Regional differences in the severity of Lewy body pathology across the olfactory cortex.
We studied alpha-synuclein pathology in the rhinencephalon of ten cases of Parkinson's disease (PD) and twelve neurologically normal controls, of which seven had incidental Lewy bodies in the substantia nigra at autopsy and five had no pathological evidence of neurological disease. In all PD and incidental Lewy bodies cases, alpha-synuclein pathology was found in all five subregions of the primary olfactory cortex that were sampled, and amongst them the pathology was significantly more severe in the temporal division of the piriform cortex than in the frontal division of the piriform cortex, olfactory tubercle or anterior portions of the entorhinal cortex. The orbitofrontal cortex, which is an area of projection from the primary olfactory cortex, was affected in some cases but overall the alpha-synuclein pathology was less severe in this area than in the primary olfactory cortex. Because different areas of the rhinencephalon are likely to play different roles in olfaction and our data indicate a differential involvement by alpha-synuclein deposition of structures implicated in smell, future prospective studies investigating the pathophysiological basis of hyposmia in PD should consider to examine the areas of primary olfactory cortex separately.
Reta Lila Weston Institute for Neurological Studies, UCL Institute of Neurology, London, UK.
Laura
L
Silveira-Moriyama
Janice L
JL
Holton
Ann
A
Kingsbury
Hilary
H
Ayling
Aviva
A
Petrie
William
W
Sterlacci
Werner
W
Poewe
Hans
H
Maier
Andrew J
AJ
Lees
Tamas
T
Revesz
D000704:Analysis of Variance; D001344:Autopsy; D018728:Entorhinal Cortex / Q000737:chemistry; D005625:Frontal Lobe / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D020961:Lewy Body Disease / Q000473:pathology*; D009833:Olfactory Pathways / Q000737:chemistry*; D010300:Parkinson Disease / Q000473:pathology*; D013378:Substantia Nigra / Q000737:chemistry; D051844:alpha-Synuclein / Q000032:analysis*
D051844:alpha-Synuclein