Two cases of Huntington's disease unmasked by the COVID-19 pandemic

Movement disorders of new-onset are increasingly being described in patients with SARS-CoV-2 infection [1]. Imaging and cerebrospinal fluid (CSF) studies in such patients suggest a possible underlying post-viral immune mechanism, ruling out structural brain lesions and encephalitic processes [1]. Interestingly, SARS-CoV-2 infection appears to be able to affect several crucial cellular pathways, which are also relevant in cellular aging and in neurodegenerative diseases [2]. These include immune activation and inflammation. Of note, both these responses are induced following immunization with effective vaccines, which are enhanced in patients who previously recovered from COVID-19 [3]. As the pandemic continues, increasing evidence has drawn attention to the indirect and systemic effects of the virus, which could be an environmental modifier in patients genetically predisposed to develop Huntington’s disease (HD).