Frequently Asked Questions on the Autonomic Nervous System Testing
Autonomic Nervous System Testing software assessment follow the diagnosis guidance of the Cardiac Autonomic Neuropathy (CAN) Subcommitee of the Toronto Consensus Panel on Diabetic Neuropathy.
Methods of CAN assessment in clinical practice include assessment of symptoms and signs, and Cardiac autonomic reflex tests (CARTs) based on heart rate, blood pressure and Sudomotor responses.
The Gold standard CARTs includes the heart rate variability and Ewing tests such as heart rate response to deep breathing, standing and Valsalva manoeuvre, and blood pressure response to standing. In addition the sudomotor response is recommended.
The CARTs score is calculated with the Jermendy Scoring System
Each Test is scored 0 =normal, 1= borderline and 2= abnormal.
* Medications that significantly affect autonomic testing results:
Chlorpromazine, thioridazine (Effects: Anticholinergic, antiadrenergic) ;Tricyclic antidepressants (Effect: Anticholinergic); Bupropion, mirtazepine, venlafaxine (Effect: NE reuptake inhibitors); Clonidine (Effect: Alpha-blocking agent); Alpha-blockers, beta-blockers, Ca-channel blockers (Effects: Alter vasomotor tone and responses); Opiates (Effects: Intoxication: smooth muscle relaxation, histamine release. Withdrawal hyperadrenergic state);Topical capsaicin (Effect:Altered skin vasomotor responses)
Can the test be performed on children?
Children cannot be tested with Autonomic Nervous System Testing. Children have a different normal test range, and the devices are not calibrated for this population. More studies with children need to be performed to determine the normal test ranges.
Frequently Asked Questions on the Autonomic Nervous System Testing
How is sudomotor dysfunction treated?
In case of diagnosed disease, the first treatment step is to treat the underlying associated disease to help prevent further nerve damage.
Studies suggest that alpha‐lipoic acid (an antioxidant) and/or Pycnogenol , B12 vitamins*, and evening primrose oil may help relieve symptoms, improve microcirculation, and improve nerve function in some patients.
* Notes : B12 Vitamins supplement can affect the reading of Hb1Ac
How long does it take to perform the test?
It take 2 minutes to perform the test(s) with the Autonomic Nervous System Testing and 7-10 minutes with the Autonomic Nervous System Testing.
How is peripheral neuropathy diagnosed?
More than 100 types of peripheral neuropathy have been identified, each with its own symptoms and prognosis. In general, peripheral neuropathies are classified according to the type of damage to the nerves. Some forms of neuropathy involve damage to only one nerve and are called mononeuropathies. More frequently however, multiple nerves are affected, called polyneuropathy.
The symptoms of peripheral neuropathy are highly variable. A thorough neurological examination is required to sort out the cause of the symptoms and involves taking an extensive medical history (covering symptoms, work environment, social habits, exposure to toxins, alcohol use, risk of HIV or other infectious diseases, and family history of neurological diseases). In addition, tests are usually performed to identify the cause of the neuropathy as well as the extent and type of nerve damage.
Based on the results of the neurological exam, physical exam, patient history, and any previous screening or testing, the following additional tests may be ordered to help determine the nature and extent of the neuropathy:
– Nerve conduction study (NCS) assesses large motor nerves.
– Electromyography (EMG) tests detect abnormal electrical activity in motor neuropathy and can help differentiate between muscle and nerve disorders.
– Magnetic resonance imaging (MRI) can show muscle quality and size, detect fatty replacement of muscle tissue, and can help rule out tumors, herniated discs, or other abnormalities that may be causing the neuropathy.
– Nerve biopsy test can provide valuable information about the degree of nerve damage, it is an invasive procedure that is difficult to perform and may itself cause neuropathic side effects.
Frequently Asked Questions on the Autonomic Nervous System Testing
– Nerve conduction study (NCS) assesses large motor nerves.
– Electromyography (EMG) tests detect abnormal electrical activity in motor neuropathy and can help differentiate between muscle and nerve disorders.
– Magnetic resonance imaging (MRI) can show muscle quality and size, detect fatty replacement of muscle tissue, and can help rule out tumors, herniated discs, or other abnormalities that may be causing the neuropathy.
– Nerve biopsy test can provide valuable information about the degree of nerve damage, it is an invasive procedure that is difficult to perform and may itself cause neuropathic side effects.
– Skin biopsy test offers some unique advantages over NCV tests and nerve biopsy. Unlike NCV, it can reveal damage present in smaller fibers; in contrast to conventional nerve biopsy, skin biopsy is less invasive, has fewer side effects, and is easier to perform.
– Vibration (biothesiometer) measures the function of large myelinated A-alpha and A-beta sensory fibers.
– Thermal stimulation (monofilament) devices are used to evaluate the pathology of small myelinated nerve fibers; they can be used to assess heat sensation as well as thermal pain thresholds. and
– The Sudomotor test measures the small unmyelinated nerve fibers (cholinergic fibers or C-Fibers).
Using some of the above tests, different scoring systems have been developed to diagnose peripheral neuropathy such as Neurological symptom score (NSS), neuropathy symptom profile (NSP) , diabetic neuropathy symptom score (DNS),Neuropathy disability score (NDS) and neuropathic impairment score in the lower limbs (NIS-LL),Diabetic neuropathy examination (DNE), Clinical neurological examination (CNE), Michigan neuropathy screening instrument (MNSI), Toronto clinical scoring system (TCSS) and Utah Early Neuropathy Scale (UENS).