Illusions, hallucinations, and visual snow - PubMed

Review

Illusions, hallucinations, and visual snow

Clare L Fraser et al. Handb Clin Neurol. 2021.

Abstract

Illusions and hallucinations are commonly encountered in both daily life and clinical practice. In this chapter, we review definitions and possible underlying mechanisms of these phenomena and then review what is known about specific conditions that are associated with them, including ophthalmic causes, migraine, epilepsy, Parkinson's disease, and schizophrenia. We then discuss specific syndromes including the Charles Bonnet syndrome, visual snow syndrome, Alice in Wonderland syndrome, and peduncular hallucinosis. The scientific study of illusions and hallucinations has contributed significantly to our understanding of how eye and brain process vision and contribute to perception. Important concepts are the distinction between topologic and hodologic mechanisms underlying hallucinations and the involvement of attentional networks. This chapter examines the various ways in which pathological illusions and hallucinations might arise in relation to the phenomenology and known pathology of the various conditions associated with them.

Keywords: Alice in Wonderland syndrome; Charles Bonnet syndrome; Epilepsy; Hallucination; Illusion; Migraine; Parkinson's disease; Peduncular hallucinosis; Schizophrenia; Visual snow.

Similar articles

• Hallucinations and illusions in migraine in children and the Alice in Wonderland Syndrome.

  Smith RA, Wright B, Bennett S. Smith RA, et al. Arch Dis Child. 2015 Mar;100(3):296-8. doi: 10.1136/archdischild-2013-305283. Epub 2014 Oct 29. Arch Dis Child. 2015. PMID: 25355729

• [Obligatory and facultative symptoms of the Alice in wonderland syndrome].

  Podoll K, Ebel H, Robinson D, Nicola U. Podoll K, et al. Minerva Med. 2002 Aug;93(4):287-93. Minerva Med. 2002. PMID: 12207198 Review. Italian.

• Complex visual hallucinations. Clinical and neurobiological insights.

  Manford M, Andermann F. Manford M, et al. Brain. 1998 Oct;121 ( Pt 10):1819-40. doi: 10.1093/brain/121.10.1819. Brain. 1998. PMID: 9798740 Review.

• Alice in Wonderland Syndrome: A real life version of Lewis Carroll's novel.

  O'Toole P, Modestino EJ. O'Toole P, et al. Brain Dev. 2017 Jun;39(6):470-474. doi: 10.1016/j.braindev.2017.01.004. Epub 2017 Feb 8. Brain Dev. 2017. PMID: 28189272 Review.

• What associates Charles Bonnet syndrome with age-related macular degeneration?

  Vojniković B, Radeljak S, Dessardo S, Zarković-Palijan T, Bajek G, Linsak Z. Vojniković B, et al. Coll Antropol. 2010 Apr;34 Suppl 2:45-8. Coll Antropol. 2010. PMID: 21305724

Cited by

• Not All Cases of Visual Snows are Benign: Mimics of Visual Snow Syndrome.

  Hang C, Leishangthem L, Yan Y. Hang C, et al. Neuropsychiatr Dis Treat. 2021 Nov 10;17:3293-3300. doi: 10.2147/NDT.S338111. eCollection 2021. Neuropsychiatr Dis Treat. 2021. PMID: 34785899 Free PMC article. Review.

• Simultaneous ¹⁸F-FDG PET/MR metabolic and structural changes in visual snow syndrome and diagnostic use.

  Van Laere K, Ceccarini J, Gebruers J, Goffin K, Boon E. Van Laere K, et al. EJNMMI Res. 2022 Dec 30;12(1):77. doi: 10.1186/s13550-022-00949-0. EJNMMI Res. 2022. PMID: 36583806 Free PMC article.

• Scanning laser ophthalmoscopy retroillumination: applications and illusions.

  Mainster MA, Desmettre T, Querques G, Turner PL, Ledesma-Gil G. Mainster MA, et al. Int J Retina Vitreous. 2022 Sep 30;8(1):71. doi: 10.1186/s40942-022-00421-0. Int J Retina Vitreous. 2022. PMID: 36180893 Free PMC article. Review.

• Visual Snow Syndrome in Patient with Migraine: Case Report and Literature Review.

  Chojdak-Łukasiewicz J, Dziadkowiak E. Chojdak-Łukasiewicz J, et al. J Clin Med. 2024 Feb 28;13(5):1373. doi: 10.3390/jcm13051373. J Clin Med. 2024. PMID: 38592219 Free PMC article. Review.

• To be or not to be hallucinating: Implications of hypnagogic/hypnopompic experiences and lucid dreaming for brain disorders.

  Foffani G. Foffani G. PNAS Nexus. 2023 Dec 19;3(1):pgad442. doi: 10.1093/pnasnexus/pgad442. eCollection 2024 Jan. PNAS Nexus. 2023. PMID: 38178978 Free PMC article.

Publication types

MeSH terms

LinkOut - more resources

• Full Text Sources

  • Elsevier Science

• Other Literature Sources

  • scite Smart Citations

• Medical

  • MedlinePlus Health Information