Large pontine lesions in demyelinating disease may mimic brainstem gliomas on magnetic resonance imaging

Abstract

This paper reports two patients who had clinical disorders of eye movements which suggested discrete brainstem lesions. When magnetic resonance imaging (MRI) was performed, areas of demyelination far larger than expected were demonstrated and which had mass effect mimicking brainstem glioma. In both cases, there was clinical improvement with resolution of the MRI lesions without steroids or other treatment. The literature on MRI scanning in demyelinating disease is reviewed. MRI is an invaluable diagnostic tool in eye movement disorders related to demyelination, although the clinician must be aware of its limitations in tissue differentiation. We suspect that many ophthalmologists are unaware that the MRI appearances of demyelination may mimic tumour, particularly if it has mass effect.

Key Words:

• Demyelination
• MRI scanning
• glioma
• brainstem