Zeynep Özdemir1, Erkan Acar2, Aysun Soysal1

1Istanbul Bakirkoy Prof. Dr. Mazhar Osman Mental Health and Neurological Diseases Training and Research Hospital, Clinic of Neurology, Istanbul, Turkey
2Acibadem Mehmet Ali Aydınlar University Faculty of Medicine, Department of Neurology, Istanbul, Turkey

Keywords: Multiple sclerosis, magnetic resonance imaging, atypical inflammatory demyelinating lesions


Objective: The diagnosis of patients with atypical demiyelinating lesions has always been challenging, sometimes leading to a biopsy. Recent literature has radiologically classified atypical inflammatory demyelinating lesions as ring-like, Balo-like, infiltrative, megacystic, and unclassified lesions. In this study, we aimed to assess the demographics and clinical and radiologic findings in patients with atypical lesions.

Materials and Methods: The records of 320 patients with demyelinating disorders were retrospectively assessed using iMed database. Patients with atypical lesions and whose magnetic resonance imaging evaluations were included. Clinical and radiologic findings were evaluated and lesions were classified according to the recommended criteria.

Results: Twenty-seven patients (16 females) were included and the mean age was 34.26±6.12 (range: 26-49) years. Fourteeen patients had ring-like, three had Balo-like, three had megacystic, five had infiltrative, and two patients had unclassified lesions. Diffusion restriction was observed in contrast-enhancing sites in ring-like lesions, heterogeneously in infiltrative lesions and also peripherally in Balo-like lesions. Two patients with infiltrative lesions had additional lesions on follow-up and had to undergo biopsy. Two patients died despite aggressive treatment. Two patients with Balo-like lesions were evaluated as having acute disseminated encephalomyelitis and did not have further relapses. Seventeen patients from the study group converted to multiple sclerosis (MS) on follow-up.

Conclusion: Differential diagnosis of atypical inflammatory demyelinating lesions is not always easy, the prognosis is not different from MS lesions. Mostly, ringlike lesions seem to convert to MS with recurrent relapses; however, infiltrative lesions seem to have poorer outcomes, especially if patients have additional relapses.

Ethics Committee Approval

The study, conducted at Bakirkoy Prof. Dr. Mazhar Osman Mental Health and Neurological Diseases Hospital, was performed in accordance with the Helsinki Declaration and approved by the Local Ethics Committee (date: 22.05.2017/19124-00045685340).

Peer Review

Externally and internally peer reviewed.

Author Contributions

Concept: Z.Ö., E.A., A.S., Design: Z.Ö., E.A., A.S., Data Collection or Processing: Z.Ö., E.A., A.S., Analysis or Interpretation: Z.Ö., E.A., A.S., Literature Search: Z.Ö., E.A., A.S., Writing: Z.Ö., E.A., A.S.

Conflict of Interest

No conflict of interest was declared by the authors.

Financial Disclosure

The authors declared that this study received no financial support.