Stroke preceding autoimmune encephalitis with neuronal potassium channel antibody

Autoimmune encephalitis related to voltage-gated potassium channel (VGKC) antibodies can occur as a complication of cancer but, more frequently, as a non-paraneoplastic disorder. The prompt recognition and treatment could mitigate the morbidity associated with this entity, but the broad-spectrum of neurological manifestations often makes the diagnosis a challenge. The authors describe, here, a unique case of autoimmune encephalitis related to VGKC antibodies preceded by an ischaemic stroke. Conditions associated with the stroke (infection, seizures, metabolic disturbances) had delayed the diagnosis. The authors suggest that autoimmune encephalitis needs to be taken into consideration as part of a differential diagnosis in patients with prolonged encephalopathy following an ischaemic stroke. Infection may trigger an inflammatory response. In addition, the rupture of blood brain barrier that occurs in stroke may have a pathogenic role by allowing antibodies to gain access to the central nervous system.