Brain Injury Lawyer

The April 2011 Archives of Clinical Neuropsychology included two interesting studies dealing with olfactory (smell and taste) dysfunction.

The first study conducted in Bergen  Norway, investigated “the accordance of self-reported and objectively assessed olfactory functioning and to compare performance on cognitive tests on individuals unaware of the olfactory dysfunction with individuals aware of their olfactory status.”  The study was comprised of 240 participants, consisting of two age groups who were evaluated with the Scandinavian Odor Identification Test, a question of self-evaluated olfactory function, tests of cognitive function, and a memory questionnaire.  Olfactory function, as all sensory modalities, is often compromised by increased chronological age.  The research revealed that about 24% of all individuals in the sample were classified as having an olfactory dysfunction and interestingly, 81% of those were unaware of this dysfunction.  The authors noted “of particular interest was the finding that participants unaware of their olfactory dysfunction showed lower performance on neuropsychological measures compared to individuals with normal olfactory function.”  Similarly, this group also did poorer when compared to impaired individuals aware of their olfactory dysfunction.  Archives of Clinical Neuropsychology 26 (2011) 260-269

The results in the study support earlier findings showing that performance on cognitive measures of memory and attention/processing speed are linked to odor identification performance in old adults.

The authors concluded:

In summary, the present study reveals that unawareness of olfactory dysfunction increases with older age.  Middle age and old (non-demented) individuals unaware of their olfactory dysfunction performed more poorly on a number of cognitive tests in individuals aware of their olfactory status.  Based on our findings, we suggest that unawareness of olfactory dysfunction may be a rather normal phenomena in aging individuals, although the impact on everyday life needs to be determined.

In a second study, this one out of Poland, the researchers studied the effect of olfactory deficits in normal aging and Alzheimer’s  Disease  in the Polish elderly population.  The studies found that in both the AD patients and the elderly control group, odor identification ability correlated with performance in cognitive tests.  It may be concluded that deficits in olfactory identification incur in Alzheimer’s Disease and may be valuable as an indicator of this condition. 

For the neuro attorney, one of the important findings of these studies was the high prevalence of people with olfactory dysfunction who were unaware of their condition.  As we know, olfactory dysfunction is often seen as a residual of traumatic brain injury.  It is therefore important that neuro attorneys investigate the possibility that their client may have sustained an olfactory injury and that treating doctors specifically test for this dysfunction.  Archives of Clinical Neuropsychology 26 (2011) 270-279.