title: Auditory Hallucinosis as a Presenting Feature of Interpeduncular Lipoma with Proximal P1 Segment Fenestration: Report of a Rare Case and Review of Literature on Peduncular Hallucinosis.
abstract: The authors present a unique case of intracranial lipoma in the interpeduncular cistern associated with proximal P1 segment fenestration. This patient is a 20-year-old male with extensive psychiatric history and complaints of recent auditory hallucinations. Cranial magnetic resonance imaging (MRI) (T1, T2, and FLAIR) showed a hyperintense lesion in the left aspect of interpeduncular cistern with a prominent flow void within the hyperintense lesion suggestive of a combined vascular-lipomatous lesion. Computed tomography (CT) angiography showed a high-riding large tortuous P1 segment on the left side with proximal fenestration, the ectatic posteromedial limb harboring a fusiform dilated segment. Since there are anecdotal cases of cerebral aneurysms associated with intracranial lipomas, a conventional angiography was done, which confirmed a proximal left P1 fenestration and a fusiform-dilated segment, and no aneurysm. There are few cases of hallucinations associated with a vascular midbrain pathology reported in literature, but hallucinations associated with a combination of lipoma and arterial ectasia have never been reported. This article not only demonstrates the MRI and angiographic appearance of this rare lipomatous lesion but also highlights this unique association and significance of auditory hallucinations as a clinical presentation, akin to peduncular hallucinosis.
authors.affiliation: Department of Neurology, Neurological Institute, University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: Ashish
authors.initials: A
authors.lastname: Kulhari
authors.affiliation: Department of Neurological Surgery, Neurological Institute, University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: Sunil
authors.initials: S
authors.lastname: Manjila
authors.affiliation: Department of Neuroradiology, Neurological Institute, University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: Gagandeep
authors.initials: G
authors.lastname: Singh
authors.affiliation: Department of Neurology, Neurological Institute, University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: Kunal
authors.initials: K
authors.lastname: Kumar
authors.affiliation: Department of Neuroradiology, Neurological Institute, University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Tarr
authors.affiliation: Department of Neurological Surgery, Neurological Institute, University Hospitals Case Medical Center, Cleveland, OH, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Bambakidis
keywords: Auditory hallucinosis; interpeduncular lipoma; peduncular hallucinosis; posterior cerebral artery fenestration; vascular ectasia