate the influence of dopaminergic transmission on regional brain utilization of serotonin (5HT), the effects of the destruction of the ascending dopamine (DA) pathways on regional brain 5HT metabolism in the rat were examined. Complete unilateral lesions of the nigrostriatal DA pathways (> 90% DA loss) were made by infusing the neurotoxin 6-hydroxy-dopamine into either the left medial forebrain bundle (MFB) or the left substantia nigra (SN). At 6 weeks after the lesions, levels of 5HT and its major metabolite, 5-hydroxyindoleacetic acid (5HIAA), were determined bilaterally in the striatum, frontal cortex, and hypothalamus. In the striatum of the lesioned hemisphere, the 5HT level decreased by more than 50%, while the ratio of 5HIAA:5HT (an index of 5HT turnover) increased by more than 90%. In the same rats, cortical and hypothalamic 5HT, 5HIAA, and 5HT turnover were not changed as a result of the MFB or SN lesions. These results suggest that the loss of DA innervation in the striatum triggers an increase in 5HT turnover and a net depletion of 5HT in the striatum. To verify that the loss of DA was responsible for the observed striatal 5HT changes, we examined the effect of intracerebral implantation of DA-containing pellets into one group of MFB-lesioned rats. The lesioned rats with placebo pellets did not differ from lesioned rats without pellets, whereas the implantation of DA pellets reversed the lesion-induced changes in the 5HT levels and 5HIAA:5HT ratios.(ABSTRACT TRUNCATED AT 250 WORDS)

Spinal cord compression in Wilms' tumor is a rare event, generally caused by invasion of the canal by paraspinal lesions or metastatically involved vertebral bodies. This case report reviews the clinical presentation, radiologic evaluation, and emergent therapy in two cases of spinal cord compromise involving patients with widely metastatic Wilms' tumor. One of these is the only known report of intradural metastasis in a child with this malignancy. Both cases illustrate the importance of anticipating and rapidly responding to neurologic complications that may arise in patients with aggressively metastatic Wilms' tumor.

A graded spinal cord injury in rats was produced by dropping a 10-g weight from 2.5, 5.0, 10,0, or 17.5 cm onto the exposed dura at the T8 vertebral level. Groups of rats (N = 10) for each of these weight drop (WD) levels as well as unoperated and WD controls (0 cm) were subjected to behavioral analysis that included evaluation of simple and complex reflexes as well as spontaneous and evoked motor patterns. On the basis of this analysis, we developed a protocol for evaluating functional deficits that follow spinal cord injury in the rat. The resulting combined behavioral score, a measure of functional deficit, closely correlated with the magnitude of the mechanical injury. The protocol used for neurologic assessment was administered routinely by personnel who were easily and rapidly trained. It should therefore prove useful in detecting the effects of treatment on recovery of function in a rat model of spinal cord injury.

We have previously reported a method for assessing functional deficits in rats after contusive spinal cord injury in which a Combined Behavioral Score (CBS) is calculated that is indicative of the overall percent deficit (Exp. Neurol., 88: 123–134, 1985). The test battery used includes several neurologic tests as well as the Motor Score in which use of the hindlimbs in locomotion is graded. In this report we present correction criteria in order to reduce potential interlaboratory variability in assessing functional deficit by the CBS. Groups of rats were subjected to contusive injury using a weight drop technique. The calculated CBS at 4 weeks was compared to that obtained if the Motor Score was over- or underestimated by 1 grade. The results indicated a considerable effect on the calculated CBS, especially when the Motor Score was underestimated in mildly injured animals. Behavioral test data were examined in terms of the distribution of the responses to the various other behavioral tests in relation to the Motor Score. The results were used to develop a set of correction criteria that minimized the effects on the CBS of subjective errors in the Motor Score.