Description and analysis of olfactory disorders after head trauma

Olfactory disorders subsequent to head trauma can raise medicolegal problem s when the olfactory deficit occurs after a work accident or a traffic acci dent and also raises the problem of psychological and functional tolerance when the patient consults late for a therapeutic solution. We studied the e pidemiology of olfactory disorders after head trauma. Such disorders have b een recognized since the XIXe century Several studies have attempted to det ermine the prevalence of olfactory sequelae after head trauma. We then desc ribe the pathophysiology of these lesions and emphasize that the degree of severity is related with the gravity of the head trauma and that the prevel ence of these disorders varies considerably depending on the site of the tr auma. Mechanisms which can lead to lesions of the olfactory system include, damage to the olfacory nerve bundles, naso-sinus lesions, or lesions of th e cerebral olfactory centers. Brain MRI in anosmic patients after head trau ma allows a visualization of intracranial lesions. The degree of reversibility of olfactory disorders after head trauma is imp erfectly evaluated and discordant results have been reported. Some authors consider loss of olfaction is definitive. Others suggest an improvement in olfaction the year following head trauma. We reviewed the literature on the se different elements. Expert opinions concerning patients complaining of o lfactory disorders should relate this disorder to the initial trauma and de termine the personal and occupational impact of the deficit Attribution of cause must take into account all the clinical, radiological and psyche-olfa ctory Factors.