Quick Answer
An EMG test measures how nerves conduct signals and how the muscles they supply respond. It runs twenty to ninety minutes, involves brief electrical pulses and a very fine needle electrode, needs no sedation, and you drive yourself home. CNS performs it in AANEM-accredited laboratories at both Southern Nevada offices.
Key Takeaways
- The study has two parts. Nerve conduction studies use surface electrodes and brief electrical pulses; electromyography uses a very fine needle electrode placed in specific muscles. Most patients have both in one appointment.
- No sedation, no fasting, no driver. You can eat normally beforehand, take your usual medications unless told otherwise, and drive yourself home afterwards.
- Duration depends on the question rather than on the patient. A single-nerve question takes twenty minutes; a study assessing a generalised process across several limbs takes closer to ninety.
- Two things must be disclosed before booking: blood thinners, and any pacemaker or implanted stimulator. Neither automatically prevents the study, but each changes how it is planned.
- The physician who performs your study interprets it and writes the report, so no result waits on a handoff between organisations before anyone can tell you what it showed.
01 — OverviewWhat the test measures, and why it is done in two parts
This page covers the procedure. What the results mean for a particular condition is on the condition pages, and the wider set of studies the practice performs is on the diagnostic testing hub. The two parts of an EMG test answer different questions, which is why they are usually done together in one appointment.
Nerve conduction studies, the first part
Small surface electrodes are taped to the skin over a nerve and over the muscle it supplies. A brief electrical pulse is delivered through the skin, and the equipment times how long the signal takes to arrive and measures how strongly it does. Repeating that at different points along the nerve locates where conduction is slowed or blocked. The pulse feels like a sharp tap or a jolt, it lasts a fraction of a second, and it is repeated a number of times at each site.
Electromyography, the second part
A very fine needle electrode is placed into specific muscles, and the electrical activity of that muscle is recorded at rest and during gentle contraction. This is not an injection; nothing is delivered into the muscle. The needle is finer than one used for a blood test and it is listening rather than administering. Which muscles are examined depends entirely on what the first part found and what the referring question was, which is why the study is planned as it proceeds rather than fixed in advance.
Why temperature and technique change the numbers
Conduction slows in a cold limb, enough that a cold hand can produce a result that looks abnormal when the nerve is fine. Controlling limb temperature is therefore part of performing the study properly, not a nicety, and it is one of the specific things the American Association of Neuromuscular & Electrodiagnostic Medicine accreditation programme examines. CNS holds that accreditation at both offices and was the first physician-owned outpatient electrodiagnostic laboratory in Nevada to reach exemplary status.
Electromyography with nerve conduction studies is a two-part electrodiagnostic test that measures the speed and strength of signals travelling along peripheral nerves and the electrical activity of the muscles those nerves supply.
02How to prepare
Preparation is light, and most of it is about what to tell us rather than what to do.
Before you come
Eat normally. Take your usual medications unless specifically told otherwise. Wash the skin and skip lotions, creams and oils on the limbs being studied, since they interfere with electrode contact.
Clothing
Loose clothing that allows access to arms and legs, or expect to change into a gown. Short sleeves help. Leave watches and bracelets off the limb being tested.
Disclose in advance
Blood thinners. A pacemaker, defibrillator or implanted nerve stimulator. A bleeding disorder. Lymphoedema. Any infection or open wound near the area to be studied.
Why the disclosures matter
None of them usually prevents the study; each changes how it is planned. Blood thinners raise the risk of bruising at needle sites, so muscle selection may be adjusted and pressure applied for longer. An implanted device requires care with where electrical stimulation is applied. A bleeding disorder or lymphoedema may make a particular limb unsuitable. Telling us at booking rather than on arrival means the study can be planned around it instead of shortened or rescheduled.
What to bring
Your complete medication list, your referral if you have one, and any previous electrodiagnostic study as the full report rather than a summary. That last point matters more than patients expect: where a prior study exists, having the actual measurements sometimes avoids repeating work and always makes a comparison possible. Records can be requested through medical records, and coverage and any prior authorisation are verified before your appointment.
Been referred for an EMG and unsure what it involves?
No sedation, no fasting, no driver. Twenty to ninety minutes depending on the question.
03What the appointment actually feels like
Anxiety about this study is common and it is usually worse than the study. Being specific about the sensations helps more than reassurance does, so here is the honest account.
The nerve conduction part
Each pulse feels like a sharp tap, a static shock, or a brief muscle twitch you did not choose. It is startling more than painful, particularly the first one, and it is over instantly. The intensity is increased gradually to the level needed to get a clean recording and no higher. Some sites are more sensitive than others; the sole of the foot and the hand tend to be least comfortable. Nothing lasting is felt afterwards.
The needle part
Insertion is a brief sting comparable to a blood draw. The more noticeable sensation is a deep ache when the muscle is contracted gently against the needle, which patients describe as a cramp. Each muscle takes under a minute. Between two and six muscles is typical, depending on the question. You will be asked to relax completely, then to push gently in a specific direction, and the electrode may be repositioned slightly within the same muscle, which is a further brief ache rather than a new insertion.
Duration, and why it varies
Twenty minutes for a focused single-nerve question. Sixty to ninety for a study assessing a generalised process across several limbs. The variable is the question, not the patient, and the study is often extended in real time because an early finding raises something worth pursuing. That is a strength of having a physician performing rather than a technician following a fixed protocol, and it is why the appointment length quoted is an estimate.
Afterwards
You can drive, work and exercise as normal. Some patients notice mild aching in the tested muscles for a day, comparable to after unfamiliar exercise, and occasionally a small bruise at a needle site. Serious complications are rare. Contact us if a needle site becomes red, hot, increasingly painful or swollen over the following days, which would need assessing rather than waiting out.
| Nerve conduction study | Electromyography | |
|---|---|---|
| What touches you | Surface electrodes taped to the skin | A very fine needle electrode |
| Sensation | Brief sharp tap or jolt | Brief sting, then a deep ache on contraction |
| What it measures | Speed and strength of nerve conduction | Electrical activity of the muscle |
| Anything delivered into you | Brief surface pulse only | Nothing; the needle records |
| Typical time | 15 to 45 minutes | 10 to 45 minutes |
04How the report is produced, and who reads it
The value of an electrodiagnostic study lies as much in the report as in the recording, and this is where an accredited laboratory differs from one that simply owns the equipment.
What a good report contains
What was tested, the actual measurements, how those compare against reference values, and what the pattern supports. A report stating a conclusion without the measurements cannot be checked by anyone reading it later. A report listing measurements without localising the finding leaves the referring clinician to draw the inference the study was commissioned to draw. Both failure modes are common, which is part of why peer review exists.
Interpreted by the physician who performed it
At CNS the study is performed and interpreted by the same physician, who has usually also examined you. That matters because the study was planned around a specific clinical question and the person answering it knows what that question was. It also means no result waits on a report travelling between two organisations before anyone can tell you what it showed. Two of the practice neurologists focus on neuromuscular medicine, and their credentials are in the provider section below.
What happens next
Results are discussed with you and sent to whoever referred you. Where a finding points to a treatable cause, that pathway starts. Where it points to a compressive lesion that may need decompression, the referral goes to a surgeon with the report attached, since CNS does not perform nerve or spinal surgery. Where a claim or a workers' compensation matter is involved, the same documented study is what carries the weight, handled through the medico-legal service line.
When a normal result is still useful
A normal study excludes possibilities, and in a field built on separating overlapping causes that is progress rather than a dead end. It is also worth knowing the limits: standard nerve conduction studies assess large myelinated fibres, so a small-fibre process causing burning pain can coexist with an entirely normal study. That is the test measuring what it measures, and it is covered on the peripheral neuropathy page.
05Which questions this study is ordered for
The study is ordered when the examination has raised a question about nerve or muscle function that it can localise. It is not a general survey and it is not ordered to confirm a diagnosis already made clinically without one.
The four commonest referring questions
Is there a generalised neuropathy, and what type. Is the median nerve compressed at the wrist, and how badly. Is a nerve root affected, at which level, and is it losing fibres. Is weakness arising from the muscle or the junction between nerve and muscle. Each has its own page: peripheral neuropathy, carpal tunnel syndrome, radiculopathy and sciatica, and myasthenia gravis.
Why more than one limb is often tested
Patients sometimes query why a study for hand symptoms includes the legs. The reason is that distinguishing a local problem from a generalised one requires comparison, and an unaffected limb is the control. Finding the same abnormality in a limb with no symptoms changes the diagnosis substantially, and it can only be found by looking. Where the study is extended for that reason, it will be explained at the time rather than simply done.
Repeat studies, and why the same laboratory helps
A second study is sometimes needed to establish whether a process is progressing or recovering, typically after several months since nerve change is slow. A comparison between two studies performed by the same laboratory on the same equipment under the same accreditation is interpretable; one spanning two organisations introduces variables that weaken it. Both CNS offices hold the accreditation independently, described on the accreditation page. The Muscular Dystrophy Association publishes patient material across the wider neuromuscular group these studies assess.
What this study does not do
It does not image a disc, a tumour or a bleed, which are questions for magnetic resonance or computed tomography, coordinated with outside facilities since CNS does not operate a scanner. It does not assess the brain, which is what electroencephalography does. It does not measure pain. And it does not diagnose fibromyalgia or chronic fatigue, both of which are sometimes referred for it. The National Institute of Neurological Disorders and Stroke catalogues these as distinct disorders.
06EMG testing across Southern Nevada
Both CNS offices carry a full accredited electrodiagnostic laboratory, so the study is performed at whichever address is the shorter drive rather than at a single hub. That was the point of consolidating from a wider footprint into two fully equipped sites.
EMG test Henderson NV and Green Valley
Patients booking an EMG test Henderson NV attend the West Horizon Ridge Parkway office, just off the 215 Beltway. An EMG test Green Valley Henderson residents can reach quickly is almost always at that address, and it holds the same accreditation as the Las Vegas site.
EMG test Summerlin and the west valley
An EMG test Summerlin patients can reach most easily is performed at West Flamingo Road, which the 215 and Summerlin Parkway feed toward. Consultation, study and interpretation all happen at that one address.
EMG test North Las Vegas and the northwest
An EMG test North Las Vegas patients need is performed at whichever of the two offices is the shorter drive. We will not imply a third location exists.
EMG test Southern Nevada: why the study and the consultation belong together
An EMG test Southern Nevada patients are sent for is frequently arranged separately from the consultation that prompted it, at a different address, with the report travelling back afterwards. Keeping both in one practice removes two handoffs and lets the study be extended in real time when an early finding raises a new question, which cannot happen when a technician is following a protocol sent from elsewhere. It also means the person explaining the result to you is the person who obtained it. Coverage and any prior authorisation are verified before your appointment, with detail on the insurance page, and preparation guidance is on the new patient page.
Nerve and Muscle Testing Guides
7 in-depth guidesThis hub covers the EMG and nerve conduction study itself. The guides below cover the neuromuscular specialist pathway, the accreditation standard behind the report, and the conditions this study is most often ordered to investigate. Start with the condition you were referred for, or with the accreditation guide if the question is about the standard.
Start Here — Cornerstone Guides
Neuromuscular specialist evaluation
What a neuromuscular assessment adds beyond the study itself.
Read the guide → StandardsWhat AANEM accreditation means
What peer review examines, including the temperature control that changes results.
Read more → Referred forPeripheral neuropathy
The commonest reason this study is ordered, and its one important limit.
Read more →Browse by Category
The study and the standard
Nerve conditions it investigates
Muscle and junction
Documentation
The Complete Index — every guide in this hub
Five board-certified physicians
Leo Germin, M.D., FAANEM, founder and medical director, triple board-certified in Neurology and Vascular Neurology through the ABPN and Neuromuscular Medicine through the ABEM, with subspecialty certification in Neurosonology and Neuroimaging. Anup Panduranga, M.D., fellowship-trained in epilepsy. Eric Gutglueck, M.D., neuromuscular medicine and neuromuscular ultrasound. Jessica A. Knirk, M.D., general adult neurology with Botox for chronic migraine. William Lujan, M.D., broad general adult neurology.
Four advanced practice providers
Fara Tan, APRN, MSCN, a Multiple Sclerosis Certified Nurse through the Multiple Sclerosis Nurses International Certification Board. Lindsey Evans, PA-C, general neurology and electromyography. Terra Fonseca, PA-C, a surgical and vascular background applied to general adult neurology. Alissa Nakamura, PA-C, board-certified through the NCCPA, with three years in pain management that transfer directly to nerve-injury and neuropathy questions.
Spread, not headcount
A referral that lands somewhere without neuromuscular or epilepsy depth often becomes a second referral, and each handoff adds weeks. Here an ambiguous nerve study can be reviewed by a neuromuscular specialist and an ambiguous EEG by a fellowship-trained epileptologist without the patient leaving the practice. Full biographies are on the providers page.
The Bottom Line
No sedation, no fasting, no driver, and twenty to ninety minutes depending on the question. Tell us about blood thinners and implanted devices at booking, and the study can be planned around them rather than shortened on the day.
Frequently Asked Questions
Does an EMG test hurt?
It is uncomfortable rather than painful for most patients. The nerve conduction pulses feel like a sharp tap or static shock lasting a fraction of a second. The needle part is a brief sting on insertion, then a deep ache when the muscle is contracted, which patients describe as a cramp. Each muscle takes under a minute.
How long does the study take?
Twenty minutes for a focused single-nerve question, sixty to ninety for a study assessing a generalised process across several limbs. The variable is the question rather than the patient, and the study is sometimes extended in real time when an early finding raises something worth pursuing.
Do I need to fast or arrange a driver?
No to both. Eat normally, take your usual medications unless told otherwise, and drive yourself home. No sedation is used.
What should I tell you before booking?
Blood thinners, any pacemaker, defibrillator or implanted nerve stimulator, a bleeding disorder, lymphoedema, and any infection or open wound near the area being studied. None of these usually prevents the study, but each changes how it is planned.
Is anything injected into my muscle?
No. The needle electrode records electrical activity and delivers nothing. It is finer than a needle used for a blood test. Nerve conduction studies deliver only a brief pulse at the skin surface.
Why are you testing my legs when my symptoms are in my hands?
Because distinguishing a local problem from a generalised one requires a comparison, and an unaffected limb serves as the control. Finding the same abnormality in a limb without symptoms changes the diagnosis substantially, and it can only be found by looking.
Can I do anything afterwards, or should I rest?
Drive, work and exercise as normal. Some patients notice mild aching in the tested muscles for a day, like after unfamiliar exercise, and occasionally a small bruise. Contact us if a needle site becomes red, hot, increasingly painful or swollen over the following days.
Who interprets my study?
The physician who performed it, who has usually also examined you. That means the person answering the question knows what the question was, and no result waits on a report travelling between organisations before anyone can tell you what it showed.
How this page was sourced
Practice facts here come from Clinical Neurology Specialists directly: the accreditation held at both addresses, the exemplary-status designation, that studies are performed and interpreted by the same physician, and that nerve and spinal surgery sit outside the scope. Study standards are sourced to the AANEM and clinical context to the organisations below.
Durations quoted are typical and vary with the question being asked. Sensations described are how most patients report the study and individual experience varies. No statistic appears without a primary source and no diagnostic outcome is promised. Scope is adults 18 and older. This page describes the procedure; it does not interpret a result you already hold.
References
- American Association of Neuromuscular & Electrodiagnostic Medicine — the accreditation programme and electrodiagnostic study standards.
- Muscular Dystrophy Association — patient information on neuromuscular disorders.
- National Institute of Neurological Disorders and Stroke — the reference catalogue of nervous-system disorders.
This page is for general education about adult neurological care and is not medical advice, a diagnosis, or a treatment recommendation. It does not create a physician-patient relationship. Adults 18 and older. For an active stroke, a first-time or prolonged seizure, sudden severe headache, sudden weakness, sudden vision loss, or a head injury with loss of consciousness, call 911 or go to the nearest emergency department. Speak with a qualified clinician about your own circumstances.