Alzheimer Abnormalities of the Amygdala With Klüver-Bucy Syndrome Symptoms

Abstract

Background Neurofibrillary tangles and β-amyloid plaques have been observed in the amygdala in Alzheimer disease. A disproportionate abundance of this abnormality in the amygdala may cause behavioral symptoms similar to Klüver-Bucy syndrome. Objectives To describe an atypical behavioral presentation of Alzheimer disease and to review the literature on the subject. Design Case study. Setting Outpatient specialty clinic. Patient A 70-year-old man with progressive behavioral symptoms of hyperorality, hypersexuality, hypermetamorphosis, visual agnosia, hyperphagia, and apathy who died at age 77 of asphyxiation on a foreign object. Main Outcome Measures Clinical symptomatology, brain imaging, and neuropathology. Results The pathologic diagnosis was Alzheimer disease with abundant tangles and plaques in the lateral amygdala. Conclusions This case represents a variant of Alzheimer disease with prominent amygdala abnormalities and a Klüver-Bucy phenotype that was misdiagnosed as frontotemporal dementia. Clinical and imaging findings that may aid in accurate diagnosis are reviewed.