Purpose: Few paediatric cases of clinically isolated syndrome (CIS) have been described in literature, even though it has been increasingly recognized also in this age group. Our study retrospectively enrolled seven Italian patients (four males and three females) who met the International Paediatric Multiple Sclerosis Study Group (IPMSSG) 2012 criteria for clinically isolated syndrome over the period 2010-2014; their clinical, laboratory and imaging findings were compared with current literature and with those seen in five patients (three males and two females) with acute disseminated encephalomyelitis, who were followed in our department over the same years (mean follow-up time 2.84 ± 1.8 years).
Results: In our CIS sample, male sex was prevalent, 42.8 % of patients had a multifocal presentation, MRI lesions mostly appeared confluent and with poorly defined margins, and CSF oligoclonal bands (OCBs) were identified in 28.6 %. All acute disseminated encephalomyelitis (ADEM) patients had polyfocal presentation and encephalopathy; large MRI subcortical lesions and polyclonal IgG distribution were identified. During the subsequent follow-up assessments, MRI scan revealed new lesions in three CIS patients, while in ADEM children it appeared normal.
Conclusions: Paediatric CIS patients often show peculiar epidemiological, clinical and radiological features, which significantly differ from adult ones. The presence of encephalopathy and of extended MRI lesions leads to a diagnosis of ADEM, instead. In CIS patients the presence of multiple asymptomatic MRI lesions and of OCBs revealed to be the most predictive risk factors for progression to clinically definite multiple sclerosis (CDMS), so a regular long-term follow-up is recommended; in ADEM, no suitable risk factors for a relapse could be identified.
Keywords: ADEM; CIS; Children; Clinically definite multiple sclerosis; Demyelinating diseases; Differential diagnosis.