Introduction Limbic encephalitis associated with voltage-gated potassium channel antibodies (VGKC-LE) is becoming increasingly recognised. However, only a few case series have been reported with the clinical phenotype known to vary widely. We aimed to establish a case series of patients with positive VGKC antibodies to investigate their clinical, radiological and biochemical features.

Methods All patients with a positive VGKC antibody result from University Hospital of Wales up until June 2012 were identified. Medical records were subsequently reviewed and data collected using a standardised proforma.

Results 25 patients were identified. Clinical presentations included memory impairment (76%), seizures (56%), confusion (52%), behavioural changes (36%), and sleep disturbances (24%). 6 patients presented with hyponatraemia. 10 patients had a diagnosis of VGKC-LE although 15 patients satisfied the diagnostic criteria. A number of other diagnoses were associated with positive antibodies including CJD and frontotemporal dementia. MRI mainly demonstrated changes in the temporal region. All patients that received immunotherapy (n=12) made some improvement.

Conclusion We show that the majority of patients with positive VGKC antibodies satisfy the diagnosis for VGKC-LE but antibodies may also be present in a range of other diagnoses.