Browsing by Author "Oh, Sam S."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    COMT Val 158 Met polymorphism is associated with nonverbal cognition following mild traumatic brain injury
    (Springer, 2016-01) Winker, Ethan A.; Yue, John K.; McAllister, Thomas W.; Temkin, Nancy R.; Oh, Sam S.; Burchard, Esteban G.; Hu, Donglei; Ferguson, Adam R.; Lingsma, Hester F.; Burke, John F.; Sorani, Marco D.; Rosand, Jonathan; Yuh, Esther L.; Barber, Jason; Tarapore, Phiroz E.; Gardner, Raquel C.; Sharma, Sourabh; Satris, Gabriela G.; Eng, Celeste; Puccio, Ava M.; Wang, Kevin K.W.; Mukherjee, Pratik; Valadka, Alex B.; Okonkwo, David O.; Diaz-Arrastia, Ramon; Manley, Geoffrey T.; Department of Psychiatry, IU School of Medicine
    Mild traumatic brain injury (mTBI) results in variable clinical outcomes, which may be influenced by genetic variation. A single-nucleotide polymorphism in catechol-o-methyltransferase (COMT), an enzyme which degrades catecholamine neurotransmitters, may influence cognitive deficits following moderate and/or severe head trauma. However, this has been disputed, and its role in mTBI has not been studied. Here, we utilize the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study to investigate whether the COMT Val (158) Met polymorphism influences outcome on a cognitive battery 6 months following mTBI--Wechsler Adult Intelligence Test Processing Speed Index Composite Score (WAIS-PSI), Trail Making Test (TMT) Trail B minus Trail A time, and California Verbal Learning Test, Second Edition Trial 1-5 Standard Score (CVLT-II). All patients had an emergency department Glasgow Coma Scale (GCS) of 13-15, no acute intracranial pathology on head CT, and no polytrauma as defined by an Abbreviated Injury Scale (AIS) score of ≥3 in any extracranial region. Results in 100 subjects aged 40.9 (SD 15.2) years (COMT Met (158) /Met (158) 29 %, Met (158) /Val (158) 47 %, Val (158) /Val (158) 24 %) show that the COMT Met (158) allele (mean 101.6 ± SE 2.1) associates with higher nonverbal processing speed on the WAIS-PSI when compared to Val (158) /Val (158) homozygotes (93.8 ± SE 3.0) after controlling for demographics and injury severity (mean increase 7.9 points, 95 % CI [1.4 to 14.3], p = 0.017). The COMT Val (158) Met polymorphism did not associate with mental flexibility on the TMT or with verbal learning on the CVLT-II. Hence, COMT Val (158) Met may preferentially modulate nonverbal cognition following uncomplicated mTBI.Registry: ClinicalTrials.gov Identifier NCT01565551.
  • Thumbnail Image
    Item
    DRD2 C957T polymorphism is associated with improved 6-month verbal learning following traumatic brain injury
    (Springer, 2017-01) Yue, John K.; Winkler, Ethan A.; Rick, Jonathan W.; Burke, John F.; McAllister, Thomas W.; Oh, Sam S.; Burchard, Esteban G.; Hu, Donglei; Rosand, Jonathan; Temkin, Nancy R.; Korley, Frederick K.; Sorani, Marco D.; Ferguson, Adam R.; Lingsma, Hester F.; Sharma, Sourabh; Robinson, Caitlin K.; Yuh, Esther L.; Tarapore, Phiroz E.; Wang, Kevin K.W.; Puccio, Ava M.; Mukherjee, Pratik; Diaz-Arrastia, Ramon; Gordon, Wayne A.; Valadka, Alex B.; Okonkwo, David O.; Manley, Geoffrey T.; TRACK-TBI Investigators; Psychiatry, School of Medicine
    Traumatic brain injury (TBI) often leads to heterogeneous clinical outcomes, which may be influenced by genetic variation. A single-nucleotide polymorphism (SNP) in the dopamine D2 receptor (DRD2) may influence cognitive deficits following TBI. However, part of the association with DRD2 has been attributed to genetic variability within the adjacent ankyrin repeat and kinase domain containing 1 protein (ANKK1). Here, we utilize the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study to investigate whether a novel DRD2 C957T polymorphism (rs6277) influences outcome on a cognitive battery at 6 months following TBI-California Verbal Learning Test (CVLT-II), Wechsler Adult Intelligence Test Processing Speed Index Composite Score (WAIS-PSI), and Trail Making Test (TMT). Results in 128 Caucasian subjects show that the rs6277 T-allele associates with better verbal learning and recall on CVLT-II Trials 1-5 (T-allele carrier 52.8 ± 1.3 points, C/C 47.9 ± 1.7 points; mean increase 4.9 points, 95% confidence interval [0.9 to 8.8]; p = 0.018), Short-Delay Free Recall (T-carrier 10.9 ± 0.4 points, C/C 9.7 ± 0.5 points; mean increase 1.2 points [0.1 to 2.5]; p = 0.046), and Long-Delay Free Recall (T-carrier 11.5 ± 0.4 points, C/C 10.2 ± 0.5 points; mean increase 1.3 points [0.1 to 2.5]; p = 0.041) after adjusting for age, education years, Glasgow Coma Scale, presence of acute intracranial pathology on head computed tomography scan, and genotype of the ANKK1 SNP rs1800497 using multivariable regression. No association was found between DRD2 C947T and non-verbal processing speed (WAIS-PSI) or mental flexibility (TMT) at 6 months. Hence, DRD2 C947T (rs6277) may be associated with better performance on select cognitive domains independent of ANKK1 following TBI.