• Neuro-Ophthalmology/Orbit

    This study examines how modern neuroimaging has influenced the diagnosis of peduncular hallucinosis (PH), a rare syndrome of vivid, dream-like visual hallucinations that intrude on normal wakefulness.

    Study design

    The authors performed a literature search to identify 85 cases of PH. Additional clinical deficits, especially ophthalmoparesis, have historically been an important part of the diagnosis and localization of this syndrome.

    Outcomes

    Eye movement abnormalities were present in 12/15 (80%) of cases lacking a neuroimaging study, but in only 24/70 (34%) of cases in which a neuroimaging study had been performed (P=0.001).

    Limitations

    A major limitation is the size and retrospective nature of the study. In addition, many reported cases lacked documentation of visual acuity and visual fields.

    Clinical significance

    Movement abnormalities were historically a key localizing clinical feature supporting the diagnosis of PH. Yet, this study shows that in the era of modern neuroimaging, co-occurring eye movement abnormalities are far less common and are not a requisite feature of the diagnosis.  This is important to the clinician tasked with diagnosing this rare and unusual disorder.