Probable dysimmune epilepsia partialis continua manifesting as epileptic moving toes syndrome: electroclinical features of a challenging case

Epilepsia partialis continua (EPC) is a rare form of focal status epilepticus. We describe a 22-year-old woman with EPC manifesting with isolated toe movements, prevalent over the left side and initially misdiagnosed as psychogenic, clinically almost indistinguishable from those observed in "painful legs and moving toes syndrome". The continuous involuntary movements with EMG correlates of twitches lasting <100 ms, the sharp waves over fronto-central regions on EEG, and the marked asymmetry in somatosensory evoked potentials with higher cortical amplitude over the right side following peripheral stimulation over the left foot confirmed the epileptic nature of the symptoms, leading to the diagnosis of EPC. The toe movements were markedly reduced following steroid therapy, whereas the infusion of immunoglobulins caused aseptic meningitis. Despite an extensive diagnostic work-up (including a search for antibodies for paraneoplastic and autoimmune encephalitis), an ultimate aetiological diagnosis was not reached, although the dramatic response to corticosteroids strongly supported an underlying dysimmune pathophysiology. Diagnosing EPC can be challenging, especially if movements are confined to a very small body region or strongly resemble movements encountered in other conditions. EEG-EMG monitoring should be performed in patients with continuous involuntary muscular jerks in order not to overlook a diagnosis of EPC. [Published with video sequences on www.epilepticdisorders.com].