28th National Clinical Education Symposium Presentation Abstracts
21 APRIL 2026, TUESDAY
PP-34 Anton Syndrome and Manic Switch: A Case Report
PP-34 Anton Syndrome and Manic Switch: A Case Report
Süleyman Çankaya1, Onur Koçhan1
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Show more (Affiliations)
1. Department of Psychiatry, Abant Izzet Baysal University, Bolu, Türkiye
DOI: 10.5080/61upk.ozt523 Page 235
OBJECTIVE:In Bipolar Disorder (BD), particularly in advanced age, atypical presentations necessitate excluding organic pathology. Interpreting vegetative symptoms as depressive can delay recognizing cerebrovascular events, while antidepressant treatments may destabilize mood. Masking neurological findings with psychiatric symptoms or medication side effects complicates diagnosis. This study addresses diagnostic challenges in a patient whose neuropsychiatric symptoms from a left occipital stroke were initially misidentified as depression, leading to mania after venlafaxine administration. CASE (The patient consent must be provided and specified with appropriate terms.):A 56-year-old male with a 35-year BD history presented with confusion and fatigue. Evaluated as depressive, venlafaxine was added to lithium, triggering a manic switch. Upon clinic admission, he exhibited disorientation and pressured speech. Initial neurological evaluation was clear, leading to psychiatric admission. Dysarthria and shuffling gait developed within a week, initially attributed to risperidone-induced extrapyramidal side effects. However, visual-motor deficits during self-care prompted detailed examination, revealing cortical blindness which the patient denied (Anton Syndrome). Computed tomography confirmed an ischemic lesion in the left occipital lobe. His expansive mood and grandiosity masked neurological anosognosia as psychotic denial, creating a diagnostic dilemma.Following manic symptom regression, he is maintained on olanzapine 30 mg/day. Consent was obtained. DISCUSSION:The literature reports that venlafaxine carries a higher risk of manic switch compared to other antidepressants.In this case, the evaluation of the patient's initial complaints of confusion and lethargy as depressive and the subsequent addition of an antidepressant to the treatment not only led to a manic presentation but also masked the findings of Anton Syndrome due to a concurrently developing cerebrovascular event (CVE).The phenomenological similarity between the grandiose denial resulting from the expansive/manic mood and neurological anosognosia can lead to the interpretation of neurological deficits as manic psychosis. Findings such as acute-onset confusion, dysarthria, and gait disturbances in individuals with psychiatric illness must be evaluated with contrast-enhanced imaging methods to rule out organic etiology. Keywords: anosognosia, anton syndrome, bipolar disorder, manic switch