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Olfactory FMRI in patients with Parkinson's disease.

Hummel T, Fliessbach K, Abele M, Okulla T, Reden J, Reichmann H, Wüllner U, Haehner A - Front Integr Neurosci (2010)

Bottom Line: All participants received either unpleasant stimuli that smelled like rotten eggs or pleasant ones that smelled like roses.Olfactory function was established using the "Sniffin' Sticks" test battery.These results may partly reflect differences between PD patients and healthy controls in the processing of primary dimensions of odors, intensity, and valence.

View Article: PubMed Central - PubMed

Affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School Dresden, Germany.

ABSTRACT
Hyposmia is one of the early signs in idiopathic Parkinson's disease (PD). Olfactory stimuli were applied during fMRI scanning to show disease-related modulation of central nervous system structures and to advance our understanding of olfactory dysfunction in PD patients. All participants received either unpleasant stimuli that smelled like rotten eggs or pleasant ones that smelled like roses. Using a block design at a 1.5 T scanner we investigated a total of 8 PD patients (mean age 60 ± 10.9 years) and 13 age matched controls (mean age 58 ± 9.6 years). PD duration ranged from 1 to 9 years (mean 6.63 years); patients had an average "Unified Parkinson's Disease Rating Scale III" score of 23.25 (range, 6-46). Olfactory function was established using the "Sniffin' Sticks" test battery. Patients tended to rate the stimuli presented during fMRI scans as less intense, but also as more pleasant than controls. fMRI results revealed differences between PD patients and controls which depended on the type of stimulation. While both pleasant and unpleasant stimulation was associated with lower activation in the amygdalo-hippocampal complex in patients compared to controls, increased activity in response to pleasant stimuli was observed in the striatum and the left inferior frontal gyrus. In contrast, unpleasant stimulation led to hypoactivation of the ventral striatum in patients (but not in controls) and did not enhance left inferior frontal activity. These results may partly reflect differences between PD patients and healthy controls in the processing of primary dimensions of odors, intensity, and valence.

No MeSH data available.


Related in: MedlinePlus

Differential brain activation in controls and patients. (A) Group × type of stimulation interaction in the left caudate head (P < 0.05, FWE-corrected for search volume left caudate). MNI coordinates of peak voxel: x = −6, y = 15, z = 3. (B) Group × type of stimulation interaction in the left inferior frontal gyrus (P < 0.05, FWE-corrected for search volume left inferior frontal gyrus, pars triangularis). MNI coordinates of peak voxel: x = −54, y = 30, z=3. (C,D) Parameter estimates separately for patients and controls, both for the pleasant PEA and the unpleasant H2S, corresponding to A and B, respectively.
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Figure 2: Differential brain activation in controls and patients. (A) Group × type of stimulation interaction in the left caudate head (P < 0.05, FWE-corrected for search volume left caudate). MNI coordinates of peak voxel: x = −6, y = 15, z = 3. (B) Group × type of stimulation interaction in the left inferior frontal gyrus (P < 0.05, FWE-corrected for search volume left inferior frontal gyrus, pars triangularis). MNI coordinates of peak voxel: x = −54, y = 30, z=3. (C,D) Parameter estimates separately for patients and controls, both for the pleasant PEA and the unpleasant H2S, corresponding to A and B, respectively.

Mentions: There were significant group × stimulation type interactions in the striatum (caudate heads bilaterally and left NAcc) and in the left inferior frontal gyrus, pars triangularis. In the striatum (Figure 2A shows the results for the left caudate head as an example) controls did not show differential responses to the two stimulus types, whereas there was a highly significant difference in the control group with activation during stimulation with the pleasant odor and deactivation during stimulation with the unpleasant odor. In the left inferior frontal gyrus the significant interaction resulted from a highly positive response to the pleasant odor in the patients group which was not present for the unpleasant odor and for both odors in the control group (Figure 2).


Olfactory FMRI in patients with Parkinson's disease.

Hummel T, Fliessbach K, Abele M, Okulla T, Reden J, Reichmann H, Wüllner U, Haehner A - Front Integr Neurosci (2010)

Differential brain activation in controls and patients. (A) Group × type of stimulation interaction in the left caudate head (P < 0.05, FWE-corrected for search volume left caudate). MNI coordinates of peak voxel: x = −6, y = 15, z = 3. (B) Group × type of stimulation interaction in the left inferior frontal gyrus (P < 0.05, FWE-corrected for search volume left inferior frontal gyrus, pars triangularis). MNI coordinates of peak voxel: x = −54, y = 30, z=3. (C,D) Parameter estimates separately for patients and controls, both for the pleasant PEA and the unpleasant H2S, corresponding to A and B, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2991239&req=5

Figure 2: Differential brain activation in controls and patients. (A) Group × type of stimulation interaction in the left caudate head (P < 0.05, FWE-corrected for search volume left caudate). MNI coordinates of peak voxel: x = −6, y = 15, z = 3. (B) Group × type of stimulation interaction in the left inferior frontal gyrus (P < 0.05, FWE-corrected for search volume left inferior frontal gyrus, pars triangularis). MNI coordinates of peak voxel: x = −54, y = 30, z=3. (C,D) Parameter estimates separately for patients and controls, both for the pleasant PEA and the unpleasant H2S, corresponding to A and B, respectively.
Mentions: There were significant group × stimulation type interactions in the striatum (caudate heads bilaterally and left NAcc) and in the left inferior frontal gyrus, pars triangularis. In the striatum (Figure 2A shows the results for the left caudate head as an example) controls did not show differential responses to the two stimulus types, whereas there was a highly significant difference in the control group with activation during stimulation with the pleasant odor and deactivation during stimulation with the unpleasant odor. In the left inferior frontal gyrus the significant interaction resulted from a highly positive response to the pleasant odor in the patients group which was not present for the unpleasant odor and for both odors in the control group (Figure 2).

Bottom Line: All participants received either unpleasant stimuli that smelled like rotten eggs or pleasant ones that smelled like roses.Olfactory function was established using the "Sniffin' Sticks" test battery.These results may partly reflect differences between PD patients and healthy controls in the processing of primary dimensions of odors, intensity, and valence.

View Article: PubMed Central - PubMed

Affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School Dresden, Germany.

ABSTRACT
Hyposmia is one of the early signs in idiopathic Parkinson's disease (PD). Olfactory stimuli were applied during fMRI scanning to show disease-related modulation of central nervous system structures and to advance our understanding of olfactory dysfunction in PD patients. All participants received either unpleasant stimuli that smelled like rotten eggs or pleasant ones that smelled like roses. Using a block design at a 1.5 T scanner we investigated a total of 8 PD patients (mean age 60 ± 10.9 years) and 13 age matched controls (mean age 58 ± 9.6 years). PD duration ranged from 1 to 9 years (mean 6.63 years); patients had an average "Unified Parkinson's Disease Rating Scale III" score of 23.25 (range, 6-46). Olfactory function was established using the "Sniffin' Sticks" test battery. Patients tended to rate the stimuli presented during fMRI scans as less intense, but also as more pleasant than controls. fMRI results revealed differences between PD patients and controls which depended on the type of stimulation. While both pleasant and unpleasant stimulation was associated with lower activation in the amygdalo-hippocampal complex in patients compared to controls, increased activity in response to pleasant stimuli was observed in the striatum and the left inferior frontal gyrus. In contrast, unpleasant stimulation led to hypoactivation of the ventral striatum in patients (but not in controls) and did not enhance left inferior frontal activity. These results may partly reflect differences between PD patients and healthy controls in the processing of primary dimensions of odors, intensity, and valence.

No MeSH data available.


Related in: MedlinePlus