Objective: To characterize the association between clinical symptoms and anatomical and functional
cerebral deficits in codeine-containing cough syrups (CCS) users using voxel-based morphometry and
resting state functional connectivity analysis.
Methods:Participantswere30CCSusers and30matchedcontrols.Bothgroupswerescannedusingavolumetric three-dimensionalfast field echo sequence and a gradient-echo echo-planar imaging sequence.
Impulsivity traits of both groups were evaluated with the Barratt Impulsiveness Scale 11 (BIS 11).
Voxel-based morphometry was used to characterize gray matter (GM) deficits in CCS users. The clinical
significanceof regional volume reductionwas investigatedbyevaluating its associationwithimpulsivity
in CCS users and with alterations in resting state functional connectivity when brain regions with GM
volume reduction were used as seed areas.
Results: Significantly decreased GM volume was observed in CCS users in bilateral ventral medial prefrontal cortex (vmPFC) which was related to greater impulsivity in CCS users. Significantly decreased
integrationwas foundinCCSusersbetweenthe vmPFCandthedefaultmodenetwork.Also, significantly
enhancedfunctional connectivitywas foundbetweenthevmPFCandtherightinsula,andtherightdorsal
lateralPFC.NegativecorrelationwasobservedbetweenBIStotal scores, scores forattentionalimpulsivity
and vmPFC-inferior parietal lobe connectivity in CCS users.
Conclusions: The findings revealed volume loss and aberrant functional organization in vmPFC among
CCS users. In addition, the decreased vmPFC GM volume and attenuated functional connectivity of the
vmPFC-inferiorparietallobenetwork were associated withclinicalhigher impulsivity traitinCCSusers.
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