Clinical Trial Summary
Study context:
The literature identifies more and more research revealing olfactory disorders, with a high
frequency after an acquired brain injury. So far, studies have mainly focused on
post-traumatic and post-infectious olfactory disorders of the upper airways. There is scarcer
data available on the olfactory disorders occurring after stroke. A recent study found 43.6%
of patients with a loss of olfactory function after a stroke (2). This type of disorder can
have repercussions in everyday life and endanger people, not being able to smell a burning
odor or gas fumes. In addition, patients frequently describe loss of pleasure associated with
these olfactory disorders (3). Tests allowing the evaluation of these difficulties exist but
remain little used in clinical routine (4). These psychophysical tests allow a quantitative
analysis of the olfactory capacities of subjects through various measures such as the
detection threshold (T SST sub-score), discrimination (D SST sub-score) or the identification
of an odor. (SST sub-score I). Some studies have shown a reduction in olfactory disturbances
following specific training. Thus, Hummel et al. proposed a self-stimulation protocol to
patients whose olfactory dysfunction was due to various aetiologies (post-infectious,
post-traumatic or idiopathic) (5). People were to smell 4 scents twice a day for 12 weeks.
The results show an improvement in the olfaction of the patients, while no change was noted
in the subjects who did not perform the training. Lehrer et al. obtained similar results in
patients with head trauma (CT) after 3 months of training (6). However, no study has looked
at the effect of specific olfaction training in post-stroke patients. The few data available
in the literature suggest that these disorders are common after stroke.
Objectives :
We propose an open, randomized controlled study, comparing the SST score between the group of
patients who received olfactory training and the group who received standard rehabilitation.
Material and methods :
In the treatment of post-stroke olfactory disorders, we will suggest to patients hospitalized
in SSR or followed in consultation to participate in a controlled, randomized open study.
All included patients will be assessed using the SST and the modified ASOF quality of life
questionnaire (7). After randomization, patients in the treatment group will benefit from a
presentation of specific olfaction training. This training consists of smelling 4 scents
twice a day using scent sticks, for 12 weeks. At the end of these 12 weeks, a post-protocol
evaluation including the SST, the modified ASOF quality of life questionnaire and a
measurement of any side effects related to training will be offered.
Hypothesis tested:
The aim of this work is to evaluate the effectiveness of a specific olfaction training
protocol in patients with olfaction disorders following stroke.
