Degeneration of cardiac sympathetic nerve can occur in multiple system atrophy

Abstract

Decreased cardiac uptake of meta-iodobenzylguanidine (MIBG) on [(123)I] MIBG myocardial scintigraphy, a sensitive biological marker for Parkinson's disease (PD), is related to cardiac sympathetic denervation in patients with PD. A slight decrease in cardiac uptake of MIBG has also been reported in some patients with multiple system atrophy (MSA). However, the pathophysiological mechanism accounting for the slight decrease in MIBG uptake in MSA remains to be elucidated. For confirmation, we examined cardiac tissue and sympathetic ganglia from patients with MSA. We immunohistochemically examined each specimen of 15 patients with MSA together with 10 control subjects using antibodies against tyrosine hydroxylase (TH) and neurofilament (NF). The number of TH-immunoreactive nerve fibers in the epicardium was preserved in 8 of 15 patients with MSA as well as in 10 control subjects. The number of TH-immunoreactive, but not of NF-immunoreactive nerve fibers in the epicardium was mildly or moderately decreased in six patients with MSA, of whom four showed a decrease of TH immunoreactivity in the neuronal somata in the sympathetic ganglia. Moreover, TH- and NF-immunoreactive nerve fibers almost entirely disappeared in the heart of one patient with MSA, in whom Lewy body pathology was present in the sympathetic ganglia. These findings suggest that mild degeneration of the cardiac sympathetic nerve can occur in MSA which is closely related to the pathological change of neurons in the sympathetic ganglia, accounting for the slight decrease in cardiac uptake of MIBG. Moreover, concurrent Lewy body pathology in the sympathetic ganglia might accelerate cardiac sympathetic denervation even in MSA.

123I-MIBG myocardial scintigraphy for the evaluation of Lewy body disease: are delayed images essential? Is visual assessment useful?

“…Therefore, in LBD, as a consequence of the degeneration of the cardiac muscle sympathetic nerve, assessment of the distribution of this nerve on early images was considered useful. [10][11][12] Orimo et al 13 suggested that a decrease in myocardial 123 I-MIBG uptake in the early stage of LBD, a neurodegenerative disease, reflects the degeneration of the cardiac muscle sympathetic nerve.…”

Biomarkers to detect central dopamine deficiency and distinguish Parkinson disease from multiple system atrophy

“…Post-mortem histopathologic analyses have confirmed profound loss of tyrosine hydroxylase immunoreactivity in cardiac nerves [18][19][20]. In contrast, most (but not all) patients with MSA have normal cardiac sympathetic innervation [21].…”

Depletion or Preservation of Cardiac Sympathetic Nerve – An Autopsy-Verified Contrast in Two Cases of Alzheimer’s Disease with or without Lewy Bodies

“…This utility is being corroborated further by pathological observations that degeneration of the cardiac sympathetic nerve is closely related to the presence of Lewy bodies [13], progressive decrease in the heart/mediastinum ratio in Parkinson’s disease [14] and contrasting preservation of MIBG uptake and cardiac sympathetic fibers in multiple-system atrophy [15]. Because Lewy bodies and depletion of cardiac sympathetic nerve were both absent in case 2, MIBG cardiac scintigraphy, if performed, might have revealed normal uptake to indicate the absence of Lewy bodies.…”