SNIFFING BEHAVIOR, OR RECOGNIZING A LILY BY SMELL, BUT NOT RECOGNIZING A SOCK ON SIGHT

We report a 65-year-old man with a post-anoxic encephalopathy who show ed compulsive sniffing at available objects, This stereotyped environm ent-driven behaviour has not been previously described. Other compulsi ve environment-driven responses, such as manipulation and utilization of tools and hyperlexia, were also present. The disorder shared severa l features with the Kluver-Bucy syndrome where mouthing of objects, ra ther than smelling them, is common. The patient had a severe dementia, with amnesia, anemia, apraxia, and visual agnosia. Whereas he could n ot recognize very familiar objects on sight, he could in contrast corr ectly identify several familiar odours. Although sniffing was a compul sive and purposeless environment-driven behaviour, the question may be asked whether a relatively preserved olfactory recognition, in the pr esence of a severe disorder of visual recognition and knowledge, could have favoured a stereotyped exploration of objects by smelling.