ALS Diagnosis and Treatment

There’s no definitive test to determine whether you have ALS. Instead, if you’re experiencing symptoms that suggest you may have it, a neurologist will likely perform a variety of tests to rule out other neurological diseases and narrow down the possibilities for what is causing your symptoms.

Some of the conditions that can cause similar symptoms to ALS include multiple sclerosis, post-polio syndrome, multifocal motor neuropathy, and spinal and bulbar muscular atrophy. (1,2)

Before ordering tests, however, your neurologist will ask you about your symptoms, your health history, your family’s health history, and possibly your work history, since military service has been linked to a higher risk of ALS. (3)

A neurologist will also examine you for muscle weakness, rigidity, shrinkage, or twitching; pain; loss of sensation; and changes in speaking ability, thinking patterns, and emotional expression.

The following are among the diagnostic tests used to assess a person with symptoms suggesting ALS.

Electromyogram (EMG)

In the nerve conduction portion of electromyography, small electric shocks are sent through the nerves to measure how fast they conduct electricity and to determine whether there is damage to the nerves.

A second portion of electromyography involves inserting a fine needle into various muscles to record the electrical activity of your muscle fibers when they are contracted and at rest.

Your EMG results can help rule out ALS or point toward its diagnosis.

The results of an EMG can also help your doctor determine the type of exercise therapy that may be helpful for you. (4)

Magnetic Resonance Imaging (MRI)

An MRI creates detailed images of your brain, spinal cord, and other internal structures. In people with ALS, MRI results usually don’t show abnormalities. But MRIs can identify other conditions, such as multiple sclerosis, tumors or cysts on the spinal cord, herniated disks, and other medical issues that cause neurological symptoms.

Blood and Urine Tests

Your doctor may want to take blood and urine samples to rule out other conditions that cause symptoms similar to ALS.

Spinal Tap

A spinal tap, or lumbar puncture, involves inserting a needle between vertebrae in your lower back to extract a sample of your spinal fluid, which is then examined for abnormal cells.

Muscle Biopsy

A muscle biopsy, or removal of a small portion of your muscle, may be done to look for muscle disorders other than ALS.