Preliminary questions before studying mild traumatic brain injury outcome

Persistent Postconcussion Symptoms: An Expert Consensus-Based Definition Using the Delphi Method

OBJECTIVE

To provide an expert consensus definition of persistent postconcussion symptoms following a mild traumatic brain injury (mTBI).

PARTICIPANTS

Canadian healthcare professionals caring for patients with mTBI.

DESIGN

Online Delphi process.

MAIN MEASURES

A first Delphi round documented important dimensions or criteria to consider when defining persistent symptoms. Expert opinions were then resubmitted in 4 subsequent Delphi rounds and their relevance was rated using a 9-point Likert scale. An item with a median rating of 7 or more and a sufficient level of agreement were considered consensual.

RESULTS

After 5 rounds, consensus was reached on a set of criteria that can be summarized as follows: presence of any symptom that cannot be attributed to a preexisting condition and that appeared within hours of an mTBI, that is still present every day 3 months after the trauma, and that has an impact on at least one sphere of a person's life.

CONCLUSION

This Delphi consensus proposes a set of criteria that support a more uniform definition of persistent symptoms in mild TBI among clinicians and researchers. This definition may help clinicians better identify persistent postconcussion symptoms and improve patient management.

Day of injury CT and late MRI findings: Cognitive outcome in a paediatric sample with complicated mild traumatic brain injury

OBJECTIVES

Complicated mild traumatic brain injury (mTBI) or cmTBI is based on the presence of visibly identifiable brain pathology on the day-of-injury computed tomography (CT) scan. In a paediatric sample the relation of DOI CT to late MRI findings and neuropsychological outcome was examined.

METHODS

MRI (>12 months) was obtained in paediatric cmTBI patients and a sample of orthopaedically injured (OI) children. Those children with positive imaging findings (MRI+) were quantitatively compared to those without (MRI-) or with the OI sample. Groups were also compared in neurocognitive outcome from WASI sub-tests and the WISC-IV Processing Speed Index (PSI), along with the Test of Everyday Attention for Children (TEA-Ch) and a parent-rated behavioural functioning measure (ABAS-II).

RESULTS

Despite the MRI+ group having significantly more DOI CT findings than the MRI- group, no quantitative differences were found. WASI Vocabulary and Matrix Reasoning scores were significantly lower, but not PSI, TEA-Ch or ABAS-II scores. MRI+ and MRI- groups did not differ on these measures.

CONCLUSIONS

Heterogeneity in the occurrence of MRI-identified focal pathology was not associated with uniform changes in quantitative analyses of brain structure in cmTBI. Increased number of DOI CT abnormalities was associated with lowered neuropsychological performance.

Clinical comparison of 99mTc exametazime and 123I Ioflupane SPECT in patients with chronic mild traumatic brain injury

Background

This study evaluated the clinical interpretations of single photon emission computed tomography (SPECT) using a cerebral blood flow and a dopamine transporter tracer in patients with chronic mild traumatic brain injury (TBI). The goal was to determine how these two different scan might be used and compared to each other in this patient population.

Methods and Findings

Twenty-five patients with persistent symptoms after a mild TBI underwent SPECT with both ^99mTc exametazime to measure cerebral blood flow (CBF) and ¹²³I ioflupane to measure dopamine transporter (DAT) binding. The scans were interpreted by two expert readers blinded to any case information and were assessed for abnormal findings in comparison to 10 controls for each type of scan. Qualitative CBF scores for each cortical and subcortical region along with DAT binding scores for the striatum were compared to each other across subjects and to controls. In addition, symptoms were compared to brain scan findings. TBI patients had an average of 6 brain regions with abnormal perfusion compared to controls who had an average of 2 abnormal regions (p<0.001). Patient with headaches had lower CBF in the right frontal lobe, and higher CBF in the left parietal lobe compared to patients without headaches. Lower CBF in the right temporal lobe correlated with poorer reported physical health. Higher DAT binding was associated with more depressive symptoms and overall poorer reported mental health. There was no clear association between CBF and DAT binding in these patients.

Conclusions

Overall, both scans detected abnormalities in brain function, but appear to reflect different types of physiological processes associated with chronic mild TBI symptoms. Both types of scans might have distinct uses in the evaluation of chronic TBI patients depending on the clinical scenario.