from Section III - Assessment and Disorders of Olfaction
Published online by Cambridge University Press: 17 August 2009
Introduction
Traditional teaching in psychiatry has been that until proven otherwise the presence of olfactory, gustatory and visual hallucinations is a marker of underlying organic pathology. Visual hallucinations are seen in delirium or Lewy body disease, while olfactory and gustatory hallucinations raise the possibility of medial temporal pathology, especially epilepsy. The aims of this chapter are first to review the literature on olfactory hallucinations and second to discern any characteristics of olfactory hallucinations which allow those of organic aetiology to be distinguished from those of functional origin, such as those related to schizophrenia.
The subjective experience of olfactory phenomena in the absence of a stimulus has been generally referred to as an olfactory hallucination, though when experienced in the context of epilepsy the term olfactory aura has been preferred. In addition, other terms used to describe the same phenomenon have included olfactory reference syndrome, experiential hallucinations, and experiential responses. Each of these terms will be used in the course of this review and their origins explained. The available literature is replete with case series, case reports, highly selected populations and widely differing methods of assessment. While this limits the comparisons between studies, it is still possible to estimate the prevalence and nature of the olfactory hallucinations in many of the studies.
Epilepsy and olfactory auras
Numerous studies have examined groups of patients with regard to the presence and characteristics of olfactory hallucinations but there has been no attempt to standardise the descriptions across different studies, an understandably difficult task.
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.