Background

Tumefactive demyelinating disease (TDD) is a rare primary demyelinating disease with diagnostic and therapeutic challenges.

Methods and results

We report a 50-year old woman with TDD successfully treated with decompressive craniectomy and corticosteroids. The patient presented with seizures, subacute progressive hemispheric syndrome, and a tumourlike abnormality on MRI. Demyelinating disease was initially considered unlikely. Due to a rapidly evolving herniation syndrome hemicraniectomy was performed. Outcome was favourable with only very mild neurological deficits 6 weeks later.

Conclusion

TDD should be considered as a differential diagnosis in tumour-like presentations, and appears to have distinctive neuroimaging features. In the advent of treatement failure from high dose corticosteroids and plasmapheresis and development of severe mass effect, decompressive hemicraniectomy is an important treatment option.