Acceso usuarios
Cristina Fernández Baizán
, Ariana García Nevares, Sergio Fernández Artamendi, Marta Méndez López
Se han documentado diversas alteraciones en las funciones ejecutivas (FFEE) en pacientes con enfermedad de Parkinson (EP), pero pocos estudios las han relacionado con el desempeño cotidiano en sus actividades de la vida diaria (AVD).
El objetivo de este estudio fue conocer la posible relación entre los déficits de las FFEE con el desempeño en las AVD en pacientes con EP. Para ello, se realizó una revisión sistemática en base a diversos criterios PRISMA en las bases de datos PubMed, PsycInfo y Google Schoolar, seleccionando 16 estudios empíricos de acuerdo con los criterios de inclusión. En los artículos analizados, se hallaron asociaciones significativas entre el desempeño en FFEE y AVD, principalmente instrumentales, en los pacientes con EP, tanto en los cognitivamente sanos como en los que recibieron diagnóstico de deterioro cognitivo o demencia. El rendimiento ejecutivo puede impactar negativamente en el desempeño funcional de pacientes con EP, aunque resulta complejo establecer qué FFEE específicas pueden tener un papel más relevante sobre actividades ocupacionales concretas.
Parkinson's disease (PD), the second most common neurodegenerative disorder, presents with motor symptoms and cognitive difficulties, including executive functions (EF), those related with planning, inhibition, cognitive flexibility, attentional control and decision-making.
Since physical and cognitive abilities are required to perform activities of daily living (ADLs) correctly, this disease leads to a loss of daily functionality. Given that in non-cognitively impaired older adults it has been shown that poorer executive functioning may be a predictor of greater impairment in instrumental and more complex ADLs, it is conceivable that greater difficulties in EFs found typically in PD patients may be related to greater limitations in ADLs.
Therefore, the aim of this study was to summarize the previous literature about the possible relationship between specific EF deficits and ADL performance in PD patients. For this purpose, a systematic review was performed following some PRISMA criteria and employing PubMed, PsycInfo and Google Schoolar databases. A total of sixteen empirical studies were selected according to the inclusion criteria.
The articles reviewed varied in the number of participants included (with a range between 10 and 216 participants), the age of the participants (varying between 59 and 78 years-old), the gender distribution, the presence or the absence of a control group or some other clinical populations in addition to PD patients, and the cognitive status of PD participants (varying between been cognitive preserved, or been diagnosed of mild cognitive impairment or dementia). With regard to the latter issue, it is worth mentioning that most of the articles used the diagnostic criteria of the Movement Disorder Task Force in a level I or II. The articles included also employed a wide variety of assessment tests for both EFs and ADLs. Regarding the EFs, most of the articles assessed them with widely used test (e.g., Trail Making test, verbal fluency or Stroop), using questionnaires with less frequently. In ADLs, questionnaires or scales were used more frequently than direct performance tests, as well as instrumental ADLs were more often assessed than basic ADLs. In addition, it is worth mentioning that, unlike the evaluation of the EFs, the great variety of ADLs tests used, so only two questionnaires (Lawton and Brody scale and Pfeffer Functional Activities Questionnaire) were repeated more than once in the 16 articles. Regarding the aim of the present article, significant associations were found between performance in EF and ADLs (mainly instrumental) in PD patients, in both cognitively preserved and in those diagnosed with mild cognitive impairment or dementia. The EF most related to ADL performance were working memory, cognitive flexibility, inhibition, processing speed, and prospective memory. Specific ADLs related to EF were medication management, financial management and driving. As for the relationship between specific EFs and specific ADLs, prospective memory was related to medication and financial management, and several EFs (working memory, cognitive flexibility, inhibition and processing speed) were associated with driving.
In conclusion, a worse executive performance may negatively impact instrumental functional performance in PD patients, situation that would happen even in cognitively healthy individuals. However, it is still complex to establish which specifics EFs may have a more relevant role on concrete occupational activities, finding several reasons for this lack of specificity. First, the great variety of assessment tools used in the different studies, especially in the ADLs evaluation. Second, the lack of specification of which concrete cognitive function a particular EF test assesses, tending to allude to the umbrella term “executive function” instead of specifying the particular ability. Third, the tendency to use global scores or composite indices in the measurement of ADLs, instead of analyzing each functional activity separately.
