Voltage gated potassium channel (VGKC) antibody encephalitis

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Voltage-gated potassium channel (VGKC) antibody encephalitis is autoimmune encephalitis with antibodies against the voltage-gated potassium channel. It is one of the most common forms of autoimmune limbic encephalitis in the absence of primary extra-CNS tumors. Autoimmune VGKC encephalitis can be diagnosed by serologic testing and is potentially treatable with immunotherapy. Most patients present with seizures and epilepsy in the absence of memory loss and neuropsychiatric symptoms which are more common in limbic encephalitis.

Clinical presentation

Clinical presentation of voltage-gated potassium channel (VGKC) antibody encephalitis is variable, few of the features include:

fever
psychosis
short-term memory deficits
vomiting
diarrhea
seizures
facial dyskinesia
hypersalivation
headache
confusion

Radiographic features

One study showed that a majority of the proven patients had unilateral or bilateral amygdala with or without hippocampal enlargement and T2 hyperintensity at some time point during the course of the disease. Also, restricted diffusion and mild ill-defined enhancement demonstrated in approximately 50% and 25% of patients, respectively. Extratemporal involvement is rare. In the long term, mesial temporal sclerosis may be seen as high as 50% of patients .