Orbitofrontal Hemorrhage and Mild Cognitive Impairment Associated with Othello Syndrome

Abstract

Dear Editor, Content-specific delusions (CSDs) are delusions that have a specific theme; for example, Othello syndrome (OS)1 is another name for delusion of infidelity. CSDs are often caused by identifiable neurological diseases. We report a patient who had experienced OS over 5 years, which seemed to have developed from multidomain amnestic mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) accompanied by an old orbitofrontal hemorrhage. A 62-year-old right-handed female was brought to the dementia clinic presenting with a persistently mistaken belief about her husband. She was illiterate, but could perform her activities of daily living (ADL) as a housewife without problems. Five years prior to this visit she had begun to have morbid suspicions about his infidelity. This delusion increased to the level of physical violence. She did not report any hallucination. Her motor, sensory functions, and reflexes were normal. She scored 19 out of 30 on the Mini Mental State Examination (MMSE). A battery of neuropsychological tests was performed, although this was restricted by her illiteracy. The tests showed marked decrements in memory and naming, with the patient being at the 4.85th percentile for delayed recall in the verbal learning test and at the 14.30th percentile in the Boston Naming Test. Normal findings were obtained in frontal/executive function tests including the contrasting program, go/no-go test, fist-edgepalm test, digit symbol coding, and Controlled Oral Word Association Test. Her global Clinical Dementia Rating (CDR) was 0.5 and CDR-Sum of Boxes was 2. Brain magnetic resonance imaging revealed an encephalomalacic change in the left orbitofrontal cortex, which suggested an old hemorrhagic stroke (Fig. 1A-D). Mild cortical atrophy was evident in the frontal and parietal lobes, whereas the gross findings for hippocampal atrophy were unremarkable (Fig. 1E and F). There were no cerebral microbleeds. 18Fflutemetamol amyloid positron-emission tomography (PET) was performed. Early dynamic brain images acquired 10 min after injecting 18F-flutemetamol showed decreased uptake in the bilateral parietal and left dorsolateral prefrontal/orbitofrontal areas (Fig. 1G).2,3 Delayed images obtained 90 min after the injection revealed amyloid deposition in the right frontal lobe (Fig. 1H). The cognitive defects of this patient had gone unnoticed by her family, but she had multidomain amnestic MCI due to AD. She denied any attack of severe headache, but an old orbitofrontal hemorrhage was found incidentally in the absence of cerebral microbleeds, and this did not seem to be associated with amyloid pathology. Therefore, the final diagnosis was made of multidomain amnestic MCI due to AD accompanied by orbitofrontal hemorrhage, both of which seemed to contribute to the development of her OS. The patient was prescribed olanzapine (15 mg), escitalopram (10 mg), and donepezil (5 mg), but her delusion persisted. Over the following year her ability to perform ADL deteriorated. She scored 18 on MMSE, 1 on global CDR, and 5 on CDR–Sum of Boxes. She was judged to have converted to AD dementia. Memantine was added to her medications, and 14 months later she no Seungyon Koh Sun Min Lee So Young Moon