Severe Isolated Cognitive Relapse in Multiple Sclerosis - Indication for High Efficacy Therapy?

Isolated cognitive relapses (ICRs) are transient deficits in cognitive performance that are not accompanied with other symptoms typical for multiple sclerosis (MS). They are often missed and can lead to long-term cognitive decline. Considering possible devastating consequences of cognitive impairment, especially in working adults, and high economic burden of MS, it is of great importance to establish whether ICRs are sufficient to start with high efficacy therapy. 42-year- old women with a recent diagnosis of relapsing-remitting multiple sclerosis developed significant impairment in almost all cognitive domains, with dominant difficulties in naming and low performance in phonemic fluency tasks, consistent with ICR. Her brain MRI showed new lesions affecting the anterior part of the thalamus and her condition partially improved on intravenous corticosteroid therapy. While waiting the disease-modifying therapy to begin, for what was now highly active MS, she developed subarachnoid haemorrhage which further narrowed the treatment options. This case illustrates the complexity of managing patients with MS and ICRs in at least three aspects. Firstly, the lack of uniform definition resulting in diagnostic delay of highly active MS and ICRs. Secondly, optimal treatment choices are often limited due to safety issues and reimbursement reasons. And thirdly, there is still an open question about the right treatment option for ICRs, so more research is needed.