Peduncular hallucinosis: A polysomnographic and spect study of a patient and efficacy of serotonergic therapy

Vetrugno, Roberto; Vella, Alessandra; Mascalchi, Mario; Alessandria, Maria; D’Angelo, Roberto; Gallassi, Roberto; Nave, Riccardo Della; Ginestroni, Andrea; Antelmi, Elena; Montagna, Pasquale

doi:10.1016/j.sleep.2009.05.005

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Volume 10, Issue 10 , Pages 1158-1160, December 2009

Peduncular hallucinosis: A polysomnographic and spect study of a patient and efficacy of serotonergic therapy

Roberto Vetrugno
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
- Corresponding author. Address: Dipartimento di Scienze Neurologiche dell’Università di Bologna, Via Ugo Foscolo 7 – 40123 Bologna, Italy. Tel.: +39 051 2092925; fax: +39 051 2092963.
Alessandra Vella
- Nuclear Medicine, “Le Scotte” Siena General Hospital, Siena, Italy
Mario Mascalchi
- Radiodiagnostic Section, Department of Clinical Physiopathology, University of Florence, Florence, Italy
Maria Alessandria
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
Roberto D’Angelo
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
Roberto Gallassi
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
Riccardo Della Nave
- Radiodiagnostic Section, Department of Clinical Physiopathology, University of Florence, Florence, Italy
Andrea Ginestroni
- Radiodiagnostic Section, Department of Clinical Physiopathology, University of Florence, Florence, Italy
Elena Antelmi
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
Pasquale Montagna
- Department of Neurological Sciences, University of Bologna, Bologna, Italy

Received 4 March 2009; received in revised form 6 May 2009; accepted 11 May 2009.

Abstract

Peduncular hallucinosis (PH) consists of formed and coloured visual images, which the patient knows are unreal; it is often associated with lesions of the pons, midbrain and diencephalon. A 72-year-old man had noted the sudden onset of visual hallucinations one year before, specifying the time and body position in a 4-week, 24-h diary. Thereafter, he underwent video-polysomnography (VPSG), brain magnetic resonance imaging (MRI), angiography (MRA), proton spectroscopy (¹H MRS), and single photon emission tomography (SPECT). Patient’s diaries and VPSG showed a strong clustering of hallucinatory experiences during the evening/night time while lying in supine position, similar to hypnagogic hallucination and sleep paralysis in supine position. Repeated episodes of REM sleep behaviour disorder (RBD) occurred during the night. MRI and MRA showed an elongated and dilated left internal carotid artery displacing the left subthalamus upwards, and ¹H MRS relatively decreased N-acetyl-aspartate in the left subthalamus. Brain SPECT during PH revealed hypoperfusion in the right temporal region and hyperperfusion in the left occipital and right opercular regions (the latter possibly related to the patient’s awareness of unreality). PH resolved with serotonergic (citalopram) therapy.

Keywords: Peduncular hallucinosis, Hypnagogic state, Circadian rhythm, Body position, Serotonergic therapy, Dream