Lupus patients are said to have acquired autonomic neuropathy and it is generally seconday. Rheumatoid arthritis, systemic lupus erythematosus, and connective tissue disorders are some of the underlying causes for secondary autonomic neuropathy. Autonomic neuropathy is a type of peripheral neuropathy that affects involuntary body functions, including heart rate, blood pressure, perspiration, digestion and other processes. Instead of a specific disease, autonomic neuropathy refers to damage to the autonomic nerves that results in a variety of signs and symptoms. This damage disrupts signals between the brain and portions of the autonomic system such as the heart, blood vessels and sweat glands, resulting in decreased or abnormal performance of one or more involuntary body functions.
Initial laboratory tests usually should include a complete blood count, basic metabolic panel, liver function testing, and immunoelectrophoresis. More specific testing will then be based upon your history and underlying medical condition. Tests that your doctor may use to aid in diagnosis will help to evaluate the reaction of several body functions controlled by the autonomic nervous system and can include:
Breathing tests; Tilt-table test; Gastrointestinal tests; Quantitative sudomotor axon reflex test (QSART)[This test evaluates how the nerves that regulate your sweat glands respond to stimulation]; Thermoregulatory sweat test [During this test, you're coated with a powder that changes color when you sweat. You then enter a chamber with slowly increasing temperature. It causes your body temperature to increase 1 to 1.5 degrees Celsius, which makes most people sweat. Digital photos document the results. Your sweat pattern may help confirm a diagnosis of autonomic neuropathy or other causes for decreased or increased sweating.]; Urinalysis; Ultrasound.
Based upon the findings after the above evaluation and clinical situation, more specific tests may be considered.
* Additional blood tests may be considered based upon the clinical history and findings on autonomic testing.
* Oral glucose tolerance test may be done in order to evaluate for diabetes mellitus, if an initial serum glucose level is normal or nondiagnostic.
* Testing for SS-A and SS-B if there is concerns for Sjögren syndrome (Sicca syndrome).
* Anti-ganglionic acetylcholine receptor (AChR) autoantibodies if the onset was acute to subacute in nature.
* Specific genetic tests for the familial forms of dysautonomia can be ordered.
* Specific tests for infections, inflammatory, autoimmune, and paraneoplastic causes can be ordered based upon the Lupus history.
* Measurement of basal plasma norepinephrine levels can be used in specific forms of autonomic neuropathy. In pandysautonomia, basal norepinephrine levels are low and do not rise on head-up tilt table testing. Following an overnight supine position, low norepinephrine levels can be found in patients with POTS.
* A history of neuropathy, mental status changes, and abdominal pain will usually prompt your doctor to evaluate you for acute intermittent porphyria. In cases of suspected porphyria, high levels of porphobilinogen and delta-aminolevulinic acid can be found in urine during acute episodes.
* Evaluation of your cerebrospinal fluid (CSF) via lumbar puncture has been used in specific cases.
In pandysautonomia, CSF protein is elevated, as is CSF enolase, which may indicate damage to the dorsal root ganglia. However, abnormal CSF protein is not specific for autoimmune, inflammatory, or infectious causes of autonomic neuropathy, such as Lupus.
* SPECT and PET scanning may identify cardiac dysfunction in both type I and type II diabetes mellitus.
Peripheral neuropathy is disorder of nerve(s) apart from the brain and spinal cord. Poeople with peripheral neuropathy may have tingling, numbness, unusual sensations, weakness, or burning pain. Autoimmune diseases, including lupus, rheumatoid arthritis or Guillain-Barre syndrome, can cause peripheral neuropathy. Peripheral neuropathy isn't a single disease, but rather a symptom with many potential causes. For that reason it can be difficult to diagnose. To help in the diagnosis, your doctor will likely take a full medical history and perform a physical and neurological exam that may include checking your tendon reflexes, your muscle strength and tone, your ability to feel certain sensations, and your posture and coordination. Your doctor may also request blood tests to check your: Vitamin levels, Thyroid function, Blood sugar levels, Liver function, and Kidney function. These tests could include:
* Electromyography - This test measures the electrical signals in peripheral nerves, and the transfer of that signal to muscles.
* Nerve biopsy - Your doctor may recommend a nerve biopsy, a procedure in which a small portion of a nerve is removed and examined for abnormalities. But even a nerve biopsy may not always reveal what's damaging your nerves.
* Imaging tests - Your doctor may also request a CT scan or MRI to look for herniated disks, tumors or other abnormalities.
I hope that I've answered your question. Please let me know if you need any more information.
Peace and Blessings