Bilateral thoracic sympathectomies or sympathotomies are done for refractory palmar hyperhidrosis [85–87]. Iontophoresis, botulinum toxin injection, and glycopyrrolate cream are alternatives. Because sweating is mediated mainly by sympathetic cholinergic fibers, autonomic neurosurgery is usually effective; however, a variety of expected and unexpected consequences can result, including ectopic (e.g., plantar) hyperhidrosis, gustatory sweating, Horner syndrome, and decreased heart rate responses to exercise. The latter seems to be related to partial cardiac denervation [88]. Anecdotally, fatigue, altered mood, blunted emotion, and decreased ability to concentrate can develop after bilateral thoracic sympathectomies.
β-Adrenoceptor blockers are a mainstay of treatment for CPVT. An automated defibrillator may have to be implanted. Treatment for CPVT also includes left sympathectomy. Such treatment leaves open the theoretical possibilities of denervation supersensitivity of cardiac adrenoceptors and compensatory activation of the adrenomedullary hormonal system; however, plasma levels of catecholamines have not been assessed in CPVT with or without therapeutic cardiac denervation.
Table 1. Neurocardiologic disorders that feature abnormal catecholaminergic function
Adie's syndrome Dopamine-β-hydroxylase deficiency
Sympathectomy
Disorders where abnormal catecholaminergic function is etiologic Hypofunctional states without central neurodegeneration
Acute, primary
Neurocardiogenic syncope Spinal cord transection Acute pandysautonomia Sympathectomy
Acute, secondary
Drug-related (e.g., alcohol, tricyclic antidepressant, chemotherapy, opiate, barbiturates, benzodiazepines, sympatholytics, general anesthesia)
Seizures
Guillain–Barre syndrome Alcohol
Acute, primary
Neurocardiogenic syncope Spinal cord transection Acute pandysautonomia Sympathectomy
Acute, secondary
Drug-related (e.g., alcohol, tricyclic antidepressant, chemotherapy, opiate, barbiturates, benzodiazepines, sympatholytics, general anesthesia)
Seizures
Guillain–Barre syndrome Alcohol
Chronic, primary
Pure autonomic failure
Horner's syndrome
Familial dysautonomia
Carotid sinus syncope
Horner's syndrome
Familial dysautonomia
Carotid sinus syncope
Sympathectomy