TENS: Transcutaneous Electrical Nerve Stimulation PDF

Trans Cutaneous Electrical Nerve Stimulation T.E.N.S Dr. Azza Attia Professor of physical therapy Transcutaneous Electrical Nerve Stimulation y't Transcutaneous : means through intact skin • So, TENS is a low frequency electrical current used to stimulate peripheral nerves using skin .si surface...

Trans Cutaneous Electrical Nerve Stimulation T.E.N.S Dr. Azza Attia Professor of physical therapy Transcutaneous Electrical Nerve Stimulation y't Transcutaneous : means through intact skin • So, TENS is a low frequency electrical current used to stimulate peripheral nerves using skin .si surface electrodes aiming to relief pain (acute or o chronic ). • TENS is non-invasive , non pharmacological d physical therapy modalities used If to relief pain through stimulation of peripheral nerve using __ surface electrodes. T Portable TENS stimulator O Multicurrent Carbon-impregnated silicon rubber electrodes (non-disposable) 4,4 Disposable SelfAdhering electrodes Typical TENS cabinet Specification (parameters) of TENS • • • • Waveforms I Frequency or Rate Pulse width or Duration Amplitude or Intensity • The delivery of TENS rests on the use of biphasic pulsed current, which may be pulse- or burst modulated. same inshapeduration magnitude • waveform is biphasic and symmetrical, thus e balanced, with either a square or a rectangular shape. TTavantay EY ittcnarge.at • The delivery of a balanced waveform, which has zero net charge, is critical because TENS treatments are often applied daily, for hours at the D time, and often over weeks and months It in IIT pain • A burst (beat ):is a group of two or more a successive pulses or cycles separated by a time __ interval during which no electrical activity occurs. no no 2g • Duration :whether it is pulse duration (PD), cycle duration (CD), burst duration (BuD), or beat duration (BeD), is the time elapsed between the beginning of the first phase and the end of the last phase. The time elapsed between each corresponds to interpulse duration (IPD), intercycle duration (ICD), interburst duration (IBuD),and interbeat duration (IBeD), respectively. n I sane 1 0 410 PEEN durGtioninterff PulsePeriod f=3 pps O duration MYed Pursedperiodehuratio interval Interval frequency 2 Noftime sec • Frequency (f) is defined as the number of times per second that a pulse, cycle, burst, or beat will repeat itself. • It is calculated using the formula Tse duration Interval • f = 1/P, where P, the period, is equal e to the summation of either PD and c IPD, CD and ICD, BuD and IBD, and C Period BeD and IBeD, respectively TBurst Period skin Period Duratio Interval YpWseD I Waveforms I Advantage In the biphasic wave, there is no accumulation of electrolytes SO prevents __ the accumulation, or buildup, of C electrical charges underneath the electrodes, which, over time, may cause skin irritation and discomfort 0 Frequency or Rate Low Low a Frequency 1-150Hz Low 1 Low Frequency (1-20 Hz): Stimulate small unmyelinated nerve fibers Increase endorphin production E (supra-spinal level) a Delayed relief of pain Used for Chronic pain chronic e Long lasting pain relief FIT 1 b 20 Ew 1 150 the 20 150 High Frequency (80-150 Hz): Stimulate Large myelinated nerve fibers Gait control theory (spinal level) Immediate relief of pain Used for Acute pain  short subsequent effect f __ b 7 Stat 5 Amplitude or Intensity TENS units intensity ranges form 1 mA to 120-150 e S mA 1201150 1 “Ideal intensity” = patient perceived comfortable sensation Ingu Patients need to increase the intensity when the body accommodates to the stimulus (when they don’t feel the stimulation anymore) y Dying batteries can cause fading intensities i classification Pulse 50μS width or Duration 100-150μs 200μs of I Large myelinated nerve fibers respond more effectively (sensory touch)) her Normal neuromuscular system 2 Small e unmyelinated nerve fibers respond more effectively >200μs so Neurological e disorders we Pulse duration 50-500 microseconds 50 500 Micro Modes of TENS Application Frequency Pattern wavelength High shortening Towhigh Amplitude Duration Low thigh If Therapist can achieve variations of TENS by adjusting the current parameters. Types of TENS I P 1. Conventional TENS ( high frequency, low intensity) or High TENS. 2. Acupuncture Like TENS (low frequency, high intensity) or Low TENS. mainly 3. Brief Intense TENS. 4. Burst Mode–TENS clinic in Conventional Mode ÉorÉfgfor org Pt • This mode involves delivery of electrical pulses with relatively short durations, high frequencies, and current amplitudes corresponding to sensory-level stimulation. S Ls • It is called conventional because, by convention or clinical experience, clinicians usually select this mode to begin TENS therapy, as it is perceived by most patients as the most comfortable of all modes. t __ • This mode implies the preferential depolarization of large-diameter A-beta fibers Is • using current amplitudes and pulse durations within the sensory-level range. e • Electrical stimulation is perceived as comfortable (pins and needles; tingling; no muscle contraction),and pain modulation occurs through the gate system. • The onset of analgesia is relatively rapid, and analgesia itself is relatively brief is __TO Chines needle M Acupuncture-Like Mode • This mode refers to the delivery of electrical pulses with relatively long durations, low so frequencies, and current amplitudes capable of d sensory- and motor-level stimulation. • It is described as acupuncture-like because the pulse frequency is low, resembling traditional needle acupuncture therapy, in which the practitioner slowly rotates the needle in the patient’s skin. • This mode implies the preferential and concomitant depolarization of afferent A-deta , C fibers and efferent alpha motor fibers innervating skeletal muscles. • Electrical stimulation is perceived as tolerable as well as a mixed sensation of tingling and muscle ___ contraction. • Pain is presumed to reduce via the opiate system. Onset of analgesia is relatively slow, and analgesia ___ is sustained for a relatively long period. Ishii e Brief-Intense Mode • This mode involves the delivery of electrical pulses with relatively long durations, high TO frequencies, and current amplitudes capable of noxious stimulation painful • It is described as brief intense because durations of application are briefer and current amplitudes much higher, or more intense, than in the other modes, therapy. causing a mixed sensation of strong muscle contraction and maximum tolerable pain. D TEN I Burst Mode • This mode refers to the delivery of bursts of 0 pulses of relatively low burst frequencies, with a current amplitudes capable of sensory and motor stimulation • It is described as burst to emphasize the use of bursts of pulses rather than individual pulses. This mode implies the preferential depolarization of sensory A-delta and motor alpha fibers. Electrical stimulation is felt as a mixed sensation of tingling and moderate motor contraction. e • Pain modulation occurs through the opiate system. • The onset of analgesia is relatively slow, and analgesia is sustained for a relatively long period e 5 Parameters 90 130 TENS (pattern ) Modes Conventional-Highfrequency Sensory TENS Acupuncture-Lowe frequency Motor TENS 9 1 Frequency (Hz) 90-130 Hz 2-4 Hz Pulse duration (µS) 60-100µS 200 -250 µS Intensity (mA) Sensory(Tangling) Sub-motor Sensory(Tangling) Motor (Rhythmic muscles contraction) Pain modulation Spinal Gait Theory Supra-Spinal (Beta-endorphin / Enkephalin) (Aβ) fibers (Aδ) and (C) fibers Nerve fibers stimulated Treatment time Onset of analgesia Duration of analgesia Uses 15-30minutes for 1 or 2 times daily of Rapid (≤30min) relief Pain Slow (30-120min) Short (30minutes to 2h) Long (6-7h) Acute/postoperative pain Chronic pain TENS (pattern ) Modes Parameters Brief -intense TENS Burst –TENS Frequency (Hz) 100-150 Hz ≥10 Hz burst (2- 3bups) Pulse duration (µS) 150 -250 µs Burst duration (300-1000µS) Sensory(noxious stimulation) Non-Rhythmic muscles contr. Sensory/ motor Intensity (mA) dosentmakestrengthto MS Strong muscles contr. strengththe ms Pain modulation Supra-Spinal (Beta-endorphin / Enkephalin) Nerve fibers stimulated A delta/C fibers Treatment time Onset of analgesia Duration of pain relief Uses 15minutes A delta/C fibers 20-30minutes Rapid (≤30min) Slow onset (≥30 min) F Long Long Painful procedure /pre-post surgery Chronic neuromuscular pain Lasting Physiologic Response To Electrical Current • As electricity moves through the body's conductive medium, changes in the physiologic functioning can occur at various levels – – – – Cellular Tissue Segmental Systematic É • • • • • go Effects at Cellular Level 6 Excitation of nerve cells of Changes in cell membrane permeability Increase protein synthesis Stimulation of fibroblasts and osteoblasts b stimulate Modification of microcirculation late healing in 1 sawEffects at Tissue Level • Smooth muscle contraction • Tissue regeneration • Skeletal muscle contraction bonehealing Effects at Segmental Level • Modification of joint mobility • Muscle pumping action to change circulation and lymphatic activity • Alteration of the microvascular circulation • Increased movement of charged proteins into the lymphatic channels that reduce edema Systematic Effects • Analgesic effects as endongenous pain suppressors are released and act at different levels to control pain. • Analgesic effects from the stimulation of __ certain neurotransmitters to control neural activity in the presence of pain stimuli. Physiological Effect of TENS: pain reduction through Gate control theory ( modulated by High TENS): • Pain is conducted either through Aδ (A delta) or C fibers. The Aδ (A delta) fibers are small myelinated, relatively slow conductive and carry sharp pain while C fibers are small unmyelinated, E slow conductive and carry chronic dull aching pain. E Convintinal tens gate I 4 bed There a two sets of afferent (incoming) nerve fibers that enter the spinal cord: o • A-beta fibers – larger diameter (faster) – carry touch sensation • C and A-delta fibers – smaller diameter (slower) carry pain sensation Theory: When an electrical current is applied to a painful area, transmission of the perception of pain (via small diameter fibers) to the brain is inhibited by the activity of the large diameter, fast-conducting highly myelinated, proprioceptive sensory nerve fibers --- closing the gate to the pain perception to the brain. Endogenous-Opioid mechanism (descending endogenous opiate system (DEOS): Stimulation of Aδ fibers 52.8 by Low TENS will stimulate the periaqueductal gray region of the midbrain and the raphe nucleus in the pons and medulla. The periaqueductal gray stimulates the raphe nucleus, which sends impulses along the efferent fibers in the dorsal lateral tract which synapse with the enkephalin interneurons. The inter neurons release enkephalin into the dorsal horn, inhibiting the synaptic e transmission of impulses to the second order neurons Ito E Stoute own new Eater XÉ serotonin II A sn É T stimulate Uses of TENS • • • • • 00 Control of acute or chronic pain Management of postsurgical pain Acute or chronic myofascial pain Reduction of post-traumatic acute pain Acute or chronic pain of musculoskeletal disorders and soft tissue injuries (e.g.LBP, arthiritis…..) Eagan • Neurologic pain (e.g. trigeminal neuralgia) • Stump and phantom pain. I a Recent uses of TENS • • • • iO Muscle strength Improve cutaneous blood flow Wound healing Fracture healing (non-united fracture) Contraindications for the use of TENS • TENS should not be used during pregnancy, because it may induce premature labor. • TENS should not be applied over the carotid sinuses due to the risk of acute hypotension through a vasovagal reflex. • TENS should not be placed over the anterior neck, because laryngospasm due to laryngeal muscle contraction may occur. I ex Follow Contraindications • The electrodes should not be placed in an area of O sensory impairment (eg, in cases of nerve lesions,In neuropathies), where the possibility of burns exists. • Arterial disease : the stimulatory effect of the current could produce emboli. • Deep Vein Thrombosis: in the acute phase, it is possible to dislodge the thrombi or increase the inflammation of the phlebitis • Infective conditions. spreading of infection Follow Contraindications • TENS should not be used in patients with a pacemaker due to the electronic interference with the pacemaker by the electric filed generated by the TENS unit. • These electronic devices are prescribed for people of all ages who have an abnormal heart rate (e.g., slower or faster than average, or irregular beating patterns). Their purpose is to ensure a normal heart rate. Pacemaker • Implanted Cardioverter-Defibrillators (ICDs) are prescribed for people who have a faster-than normal heart rate, or tachycardia, as well as for patients suffering from ventricular fibrillation. For example, when tachycardia occurs, the ICD device immediately delivers a mild shock to the heart, redirecting its rhythm to a normal beating pattern. Interference between TENS units and ICD devices has been reported in numerous case ax reports . • So in patients with ICDs is contraindicated, unless the unit is turned off during the application min • Areas of skin irritation, damage or lesions. be cans it's Lowgresistan Burn O • Over abdominal, lumbosacral or pelvic regions during pregnancy other than for labor/delivery. • Tissues vulnerable to hemorrhage or hematoma. • Extreme caution is needed with patients taking narcotic medication D or who are known to have hyposensitive areas. • Incompetent patients may not be able to manage the device and it must be kept out of reach of children. • For patients with diagnosed malignancies that have been diagnosed as terminal, TENS can be used for pain control with informed consent of the patient. Otherwise, TENS should not be used when malignancies are present.. consent Electrode placement: I • Over the painful site, or trigger point which is the most commonly used technique where pain is caused by soft tissues injuries. • Acupuncture point proximal and distal o to the painful area. Furman googht Fr lab • Over the same dermatome. In case the pain is distributed across a large area I • Contiguous placement. In conditions such as postoperative incisions, lacerations in which direct electrode placement is contraindicated as in incisional pain Electrode placement • Peripheral nerves. The effect of TENS can be maximized if the nerve involved in the transmission of pain can be identified and stimulated. • Joint pain : around the joint • Impaired circulation: proximal and distal to extremity. OO INE Nair Advantages: 1. Non invasive. 2. Easy to operate and apply. 3. Has few side effects. 4. Patients can administer themselves. 5. Cheap.