Screenings and Tests
The Neuromuscular Diagnostic Laboratory/EMG Testing
The Neuromuscular Diagnostic Lab at Methodist Plaza is the premier site in Des Moines to obtain testing for patients with suspected disorders of peripheral nerves and muscles. The lab is equipped with advanced technology and highly sophisticated computerized equipment. This allows our physicians to assess the condition or damage of a patient's nerves and muscles.
Common disorders that we identify include:
- Carpal Tunnel Syndrome
- Ulnar neuropathy
- Cervical and Lumbar Nerve Root Problems (e.g., sciatica)
- Peripheral neuropathy
- Guillain-Barre syndrome
- Amyotrophic lateral sclerosis (ALS)
- Myasthenia Gravis (MG)
- Muscular Dystrophies
- Other myopathies
Why Choose Our EMG Lab Services
Our physicians are board-certified in Neurology and Clinical Neurophysiology. We are equipped to provide comprehensive evaluations in a thoughtful, caring manner so we can determine if a patient is suffering from a simple nerve compression or something more serious. Our technologist is also highly experienced and certified in Neurophysiology.
We are one of the few neuromuscular labs in Iowa that can perform complex neurophysiologic testing, such as single fiber EMG, repetitive nerve stimulation, blink reflex and EMG-guided botulinum toxin injections.
Types of Tests
EMGs
Electromyography (EMG) is a form of electro-diagnostic testing that is used to study nerve and muscle function. This procedure is performed by our EMG technologist or by our EMG technologist and a neurologist. EMG testing can provide a neurologist with specific information about the extent of nerve and/or muscle injury and can also determine the exact location of injury and give some indication whether the damage is reversible.
What to Expect
There are commonly two parts to EMG testing: a nerve conduction study and a needle exam for muscle testing. Both may result in some discomfort, but are usually well tolerated without the need for medication beforehand. The nerve condition study entails stimulating the nerves at different points with small electric shocks so their function can be measured. The needle exam involves inserting very fine needles into several muscles. The needle has a microscopic electrode that picks up both the normal and abnormal electrical signals give off by a muscle.
EMG testing usually takes anywhere from 60 to 90 minutes, depending on the condition being tested and findings of the study. A report that includes the results and interpretation will be sent to your referring doctor.
Scheduling EMG Tests
EMG testing requires a physician referral but does not require consultation with a neurologist. We can provide EMG testing alone or EMG testing with a neurology consultation.
An EMG test is extremely safe. Side effects may include some muscle soreness, which rarely lasts more than an hour or two after the exam. Patients on anticoagulation or blood thinners and those with pacemakers or implanted defibrillators should notify the physician performing the test. Patients with joint replacements or other artificial components in their body do not need to take antibiotics specifically for the EMG. Patients on medication should take their usual medication on the day of the test. No special preparation is necessary.
Nerve Conduction Studies
Nerve conduction studies (NCSs) show how well the body's electrical signals are traveling to a nerve.
Needle EMG
This test is used to obtain information about electrical signals in the nerves of a muscle during rest and when the muscle is contracted. The shape, size, and frequency of resulting motor unit potentials can be measured.
Repetitive Nerve Stimulation
This electro-diagnostic test is used to evaluate neuromuscular junction disorders, such as Myasthenia Gravis or Lambert-Eaton syndrome.
Ischemic Forearm Exercise Test
This test is used to help diagnose metabolic myopathies, such as Glycogen storage diseases and myoadenylate deaminase deficiency.
Skin Biopsy (for inter-epidermal nerve fiber analysis)
This test aids in the diagnosis of small fiber neuropathy. A lower number of identified nerves in the epidermis are consistent with damage to small nerve fibers.
Neuroimaging
Neuroimaging uses a variety of techniques to either directly or indirectly image the structure, function and pharmacology of the brain.
Neuroimaging includes both structural imaging for the diagnosis of gross intracranial disease and injury, and functional imaging, used to diagnose metabolic diseases and lesions.
Depending on the patient's symptoms, our neurologists will use a variety of tests to make an accurate diagnosis.