Astudy with the participation of the Instituto de Saúde Pública da Universidade do Porto (ISPUP) assessed a sample of Portuguese patients recently diagnosed with multiple sclerosis, and followed up in five hospitals in the country.
The aim? To find early markers of neurological changes in these patients, who, due to an early stage of the pathology, do not yet show symptoms of cognitive deterioration (although cognitive impairment may already exist).
According to Luís Ruano, ISPUP researcher and member of the Cognitive Impairment in Diseases Involving the Nervous System laboratory, which is part of the associated Laboratory for Integrative and Translational Research in Population Health (ITR), “it is important to understand if people who do not yet have cognitive or visual complaints, as a consequence of multiple sclerosis, already show signs in specific tests that they may be at risk of having vision problems due to degeneration of the optic nerve and cognitive problems”.
“Cognitive impairment and retinal atrophy are two potential biomarkers that can identify signs of neurodegeneration in multiple sclerosis patients,” explains the researcher.
The research, published in the Neurological Sciences journal, aimed to understand to what extent the detection of atrophies in two vision-related biomarkers – the peripapillary retinal nerve fber layer (pRNFL) and the macular ganglion cell layer (mGCL) – might relate to deterioration in cognitive performance in early-stage multiple sclerosis patients.
Fifty-two participants, aged between 18 and 65, were recruited for Optical Coherence Tomography (a test used to diagnose retinal diseases) and neuropsychological assessments.
These patients, whose average age was 37, had been diagnosed with multiple sclerosis for about three and a half years.
According to Luís Ruano, who is also the coordinator of the study, the patients tested are a representative sample of the population newly diagnosed with multiple sclerosis in Portugal.
The results of the study showed that 28.8% of the research participants already presented cognitive impairment at an early stage of the disease.
No differences in retinal nerurodegeneration biomarkers (pRNFL and mGCL) were found between patients – both in those with signs of cognitive impairment and those with no signs of cognitive deterioration – after testing.
Cognitive assessment was found to be an earlier way of finding markers of neurodegeneration in patients than optical assessments.
“The final message of this work is that there is, in a young population and with a recent diagnosis of multiple sclerosis, a very large proportion of people who already have cognitive impairment, and that it is important to spread this information so that there is greater sensitivity to this problem, in order to improve treatment strategies,” underlines Ruano.
The researcher also stresses that ideally all patients diagnosed with multiple sclerosis should have a cognitive and optic nerve assessment at an early stage of the disease.
Multiple sclerosis is a chronic disease that affects most people of young age, with a prevalence of around 60 or 80 per 100,000 inhabitants in Portugal, and its prevalence is increasing.
This is a pathology that develops gradually and can affect any part of the central nervous system, eventually causing neurodegeneration and later cognitive incapacity. It can affect prolonged concentration, speed in processing information, episodic memory, and the execution of functions.
Multiple Sclerosis is no longer an incurable disease with several effective treatments. Nevertheless, these treatments are still very dependent on the symptoms that patients report, so it is important to detect neurological changes before they cause symptoms to better guide therapeutic decisions and prevent patients from ending up with a disability.
This study, entitled Cognitive impairment and markers of optical neurodegeneration in early multiple sclerosis, also included the participation of researchers from several Hospital Centres in Portugal – Centro Hospitalar de Entre Douro e Vouga, Centro Hospitalar Universitário Lisboa Norte, Centro Hospitalar e Universitário de São João, Centro Hospitalar e Universitário do Porto and the Centro Hospitalar e Universitário de Coimbra, as well as Universities in the North and Centre of the country.