Involvement of medullary regions controlling sympathetic output in Lewy body disease.
We sought to determine the involvement of medullary regions controlling sympathetic output in pathologically confirmed diffuse Lewy body disease (LBD). We studied eight limbic or neocortical stage LBD and eight multiple system atrophy (MSA) cases, confirmed neuropathologically, and eight age-matched controls. Five of the LBD cases and all MSA cases had orthostatic hypotension. Serial 50-mum sections obtained from the medulla rostral to the obex were immunostained for tyrosine hydroxylase, tryptophan hydroxylase and alpha-synuclein. Analysis was focused on the ventrolateral medulla and medullary raphe nuclei. In LBD cases, there were Lewy bodies and neurites, as well as dystrophic neurons in the ventrolateral medulla, but the number of catecholaminergic and serotonergic neurons was not significantly reduced. All these groups were depleted in MSA. There were Lewy body pathology and dystrophic neurons in the raphe in all LBD cases. Cell numbers were reduced in both the raphe obscurus and raphe pallidus. Our findings suggest that, although LBD affects medullary autonomic areas, it does so less severely than MSA, particularly in the case of the VLM, which controls sympathetic outputs maintaining arterial pressure. In LBD, orthostatic hypotension may be due primarily to involvement of sympathetic ganglion neurons rather than ventrolateral medulla neurons.
Benarroch
Eduardo E
EE
Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA. benarroch.eduardo@mayo.edu
Schmeichel
Ann M
AM
Low
Phillip A
PA
Boeve
Bradley F
BF
Sandroni
Paola
P
Parisi
Joseph E
JE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000209:etiology; D016631:Lewy Bodies / Q000473:pathology; D020961:Lewy Body Disease / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008526:Medulla Oblongata / Q000473:pathology*; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D011903:Raphe Nuclei / Q000473:pathology; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D014365:Tryptophan Hydroxylase / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D014446:Tyrosine 3-Monooxygenase; D014365:Tryptophan Hydroxylase