1. Assessing Impairments In Hedonic
Olfaction In Preclinical Parkinson’s
Individuals
Kiara T. Vann
Athanasia Moungou
Claro Ison
Katarzyna Kisiel-Sajewicz
2. Parkinson’s Disease
• Parkinson disease (PD) is a neurodegenerative
disorder, where there is a depletion of dopaminergic
neurons in the substania nigra
• Dopamine is necessary for smooth, coordinated
function of the body's muscles and movement.
3. Symptoms of Parkinson’s Disease
The key signs of Parkinson
disease are:
• Tremor (shaking)
• Slowness of movement
• Rigidity (stiffness)
• Difficulty with balance
• Olfactory Dysfunction
4. Olfaction
• Most mammals have two
distinct parts to their olfactory
system: a main olfactory system
and an accessory olfactory
system
• The major components of the
olfactory system : Olfactory
bulb ,Mitral cells Bone, Nasal
Epithelium ,Glomerulus and
Olfactory receptor cells
5. The General Question
• Is assessing impairments in hedonic olfaction: a
possible diagnostic tool for preclinical Parkinson’s
disease?
7. Selection Criteria
• Participants: 2 groups
• 1st group: Normosmic volunteers (healthy control, age
and sex matched)
• 2nd group: Patients with olfactory deficiency with
strong family history of Parkinson’s disease
• Sniffin’ Sticks test will be administered (odors are
presented using felt tip pens placed approximately 2 cm in
front of both nostrils)
• This test is used to determine olfactory threshold (T),
discrimination (D), and identification (I) scores --- TDI
score
8. Exclusion/Inclusion Criteria
• Individuals with disorders of the nasal cavities, who
had undergone surgery on the nasal septum,
turbinates or paranasal sinuses, patients with head
trauma, with neuro-psychiatric disorders were not
included in the study
9. The Specific Question
• We expect to find differences in the amplitude of the
elicited cortical responses for pleasant vs. unpleasant
odour stimuli
• We want to further characterise and investigate this
difference in the group with genetic tendency for
Parkinson’s
To address these questions, EEG/MEG will be used to
detect changes/activities
10. Stimulus and Conditions
• Three stimulus
• 1. pleasant odours (i.e. vanilla )
• 2. unpleasant odours (i.e. indole)
• 3. neutral (fresh air)
• randomized
• Each condition will be presented using an MEG
compatible olfactometer
11. A B C B
Baseline Baseline Baseline Baseline Baseline
20-30 s
200 ms
20-30 s
200 ms
20-30 s
200 ms
20-30 s
200 ms
20-30 s
…
Randomized Stimulus Presentation:
A: Pleasant
B: Unpleasant
C: Neutral
Instructions: Subjects are instructed to breathe through the
mouth without active sniffing
Timing Paradigm for EEG/MEG
12. EEG/MEG parameters
• MEG compatible EEG-70 channel system
• EEG and MEG will be recorded continuously
from 70 Ag/AgCl electrodes placed on the scalp.
• Ocular movements and eye-blinks will be
recorded using six additional bipolar surface
electrodes.
13. The Analysis Plan
Continuous EEG/MEG recordings will be segmented
into 2.0s long epochs ranging from -0.5 to +1.5s for
each condition relative to the stimulus onset.
- Event related potentials (ERPs) approach
- Complimentary Time Frequency analysis can be
found in the paper of Huart et al. 2012, Plos One
14. Predicted/Expected Results
• We expect to identify decreased amplitude of the
EEG/MEG responses elicited by olfactory
chemosensory stimulation in patients with preclinical
Parkinson’s compared to the control group
• The scalp topographies will give us an estimation of
the brain areas involved in olfactory processing
(pleasant vs. unpleasant odours)
15. Conclusion
• We believe that this study demonstrates the
possibility of hedonic olfaction as a preclinical
diagnostic tool for PD
