Abnormal asymmetry correlates with abnormal enlargement in a patient with chronic moderate traumatic brain injury.

Aim: Recent studies found patients with chronic, mild or moderate traumatic brain injury had more regions of enlargement than atrophy. There is little research discussing brain volume enlargement, asymmetry and TBI. Materials & methods: In this report, we describe a 40-year-old man who suffered a left cerebral hemorrhage resulting in a moderate TBI, suggesting greater forces on the left side of his brain. NeuroQuant® brain volumetric analyses of his MRI obtained 1.7 years post injury showed left cerebral white matter atrophy but right gray matter abnormal enlargement. Abnormal asymmetry of multiple regions (R >L) was confirmed by NeuroGage® asymmetry analyses. Discussion: The findings suggested that abnormal brain volume enlargement was due to hyperactivity and hypertrophy of less-injured brain regions as a compensatory response to more-injured regions.

Updated Review of the Evidence Supporting the Medical and Legal Use of NeuroQuant® and NeuroGage® in Patients With Traumatic Brain Injury.

Over 40 years of research have shown that traumatic brain injury affects brain volume. However, technical and practical limitations made it difficult to detect brain volume abnormalities in patients suffering from chronic effects of mild or moderate traumatic brain injury. This situation improved in 2006 with the FDA clearance of NeuroQuant®, a commercially available, computer-automated software program for measuring MRI brain volume in human subjects. More recent strides were made with the introduction of NeuroGage®, commercially available software that is based on NeuroQuant® and extends its utility in several ways. Studies using these and similar methods have found that most patients with chronic mild or moderate traumatic brain injury have brain volume abnormalities, and several of these studies found-surprisingly-more abnormal enlargement than atrophy. More generally, 102 peer-reviewed studies have supported the reliability and validity of NeuroQuant® and NeuroGage®. Furthermore, this updated version of a previous review addresses whether NeuroQuant® and NeuroGage® meet the Daubert standard for admissibility in court. It concludes that NeuroQuant® and NeuroGage® meet the Daubert standard based on their reliability, validity, and objectivity. Due to the improvements in technology over the years, these brain volumetric techniques are practical and readily available for clinical or forensic use, and thus they are important tools for detecting signs of brain injury.

Journey to the other side of the brain: asymmetry in patients with chronic mild or moderate traumatic brain injury.

Aim: Patients with chronic mild or moderate traumatic brain injury have some regions of brain atrophy (including cerebral white matter) but even more regions of abnormal brain enlargement (including other cerebral regions). Hypothesis: Ipsilateral injury and atrophy cause the eventual development of contralateral compensatory hypertrophy. Materials & methods: 50 patients with mild or moderate traumatic brain injury were compared to 80 normal controls (n = 80) with respect to MRI brain volume asymmetry. Asymmetry-based correlations were used to test the primary hypothesis. Results: The group of patients had multiple regions of abnormal asymmetry. Conclusion: The correlational analyses supported the conclusion that acute injury to ipsilateral cerebral white matter regions caused atrophy, leading eventually to abnormal enlargement of contralateral regions due to compensatory hypertrophy.

Patients with chronic mild or moderate traumatic brain injury have abnormal brain enlargement.

Introduction: Much less is known about brain volume abnormalities in patients with chronic mild or moderate traumatic brain injury (TBI) compared with patients with more severe injury. Commercially available software methods including NeuroQuant® are being used increasingly to assess MRI brain volume in patients with TBI.Methods: 50 patients with mild or moderate TBI were compared to the NeuroQuant® normal control database (n = thousands) with respect to MRI brain volume.Results: The patients had many areas of abnormal enlargement and fewer areas of atrophy, including abnormally small cerebral white matter (CWM) limited to the first 10 months after injury. Examination of correlations within the patient group between CWM volume and volumes of the abnormally enlarged regions showed multiple significant negative correlations, indicating that CWM atrophy correlated with enlargement of the other regions.Discussion: The finding of many regions of abnormal brain enlargement was relatively new, although a couple of previous studies of patients with mild TBI found similar but more limited findings. The cause of the abnormal enlargement was unknown, but possibilities included: (1) hyperactivity and hypertrophy; or (2) chronic neuro-inflammation and edema.Abbreviations: ADNI: Alzheimer's Disease Neuroimaging Initiative; CWM: cerebral white matter; GM: cerebral cortical gray matter; ICC: intraclass correlations coefficient; IFT: infratentorial; MRI: magnetic resonance imaging; mTBI: mild TBI; NQ: NeuroQuant®; SCN: subcortical nuclei; t0: time of injury; t1: time of first NeuroQuanted MRI scan after injury; t2: time of second NeuroQuanted MRI scan after injury; TBI: traumatic brain injury; VBR: ventricle-to-brain ratio; WBP: whole-brain parenchyma.

NeuroQuant® and NeuroGage® reveal effects of traumatic brain injury on brain volume.

This report describes the case of a 58-year-old man with moderate traumatic brain injury (TBI) and pre-accident brain disorders who had multiple persistent neuropsychiatric symptoms. NeuroQuant® 2.0 and NeuroGage® 2.0 MRI brain volume analyses were used during the chronic stage of injury (> 1 year after injury) to help understand the effects of the TBI on his brain volume. NeuroQuant® showed widespread cross-sectional atrophy, especially in the frontal and temporal lobes, consistent with encephalomalacia seen on the MRIs. Several of his clinical symptoms were consistent with the volume abnormalities. NeuroGage® longitudinal analyses of volume change from the time 1 to time 2 magnetic resonance imaging showed abnormally rapid atrophy and ventricular enlargement. The high rates of volume change were much more consistent with the relatively recent effects of TBI than with effects of the much more chronic pre-accident brain disorders.

High correlations between MRI brain volume measurements based on NeuroQuant® and FreeSurfer.

NeuroQuant® (NQ) and FreeSurfer (FS) are commonly used computer-automated programs for measuring MRI brain volume. Previously they were reported to have high intermethod reliabilities but often large intermethod effect size differences. We hypothesized that linear transformations could be used to reduce the large effect sizes. This study was an extension of our previously reported study. We performed NQ and FS brain volume measurements on 60 subjects (including normal controls, patients with traumatic brain injury, and patients with Alzheimer's disease). We used two statistical approaches in parallel to develop methods for transforming FS volumes into NQ volumes: traditional linear regression, and Bayesian linear regression. For both methods, we used regression analyses to develop linear transformations of the FS volumes to make them more similar to the NQ volumes. The FS-to-NQ transformations based on traditional linear regression resulted in effect sizes which were small to moderate. The transformations based on Bayesian linear regression resulted in all effect sizes being trivially small. To our knowledge, this is the first report describing a method for transforming FS to NQ data so as to achieve high reliability and low effect size differences. Machine learning methods like Bayesian regression may be more useful than traditional methods.