Chemosensory Rehabilitation
Margarete Di Benedetto, MD
The awareness of an odor is based on the combined function of the olfactory and 
trigeminal systems. Cranial nerve (CN) I serves to recognize and differentiate a large number of different fragrances, while CN V conducts the sensory modalities which significantly influence the quality of the experience.
With age the acuity of the sense of smell diminishes, but with certain nasal and neuro-degenerative diseases or neural injuries this loss is much accentuated, frequently to the point of total anosmia, usually with preservation of the trigeminal system. The anatomical as well as physiological closeness of olfactory pathways with other vital functions, especially 
memory and emotion largely processed in the limbic system structures, is the basis of significant impairment in anosmia. This is not fully appreciated nor is the ensuing disability recognized. This is expressed in the comprehensive physical examination reports of “CN II-XII” intact. Yet, 16 million Americans suffer from taste and smell disorders.
There are three separate modalities tested for a psychophysical smell test:
1. Odor Threshold
2. Odor Discrimination
3. Odor Identification
Much information can be gathered by these clinical evaluations. Early recognition of olfactory 
function decline will be especially rewarding if effective treatment of this deficit becomes a reality.
Chemosensory research within the department of Physical Medicine and Rehabilitation has engaged in the development of an olfactory sensitivity training program to minimize or at least delay olfactory dysfunction in subjects who are losing the sense of smell. It is hoped that this will also have positive influences on memory and emotions. We have also investigated olfactory dysfunction related to Parkinson’s disease, high spinal cord Injuries, and chronic medical illness. Research interests have also included olfactory performance in soccer players and football players with histories of multiple concussions or any other sport injuries involving head insult.