Association between motor timing and treatment outcomes in patients with alcohol and/or cocaine addiction in a rehabilitation programme

Date
2017-12
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH SUMMARY : Introduction: Motor timing deficits have been found in DA system related disorders and, more recently, also in individuals with Substance Use Disorders (SUD). Motor timing is fundamental to our ability to coordinate movements and is defined as a component of temporal brain processing. Modifications to neural systems associated to these domains contribute to motor timing deficits and pathology; however, the underlying mechanisms that lead to these deficits are still poorly understood. A bimodal distribution and evolutionary neurobiological model may provide a useful pathogenic framework for the classification of major psychiatric disorders, including SUD. In this model, major psychiatric disorders (including SUD) may be understood as progressive manifestations of imbalances between dual neural circuitries in the brain. These include an automatic mechanism (referred to as the Drive Mechanism, DM) and a more cognitive-predictive mechanism (referred to as the Guidance Mechanism, GM). To our knowledge, motor timing has not been investigated in populations with SUDs with regard to treatment outcome and relapse. The main question of this study was: Do imbalances between the DM and GM, as expressed in motor timing deficits, differentiate individuals with SUD from normal controls and predict poorer treatment response and relapse? Methods: This study investigated motor timing and its relation to treatment response and relapse in individuals with Alcohol and/or Cocaine Use Disorder (AUD and/or CUD) compared to a Healthy Control (HC) group. Owing to the novelty of the motor task battery, the tested sensitivity values of motor timing parameters were assessed on test retest variability. The possible confounding effects of attention and working memory on motor timing paradigms, and the high impulsivity levels found in individuals with SUD were addressed by comparing the motor task paradigms with a battery of neuropsychological tests. Results: Motor timing was found to be predictive of treatment outcomes at 8 weeks. Synchronisation abilities were predictive, but decision making and motor planning abilities were not predictive. Owing to the small size of the follow up sample, a prediction of motor timing with regards to relapse at 12 months was not possible. Motor timing improved with prolonged abstinence. Specifically, synchronisation abilities improved. Decision making and motor planning abilities did not improve over time. Motor timing performance found in our AUD and/or CUD population only partially supported van Hoof’s proposed model. However, no deficits were found in internal clock rates or the capacity to plan and coordinate actions. Deficits were found in decision making (DM) and synchronisation abilities (GM) in patients versus HC. Decision making abilities were poorer in CUD compared to AUD. No correlation was found between motor timing and impulsivity. Working memory and attention were found to bepredictive of motor timing. Robust test-retest reliability of the test battery was found. Discussion: These findings provide partial support for the deficits in neurocircuitry, as proposed by van Hoof. Additionally, the findings show that motor timing holds prognostic for recovers with prolonged abstinence. These findings may have significant implications for future studies and warrant further investigation in SUD populations going forward.
AFRIKAANSE OPSOMMING : Inleiding: Kognitiewe aandagtekort, impulsiwiteitswerkgeheue is by individue met ʼn middelgebruikstoornis (MGS; SUD in Engels) gevind en is aanduiders van slegte uitkomste in die behandeling van MGS en terugvalling. Motoriesetydsberekeningsgebreke is ook in stoornisse wat verband hou met die dopamienstelsel en, meer onlangs, by individue met MGS geïdentifiseer. Motoriese tydsberekening lê ten grondslag van ons vermoë om bewegings te koördineer, word gedefinieer as ʼn komponent van temporale breinprosessering én korreleer met aandag-, impulsiwiteits- en werksgeheuegebreke. Veranderinge aan die senustelsels wat met hierdie areas geassosieer word dra by tot motoriesetydsberekeningsgebreke en -patologieë, hoewel die onderliggende meganismes wat tot hierdie gebreke lei nog nie voldoende verstaan word nie. ʼn Bimodale verspreidingsen evolusionêre neurobiologiese model kan moontlik ʼn bruikbare patogeniese raamwerk vir die klassifikasie van die vernaamste psigiatriese stoornisse bied – insluitende MGS. Volgens hierdie model kan die vernaamste psigiatriese stoornisse (insluitende MGS) verstaan word as progressiewe manifestasies van wanbalanse tussen dubbele neurale baanwerke in die brein. Dit sluit ʼn outomatiese meganisme (genaamd die drifmeganisme of DM) en ʼn kognitief-voorspellende meganisme (genaamd die leidingsmeganisme of LM; GM in Engels). So ver ons kennis strek is motoriese tydsberekening nog nie in populasies met MGS ondersoek met betrekking tot behandelingsuitkomste en terugvalling nie. Die hoofvraag van hierdie studie was: Doen wanbalanse tussen die DM en GM wat in motoriese tydsberekeninge uitgedruk word, onderskei individue met SUD van normale beheermaatreëls en voorspel swakker behandelingsreaksie en terugval? Metode: Hierdie studie ondersoek motoriese tydsberekening en die verband met behandelingsrespons en terugvalling in individue met alkohol- en/of kokaïengebruikstoornis (AGS en/of KGS), vergeleke met ʼn gesonde kontrolegroep (GK; HC in Engels). Daarbenewens is steun vir die erger wordende manifestasies van wanbalanse tussen DM en LM ook ondersoek. Gesien die nuutheid van die battery motoriese take is die getoetsde sensitiwiteitswaardes van die parameters vir motoriese tydsberekening op grond van toets-hertoets-veranderlikheid geassesseer. Die moontlike strengeleffek wat aandag en werksgeheue op motoriesetydsberekeningsparadigmas kan hê sowel as die hoë impulsiwiteitsvlakke van diegene met MGS is verreken deur die motoriesetydsberekeningsparadigmas met ʼn battery neurosielkundige toetse te vergelyk. Resultate: Daar is bevind dat motoriese tydsberekening kan voorspel wat die behandelingsuitkomste op agt weke sal wees. Sinkroniseringsvermoëns was voorspellend, maar nie besluitnemings- en motoriesebeplanningsvermoëns nie. Weens die beperkte grootte van die steekproef tydens die opvolgondersoek, was dit nie moontlik om te voorspel of daar op 12 maande terugsakking sou wees wat motoriese tydsberekening betref nie. Daar is bevind dat motoriese tydsberekening met langdurige onthouding verbeter. Sinkroniseringsvermoëns het veral verbeter. Besluitnemings- en motoriesebeplanningsvermoëns het nie mettertyd verbeter nie. Die motoriese tydsberekeningsprestasie wat by MGS-deelnemers bevind is, ondersteun ten dele Van Hoof se model. DM-wanbalanse wat op verhoogde interne chronometergang en/of die vermoë om handelinge te beplan en te koördineer, gebaseer is, is nie deur die data ondersteun nie. Gemeet aan besluitneming (DM) en sinkroniseringsvermoëns (LM) in pasiënte (teenoor GK), is daar bevind dat DM effens beter funksioneer vergeleke met LM. Daarbenewens is sterker DM-funksionering relatief tot GM in KGS gevind ten opsigte van besluitnemingsvermoëns – in teenstelling met AGS. Daar is geen beduidende korrelasies gevind tussen die prestasies in die motoriese take en metings vir impulsiewe keuses en snelreaksieimpulsiwiteit in die neurosielkundigetoetsbattery nie. Daar is gevind dat visuele en ouditiewe werksgeheue en aandag ten dele voorspellend is vir motoriese tydsberekening, maar slegs met verhoogde taakkompleksiteit. Laastens is sterk toets-hertoets-betroubaarheid vir die impulsiwiteitstoetsbattery in alle motoriesetydsberekeningstake gevind. Bespreking: Hierdie bevindinge bied gedeeltelike steun vir gebreke in neurobaanwerke, soos deur Van Hoof voorgestel. Daarbenewens toon hierdie bevindinge ook dat motoriese tydsberekening prognostiese waarde inhou vir motoriese tydsberekening in MGS sowel as vir hersteltekens met langdurige onthouding. Hierdie bevindinge hou beduidende implikasies in vir toekomstige studies. Motoriese tydsberekening behoort in nuwe navorsingsparadigmas oorweeg te word.
Description
Thesis (PhD)--Stellenbosch University, 2017.
Keywords
Motor timing, Motor ability -- Testing, Substance abuse, Cocaine abuse, Alcoholism, Temporal processing, UCTD
Citation