An international group of experts, including Dr. Saül Martínez-Horta, researcher at the Sant Pau Research Institute (IR Sant Pau) and neuropsychologist at the Movement Disorders Unit of Hospital Sant Pau, has published in the journal Movement Disorders a scientific review that thoroughly analyzes the most widely used neuropsychological tools to assess attention, working memory, and executive functions in Parkinson’s disease. The work, promoted by the International Parkinson and Movement Disorder Society (MDS), provides clear recommendations on which instruments should be used for a more accurate evaluation of the cognitive status of these patients, both in clinical practice and in research.
The evaluation of these cognitive functions is key because their deterioration is one of the most common non-motor complications in Parkinson’s disease. It can appear in very early stages, even before motor symptoms, and is associated with a progressive loss of autonomy and quality of life. However, the great variety of existing tests, differences in their psychometric quality, and the lack of unified criteria have so far hindered consistent assessment. According to Dr. Martínez-Horta, “It is not enough to use any test available; we need instruments with a solid scientific basis, adapted to the clinical reality of the Parkinson’s patient, and that allow us to detect subtle but significant changes.”
The review assessed a total of 30 instruments and concluded that 8 of them offer the best guarantees of reliability, validity, and clinical applicability. Four focus mainly on attention and working memory: three subtests of the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV)—Digit Span, which measures immediate memory and the ability to manipulate information; Coding, which evaluates processing speed and visuomotor coordination; and Symbol Search, which examines speed in visual discrimination and concentration—as well as the Trail Making Test, which analyzes processing speed, mental flexibility, and visual search. The WAIS-IV is one of the most widely used scales internationally to measure cognitive abilities, and its subtests provide results that can be compared with large normative datasets.
The other four recommended tests are oriented toward executive functions: Similarities, another WAIS-IV subtest that explores abstract verbal reasoning; the Wisconsin Card Sorting Test, considered the benchmark for evaluating cognitive flexibility and the ability to adapt to new rules; the Verbal Fluency Tests, which measure the ability to generate words according to phonemic or semantic criteria; and the Stroop Color-Word Test, in its abbreviated Victoria version, which evaluates the inhibition of automatic responses and adaptation to changing conditions. As Dr. Martínez-Horta points out, “These tools have not only proven to be reliable and valid, but they are also sensitive to changes that occur during the disease and to the effects of certain treatments.”
For the authors, having this classification has an immediate impact on clinical practice, as it provides professionals with a clear guide to making informed decisions. Dr. Martínez-Horta emphasizes that “In the clinic, choosing the right test can make the difference between detecting an early cognitive change or overlooking it.” This is especially relevant in Parkinson’s disease, where cognitive changes may be subtle in the early stages and go unnoticed if tools with sufficient sensitivity are not used.
The review also highlights that the selection of the test should be adapted not only to the purpose of the evaluation—early detection, long-term monitoring, or assessing the effect of therapies—but also to the characteristics and limitations of the patient. Factors such as educational level, emotional state, fatigue, or motor fluctuations can influence performance and, therefore, the interpretation of results. “If a patient presents motor impairment that makes writing or manual speed difficult, a test requiring these skills could show low performance not because of a real cognitive deficit, but because of interference from motor symptoms,” the researcher explains. In such cases, the recommendation is to prioritize verbally administered or adapted tools that minimize the impact of these limitations.
The paper stresses that using standardized, evidence-based tests improves diagnostic accuracy and promotes homogeneity in research, making it easier to compare results across different centers and studies. This, in turn, helps advance knowledge of the disease and develop more effective interventions to preserve cognitive function.
The review establishes which tests are the benchmarks and identifies those that, despite their common use, have limitations and require further research to confirm their utility. The analysis indicates that some widely used instruments lack normative studies specific to the Parkinson’s population or present reliability issues when applied in real-world clinical contexts. In such cases, the expert group recommends cautious use, always combined with complementary measures.
For Dr. Martínez-Horta, this work represents “an important step toward standardizing cognitive evaluation in Parkinson’s disease on a global scale.” The researcher stresses that “We want this guide to serve as a tool to unify criteria and improve the quality of cognitive evaluations in Parkinson’s disease worldwide.” Having an international reference framework allows data obtained in different countries and centers to be comparable, which is essential for establishing progression patterns, identifying risk factors, and evaluating the impact of new treatments.
In addition, homogeneity in the choice of tools will make it possible to integrate large international databases, fostering collaborative studies with larger and more representative samples. “Homogeneity in evaluation is key to advancing research, comparing data between centers, and ultimately offering better care to patients,” he concludes. The ultimate goal, as the author group highlights, is for this consensus to translate into more precise evaluations, earlier diagnoses, and more effective intervention strategies.
Biundo R, Bezdicek O, Cammisuli DM, Cholerton B, Dalrymple-Alford JC, Edelstyn N, Fiorenzato E, Holker E, Martinez-Horta S, Martini A, Santangelo G, Segura B, Siri C, Tröster A, Mestre TA, Ferro ÁS, Hyczy de Siqueira Tosin M, Skorvanek M, Weintraub D, Geurtsen GJ, and the members of the MDS Clinical Outcome Assessment Scientific Evaluation Committee. Attention/working memory and executive function in Parkinson’s disease: Review, critique, and recommendations. Mov Disord 2025. https://doi.org/10.1002/mds.30293
