Eloquent Cortex Resection in Rasmussen’s Syndrome

Searching through brain slices at the Montreal Neurological Institute in the 1950s, Dr. Theodore Rasmussen noted signs of chronic inflammation in resected cortical specimens from pediatric patients with epilepsia partialis pars continua (Rasmussen et al. Neurology 8:435–445, 1958). This disease, which has come to bear his name, is characterized by progressive cortical sclerosis of one hemisphere that typically begins with a perisylvian volume loss and relatively spares the occipital lobe until late in the disease process (Varadkar et al. Lancet Neurol 13:195–205, 2014). Standard therapy is directed at the acute inflammatory component of Rasmussen’s syndrome, and treatment involves steroids and intravenous immunoglobulin and, less commonly, plasmapheresis or tacrolimus, though these treatments do not prevent progression to permanent disability (Varadkar et al. Lancet Neurol 13:195–205, 2014; Hart et al. Neurology 44:1030–1030, 1994; Takahashi et al. Brain Dev 35:778–785, 2013). As the disease progresses with further unilateral weakness, vision loss, and cognitive deficits, the contralateral hemisphere progressively supports some of the lost function. Since medication-refractory seizures typically become persistent to the degree that activities of daily life are impossible, hemispherotomy to remove the affected hemisphere becomes the sole therapeutic option (Varadkar et al. Lancet Neurol 13:195–205, 2014; Bien et al. Brain 128:454–471, 2005). However, there are patients for whom a hemispherotomy is not possible due to residual essential function in the affected hemisphere.