Principles of insertion of needle electrodes

Video clips from the program, instead focusing on the entry. Is also important to maintain continuity and facilitate the movement of patient and doctor during the examination. Saving electrode wires to the preamp on hand so that the teacher, or electrode is not disturbed, disabled, or lost to facilitate a smooth investigation.

Instead, it is useful to teach the skin little time to point the finger and index finger thrusting his hand, which has a needle electrode. This allows rapid penetration of the needle electrodes into the skin and subcutaneous tissue. In some muscles, this maneuver also serves to identify the boundaries of isolated muscle under investigation. It is not always possible to "skin tight" maneuver, show and prove the point of entry into the video. Although the author tends to stabilize the needle electrodes placed electrodes gloved hand holds the patient. This allows for better control while maintain the needle electrode placement.

When studied the inner muscles of the hand or foot, trying to set the electrode in the dorsal skin is less sensitive, rather than on the bare skin of the palm or sole (which can be beneficial for some individuals calloused). In most cases, inserting the needle electrode is perpendicular to the orientation of muscle fibers, leather. The needle electrode is inserted on the track more deep or corridor as an example of how superficial and deep sites in the muscle.

In most muscles, the electrodes located halfway between midbelly or suspected endplate of the muscle and its origin, or automatically. Although the electrode may take a more inclined direction parallel to the muscle fibers, the danger is that in most muscles, especially the larger ones, the same motor units to be sampled as the electrode through the muscle fibers under the same length of penetration. periodic activation of the needle is advanced through the process, reduces a few patient discomfort. Exceptions come about, аs in the frontalis or orbicularis oculi muscle, which is relatively thin plate and add an angle to the skin surface are needed.

In addition to straight line perpendicular to the longitudinal axis of muscle fibers, you can usually sample two other corridors around 45 degrees on each side of the first course to deviate from the longitudinal axis of muscle fibers. Corridor and the angles are computed from the surface of the muscle, not skin. The electrodes should be re-run in parallel to the longitudinal axis of the muscle fibers are deposited in a new income for the more proximal or distal to the original location of sites like this one almost the same probability of motor units of the samples provided. other insertion sites to be on the medial side, or original, far enough so that the sloping side passage to match. The exception is in the paraspinal musculature in a separate article for her.

Even with the normal location, appearance MUAP change significantly as the needle electrode "opinions" from different positions in the motor unit (Exhibit Berg, 1991, Barkhaus, 2005). In Figure 1, and either electrode A or B can be the same MUAP (s) as a tip advance registration on the car unit, but it may look "different" for different positions in the motor unit is enough to tip registration record. Assuming no change in the level of activation, a lecturer has a bad idea to buy a larger number of motor units to actually see an artist paint the same subject but from different angles, or other variables, such as lighting. For example, a fin de siècle French Impressionist Claude Monet painted a series of paintings depicting the same straw at different times, such as a change in relief. Although the straw in some paintings seem quite similar, in other pictures, it looks completely different. In case of doubt whether a vehicle is present, the needle electrode must be mature enough to make it through its territory.

This risk is further reduced with further steps in the middle or side, as shown in Figure 2, but only certain way to limit the motor unit, respectively. How big the motor unit territory? It depends on muscle mass, or smaller muscles in the distal large proximal muscles. Biceps brachii is estimated that 50-10 mm in diameter. If other countries are essential inputs in the same muscle, it is recommended that so far from the original passage so that only the medial / lateral disagree.

Although usually unnecessary in the review of several major muscle, small superficial muscles or deeper must be identified and isolated by activating localization confirmed before and immediately after, the entry needle electrodes. Insertion sites that are specific to muscle in this program is recommended on the basis of anatomy and experience. This implies the absence of further justifying factors, such as apparent veins, scars, vascular anastamoses dialysis, superficial infection, etc.

If the muscle is activated and controlled, but no needle electrodes record activity, the re-location required prior to entry into the monitoring and spontaneous activity (see activity above). In many muscles, which confirms the location to see a short activation is beneficial. The muscle is then easily "turn off" entry and assessment of spontaneous activity permit.

After the scan insertion and spontaneous activity, but before the muscle MUAPs estimated, it is appropriate that the needle electrodes pulled to a low point only point of entry. The patient must activate the muscles on a scale of mild or moderate and the needle gradually re-introduced in the same corridor (s). Activities can be tailored to MUAPs most visible on the screen.

As little bleeding occurs after removing the needle electrode is used with fast printing thin. Sometimes minor bleeding was delayed a few moments. This is an important point on the label lecturing skills, and respecting the patient's bleeding is minimized and controlled immediately. After each completion, the investigator may want to periodically apply pressure for a few moments. It was slow test, while the analyst asks the gentle pressure with one hand, studies show, place, or prepare for study. Even when the needle electrodes are usually very sharp, dull quickly with repeated insertions, particularly when the issue is pushed too hard against the bone (periosteum afferent remember the pain!).

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Needle electrodes

Technical aspects of needle electrodes are covered to а different place (Bа rkhaus, 1998 Barkhaus, 2005, Nandedkar, 2001, Nandedkar, 2002). Choose versus monopolar concentric needle electrodes are usually based on teacher education and biases. Some of the historical reasons, is no longer valid, because nearly all laboratory electrodes or disposable type. Both are available in various lengths. In general, often using electrodes of 50 mm both required a deeper, bigger muscles examined in many adults, particularly multifidus. with 75 mm in case of need, as in obese patients. In the following discussion, the principles apply to both electrodes covered by concentric and monopolar needle, unless stated otherwise (eg potentials burner).

25 mm concentric needle electrodes (sometimes referred to these as "cheek" concentric needle) is thinner (0.3 mm in diameter) and small absorption of the active area (0.019 mm2) than other standard concentric electrode (ie 0, 46 mm in diameter , recording area 0.07 mm2). Thus, their physical properties, such as high strength and reduces the absorption of the surface differs from the standard meter concentric needle electrodes. real differences in measured MUAP features such as amplitude, duration, complexity, etc between standard and small concentric needle electrodes linger unsettled. As a general rule, but MUAP amplitudes tend to be higher and may appear "neurogenic", especially in the distal muscles.

Benefits of concentric needle electrodes, with only one place for an active and reference (ie burner) recording electrode surfaces. There is also a large base of quantitative data on the characteristics of different MUAP on the muscles of subjects of different age groups. Other electrodiagnostic consultants believe that the monopolar electrode is not as much of harmful or better tolerated by patients. In our experience, patient tolerance depends mainly on the experience and skill of electrodiagnostic consultant.

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Preparation of the examiner

Preparing for the electrodiagnostic consultant began to develop a working hypothesis or diagnosis of the patient investigated. It is based on the request of the referring physician, a consultant clinical electrodiagnostic evaluation of nerve activity or other evidence, have been completed at this point. Part provocative and damaging the needle electrode examination is a major study of a select few muscles to handle fewer patients to change their attitude to the plan. Based on these results, revenues other muscles trying to help confirm or refute the impression of diagnostic studies.

The effectiveness and appropriateness of needle electrode examination based on the experience of lecturing. It is important that less experienced managers, refrain from turning the pages of introduction, in which the author terms "inertion 'Web sites. In this depressed situation,
analysts are still uncertain about the signal on the screen, their uncertainty accelerate in section to the length of time at some point in which the electrode is a twist іn the muscle. Even though most often practiced on each electromyographer experience from time to time to measure this phenomenon. Patients are insightful to time. Examiner should always be on guard, because the point of service in the country exceeded income. When considering a particular muscle is a problem, it is best to go along to the next muscle. One such problem can be solved by replacing or study other muscles, or return to the same muscles at the end of the study with data from other muscles are available.

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Preparation of the patient

Patient tolerance is often directly proportional to their awareness of the process. This process is explained to the patients' access to the laboratory. patient comfort and confidence in the analyst, is a priority.

proper dress, depending on what muscles to be studied. It is said that if the study is focused on cervical radiculopathy, only partially disrobing outer clothing such as shirt or blouse with a dress code is required. Ability to identify bars, however, requires study of the lower extremities. In most cases it is less worrisome if the patient is prepared for the occasion, rather than to stop, while the patient disrobes others, especially if they need help. It also facilitates the pre-clinical tests.

subjective perception of pain varies greatly between individuals. Given that the needle electrode examination is considered the least harmful at least in most patients, it is necessary to ensure that this process is fully explained at the beginning of the test. After preliminary examination and nerve activity, or other studies, the patient should be informed again the needle electrode examination. At this point it is appropriate to investigate the history of recurring infections (eg hepatitis, HIV, etc.), risk factors for infection or the use of coagulation.

Electromyographer be reviewed with the patient about 2-3 times in the muscles examined, including how to position and activate the muscles, as well as testimony about where the needle will be placed. Even though the patient may be concerned, it is much easier to "coach" the patient activation, and it is released before the injection. Patients who participate in the activation of their muscles tend to lead them from the discomfort of the process.

Patients often ask how many "sticks" or "pokes" that the "needle". The experienced investigator knows that it is impossible to have exact figure given for the exam. Direct response can be avoided by diplomatic nonspecific reactions as "very" or not ", much more. When asked again, as in question is near completion, the answer to" something more "is at least encouraging. At present the numbers usually require the patient started, just to feel confident when it is quoted out of date.

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Positioning of the Patient

Lateral Decubitus

The patient is placed on their side. For purposes of this program, this position means that the patient's torso and legs straight without turning their shoulders or pelvis. their head is supported by a pillow or similar device on the head and neck straight and in line with the long axis of their backs, without lateral deviation. In most cases, after examination of a limb or area to be in this position to be superior. Other specific location of the lower limbs should be activated when the patient (see, eg, multifidus, etc.).

Prone

The patient was lying face down on the examining table. If necessary the head and neck in a neutral position, the upper shoulders and neck pillow to your face, so it will not come down on
the examining table. Feet should be positioned so that they are slightly raised or extended from the end of the rotation table leg or unnecessary activation of leg muscles as well.

Supine

The patient was lying face up on the examining table.

A variant is the supine lithotomy position. This will be discussed separately in the pelvic floor muscles and a chapter on them.

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Anatomic Planes

Anatomical position, the crown diameter of the body vertical plan in order to lead to earlier segments of / back cover. Horizontal or axial plane of the diameter of the body leads to rostral tail / "sectoral" segments. Axial or sections in this presentation, the convention is to look at rostral (or vice versa). Sagittal plane extends the previous subsequent breakdown of the body vertical to the left and right segments.

Electrodes

This program puts emphasis on the location of the intramuscular needle electrodes for direct recording of myogenic signals. The two most commonly used is the concentric needle electrodes and monopolar needle electrodes. Other less commonly used are single fiber electrodes for the
EMG electrodes and motion study of fiber density, macro-EMG electrode is used to study macro-EMG and fiber density, and intramuscular needle electrode, which is both myogenic data signals and allow therapeutic injections chemodenervation muscle . Etc., that this program is not synonymous with surface electrode recording during the studies of engine power. Some of them are considered a special relationship to this program.

Isometric contraction

This is the most common form of contraction or the model used in the EMG activation. The tension in the muscle via activation without altering its length. So there is less chance of accidental needle electrodes into muscle movement. Although the standard length of the isometric contraction of the muscle EMG does not seem to change the surface observations in clinical practice, the needle electrode may bow or bend in some muscles (eg, anterior tibial, flexor carpi radialis, etc.). In these muscles, it is appropriate to activate the muscles before getting the needle electrodes in an oblique direction (perpendicular to the preferred approach). Resting activity, can be examined later when the muscles are relaxed.

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Activation of muscle

This is a voluntary muscle contraction results in muscle group or joint motion (s). muscle activation in the electrodiagnostic examination is similar to activation in the test manual muscle during clinical examination. This is due to maximum strength determines the strength. The EMG, however, the emphasis is on minimum recruitment through graduation, activation of durable, voluntary muscle.

Respect progressive EMG activation is known as recruitment. maximal activation was mentioned as a model intervention. Motor unit action potential (MUAP) analysis, this observation is MUAP discharges at a relatively low level of activation that is critical to measure their properties (eg amplitude, area, duration, phase, etc.). Hence the emphasis on EMG, the patient's ability to achieve and maintain a minimum control activation of specific muscles to facilitate effective.

In this program, typically in search of the muscles in this program based on activation. So it is important for the insertion, origin and action understanding. Moreover, the most important aspects of their origin, and data entry, along with recommended methods of activation. Many muscles have more than one action or direction of joint movement. Activation of the method used in this text is usually the main action of a muscle (or action that is simple with minimal movement of the limbs used).

Some patients may have problems with the activation of muscle (s). The analyst should then literally "hand" to help them resist. This can be avoided in most cases, the speakers when a free hand to manipulate the settings on the electromyograph. It is important to perform special studies such as quantitative MUAP analysis and single fiber EMG, which won the minimal muscle activation is required. Useful "tricks" to activate (eg, adductor longus eyes, triangle, frontalis), where this is possible. Note that if the examiner touches the patient with one hand without gloves, interference may be experienced. Use direct eye contact with the skin to prevent removal of the patient often.

As in the clinical examination, needle electrode examination must be changed if the patient has significant weakness. Tests in this video is simple, where the patient is thought to have forced at least 3 degrees (Medical Research Council rating system, guarantors Brain, 2000). When you can be a major weakness or complete paralysis is currently reviewing other changes necessary. In such cases, the electrodiagnostic consultant with skills in navigating through the subcutaneous tissue and muscle electrodes.

It could be argued that the location of the muscle can be made only on the surface landmarks and anthropometric measurements in relation to the unnecessary activation localization. No matter how careful location of any strategy, muscle activation is still required in the production of MUAP. Where they can atrophy, or muscle weakness occurred in subacute denervation and chronic care in interpretation must be done, especially with the deep muscles and landmarks change as a result of reduction in muscle mass.

In some cases, particularly in large limb muscles, the screen is "silent", despite what appears clinically appropriate patient activation. Trainee Financial usual response is even greater efforts to find patients, all with no result other than the patient's fatigue and discomfort. This phenomenon is usually due to misunderstanding the instructions to activate the Commissioner. The patient, a different muscle activation to achieve the same desired result without the additional discomfort of needle electrodes (eg, knee flexion in the brachioradialis where the electrodes in the biceps brachii). If the needle electrode is placed accurately and precisely maneuver activation of MUAP discharges ready for publication at a lower intensity level. activation of compensatory maneuvers patient, however, can important data for the localization of pathological process (eg use of long extensor palmar abduction of thumb to run, when the abductor pollicis brevis is bad!)

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