Visual Hypoemotionality (Secondary Visual Derealization) in a Patient with a Right Posterior Temporoparietal Lesion (P2.154)

OBJECTIVE: We report a rare case of secondary visual derealization/hypoemotionality in a patient with a right posterior temporoparietal lesion. BACKGROUND : Derealization is a perceptual alteration of the external world such that it is experienced as unreal. Secondary derealization is most frequently encountered in patients with epilepsy and migraine; less commonly patients with bilateral or right-lateralized occipitotemporal lesions have reported visual hypoemotionality. METHODS: Case history of an individual with modality-specific, visual derealization following neurosurgical intervention. RESULTS: 50-year-old, right-handed man with no past neurologic history presented to the emergency department after a generalized tonic-clonic seizure. Patient endorsed 3-6 months of recurrent deja vu. His medical-neuropsychiatric history was notable for three prior military-related head trauma events with loss of consciousness, remote transient depression in the context of psychosocial stress, and alcohol misuse. Magnetic resonance imaging(MRI) revealed a 15x7mm T1 hypointense non-enhancing lesion in the right medial temporal lobe. A dysembryoplastic neuroepithelial tumor was diagnosed following stereotactic biopsy. Patient responded sub-optimally to multiple anti-epileptic drugs and was evaluated for surgery. Inpatient video-electroencephalography(EEG) captured a right temporal onset seizure. The day following MRI-guided lesional thermal ablation, patient developed a new left-visual field defect. Non-contrast computed tomography showed a 3.7x2.6x3.3cm right posterior temporoparietal intraparenchymal hemorrhage. While his visual-field deficits gradually improved, he endorsed feeling estranged from his visual experiences despite normal visual acuity. He reported that visual stimuli “didn’t feel real” and appeared devoid of emotional coloring. Other sensory modalities, including auditory and somatosensory, were reportedly unaffected. He endorsed derealization on the Dissociative Experiences Scale (pre vs. post surgery score change: 19 to 30). EEG showed right>left temporal theta-delta slowing without epileptiform activity. His visual hypoemotionality has persisted for 10 months. CONCLUSIONS: This case implicates the right posterior temporoparietal cortex in secondary visual derealization, potentially through inferior longitudinal fasciculus mediated visual-limbic disconnection. Study Supported by: none Disclosure: Dr. Perez has nothing to disclose. Dr. Prasad has nothing to disclose. Dr. Acar has nothing to disclose. Dr. Meadows has nothing to disclose. Dr. Golby has nothing to disclose. Dr. Dworetzky has received personal compensation for activities with Sleep Health/Digitrace Company, Best Doctors, and Second Opinion Neurology.