Plasma Neurofilament Light Chain: A Potential Biomarker for Neurological Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disorder characterized by heterogeneous symptoms, which lack specific biomarkers for its diagnosis. This study aimed to investigate plasma neurofilament light chain (NfL) levels as a potential biomarker for ME/CFS and explore associations with cognitive, autonomic, and neuropathic symptoms. Here, 67 ME/CFS patients and 43 healthy controls (HCs) underwent comprehensive assessments, including neuropsychological evaluation, autonomic nervous system (ANS) testing, and plasma NfL level analysis. ME/CFS patients exhibited significantly higher plasma NfL levels compared to HC (F = 4.30, p < 0.05). Correlations were observed between NfL levels and cognitive impairment, particularly in visuospatial perception (r = -0.42; p ≤ 0.001), verbal memory (r = -0.35, p ≤ 0.005), and visual memory (r = -0.26; p < 0.05) in ME/CFS. Additionally, higher NfL levels were associated with worsened autonomic dysfunction in these patients, specifically in parasympathetic function (F = 9.48, p ≤ 0.003). In ME/CFS patients, NfL levels explained up to 17.2% of the results in cognitive tests. Unlike ME/CFS, in HC, NfL levels did not predict cognitive performance. Elevated plasma NfL levels in ME/CFS patients reflect neuroaxonal damage, contributing to cognitive dysfunction and autonomic impairment. These findings support the potential role of NfL as a biomarker for neurological dysfunction in ME/CFS. Further research is warranted to elucidate underlying mechanisms and clinical implications.

Trastornos del sueño en la enfermedad de Parkinson: trastorno de conducta del sueño REM y síndrome de piernas inquietas / Sleep disorders in Parkinson’s disease: REM sleep behaviour disorder and restless legs syndrome

Introducción. De sobra es conocido que pacientes con enfermedad de Parkinson (EP) y otras enfermedades neurodegenerativas resentan con alta frecuencia trastornos del sueño, siendo posible que compartan mecanismos fisiopatológicos comunes con los signos motores. Desarrollo. En el caso del trastorno de conducta del sueño REM, numerosos estudios han demostrado que puede preceder en más de diez años a la aparición de signos motores. Si bien no se ha demostrado un aumento del riesgo a padecer EP en pacientes con síndrome de piernas inquietas, la mayor prevalencia de este síndrome en la EP y la buena respuesta a agonistas dopaminérgicos hacen suponer una relación entre ambas entidades. Conclusión. El impacto de estas entidades en la calidad de vida de los pacientes hacen que su conocimiento, diagnóstico y tratamiento sean de gran importancia (AU)

Introduction. It is well known that patients with Parkinson’s disease (PD) and other neurodegenerative diseases very commonly present sleep disorders, and that they possibly share common pathophysiological mechanisms with motor signs. Development. In the case of REM sleep behaviour disorder, a number of studies have shown that it may appear more than ten years before the motor signs. Although there is no evidence to prove that patients with restless legs syndrome have an increased risk of suffering from PD, the high prevalence of this symptom in PD and the good response to dopamine agonists suggest the existence of a relation between the two conditions. Conclusions. The impact that these conditions have on patients’ quality of life makes it very important to know how to diagnose and treat them (AU)