- chemosensory disorders
- Also known as chemosensory deficits and disorders of taste and smell. Traditionally, the group of chemosensory disorders is divided into six broad categories of taste disorders and five categories of smell disorders. The group of taste disorders comprises ageusia, hypogeusia, *dysgeusia, *hypergeusia, *parageusia, and taste agnosia. The group of smell disorders comprises anosmia, hyposmia, *dysosmia (also referred to as parosmia), *hyperosmia, and smell agnosia. The history of taste and smell research, however, yields a rich legacy of additional terms, such as * gustatory hallucination, * olfactory hallucination, *phantosmia (which tends to be used as a synonym for olfactory hallucination), * cacosmia (bad smell), coprosma (the smell of faeces), * agathosma (good smell), crocosmia (the smell of saffron), and diosma (heavenly or divine smell). Etiologically, the chemosensory disorders are associated with a wide variety of conditions, including normal ageing, poor oral hygiene, Alzheimer's disease, local or general medical conditions such as rhinitis, oral candidiasis, nasal polyps, and influenza, as well as the use of certain therapeutics and illicit substances. Pathophysio-logically, the chemosensory disorders are associated with one of three major types of losses, referred to as transport losses, sensory losses, and neural losses. The term transport loss refers to the obstruction of chemical stimuli before these can reach the peripheral taste or smell receptors. Sensory losses are those attributed to damage to the sensory organs themselves. This damage may be caused by a variety of conditions, mechanisms, and substances, including therapeutics, toxic chemicals, radiation therapy, neoplasms, and viral infections. Neural losses are those resulting from damage to the peripheral and/or central neural pathways, including the cortical taste area, and the part of the temporal (primitive) cortex involved in the mediation of smell. Known causes of neural loss include head trauma, neoplasms, and neurosurgical procedures. The term sensori-neural loss is used when a clear distinction between a sensory and neural involvement cannot be made with certainty.ReferencesAckerman, B.H., Kasbekar, N. (1997). Disturbances of taste and smell induced by drugs. Pharmacotherapy, 17, 482—196.Schiffman, S.S., Gatlin, C.A. (1993). Clinical physiology of taste and smell. Annual Review of Nutrition, 13, 405-436.Stearn, W.T. (1993). The gender of the generic name onosma (Boraginaceae). Taxon, 42, 679-681.
Dictionary of Hallucinations. J.D. Blom. 2010.