1. Sudoscan An Overview

2. Objectives What is SUDOSCAN How does SUDOSCAN work
Benefits of utilizing SUDOSCAN
American Diabetes Association Screening Mandate
Billing and Reimbursement
Next Steps

3. SUDOSCAN in clinical practice
A critical tool in the era moving more to preventive medicine
Regular AN screening is now mandated by the ADA in the DM population
SUDOSCAN is the easiest, most practical tool for AN screening in ANY patient population
Diabetic peripheral neuropathies are among the most frequent complications of diabetes mellitus, affecting up to 70% of patients over a lifetime.
Diabetic sensorimotor polyneuropathy is insidious and up to 50% of patients with neuropathy may be asymptomatic
An objective assessment in cases of unclear neuropathy
Patients with no clinical exam abnormalities complaining of severe pain or burning

4. How does SUDOSCAN work?
SUDOSCAN is an innovative technology used to assess sudomotor function and how it relates to peripheral autonomic neuropathies
A non-invasive device which quickly assesses sudomotor (sweat gland) function via Reverse Iontophoresis and Chronoamperometry
Sudomotor function is used as a marker for small fiber peripheral neuropathy
Abnormal sweat response is often associated with populations at risk for diabetes
Iontophoresis: using an electric charge to open up skin pores for a drug to enter through the skin; reverse iontophoresis: using a small electric charge to draw OUT ions (in our case chloride) from the sweat glands
Chronoamperometry: incremental step up of the electric charge used to measure the current produced
The device consists of a computer with touch screen display in which the data is entered, measured, and stored; and two sets of stainless steel electrode plates

5. What is SUDOSCAN? No Patient preparation Easy to use Fast
Immediate results
Quantitative
Reproducible
Iontophoresis: using an electric charge to open up skin pores for a drug to enter through the skin; reverse iontophoresis: using a small electric charge to draw OUT ions (in our case chloride) from the sweat glands
Chronoamperometry: incremental step up of the electric charge used to measure the current produced
The device consists of a computer with touch screen display in which the data is entered, measured, and stored; and two sets of stainless steel electrode plates

6. Benefits of Sudoscan
There is currently no other tool on the market that is as easy to use, as fast and clinically proven to be as accurate as Sudoscan to test for:
Initial evaluation of autonomic neuropathy/autonomic symptoms
Evaluation of peripheral small fiber neuropathy, especially painful peripheral neuropathy
There is currently no other sudomotor function test on the market that is as cost-effective as Sudoscan while also rigorously clinically proven to be medically accurate

7. Why Test Sweat Gland Function?
Sweat glands are innervated by long and small sympathetic C-fibers within the peripheral nervous system. Sweat dysfunction can be one of the earliest detectable neurophysiologic abnormalities in small fiber neuropathies
The bottom line: Structure and Function
Sweat glands don’t just decide independently to produce sweat; they are each attached to a nerve ending which commands them. If sweat glands don’t sweat correctly, there’s something wrong with the nerves controlling them

8. Sudorimetry
Measuring sweat gland function as a biomarker for ANS function
Sympathetic innervation
Thin, unmyelinated C-fibers: no protective coating – easily damaged
Long: from spine to soles of feet: sensitive to length-dependent damage (dying back disorders)
Therefore sweat dysfunction will be the first detectable damage to the small fibers of the peripheral nervous system – BEFORE ANY CLINICAL SIGNS OR SYMPTOMS
Sudorimetry is the measurement of sweat gland function for assessment of the autonomic nervous system.
Sweat glands are innervated by small sympathetic unmyelinated C-fibers.
Because these fibers are so small, they are exquisitely sensitive to metabolic derangements.
Because these fibers can be very long (soles of the feet), they are often the first to suffer retroactive damage
Illigens et al. Clin Auton Res 2009

9. What is SUDOSCAN used for?
Screening tool for autonomic neuropathy (AN), which can affect: heart, BP, GI tract, GU functions
Causes severe morbidity and reduced quality of life if symptomatic:
In diabetes, symptoms can be: gastroparesis, nocturnal diarrhea, overflow incontinence, erectile dysfunction, erratic blood glucose, recurrent UTI or pyelonephritis, abnormal sweating (dry feet but gustatory sweating)
Other patients may experience: exercise intolerance (no HR response), orthostatic hypotension, dizziness, faintness, headaches
The greatest risk of AN is when it affects the heart: cardiac autonomic neuropathy
Increased morbidity, mortality with CAN
Prevalence as high as 60% in long-standing T2DM
CAN is always present if GI or GU autonomic dysfunction exists
Increases risk of stroke, operative complications, progression of renal failure
Significant cause of cardiac arrhythmias, silent MI and sudden death
5-yr mortality rates 16-50% in T1DM and T2DM
5 fold increase in mortality for DM patients with CAN; it is the strongest predictor of mortality in DM
Occurs in metabolic syndrome and IGT, not just DM

10. What is SUDOSCAN used for?
Screening for AN:
Per ADA Position Statements 2012 & 2013
At the time of diagnosis for T2DM, 5 years after diagnosis for T1DM (earlier if high risk)
Elicit autonomic dysfunction history
Symptomatic patients: orthostatic hypotension, exercise intolerance, nocturnal diarrhea, bladder dysfunction, gastroparesis, hyperhidrosis, ED
Suggestive medical history: alcoholism, hypothyroidism, neurotoxic meds, Vitamin B12 deficiency, autoimmune disease
Response of AN to intervention:
Damage to small nerve fibers is reversible, unlike most damage to large myelinated fibers
AN may be asymptomatic – but if detected early by SUDOSCAN, you can measure any improvement or worsening from a change in treatment
Prevention of complications:
Early screening and regular follow-up of AN with a simple test like SUDOSCAN can lead to referral for cardiac autonomic neuropathy assessment before a sudden death ensues
The 2012 and 2013 ADA Position Statementa recommend that all T2DM patients be screened for CAN at the time of diagnosis, and that all T1DM patients be screened for CAN 5 years after initial DM diagnosis.
High risk T1DM: poor glycemic control, CV risk factors, DPN, other macro- or microangiopathic complications of DM
The ADA talks about eliciting symptoms of autonomic dysfunction (resting tachycardia, orthostatic hypotension, exercise intolerance, gastroparesis, constipation, erectile dysfunction) but do not specifically recommend sophisticated testing.
The problem with these recommendations is that hx will miss ALL asymptomatic autonomic dysfunction, at a time when the course of the disease may be altered.
THIS IS WHEN SUDOMOTOR TESTING IS MOST VALUABLE: IN SCREENING FOR EARLY CAN

11. SUDOSCAN and peripheral neuropathy
Distal symmetrical polyneuropathy (DSP) is the most common complication of diabetes, affecting 50 to 90% of patients
Many are asymptomatic; almost 30% have painful symptoms
About 15% of diabetic patients will develop a foot ulcer, 1 in 6 will need an amputation
Ulcer = 45% risk of death in the next 5 years
DSP usually affects both sensory and motor nerves, with small nerve fibers in the feet being damaged first
Many peripheral small fiber neuropathies present with pain/burning, are idiopathic, and have no clinical abnormalities
SUDOSCAN may detect early DSP or small fiber neuropathy before any other signs or symptoms

12. How do you select patients for Sudoscan?
All DM patients at least yearly
Monitoring of autonomic neuropathy
Monitoring for compliance
Visual objective evidence of compliance with exercise, diet, glucose control
Patients with unexplained pain in the feet or hands
Is it a small fiber neuropathy?
Patients with autonomic symptoms
Is the dizziness from autonomic dysfunction and does the patient need to see a cardiologist?

13. Features and Benefits
Many advantages compared to other methods for sudomotor function testing (more to come)
Objective and quantitative
Other tests of small nerve fibers: IENFD & QST
IENFD is objective and quantitative but invasive
QST is quantitative but subjective
Alternating polarity of the electrodes
Provides measure of asymmetry of great precision
Mean % difference between L and R: 15 ± 9% for foot ESC versus 22 ± 24% for VPT (Gin et al. 2011).
Essential to differentiate unilateral vs. bilateral process
Ease of use
Simple and quick for technician and patient
IENFD: complex for clinician, painful for patient
QST: moderately complex and time-consuming for technician, tedious for patient
Asymmetry: this is how the 20% cut-off for asymmetry was determined as the threshold between expected differences btwn L and R sides

14. Features and Benefits Reproducibility
There is no other sudomotor test with as good reproducibility as SUDOSCAN
Reproducibility allows the clinician to accurately measure if neuropathy is worsening or improving
Sudoscan: coefficient of variation ESC feet 5 to 7%
QSART: intraclass correlation of coefficient (ICC) = 0.52 (Peltier et al. 2009)
SSR: variablity between and within patients: Amplitude 13-15%, latency 9%, worse with habituation
SudoPath: no data available on the device’s reproducibility

15. Other measures of small fiber testing
 Clinical Examination:
Clinicians use monofilament testing, vibration perception, and reflexes in routine practice
These are measures of LARGE nerve fibers
Intraepidermal Nerve Fiber Density (Skin Biopsy):
The current gold standard for small nerve fiber function. High sensitivity and specificity – around 80 to 90% each.
Shortcomings: invasive with risks of bleeding and infection; painful; cannot be repeatedly performed for follow-up easily; does not always correlate with symptoms of pain; does not always correlate with autonomic symptoms; poor reimbursement to the performing physician; requires follow-up for biopsy site healing; overall an expensive test for the third party payer
Quantitative Sensory Testing:
Tests small and large fiber functions: vibration (large), cold and warm thermal perception, cold pain and heat pain perception (small).
Shortcomings: Mostly used in specialty clinics; requires a well-trained technician, standardized methods, and a moderate amount of time; non-invasive but requires patient cooperation, therefore it is relatively subjective; not accurate for measuring asymmetry

16. Sudoscan Result
Radar Views
Patient info
Symmetry
Quantitative

17. Reimbursement Our current CPT code is 95923:
“Testing of autonomic nervous system function; sudomotor, including one or more of the following: quantitative sudomotor axon reflex test (QSART), silastic sweat imprint, thermoregulatory sweat test, and changes in sympathetic skin potential”
Sympathetic skin potential is the old term for galvanic skin response
Therefore ALL devices listed under GSR can use this CPT code for reimbursement

18. Reimbursement “Suggested” ICD-9 codes for 95923
The ICD-9 is the responsibility of the physician
We are actively preparing suggested ICD-10 codes for our customers

19. Reimbursement LEGEND: Data Input (assumptions) Fields
Spreadsheet calculations
Straight Purchase
reimbursement per patient per test
$200
cost of Sudoscan instrumentation
$35,000
number of patients per day 2 6
working days per month 21
staff assistant annual salary $0
minutes per patient cycle (**Actual test takes 3-5 min) 15
consumables per test
$20
gross margin per test
$180
net revenues per month
$7,560
$22,680
net revenues per year
$90,720
$272,160
number of months to breakeven
4.6
1.5

20. Testing
How often can Sudoscan testing be performed on a patient and still be reimbursed?
There is no officially prescribed interval between 2 scans
For the diabetic population, the ADA guidelines (2012, 2013) state the following:
All diabetics should be monitored for autonomic neuropathy at least yearly
Autonomic nerves recover function, and their speed of regeneration can help define scanning intervals:
Autonomic nerves recover function in 30 days after damage from capsaicin in healthy individuals
Autonomic nerves recover structural integrity in 58 days after capsaicin application in healthy individuals
Nerve regeneration in diabetic and neuropathic patients may be somewhat slower than the timelines determined in healthy subjects
The bottom line is that retesting can be performed at 90 day intervals if:
An intervention/change in therapy has been implemented
Medical necessity (a change in patient status) mandates retesting

21. Market Focus: Reimbursement
Make a slide on the ROIs, LCDs, etc

22. Testing
How often can Sudoscan testing be performed on a patient and still be reimbursed?
There is no officially prescribed interval between 2 scans
For the diabetic population, the ADA guidelines (2012, 2013) state the following:
All diabetics should be monitored for autonomic neuropathy at least yearly
Autonomic nerves recover function, and their speed of regeneration can help define scanning intervals:
Autonomic nerves recover function in 30 days after damage from capsaicin in healthy individuals
Autonomic nerves recover structural integrity in 58 days after capsaicin application in healthy individuals
Nerve regeneration in diabetic and neuropathic patients may be somewhat slower than the timelines determined in healthy subjects
The bottom line is that retesting can be performed at 90 day intervals if:
An intervention/change in therapy has been implemented
Medical necessity (a change in patient status) mandates retesting

23. The Specialties Clinicians most likely to need a Sudoscan include:
Those with a large diabetes patient population
GPs and Endocrinologists
Those who see idiopathic and small fiber neuropathies
Neurologists, PM&R, pain clinics
Those who see patients for autonomic neuropathy
GPs, cardiologists
The following slides include information on use of Sudoscan in individual medical specialties and relevant literature to present to those specialists. This is a lot of information and is presented only to let you know that we will provide you with a written reference booklet so that you can immediately know how to prepare your pitch for each specialty

24. General Practice and Internal Medicine
Uses of Sudoscan in their practice
Initial evaluation and follow-up of peripheral pain syndrome
Initial evaluation and follow-up of autonomic symptoms (orthostatic hypotension, gastroparesis, exercise intolerance, etc)
Early detection and follow-up of autonomic and peripheral neuropathy in diabetic patients; aid in determining need for in-depth work-up
Detection of patients with dysglycemia/metabolic syndrome based on peripheral neuropathy symptoms; follow-up after intervention
Recommended articles
Neurovascular function and Sudorimetry in Health and Disease. A.I. Vinik, M. Nevoret, C. Cassellini, H. Parson. Curr Diab Rep Aug;13(4):
Vinik AI, Maser RE, Ziegler D. Neuropathy: the crystal ball for cardiovascular disease? Diabetes Care Jul;33(7):
Eranki VG, Santosh R, Rajitha K, Pillai A, Sowmya P, Dupin J, Calvet JH. Sudomotor function assessment as a screening tool for microvascular complications in type 2 diabetes. Diabetes Res Clin Pract Jul 20. pii: S (13)

25. Endocrinology Uses of Sudoscan in their practice Recommended articles
Follow-up autonomic and peripheral neuropathy in diabetic patients, especially response to therapeutic intervention. Decision for referral to neurology or cardiology
Recommended articles
Casellini CM, Parson HK, Richardson MS, Nevoret M, Vinik AI. Sudoscan, a Noninvasive Tool for Detecting Diabetic Small Fiber Neuropathy and Autonomic Dysfunction. Diabetes Technol Ther. 2013;15(11)
Smith et al. SUDOSCAN as a Diagnostic Tool for Peripheral Neuropathy. Poster presentation at Peripheral Nerve Society. Jun-Jul Saint-Malo (France).
Calvet JH, Dupin J, Winiecki H, Schwarz PE. Assessment of small fiber neuropathy through a quick, simple and non invasive method in a German diabetes outpatient clinic. Exp Clin Endocrinol Diabetes Feb;121(2):80-3.
Calvet JH, Dupin J, Deslypere JP. Screening of Cardiovascular Autonomic Neuropathy in Patients with Diabetes by Quick and Simple Assessment of Sudomotor Function. J Diabetes Metab. 2012;3:192.
A new tool to detect kidney disease in Chinese type 2 diabetes patients—comparison of EZSCAN with standard screening methods. R. Ozaki, KKT Cheung, E. Wu, A. Kong, X. Yang, E. Lau, P. Brunswick, JH. Calvet, JP. Deslypere, JCN. Chan. Diabetes technology & therapeutics. 2011;13(9):
Vinik AI, Maser RE, Ziegler D. Neuropathy: the crystal ball for cardiovascular disease? Diabetes Care Jul;33(7):
Freedman BI, Bowden DW, Smith SC, Xu J, Divers J. Relationships between electrochemical skin conductance and kidney disease in Type 2 diabetes. J Diabetes Complications Oct 16. pii: S (13)
Eranki VG, Santosh R, Rajitha K, Pillai A, Sowmya P, Dupin J, Calvet JH. Sudomotor function assessment as a screening tool for microvascular complications in type 2 diabetes. Diabetes Res Clin Pract Jul 20. pii: S (13)

26. Neurology Uses of Sudoscan in their practice Recommended Articles
Investigation and follow-up of painful, suspected small fiber, or autonomic neuropathy
Investigation and follow-up of any other unusual neuropathy when nerve conduction study is inconclusive
Recommended Articles
Therapath Explanation
Neurovascular function and Sudorimetry in Health and Disease. A.I. Vinik, M. Nevoret, C. Cassellini, H. Parson. Curr Diab Rep Aug;13(4):
Smith et al. SUDOSCAN as a Diagnostic Tool for Peripheral Neuropathy. Poster presentation at Peripheral Nerve Society. Jun-Jul Saint-Malo (France).
Casellini CM, Parson HK, Richardson MS, Nevoret ML, Vinik AI. Sudoscan, a Noninvasive Tool for Detecting Diabetic Small Fiber Neuropathy and Autonomic Dysfunction. Diabetes Technol Ther. 2013;15(11)
Quick and simple evaluation of sudomotor function for screening of diabetic neuropathy. CS. Yajnik, V. Kantikar, AJ. Pande, JP. Deslypere. ISRN Endocrinology. doi: /2012/
Non invasive and quantitative assessment of sudomotor function for peripheral diabetic neuropathy evaluation. H. Gin, R. Baudouin, C. Raffaitin, V. Rigalleau, C. Gonzalez. Diabetes & Metabolism. 2011;11(6):

27. Cardiology Uses of Sudoscan in their practice Recommended articles
Initial evaluation for cardiac autonomic neuropathy in a symptomatic patient
Follow-up of its progression after therapeutic intervention
Recommended articles
Screening of cardiovascular autonomic neuropathy in patients with diabetes using non-invasive quick and simple assessment of sudomotor function. C.S. Yajnik, V. Kantikar, A. Pande, J.-P. Deslypere, J. Dupin, JH. Calvet, B. Bauduceau. Diabetes & Metabolism. In press.
Calvet JH, Dupin J, Deslypere JP. Screening of Cardiovascular Autonomic Neuropathy in Patients with Diabetes by Quick and Simple Assessment of Sudomotor Function. J Diabetes Metab. 2012;3:192.
Pavy-Le Traon A, Mouly C, Gerdelat A, Calvet JH, Hanaire H, Senard JM. Comparison of Sudoscan and cardiovascular testing for assessment of cardiovascular autonomic neuropathy. Poster presentation at Neurodiab. Sep Barcelona (Spain).

28. PM&R Uses of Sudoscan in their practice Recommended articles
Initial evaluation and follow-up of peripheral pain syndromes
Investigation of autonomic symptoms (orthostatic hypotension, gastroparesis, exercise intolerance, etc) and follow-up after intervention
Recommended articles
Casellini CM, Parson HK, Richardson MS, Nevoret ML, Vinik AI. Sudoscan, a Noninvasive Tool for Detecting Diabetic Small Fiber Neuropathy and Autonomic Dysfunction. Diabetes Technol Ther. 2013;15(11)
Smith et al. SUDOSCAN as a Diagnostic Tool for Peripheral Neuropathy. Poster presentation at Peripheral Nerve Society. Jun-Jul Saint-Malo (France).
Therapath Explanation
Calvet JH, Dupin J, Deslypere JP. Screening of Cardiovascular Autonomic Neuropathy in Patients with Diabetes by Quick and Simple Assessment of Sudomotor Function. J Diabetes Metab. 2012;3:192.

29. Pain Clinics Uses of Sudoscan in their practice Recommended articles
Evaluation and follow-up of suspected small fiber or painful neuropathy
Identification of small fiber neuropathy in patients with various indeterminate peripheral pain syndromes (e.g. fibromyalgia)
Recommended articles
Casellini CM, Parson HK, Richardson MS, Névoret ML, Vinik AI. Sudoscan, a Noninvasive Tool for Detecting Diabetic Small Fiber Neuropathy and Autonomic Dysfunction. Diabetes Technol Ther. 2013;15(11)
Smith et al. SUDOSCAN as a Diagnostic Tool for Peripheral Neuropathy. Poster presentation at Peripheral Nerve Society. Jun-Jul Saint-Malo (France).
Note: for now our CPT code applies to the evaluation of autonomic neuropathy – so I would not be pressed to target this group of specialists right now

30. Common Questions
Why should I purchase a Sudoscan and diagnose a small fiber neuropathy or autonomic neuropathy if there is no treatment?
What do I do with the results of an abnormal Sudoscan test?

31. Abnormal Sudoscan results
There are treatments for small fiber neuropathies; the greatest barrier is lack of proper diagnosis
Small nerve fibers have the potential for regeneration if the insult on the nerves is stopped; large nerve fibers rarely recover
Small fiber neuropathy is most frequently caused by DM and pre-DM: treat the DM and the neuropathy will improve
Many small fiber neuropathy causes are treatable: hypothyroidism, vitamin B12 deficiency, celiac disease
Hyperglycemia-induced neuropathies (DM, metabolic syndrome) can improve:
Aggressive lifestyle and diet modification, exercise
Glycemic control – in particular insulin
Anti-oxidants: alpha lipoic acid
Metanx
Topiramate

32. Abnormal Sudoscan results
Autonomic neuropathy MUST be recognized to reduce the mortality of CAN (cardiac autonomic neuropathy).
Treatments include β-blockers, ACE Inhibitors, clonidine, pyridostigmine, etc depending on symptoms
Nerve entrapments can be released (hand or foot)
CIDP, autoimmune neuropathies, vitamin B12 or infectious neuropathies (Lyme disease) are treatable
Chemotherapy-induced neuropathy can be controlled with appropriate chemotherapy management
See your booklet for the articles supporting each of these statements!

33. Nerve Conduction Study
How is this different than a nerve conduction study?
Sudoscan measures SMALL fiber function, not large fiber function
Nerve conduction studies measure LARGE fiber function – not small fiber function
The voltage applied and current measured by NCS are so much higher than those used by Sudoscan that it is impossible to detect the feeble signal of unmyelinated nerves under that of large nerves
Sudoscan detects earlier nerve damage than NCS
NCS voltage must penetrate skin and deep tissues to stimulate the nerves

34. Handling Obstacles and Objections
Know what types of disease/patient groups your customer sees in his/her office
Provide them with the literature that supports diagnosing neuropathy in their patient population
Review the Interpretation Guide with them: the easier it is for the clinician to understand the results and how they support the clinical diagnosis, the more likely they are to adopt the technology

35. Handling Obstacles and Objections
The Interpretation Guide provides concrete clinical guidance to read Sudoscan reports

36. Information that Sudoscan needs to perform a test
Name/Patient ID
For file storage and ability to compare multiple scans of the same patient
Age, height, weight
In the US, used for reference only
In other countries, factors in calculations of diabetes risk, CAN risk
Racial background
In new software, this is critical
Adjusts the normal/moderate dysfunction/severe dysfunction thresholds

37. Sudoscan Musts Clean sensor plates with Surfa Safe ONLY:
Assures accuracy of test
Protects against electrode metal corrosion
However, electrodes are disposables because we can’t guarantee that clinicians follow best practices
Clean hands and palms but NOT with Surfa Safe:
Surfa Safe is an industrial-grade chemical and is NOT approved for skin contact
Wash skin thoroughly if it comes in contact with Surfa Safe
Ensure good contact of the palms and soles with the electrodes:
Flatten the palms as much as possible, applying some pressure, especially if the patient is sitting during the test
Let long toes and fingers hang off the ends of the electrodes

38. Sudoscan No-no’s Pregnancy – untested/unknown risk
Touching the patient during the test – this would ground the patient
Lotion, dirt, etc on hands and feet
Amputations – toe or finger amputations are not a contraindication to Sudoscan
Open skin or ulcers on the soles or palms – likely to skew results – and not hygienic
Pacemakers and implanted defibrillators are OK for scanning, with physician present in the clinic

39. Correcting Misconceptions about Sudoscan Testing
Room or patient temperature, heavy sweating (after exercise) do not affect Sudoscan
The concentration of chloride in eccrine sweat glands is very constant, regardless of sweat rate – this is why temperature and exercise will not change Sudoscan results
The voltage applied to the electrodes is small (<4V) but enough to maximally ‘stress’ or activate sweat gland nerves; this is also why temperature and exercise do not influence test results

40. Sudoscan Trouble-shooting
What can go wrong during a test?
If the device detects a loss of contact during the test, it will complete the scan but not give results
The device will not ‘count down’ one test
Stop the scan as soon as contact loss detected and restart a new scan
If the scan results are not as expected (low)
Clean electrodes, hands, feet
Remove jewelry, roll up sleeves and pant legs
Do not install other software on the device
Call the Impeto help desk
IT can access your device remotely and analyze it
It’s free!

41. Reading a Sudoscan Report: The Physician’s Report
Presentation is different, but the information stays the same
The added value is the conductance history on the second page, space for the physician to write his impression

42. Reading a Sudoscan Report:
Conclusion:
Test measurements show higher than average asymmetry (left versus right side) for peripheral neuropathy.
Plan to retest patient on Sudoscan in 3 months. Consider additional examination to better discriminate
source of asymmetry.

43. Reading a Sudoscan Report
Hand versus Feet ESC:
In general, it is not unusual to have hand ESC scores that are slightly lower than feet ESC scores.
This is likely physiological: sweat glands on different parts of the body function differently and their exact ionic concentrations are specific to that body surface
If feet ESC scores are lower than the hand scores, there is likely a significant dysfunction of the foot sweat gland nerves

44. Reading a Sudoscan Report: Asymmetry
Asymmetry greater than 20% signals a process primarily affecting one extremity
This 20% threshold ONLY applies if the other side falls in the green zone.
If the left side scores 33μS and the right side scores 48μS, asymmetry is 32%, but both sides are obviously affected!
NOTE: There may be 1 cause affecting both sides but asymmetrically, or there may be 1 cause affecting both sides and a 2nd cause affecting just the left side
E.g. diabetic neuropathy + left carpal tunnel

45. Reading a Sudoscan Report: Asymmetry
Asymmetry on the radar views: left is the patient’s right side and right is the patient’s left side on the radar views; i.e. the patient is FACING YOU
Here, the right is worse than the left, but both sides are very damaged

46. Reading a Sudoscan Report: Asymmetry
Asymmetry on the red/yellow/green graph: read it like an x and y axis graph. If x=2 and y=3, the mark will be deviated to the LEFT (see below). Therefore the mark leans on the HEALTHIER side

47. Reading a Sudoscan Report: Asymmetry
Note that some of these conditions may impair only large nerves and leave small and sympathetic nerves intact, and vice versa.

48. Sudoscan confounders
As Sudoscan is still a very new technology, we do not yet have complete knowledge of all the variables that may affect results
Despite NOT controlling for possible confounders, reproducibility and accuracy are very high compared to other sudomotor function tests
What is a confounder?
An interference that causes Sudoscan results to be ABNORMAL when in fact the sudomotor nerves are INTACT
Some confounders may include:
Racial background, ethnicity
Medications
Skin trauma
Acute alcohol intake

49. Sudoscan confounders : Medications
These medications are frequently used by patients with diabetes!
Pharmacist’s Letter/Prescriber’s Letter – Document # Therapeutic Research Center. December Available at

50. Sudoscan Confounders: Other
Different races naturally have different sweat gland physiology.
Racial background needs to be correctly entered into the device to provide an accurate scale against which the results are measured
For mixed racial background, enter the non-Caucasian race of the patient
Skin trauma to the hands or feet
open wounds/ulcers: break in the capacitance role of the skin
Large areas of scarring (burns), palmoplantar keratodermas
Moderate/heavy alcohol intake in the last 24 hours

51. Sudoscan Confounders
Do not confuse a confounder with an actual condition that damages the nerves!
These conditions may cause abnormal Sudoscan results from temporary or permanent nerve damage
Note that chronic alcohol abuse produces a permanent neuropathy

52. Large and Small Fibers: Size Matters

53. Large and Small Fibers: Size Matters
Physicians in clinical practice rely on 2 tests to assess neuropathy (if they bother at all):
10g monofilament and the tuning fork to test vibration (increases reimbursement for the patient visit)
Both of these are measures of large fibers and may signal advanced neuropathy
These impact ADLs: patients fall when they lose their sense of position/balance
Most physicians don’t know that they are only testing large fibers
Small fibers need to be measured for 3 reasons:
Detect neuropathy as early as possible in order to correct the underlying disease and possibly reverse the neuropathy
Prevent progression of the neuropathy to ulcers, amputations
Decrease mortality from autonomic neuropathy 

54. Physician Interpretation Guide

55. Physician Interpretation Guide
The Interpretation Guide was written to assist the physician interpret Sudoscan reports.
Sudoscan does not provide a diagnosis
The FDA clearance specifically stipulates that the test does not provide a diagnosis
Sudoscan is a corroborating measure similar to an ECG or an x-ray
It is the physician’s responsibility to make a diagnosis in the context of each patient’s complete clinical scenario
The Interpretation Guide is divided into 3 sections:
An initial discussion about the measurements made by Sudoscan and the diagnostic strategy for proper interpretation of results
Tables of validated and as yet unvalidated causes for Sudoscan disturbances, including suggested work-up evaluation
Clinical case reports illustrating patterns of Sudoscan disturbances likely to be encountered in the clinical environment
The Interpretation Guide will evolve as new research data is accrued

56. Sudoscan and CRPS What is CRPS? CRPS is complex regional pain syndrome
It comes in 2 varieties: type 1 and type 2
Type 1
More common (90% of patients) and occurs after an illness or injury that DID NOT directly damage the nerves of the affected limb (e.g. ulna fracture, stroke)
Previously called Reflex Sympathetic Dystrophy (RSD)
Type 2
Follows a distinct nerve injury
Previously known as causalgia
CRPS is a type of chronic pain syndrome in which the signs and symptoms are disproportional to the original injury; there may be burning or throbbing; changes in skin color, texture or temperature; and even muscle atrophy.
One limb is usually affected and several stages are described

57. Sudoscan and CRPS Is Sudoscan useful clinically in CRPS?
A frequent question from PM&R and pain physicians 
We have not completed any clinical trial in these patients as of now
However, diagnosis of CRPS is difficult
Autonomic tests are often abnormal
There is increased sweating initially, with loss of sweating in the later stages
Therefore Sudoscan MAY be useful for CRPS diagnosis and follow-up
Sudoscan results may be asymmetric between the normal and the CRPS limb

58. Ongoing Research Efforts
Peripheral and autonomic neuropathy: further correlations with IENFD, SGNFD, QSART from independent investigators
Correlations with diabetic kidney disease
Change in peripheral and autonomic neuropathy following bariatric surgery
Effect of different treatments for prediabetes on the progression of neuropathy
Peripheral neuropathy in PAD, Parkinson’s disease, Scleroderma, chemotherapy
Cystic fibrosis, Fabry disease