Top of the basilar syndrome (TOB-S) is defined as the infarction of the rostral brain stem thalamus, cerebellum, temporal and occipital regions of the brain that are supplied by the distal basilar artery. Different symptoms can be seen such as visual, oculomotor disturbances, altered consciousness, speech disorders, seizure, and hallucinations. In this article, we report that a 51-year-old female patient whose initial symptoms were social withdrawal, decreased of speech and inappropiate laugh affects and diagnosed with top of the basilar syndrome. This report emphasizes that the importance of neurological examination and neuroimaging in the management of cases presenting with sudden behavioral disorders at older age. We report a patient with TOB-S which a rare presentation. Clinicians must be alert to exist TOB-S which may occurs with different symptoms and signs like as changes in mood, personality and behavioral disorders.