Treatment of Rasmussen encephalitis half a century after its initial description: promising prospects and a dilemma.

Rasmussen encephalitis (RE), initially described half a century ago, is an inflammatory unihemispheric brain disorder. Its two clinical key facets are the progressive tissue and function loss and the epilepsy, often in form of epilepsia partialis continua. For both, treatment options are available. Anti-seizure effect of anti-epilepsy drugs is usually limited to secondarily generalized seizures and complex partial seizures whereas epilepsia partialis continua usually is totally refractory. Hemispherectomy in one of its modern variants offers a very high chance of seizure freedom, however at the price of irreversible loss of functions located in the affected hemisphere. In a proportion of patients, long-term immunotherapy is able to prevent or slow down hemispheric tissue loss and the associated functional decline. It does, however, mostly not improve the epilepsy. Whereas for many patients unequivocal treatment proposals can be readily made, a dilemma may emerge in those with severe epilepsy but still preserved hemispheric function.