Autoimmune autonomic ganglionopathy
Autoimmune autonomic ganglionopathy is a type of immune-mediated autonomic failure that is associated with antibodies against the ganglionic nicotinic acetylcholine receptor present in sympathetic, parasympathetic, and enteric ganglia. Typical symptoms include gastrointestinal dysmotility, orthostatic hypotension, and tonic pupils.[1] Many cases have a sudden onset, but others worsen over time, resembling degenerative forms of autonomic dysfunction. For milder cases, supportive treatment is used to manage symptoms.[2] Plasma exchange, intravenous immunoglobulin, corticosteroids, or immunosuppression have been used successfully to treat more severe cases.[1]
| Autoimmune autonomic ganglionopathy | |
|---|---|
| Other names | Autoimmune autonomic neuropathy, Acute pandysautonomia |
 | |
| Functions of the autonomic nervous system. | |
| Specialty | Neurology  |
| Symptoms | Gastrointestinal dysmotility, orthostatic hypotension, and tonic pupils.[1] |
Signs and symptoms
Although symptoms of AAG can vary from patient to patient, symptoms are dysautonomia. Hallmarks include:
- Gastrointestinal dysmotility, including lack of appetite, nausea, constipation, diarrhea
- Anhidrosis (decreased ability to sweat), often preceded by excessive sweating
- Bladder dysfunction (neurogenic bladder)
- Small fiber peripheral neuropathy
- Severe orthostatic hypotension
- Pupillary dysfunction
- Syncope (fainting)
- Sicca syndrome (chronic dryness of the eyes and mouth) See: Xerostomia § Sicca syndrome
- No indication from the history or physical examination of cerebellar, striatal, pyramidal, and extrapyramidal dysfunction, as these features suggest the more serious multiple system atrophy.[3]
Causes
The cause is generally either paraneoplastic syndrome or idiopathic. In idiopathic AAG, the body's own immune system targets a receptor in the autonomic ganglia, which is part of a peripheral nerve fiber. If the AAG is paraneoplastic, they have a form of cancer, and their immune system has produced paraneoplastic antibodies in response to the cancer.[3]
Diagnosis
Traditional autonomic testing is used to aid in the diagnosis of AAG. These tests can include a tilt table test (TTT), thermoregulatory sweat test (TST), quantitative sudomotor autonomic reflex testing (QSART) and various blood panels. Additionally, a blood test showing high levels of the antibody ganglionic nicotenic acetylcholine receptor (gAChr) occur in about 50% of patients with AAG (seropositive AAG). The seronegative patients (those without detectable gAChR levels) are theorized to have one or more different antibodies responsible for the autonomic dysfunction. However, both seropositive and seronegative patients have been seen to respond to the same treatments. A paraneoplastic panel may also be ordered to rule out paraneoplastic syndrome.[4]
Treatment
Where an underlying neoplasm is the cause, treatment of this condition is indicated to reduce progression of symptoms. For cases without a known cause, treatment involves suppression of the immune system with corticosteroid treatment, intravenous immunoglobulin, immunosuppressive agents like rituximab, mycophenolate mofetil (Cellcept), or azathioprine (Imuran) or plasmapheresis.[5]
See also
References
- Winston, Nicole; Vernino, Steven (2009). "Autoimmune Autonomic Ganglionopathy". Frontiers of Neurology and Neuroscience. Basel: KARGER. p. 85–93. doi:10.1159/000212370. ISSN 1660-4431.
- Wang, Z.; Low, P. A.; Jordan, J.; Freeman, R.; Gibbons, C. H.; Schroeder, C.; Sandroni, P.; Vernino, S. (May 29, 2007). "Autoimmune autonomic ganglionopathy: IgG effects on ganglionic acetylcholine receptor current". Neurology. Ovid Technologies (Wolters Kluwer Health). 68 (22): 1917–1921. doi:10.1212/01.wnl.0000263185.30294.61. ISSN 0028-3878.
- Paola Sandroni & Phillip A. Low (2009). "Other Autonomic Neuropathies Associated with Ganglionic Antibody". Autonomic Neuroscience. 146 (1–2): 13–17. doi:10.1016/j.autneu.2008.10.022. PMC 2671239. PMID 19058765.
- Vernino, Steven; Low, Phillip A. (2012). "Autoimmune Autonomic Ganglionopathy". Primer on the Autonomic Nervous System. pp. 489–492. CiteSeerX 10.1.1.657.2841. doi:10.1016/B978-0-12-386525-0.00100-1. ISBN 9780123865250.
- Christopher H. Gibbons, MD, MMSc; Steven A. Vernino, MD & Roy Freeman, MD (2007). "Combined Immunomodulatory Therapy in Autoimmune Autonomic Ganglionopathy". Arch. Neurol. 65 (2): 213–217. doi:10.1001/archneurol.2007.60. PMID 18268189.
{{cite journal}}: CS1 maint: multiple names: authors list (link)