This post is prompted by parkie13's description of blood pressure
extremes. Is it possible that the BP extremes Mary described are being
induced by PD pathology and not by more common causes? Damage to the
locus coeruleus (aka ceruleus) often precedes and may
exceed damage to the substantia nigra. In PD, more than dopamine merits
attention.
healthunlocked.com/parkinso...
"recent evidence suggests that LP in the locus coeruleus (LC), the
brain's main source of norepinephrine (NE), precedes that of the SN,
and, may be one of the very first etiological events in PD."
Targeting the
norepinephrinergic system in Parkinson's disease and related
disorders: The locus coeruleus story.
ncbi.nlm.nih.gov/pubmed/278...
See text excerpt in image.
Neuronal loss
is greater in the locus coeruleus than nucleus basalis and
substantia nigra in Alzheimer and Parkinson diseases.
jamanetwork.com/journals/ja...
"Because PD involves postganglionic sympathetic noradrenergic lesions,
the disease seems to be not only a movement disorder with dopamine loss
in the nigrostriatal system of the brain, but also a dysautonomia, with
norepinephrine loss in the sympathetic nervous system of the heart."
"These findings suggest that, in PD, orthostatic hypotension results
from the disease process, not the treatment, although drugs that
directly or indirectly produce vasodilation can worsen orthostatic
tolerance and decrease blood pressure when the patient stands."
Dysautonomia in Parkinson disease.
ncbi.nlm.nih.gov/pmc/articl...
The noradrenaline transporter as site of action for the anti-Parkinson drug amantadine.
ncbi.nlm.nih.gov/pubmed/221...
"Non-motor aspects of Parkinson disease (PD) are now recognized to be
important both clinically and scientifically. Among these facets are
abnormalities in blood pressure regulation. As much as 40% of PD
patients have orthostatic hypotension (OH), which is usually associated
with supine hypertension (SH). Symptoms of OH range from
light-headedness to falls with serious trauma. SH, while typically
asymptomatic, poses a significant increased risk for cardiovascular
morbidity and mortality. Neuroimaging, neurochemical, and
neuropharmacological studies indicate cardiac and extra-cardiac
sympathetic noradrenergic denervation and baroreflex failure in
virtually all PD patients with OH, and cardiac sympathetic denervation
has been confirmed histopathologically."
Mechanisms of orthostatic hypotension and supine hypertension in Parkinson disease.
ncbi.nlm.nih.gov/pmc/articl...