MRI AND EVOKED POTENTTIALS IN DIFFERENTIAL DIAGNOSIS OF ENCEPHALITIS, DISSEMINATED ENCEPHALOMYELITIS AND MULTIPLE SCLEROSIS IN CHILDREN

Abstract

Last years are characterized by the growth of encephalitis (Ef) frequency and demyelination diseases of CNS in children, especially, among teenagers. The diseases are characterized by similar of clinical features of the disease onset, absence of differential diagnostical criteria and frequency of the disease chronisation and possibility of transformation in multiple sclerosis (MS), all this determines the problem of differential diagnosis. The aim is to determine differential-diagnostical features of Ef, disseminated encephalomyelitis (DEM) and MS in children by analysis of structure MRI and brain multi-modal evoked potentials (MEP). We observed 35 children with Ef, 40 with DEM and 40 with MS. All patients were from 3 to 17 years old. All patients were diagnosed clinically in acute period and in catamnesis — after 3 and 6 months. MS diagnosis was based on McDonald criteria, 2010 year. ADEM diagnosis was also based on international criteria. We analyzed brain MRI, spinal MRI and MEP in all patients during the first day of hospitalization and after 3 and 6 months later. The analysis of the MRI of the brain and spinal cord in encephalitis (EF, n=35), disseminated encephalomyelitis (ADEM, n=60) and multiple sclerosis (MS, n=60) of children on admission to hospital, and then — after 3 and 6 months. Up to 85% of foci with ADEM and EF had irregular shapes, accompanied by swelling phenomena, and mass effect and in 2⁄3 cases were localized in the gray or white and gray matter of the CNS. In 60% of cases in patients with EF and ADEM based on the localization of foci could suggest the etiology of the disease. In MS 67,5% were detected multifocal white matter lesions (more than 10 lesions), and most of the foci had a size of up to 1 cm and the correct round-oval and the absence of signs of inflammation. The presence of lesions in the gray matter at EF, ADEM and MS respectively observed in 82,5%, 40% and 7,5% of cases. After 3–6 months of MRI in the majority of EF and DEM foci regressed, and in MS were reduced in size, but not completely disappeared. According to the study of evoked potentials (EP) of the brain in children with MS and ADEM often increased latency of the responses, while the EF decreased cortical or brainstem response amplitude. The majority of patients with MS have changed the parameters both 3–4 different EP (somatosensory from the upper and lower limbs, acoustic stem and/or visual), while ADEM and EF-1–2 evoked potentials. Chronic EF, and the progression of neurological symptoms was not associated with the advent of the «new» lesion, and up to 75% of the foci can regress completely after 3–6 months. Chronic EF characterized by increase of only brain atrophy, which involves communication of these changes only with neuronal process. Whereas in MS and multiphase ADEM appeared «new» foci accumulating contrast agent that allows you to talk about preserving the pathogenesis of vascular component in their progression. Study of MEP and MRI in children with Ef, DEM and MS in dynamics can be useful for differential diagnosis and monitoring of therapy efficacy.