Pediatric onset primary progressive multiple sclerosis with predominant cognitive presentation: a MRI follow-up

Case Presentation: a female Caucasian patient, without family history of psychiatric disorders, started at 7-years-old with progressive learning difficulties that persisted during high school. At age 14, she started with symptoms of depression, aggressive behavior, impulsivity and disinhibition, being diagnosed with bipolar affective disorder and followed up with a psychiatrist. Her cognitive dysfunction progressively worsened. At the age of 23 years old, after a fainting episode, a brain MRI was requested, showing lesions suggestive of a demyelinating disease, but without gadolinium enhancement. She was referred to our MS center for investigation. The neurological examination, except for the mental state, was unremarkable, and extensive etiological investigation was carried out, with negative investigation. As a result, the 2005 McDonald's criteria were not met (valid criteria at that time), having only dissemination in space. From 23 to 26 years old, she had several psychiatric hospitalizations due to psychotic relapses and severe behavioral changes. At the age of 27, she underwent a new brain MRI, showing a significant increase in the lesion load and a gadolinium-enhancing lesion was found. At that time, she had Expanded Disability Status Scale (EDSS) 3. Thus, based on the insidious progression of neurological symptoms and new lesions on MRI, the diagnosis of PPMS was made and glatiramer acetate was started. Discussion: In PPMS, at the beginning of the disease, 74% of patients present without cognitive symptoms. In some rare cases, MS may initially present with a severe and disabling CI, sometimes associated with neuropsychiatric symptoms, making the diagnosis difficult and delayed for years. Final Comments: Despite being rare, PPMS can present with cognitive predominance and already at childhood. In this scenario, diagnosis is often delayed by several years but requires exclusion of alternative causes.