Multiple sclerosis (MS) is the most common inflammatory demyelinating disease, affecting approximately one million adults worldwide. This paper describes a young female patient who presented to the acute medical team with generalised tonic-clonic seizures and right hemiplegia on a background of MS. Radiological imaging revealed a large ring enhancing lesion exerting mass effect. We describe an unusual form of MS and discuss diagnostic pitfalls of tumefactive demyelinating lesions which can be mistaken for brain tumours and abscesses.
