New autonomic and sensory neuropathy with loss of adrenergic sympathetic function and sensory neuropeptides

Abstract

A 30-year-old woman with longstanding dizziness was found to have a severe postural fall in blood pressure and a reduced skin axon-reflex flare response. Autonomic tests indicated selective impairment of adrenergic sympathetic function. Plasma noradrenaline, adrenaline, dopamine, and dopamine beta hydroxylase were undetectable. Skin biopsy specimens showed loss of tyrosine hydroxylase and neuropeptide Y (markers of adrenergic sympathetic fibres) and of substance P and calcitonin gene-related peptide (sensory neuropeptides). A sural nerve biopsy specimen showed severe depletion of unmyelinated fibres. The constellation of losses were compatible with nerve growth factor (NGF) deprivation, which was confirmed on assay. This new syndrome may be explained by loss of trophic action of NGF.