Department of Neurology,
M S Ramaiah Medical
College and Hospitals
The Cutaneous Silent Period
An Electrophysiological tool to assess
small fiber function
Rahul Kumar, P V Meenakshi, Shripa...
Cutaneous Silent Period
•
•
•
•
•
•
•

Introduction
Need for the study
Aims and Objectives
Materials and Methods
Results
D...
Outline for the session
•
•
•
•
•
•
•

Introduction
Need for the study
Aims and Objectives
Materials and Methods
Results
D...
• The silent period consists in a transient suppression of the
EMG voluntary activity that occurs in response to an
electr...
Can be recorded from…
• Most skeletal muscles
• More pronounced in the distal muscles
• Consistent, reproducible
• Can be ...
Importantly ……

7
Need for the Study
• Small fibre neuropathy - 30% in IGT !!!
– Altered C-Fiber Function as an Indicator of Early Periphera...
Aims and Objectives
 To establish the methodology for recording Cutaneous silent

period in humans, from upper and lower ...
Materials and Methods
• Total Number of Volunteers - 50
• M:F – 28:22 (p=0.56)

• Rt handed : Lt handed - 27:13 (p=0.82)
•...
Equipment
• Nihon Kohden Neuropack from Nihon Kohden
inc, Japan
• Surface Electrodes – ring, disc
• Stimulator
• Single Si...
Pilot Phase
• 6 subjects
• Muscles sampled
• APB, ADM, FDI, Biceps Brachii, Triceps, Deltoid
• Quadriceps, TA, Triceps Sur...
Pilot Phase
• 6 subjects
• Muscles sampled
• APB, ADM, FDI, Biceps Brachii, Triceps, Deltoid
• Quadriceps, TA, Triceps Sur...
Patient’s Position
• Supine on couch

• Muscles contracted voluntarily on command
• Maximum voluntary contraction was asse...
Electrode placement
• Stimulating Electrodes –
• Ring Electrodes UL
• Conventional Stimulator LL

• Recording Electrodes •...
System Settings
• Maximum voluntary contraction was assessed by audiovisual
feedback.
• filters - 2 Hz to 10 kHz.
• sweep ...
Stimulus Intensity
• maximal voluntary contraction
• single stimuli of increasing intensities and 0.3 ms duration on
pre s...
Stimulus Intensity vs Latency, UL
1.2

1
Stimulus Intensity
0.8
0.6
Onset latency

0.4
0.2
0
20 mA

40 mA

P=0.002

P=0.03...
Stimulus Intensity vs Latency, LL

Stimulus Intensity

Onset latency

42 mA

50 mA

P=0.04

P=0.036

19
Stimulus Intensity vs Duration, UL

Stimulus Intensity

Duration

20 mA

36 mA

P=0.012

P=0.0354

20
Stimulus Intensity vs Duration, LL

Stimulus Intensity

Duration

46 mA

74 mA

P=0.086

P=0.01

21
Stimulus Intensity
• Based on these findings
– single stimuli of increasing intensities and 0.3 ms duration on pre
specifi...
Results…

23
CuSP Lat, UL
Recording
Site

Stimulation Site

Latency in ms,
Mean (SD)
Right

P value

R value

Left

APB

II

72.6(6.6) ...
CuSP Duration, UL
Recording Site

Stimulation Site

Duration in ms, Mean
(SD)
Right

P value

R value

Left

APB

II

38.6...
CuSP Lat, LL
Recording
Site

Stimulation Site

Latency in ms, Mean
(SD)
Right

P value

R value

Left

EDB

Superficial Pe...
CuSP Duration, LL
Recording
Site

Stimulation Site

Duration in ms, Mean
(SD)
Right

P value

R value

Left

EDB

Superfic...
Conclusions
• Methodology
o - Distal UL, LL Muscles, Max. voluntary contraction.
o - Current > 36mA UL, >45mA LL, pulse wi...
Conclusions
• Normative Data
•
•
•
•

Upper Limb Latency – 62 to 86 msec *
Upper Limb Duration – 26 to 40 msec *
Lower Lim...
Comparison with other modalities to
assess small fibre function
– Sympathetic skin response – No data

– Quantitative sens...
Cutaneous silent period changes in Type 2 diabetes
mellitus patients with small fiber neuropathy
M.R. Onala, U.H. Ulasa, O...
Renshaw
Cell

-
Cutaneous silent period_ian_2010_pl_144
Cutaneous silent period_ian_2010_pl_144
Cutaneous silent period_ian_2010_pl_144
Cutaneous silent period_ian_2010_pl_144
Cutaneous silent period_ian_2010_pl_144
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Cutaneous Silent Period - Technique, Normative data and Anatomical Subrtrate - Non Invasive Method to assess small diameter nerve fiber function

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Cutaneous silent period_ian_2010_pl_144

  1. 1. Department of Neurology, M S Ramaiah Medical College and Hospitals
  2. 2. The Cutaneous Silent Period An Electrophysiological tool to assess small fiber function Rahul Kumar, P V Meenakshi, Shripal Shah, M Vivekananda, R Pavithra, P T Acharya, Pushparaja Shetty H, R Srinivasa M S Ramaiah Medical College and Hospitals, Bangalore 560094 2
  3. 3. Cutaneous Silent Period • • • • • • • Introduction Need for the study Aims and Objectives Materials and Methods Results Discussion Conclusions 3
  4. 4. Outline for the session • • • • • • • Introduction Need for the study Aims and Objectives Materials and Methods Results Discussion Conclusions 4
  5. 5. • The silent period consists in a transient suppression of the EMG voluntary activity that occurs in response to an electrical stimulus. • Described for the first time by W. W. Hoffmann in 1922 5
  6. 6. Can be recorded from… • Most skeletal muscles • More pronounced in the distal muscles • Consistent, reproducible • Can be recorded on conventional EP equipment • Non Invasive 6
  7. 7. Importantly …… 7
  8. 8. Need for the Study • Small fibre neuropathy - 30% in IGT !!! – Altered C-Fiber Function as an Indicator of Early Peripheral Neuropathy in Individuals With Impaired Glucose Tolerance, Alistair Q. Green, MRCP1, Singhan Krishnan, MD, MRCP1, Francis M. Finucane, MD, MRCP, Gerry Rayman, MD, FRCP, Diabetes Care January 2010vol. 33 no. 1 174-176 • Available techniques – Sympathetic skin response – Quantitative sensory testing – Quantitative sudo-motor axon reflex test – Skin biopsy 8
  9. 9. Aims and Objectives  To establish the methodology for recording Cutaneous silent period in humans, from upper and lower limbs  To determine the normative values of onset, latency and duration from various muscles in upper and lower limbs 9
  10. 10. Materials and Methods • Total Number of Volunteers - 50 • M:F – 28:22 (p=0.56) • Rt handed : Lt handed - 27:13 (p=0.82) • Normal NCS • Ethics committee • Informed consent. 10
  11. 11. Equipment • Nihon Kohden Neuropack from Nihon Kohden inc, Japan • Surface Electrodes – ring, disc • Stimulator • Single Simulus 11
  12. 12. Pilot Phase • 6 subjects • Muscles sampled • APB, ADM, FDI, Biceps Brachii, Triceps, Deltoid • Quadriceps, TA, Triceps Surae, Peronei, EDB, AH 12
  13. 13. Pilot Phase • 6 subjects • Muscles sampled • APB, ADM, FDI, Biceps Brachii, Triceps, Deltoid • Quadriceps, TA, Triceps Surae, Peronei, EDB, AH 13
  14. 14. Patient’s Position • Supine on couch • Muscles contracted voluntarily on command • Maximum voluntary contraction was assessed by audiovisual feedback. 14
  15. 15. Electrode placement • Stimulating Electrodes – • Ring Electrodes UL • Conventional Stimulator LL • Recording Electrodes • Surface electrodes • Standard Belly-Tendon Montage 15
  16. 16. System Settings • Maximum voluntary contraction was assessed by audiovisual feedback. • filters - 2 Hz to 10 kHz. • sweep - 20 ms/div for UL and 50 ms/div for LL. • Sensitivity 0.5 mV to 2 mV/div depending on the amplitude of voluntary activity. 16
  17. 17. Stimulus Intensity • maximal voluntary contraction • single stimuli of increasing intensities and 0.3 ms duration on pre specified points • repeated till a silent period of reproducible latency and duration was obtained. • When this could not be achieved, stimulus duration was increased in steps of 0.1 ms, up to 1.0 ms. • . 17
  18. 18. Stimulus Intensity vs Latency, UL 1.2 1 Stimulus Intensity 0.8 0.6 Onset latency 0.4 0.2 0 20 mA 40 mA P=0.002 P=0.034 18
  19. 19. Stimulus Intensity vs Latency, LL Stimulus Intensity Onset latency 42 mA 50 mA P=0.04 P=0.036 19
  20. 20. Stimulus Intensity vs Duration, UL Stimulus Intensity Duration 20 mA 36 mA P=0.012 P=0.0354 20
  21. 21. Stimulus Intensity vs Duration, LL Stimulus Intensity Duration 46 mA 74 mA P=0.086 P=0.01 21
  22. 22. Stimulus Intensity • Based on these findings – single stimuli of increasing intensities and 0.3 ms duration on pre specified points – repeated till a silent period of reproducible latency and duration was obtained. – If this cannot be achieved, stimulus duration can be increased in steps of 0.1 ms, up to 1.0 ms. For Upper Limbs – 0.3msec, 30-50mA For Lower Limbs – 0.3msec, 46-65mA • . 22
  23. 23. Results… 23
  24. 24. CuSP Lat, UL Recording Site Stimulation Site Latency in ms, Mean (SD) Right P value R value Left APB II 72.6(6.6) 71.7(5.9) 0.02 0.88 APB V 71.5(5.9) 72.4(6.2) 0.35 0.72 ADM II 73.2(6.1) 74.6(5.8) 0.003 0.66 ADM V 74.1(6.3) 73.9(5.9) 0.04 0.98 24
  25. 25. CuSP Duration, UL Recording Site Stimulation Site Duration in ms, Mean (SD) Right P value R value Left APB II 38.6(8.2) 37.8(7.8) 0.0024 0.92 APB V 32.4(6.5) 33.2(6.3) 0.52 0.54 ADM II 30.62(6.2) 32.3(5.9) 0.08 0.78 ADM V 35.6(5.8) 36.1(5.7) 0.3 0.92 25
  26. 26. CuSP Lat, LL Recording Site Stimulation Site Latency in ms, Mean (SD) Right P value R value Left EDB Superficial Peroneal 98.6(12.2) 97.2(10.8) 0.9 0.5 TA Superficial Peroneal 94.2(8.8) 96.6(9.4) 0.6 0.73 AH Sural nerve 0.02 0.6 105.4(9.2) 104.9(10.6) 26
  27. 27. CuSP Duration, LL Recording Site Stimulation Site Duration in ms, Mean (SD) Right P value R value Left EDB Superficial Peroneal 54.2(10.6) 52.8(14.8) 0.02 0.88 TA Superficial Peroneal 44.8(8.6) 46.6(9.4) 0.05 0.65 AH Sural nerve 48.9(9.2) 51.6(9.8) 0.023 0.69 27
  28. 28. Conclusions • Methodology o - Distal UL, LL Muscles, Max. voluntary contraction. o - Current > 36mA UL, >45mA LL, pulse width 0.3 msec. o - Higher intensities may be needed in patients. o - Filters - 2 Hz to 10 kHz. o - Sweep - 20 ms/div for UL and 50 ms/div for LL. o - Sensitivity 0.5 mV to 2 mV/div depending on the o amplitude of voluntary activity. 28
  29. 29. Conclusions • Normative Data • • • • Upper Limb Latency – 62 to 86 msec * Upper Limb Duration – 26 to 40 msec * Lower Limb Latency – 78 to 120 msec * Lower Limb Duration – 36 to 48 msec * * - Mean ± 2SD 29
  30. 30. Comparison with other modalities to assess small fibre function – Sympathetic skin response – No data – Quantitative sensory testing - equal » Grazia Devigili, Valeria Tugnoli, Paola Penza, Francesca Camozzi, Raffaella Lombardi, Giorgia Melli, Laura Broglio, Enrico Granieri and Giuseppe Lauria The diagnostic criteria for small fibre neuropathy: from symptoms to neuropathology; Brain;Volume131, Issue7; Pp. 1912-1925. – Quantitative sudo-motor axon reflex test – no data – Skin biopsy – 88%sensitive, 92% specific » Lauria G, Morbin M, Lombardi R, Borgna M, Mazzoleni G, Sghirlanzoni A,et al. Axonal swellings predict the degeneration of epidermal nerve fibers in painful neuropathies. Neurology 2003;61:631-6. 31
  31. 31. Cutaneous silent period changes in Type 2 diabetes mellitus patients with small fiber neuropathy M.R. Onala, U.H. Ulasa, O. Oza, V.S. Beka, M. Yucela, A. Taslıpınarb, Z. Odabasıa • Conclusion • The CSP evaluation together with nerve conduction study, has been demonstrated to be beneficial and performance of latency difference in addition to CSP latency and duration may be a valuable parameter in electrophysiological assessment of diabetic patients with small fiber neuropathy. • Significance • An additional CSP evaluation may be considered in cases which nerve conduction studies do not provide sufficient information. » Clinical Neurophysiology; Volume 121, Issue 5, Pages 714-718 (May 2010) 32
  32. 32. Renshaw Cell -

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