Fatigue in multiple sclerosis: cross-sectional correlation with brain MRI findings

Intruduction: Multiple sclerosis (MS) is one the most common disabling neurologic disorders, which is characterized by a triad of inflammation, demyelination, and gliosis(scaring). MS affects More than 2.5 million individuals worldwide. Its highest prevalence is in young adults.. Fatigue is experienced by 75-90% of MS patients in various degrees. Although fatigue is the most common cause of disability in MS patients, But yet clinicians have problems in its diagnosis and treatment. MRI is a non invasive appropriate method for MS diagnosis, and shows 95% of lesions. Considering some studies showed quality of life in MS patients is correlated to lesions in MRI, it can be expected that fatigue is indirectly correlated to cerebral lesions too. As limited studies were done in this field, more studies are required; so we decided to study the relationship between fatigue and cerebral and spinal MRI findings in patients with multiple sclerosis. This study is analytical cross-sectional that has been done on 36 patients with multiple sclerosis and various degrees of fatigue. Exclusion criteria in this study were depressed patients & Patients used anti depressant drugs or amantadin, pemolin, methylphenidate, modafinil for them fatigue.At first, level of fatigue was defined with standard FIS (Fatigue Impact Scale) and FAI (Fatigue Assessment Instrument) questionnaire. Then EDSS (the Expanded Disability Status Score) was computed. Finally lesions'' load & region in brain & cervical spinal cord, & Atrophy of these places in MRI of patients were assessed by our radiologist. Results indicate that high fatigue score & EDSS was not significantly associated with high brain & cervical lesions'' load; as well sa high Fatigue score with atrophy of brain, cervical spinal cord. But there was significant correlation between right periventricular area and fatigue score, and also between EDSS and brain atrophy(p<0.05), and as well as between fatigue score and pyramidal function (p<0.01)& mental func.(p<0.05), and also between EDSS and pyramidal function, bowel-bladder function, cerebellar function(p<0.01) & between this score and mental func.,brain stem func.(p<0.05).Finally in this study highly educated patients were significantly less fatigued (p<0.05). As it was shown in our results, there was significant correlation between right periventricular area and fatigue score, and also between EDSS and brain atrophy.But high fatigue score & EDSS was not significantly associated with high brain & cervical lesions'' load; as well sa high Fatigue score with atrophy of brain, cervical spinal cord. And highly educated patients were significantly less fatigued.