Abstract Details

Title Peduncular Hallucinosis: A Systematic Review of Case Reports and Proposed Diagnostic Criteria

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P7 - Poster Session 7 (8:00 AM-9:00 AM)

Poster/Presentation
Number 12-003

Objective We aim to propose diagnostic criteria for peduncular hallucinosis through a systematic review

Background Peduncular Hallucinosis (PH), is defined as a rare clinical syndrome characterized by vivid and colorful visual hallucinations of both humans and animals, which are recognized as not real, accompanied by manifestations such as ophthalmoparesis, hemiparesis, gait ataxia, among others. However, there are discrepancies in the correct diagnostic criteria.

Design/Methods We conducted a systematic review across seven databases and screened reports describing PH until August 2025. Based on a narrative synthesis, we proposed diagnostic criteria.

Results We found 105 reported cases across 94 publications. More than half were females (53.4%) with a median age of 60 years old (Range: 8 to 85). The most common identified etiologies were ischemic stroke (54; 51.4%), brain tumor (21; 20.0%), hemorrhagic stroke (9; 8.6%), and demyelinating disease (7; 6.7%). We found the following frequent characteristics in patients with a diagnosis of PH: Complex (100; 95.2%), vivid and colorful (67, 63.8%) visual hallucinations with content of people (78; 74.3%), objects (36, 34.3%), and/or animals (56; 53.3%). Hallucinations were present during wakefulness (54; 51.5%) and with insight predominance (62, 59.0%). Most of the cases had an identified intraparenchymal lesion in the thalamus (27; 25.4%), midbrain (39; 37.1%), and/or pons (39; 37.1%), and with partial or total improvement (79; 75.2%).

Conclusions Peduncular Hallucinosis represents a distinctive clinico-anatomical syndrome. Our synthesis supports the following proposed diagnostic criteria: 1) Complex and vivid complex visual hallucinations with objectivable content; 2) Preserved insight and wakefulness predominance; 3) Neuroimaging evidence of a lesion involving the midbrain-pontine-thalamic network; 4) Partial or total improvement; and 5) Exclusion of psychiatric or metabolic causes.

Authors/Disclosures
Jesus Daniel Gutierrez Arratia, MD PRESENTER	Dr. Gutierrez Arratia has nothing to disclose.
Luciana T. Jara Abarca, MD	Miss Jara Abarca has nothing to disclose.
Fitzgerald Aquiles Arroyo Ramirez, MD (Instituto Nacional de Ciencias Neurologicas)	Dr. Arroyo Ramirez has nothing to disclose.
Christoper A. Alarcon Ruiz, MD (Instituto Nacional de Ciencias Neurológicas)	Dr. Alarcon Ruiz has received research support from Universidad Científica del Sur.
Brenda Oporto, MD	Dr. Oporto has nothing to disclose.
Gina V. Noriega Vera, MD	Mrs. Noriega Vera has nothing to disclose.
Christoper A. Alarcon Ruiz, MD (Instituto Nacional de Ciencias Neurológicas)	Dr. Alarcon Ruiz has received research support from Universidad Científica del Sur.

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