Potassium channel antibody associated encephalopathy presenting with a frontotemporal dementia like syndrome

Arch Neurol. 2007 Oct;64(10):1528-30. doi: 10.1001/archneur.64.10.1528.


Objective: To describe a patient who presented with features suggestive of frontotemporal dementia (FTD) but with some atypical findings and antibodies to neuronal voltage-gated potassium channels (VGKC-Abs).

Design: Case report.

Setting: Mater Misericordiae University Hospital, Dublin, Ireland.

Results: An 82-year-old man presented with progressive changes in personality, social conduct, and executive function with preservation of memory, deteriorating from baseline to requiring acute hospitalization within 6 months. Transient deterioration (episodic speech arrest) with spontaneous recovery, atypical for frontotemporal dementia, was observed. The patient had an elevated VGKC-Ab titer (2624 pM [normal range, < 100 pM]), elevated protein levels in cerebrospinal fluid, and a negative evaluation for malignancy. Magnetic resonance imaging of brain was normal but [(18)F]-fluorodeoxyglucose positron emission tomographic imaging revealed bifrontal hypometabolism. A marked and sustained improvement with steroid therapy was observed.

Conclusion: Workup for a potentially reversible autoimmune-mediated encephalopathy, including a VGKC-Ab titer, should be considered in patients presenting with rapidly progressive behavioral and cognitive decline.

Publication types

  • Case Reports

MeSH terms

  • Aged, 80 and over
  • Anti-Inflammatory Agents / therapeutic use
  • Autoantibodies / immunology*
  • Brain Damage, Chronic / drug therapy
  • Brain Damage, Chronic / immunology*
  • Brain Damage, Chronic / psychology*
  • Dementia / psychology*
  • Diagnosis, Differential
  • Fluorodeoxyglucose F18
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Neurons / immunology
  • Neuropsychological Tests
  • Positron-Emission Tomography
  • Potassium Channels, Voltage-Gated / immunology*
  • Prednisolone / therapeutic use
  • Radiopharmaceuticals


  • Anti-Inflammatory Agents
  • Autoantibodies
  • Potassium Channels, Voltage-Gated
  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • Prednisolone