Unusual amnesia in a patient with VGKC-Ab limbic encephalitis: a case study

Area of Science:

• Neurology
• Immunology

Background:

• Voltage-gated potassium channel antibody-associated encephalitis (VGKC-Ab) is a rare autoimmune disorder affecting the nervous system.
• Limbic encephalitis, a subtype of VGKC-Ab, typically presents with memory deficits and cognitive impairment.

Observation:

• A patient with confirmed VGKC-Ab encephalitis presented with bilateral hippocampal hyper-intensity on MRI, preserved hippocampal volumes, and significant anterograde and retrograde memory impairment.
• The patient exhibited fluctuating recall abilities and a notable tendency to confabulate during unstructured interviews, even after cognitive recovery.

Findings:

• Immunotherapy led to substantial clinical improvement, with the patient performing within or above average on formal memory and executive function tests.
• Despite cognitive recovery, the persistent confabulation suggests a complex and unusual memory disorder associated with VGKC-Ab encephalitis.

Implications:

• This case expands the known clinical spectrum of VGKC-Ab limbic encephalitis.
• The findings prompt further investigation into the neurobiological mechanisms underlying memory disorders and confabulation in autoimmune encephalitis.