Autoimmune autonomic ganglionopathy
| Autoimmune autonomic ganglionopathy | |
|---|---|
| Classification and external resources | |
| Specialty | neurology |
| ICD-10 | G90.9, G13.0 |
Autoimmune autonomic ganglionopathy (AAG) is an extremely rare form of dysautonomia in which the patients immune system produces ganglionic AChR antibodies, inhibiting ganglionic AChR currents and impairing transmission in autonomic ganglia.[1] Approximately 100 Americans are diagnosed with AAG each year. Symptoms onset can be acute, subacute or gradual.
Signs and symptoms
Although symptoms of AAG can range from patient to patient, hallmark symptoms include:
- gastrointestinal dysmotility
- anhidrosis (decreased ability to sweat)
- bladder dysfunction (neurogenic bladder)
- small fiber peripheral neuropathy
- Severe orthostatic hypotension
- Pupillary dysfunction
- syncope (fainting)
- Sicca syndrome (chronic dryness of the eyes and mouth)
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.[3]
Causes
The cause is generally either paraneoplastic syndrome or idiopathic. In idiopathic AAG, the body's own immune system damages a receptor in the autonomic ganglia, which is part of a peripheral nerve fibre. If the AAG is paraneoplastic, they have a form of cancer, and their immune system has produced paraneoplastic antibodies in response to the cancer.[2]
Treatment
Where an underlying neoplasm is the cause, treatment of this condition is indicated in order 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, Cellcept, or Imuran or plasmapheresis.[4]
See also
- Myasthenia gravis
- Dysautonomia
- Postural Orthostatic Tachycardia Syndrome
- Orthostatic Hypotension
External links
References
- ↑ Steven Vernino, MD; Steve Hopkins & Zhengbei Wang, MD (2009). "Autonomic ganglia, acetylcholine receptor antibodies, and autoimmune ganglionopathy". Autonomic Neuroscience. 146 (1-2): 3–7. PMC 2677210
. PMID 18951069. doi:10.1016/j.autneu.2008.09.005. - 1 2 Paola Sandroni & Phillip A. Low (2009). "Other Autonomic Neuropathies Associated with Ganglionic Antibody". Autonomic Neuroscience. 146 (1-2): 13–17. PMC 2671239 . PMID 19058765. doi:10.1016/j.autneu.2008.10.022.
- ↑ "Autoimmune Autonomic Ganglionopathy".
- ↑ 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.