TABLE 6.
Brain Structure and Function
| Study/Cohort | Subjects | Outcome Measures | Age, y | Substance Exposures | Selection/Matching | Control | PCE Effect | Other Effects/Comments |
|---|---|---|---|---|---|---|---|---|
| Avants et al33 (2007), cohort 8 | 25 POLY, 24 CON | Bilateral caudate volume | 14 | C, A, T, M | Low income, black, GA >34 wk | None reported | Children with PCE had smaller caudate | PCE is associated with reduced caudate volume; caudate is an area of dopaminergic innervation and implicated in attention; limited sample size and covariate control |
| Rivkin et al34 (2008), cohort 5 | 14 POLY, 21 CON | Volumes of cortical gray and white matter, subcortical gray matter, cerebral spinal fluid, and total parenchyma, HC | 12 | C, A, T, M | Low income, black, GA >36 wk | Child: A, M, T, age, gender, total intracranial volume | Children with PCE had reduced cortical gray, total parenchymal volumes, and HC | As number of prenatal substance exposures increased, cortical gray and total parenchymal volume decreased; smallest volumes found in children with PCE exposed to multiple substances; limited sample size and covariate control |
| Hurt et al35 (2008), cohort 8 | 17 POLY, 17 CON | Behavioral accuracy to nonspatial working memory task and mean BOLD signal from fMRI | 14 | C, A, T, M | Low income, urban, black, GA >34 wk | Discrimination scores from behavioral task; no covariates but matched by gender and IQ | None | No PCE effects detected in behavioral or imaging data; limited sample size and covariate control |
| Warner et al36 (2006), cohort 14 | 28 POLY, 25 CON | Frontal white matter integrity using DTI during Stroop and Trail Making Test | 10 | C, A, T, M | Black, GA >36 wk | Child: A, M, T, IQ, gender | DTI: children with PCE had higher average diffusion coefficients in frontal fibers; Behavior: children with PCE had longer completions times on part B of the Trail Making Test | PCE was related to higher diffusion values in frontal white matter, which suggests less integrity and/or slower maturation of frontal areas; differences were related to poorer performance on Trail Making Test by PCE group |
| Smith et al37 (2001), cohort 15 | 14 POLY, 12 CON | Whole and regional brain volumes; metabolite concentrations using 1H-MRS in right frontal white matter and right striatum | 8–9 | Not reported | Variable SES, urban, 40% black, 40% white, GA >36 wk | Child: age, gender | Volume: none; Metabolites: children with PCE had a 13% increase in right frontal white matter levels of creatine | Increased creatine found in right frontal white matter suggests that biochemical changes caused by PCE may occur at cellular level; no evidence for PCE-related structural or volumetric damage; limited sample size and covariate control |
| Singer et al38 (2006), cohort 11 | 21 POLY, 14 CON | Gray and white matter volumes; NEPSY subtests; CASL | 8 | C, A, T, M | Low income, urban, black, GA >37 wk | Not reported | Volume: children with PCE had gray matter reductions in occipital and parietal lobes; White matter reductions in corpus callosum; PCE dose effects for gray and white matter volume | PCE associated with long-term changes in brain composition, which were related to performance on neuropsychological tests; limited sample size and covariate control |
| Mayes et al39 (2005), cohort 13 | 15 POLY, 14 CON | Reaction time, accuracy, latency and amplitude of ERP signals during a Stroop paradigm | 8 | C, A, T, M | Urban, black, GA not reported | Experimental and control groups were matched on the basis of age, race, and SES; no covariate control | Children with PCE had slower and prolonged ERP signals across a wider range of electrode sites | Brain responses in PCE group were slower and more distributed suggesting PCE inhibits regional specialization; limited sample size and covariate control |
| Rao et al40 (2007), cohort 8 | 25 POLY, 24 CON | Absolute and relative CBF using perfusion fMRI, overall and regional gray matter volume in frontal lobe, limbic structures, occipital lobe, and thalamus | 14 | C, A, T, M | Low income, urban, black, GA >34 wk | Child: age, gender, global CBF and gray matter volume | CBF: children with PCE had reduced global CBF intensities in posterior and inferior brain regions and relative increases in adjusted-CBF in anterior and superior brain regions; Volume: children with PCE had regional decreases in gray matter in caudate and increased gray matter in amygdala | PCE was related to reductions in global CBF during adolescence and specific gray matter alterations, which suggests that compensatory mechanisms may develop during neural ontogeny; limited covariate control |
POLY indicates exposure to multiple drugs; CON, nonexposed controls; C, cocaine exposure; A, alcohol exposure; T, tobacco exposure; M, marijuana exposure; GA, gestational age; HC, head circumference; BOLD, blood oxygen level dependent; DTI, diffusion tensor imaging; 1H-MRS, proton magnetic resonance spectroscopy; NEPSY, Developmental Neuropsychological Assessment; CASL, Comprehensive Assessment of Spoken Language; ERP, event-related potential; CBF, cerebral blood flow.