Incidental Lewy body disease: do some cases represent a preclinical stage of dementia with Lewy bodies?
Lewy pathology occurs in 8-17% of neurologically normal people age >60, termed incidental Lewy body disease (iLBD). It is often assumed to represent preclinical Parkinson disease (PD). However, some iLBD cases have diffuse pathology inconsistent with preclinical PD. We analyzed iLBD cases (α-synuclein immunohistochemistry) using the Braak PD staging scheme and determined if some had a neuropathological pattern suggestive of preclinical dementia with Lewy bodies (DLB). Of the 235 brains examined, 34 had iLBD (14.5%) and all but one could be assigned a Braak PD stage. The distribution of α-synuclein pathology in the 33 cases fell into three patterns: (1) diffuse cortical and subcortical α-synuclein pathology; (2) no cortical α-synuclein pathology, but a caudal-to-rostral ascending pattern, primarily involving brainstem; and (3) intermediate between these two categories. Also, 6/33 cases failed to follow the pattern of contiguous spread proposed by Braak. These findings suggest dichotomy in the distribution of iLBD: some cases fit the Braak ascending scheme, conceptually consistent with preclinical PD, whereas others displayed prominent cortical involvement that might represent preclinical DLB.
Frigerio
Roberta
R
Department of Neurology, Mayo Clinic, Rochester, MN, United States.
Fujishiro
Hiroshige
H
Ahn
Tae-Beom
TB
Josephs
Keith A
KA
Maraganore
Demetrius M
DM
DelleDonne
Anthony
A
Parisi
Joseph E
JE
Klos
Kevin J
KJ
Boeve
Bradley F
BF
Dickson
Dennis W
DW
Ahlskog
J Eric
JE
D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology; D003704:Dementia / Q000473:pathology*; D005260:Female; D006801:Humans; D016631:Lewy Bodies / Q000473:pathology*; D020961:Lewy Body Disease / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology; D012189:Retrospective Studies; D051844:alpha-Synuclein / Q000302:isolation & purification
D051844:alpha-Synuclein