RESUMEN
Frontotemporal dementia (FTD) is a heterogeneous neurodegenerative disease of presenile onset. A better characterization of neurodegenerative disorders has been sought by using tools such as genome-wide association studies (GWAS), where associations between single nucleotide polymorphisms (SNPs) and cognitive profiles could constitute predictive biomarkers for these diseases. However, in FTD, associations between genotypes and cognitive phenotypes are yet to be explored. Here, we evaluate a possible relationship between genetic variants and some cognitive functions in an FTD population. Methodology: A total of 47 SNPs in genes associated with neurodegenerative diseases were evaluated using the Sequenom MassARRAY platform along with their possible relationship with performance in neuropsychological tests in 105 Colombian patients diagnosed with FTD. Results and discussion: The SNPs rs429358 (APOE), rs1768208 (MOBP), and rs1411478 (STX6), were identified as risk factors for having a low cognitive performance in inhibitory control and phonological verbal fluency. Although the significance level was not enough to reach the corrected alpha for multiple comparison correction, our exploratory data may constitute a starting point for future studies of these SNPs and their relationship with cognitive performance in patients with a probable diagnosis of FTD. Further studies with an expansion of the sample size and a long-term design could help to explore the predictive nature of the potential associations we identified.
RESUMEN
RESUMEN INTRODUCCIÓN: Los pacientes con trastorno afectivo bipolar pueden presentar alteraciones cognoscitivas que en algunos casos tienen un curso progresivo, por lo cual se ha cuestionado si la evolución de esta enfermedad se asocia a demencia, particularmente aquellas pertenecientes al espectro de la degeneración lobar frontotemporal. En este contexto, discriminar si un paciente presenta una demencia secundaria a la enfermedad psiquiátrica de base o si cursa una enfermedad neurodegenerativa además del trastorno afectivo bipolar, es un desafío para el diagnóstico diferencial. OBJETIVO: Comparar los desempeños cognoscitivos en pacientes con trastorno afectivo bipolar, con veinte años o más de evolución de la enfermedad y pacientes con demencia frontotemporal variante conductual. MATERIALES Y MÉTODOS: Estudio exploratorio, descriptivo y transversal en una cohorte seleccionada de casos por método no probabilístico. Los datos se analizan por medio de estadísticos no paramétricos. RESULTADOS: Eespecto al grupo control (N:27), los pacientes con demencia frontotemporal (N:24) presentan desempeños significativamente bajos en memoria verbal, funciones ejecutivas, praxias visoconstruccionales y atención (p <0,01). El grupo de trastorno bipolar (N:17) tiene bajos desempeños en estos procesos, pero no presenta fenómenos patológicos significativos asociados a intrusiones y perseveraciones. Entre los grupos clínicos no se identifican diferencias significativas. CONCLUSIÓN: Aunque los grupos clínicos comparten el compromiso en los procesos cognoscitivos evaluados, los desempeños son más bajos en el grupo de demencia frontotemporal, lo que sugiere que en una enfermedad degenerativa de menor tiempo de evolución y aparición en etapa presenil el déficit cognitivo es mayor que en una enfermedad psiquiátrica crónica.
SUMMARY INTRODUCTION: Patients with Bipolar Disorder may present cognitive alterations that in some cases have a progressive course, whereby it has been questioned if the evolution of this disease is associated with dementia, in particular those that belong to the spectrum of frontotemporal lobar degeneration. Thereby, discriminate if a patient has a dementia secondary to the underlying psychiatric illness or if the patient presents a neurode-generative disease besides the bipolar disorder is a challenge for the differential diagnosis. OBJECTIVE: To compare the cognitive performance in a sample of patients with Bipolar Disorder and twenty years or more of disease progression, and patients with behavioral variant of frontotemporal dementia. MATERIALS AND METHODS: Exploratory, descriptive and transversal study in a cohort of cases selected with a non probabilistic method. Dates are compared through non parametric statistics. RESULTS: Relative to Control group (N:27), Frontotemporal Dementia Patients (N:24) have significantly lower performances in verbal memory, executive functions, visoconstructional praxis and attention tasks (p <0,01). Bipolar Disorder group (N:17) has lower performances in this processes but don't present pathological markers such as intrusions and perseverative responses. There are no significant differences when comparing between clinical groups. CONCLUSION: Although clinical groups share the compromise in most of the cognitive process evaluated, the performances are lower in Frontotemporal dementia group, which suggests that in a degenerative disease of less evolution time and onset in presenile stage, the cognitive deficit is greater than in a chronic psychiatric illness.