Apolipoprotein E epsilon 4 (APOE-ε4) genotype is associated with decreased 6-month verbal memory performance after mild traumatic brain injury.

Abstract

INTRODUCTION:

The apolipoprotein E (APOE) ε4 allele associates with memory impairment in neurodegenerative diseases. Its association with memory after mild traumatic brain injury (mTBI) is unclear.

METHODS:

mTBI patients (Glasgow Coma Scale score 13-15, no neurosurgical intervention, extracranial Abbreviated Injury Scale score ≤1) aged ≥18 years with APOE genotyping results were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Cohorts determined by APOE-ε4(+/-) were assessed for associations with 6-month verbal memory, measured by California Verbal Learning Test, Second Edition (CVLT-II) subscales: Immediate Recall Trials 1-5 (IRT), Short-Delay Free Recall (SDFR), Short-Delay Cued Recall (SDCR), Long-Delay Free Recall (LDFR), and Long-Delay Cued Recall (LDCR). Multivariable regression controlled for demographic factors, seizure history, loss of consciousness, posttraumatic amnesia, and acute intracranial pathology on computed tomography (CT).

RESULTS:

In 114 mTBI patients (APOE-ε4(-)=79; APOE-ε4(+)=35), ApoE-ε4(+) was associated with long-delay verbal memory deficits (LDFR: B = -1.17 points, 95% CI [-2.33, -0.01], p = .049; LDCR: B = -1.58 [-2.63, -0.52], p = .004), and a marginal decrease on SDCR (B = -1.02 [-2.05, 0.00], p = .050). CT pathology was the strongest predictor of decreased verbal memory (IRT: B = -8.49, SDFR: B = -2.50, SDCR: B = -1.85, LDFR: B = -2.61, LDCR: B = -2.60; p < .001). Seizure history was associated with decreased short-term memory (SDFR: B = -1.32, p = .037; SDCR: B = -1.44, p = .038).

CONCLUSION:

The APOE-ε4 allele may confer an increased risk of impairment of 6-month verbal memory for patients suffering mTBI, with implications for heightened surveillance and targeted therapies. Acute intracranial pathology remains the driver of decreased verbal memory performance at 6 months after mTBI.

• Authors: John K Yue, Caitlin K Robinson, John F Burke, Ethan A Winkler, Hansen Deng, Maryse C Cnossen, Hester F Lingsma, Adam R Ferguson, Thomas W McAllister, Jonathan Rosand, Esteban G Burchard, Marco D Sorani, Sourabh Sharma, Jessica L Nielson, Gabriela G Satris, Jason F Talbott, Phiroz E Tarapore, Frederick K Korley, Kevin K W Wang, Esther L Yuh, Pratik Mukherjee, Ramon Diaz-Arrastia, Alex B Valadka, David O Okonkwo, Geoffrey T Manley, TRACK‐TBI Investigators
• Journal: Brain and behavior (Brain Behav) Vol. 7 Issue 9 Pg. e00791 (09 2017) ISSN: 2162-3279 [Electronic] United States
• PMID: 28948085 (Publication Type: Journal Article)

Chemical References

• Apolipoprotein E4
• Apolipoproteins E

Topics

• Adult
• Alleles
• Apolipoprotein E4 (genetics)
• Apolipoproteins E
• Brain Concussion (complications, genetics)
• Female
• Genotype
• Humans
• Male
• Memory (physiology)
• Memory Disorders (etiology, genetics)
• Middle Aged