Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting the nerve cells in the brain. An ALS diagnosis usually involves various tests, including testing the nerves, blood tests, spinal tap, X-rays, and neurological exams.

A person with early ALS symptoms, such as muscle twitches, weakness, or cramps, should seek medical attention. There is no single test for an ALS diagnosis, so usually, the doctor begins by requesting a medical history and performing a physical exam to look for signs of nerve damage and muscular weakness.

A person may also undergo imaging studies and tests to detect the electrical activity of muscle fibers and measure the strength of voluntary muscle contractions. The doctor may also order tests to rule out other diseases with similar symptoms to ALS, such as Lyme disease or multiple sclerosis (MS).

If the doctor suspects ALS after reviewing the test results, they may refer the person to a specialist for further tests and confirmation.

An ALS diagnosis can be overwhelming, but knowing what to expect can give individuals more time to make decisions about and create a long-term care plan. It may give them peace of mind during what can be a challenging experience.

This article explains what to expect with an ALS diagnosis, what it involves, and what next steps may look like.

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ALS can be difficult to diagnose, as there is no single test or procedure to identify the condition conclusively. To reach an ALS diagnosis, medical professionals typically need to conduct a comprehensive clinical examination and order a series of tests to definitively rule out any other conditions that they may mistake for ALS. This thorough evaluation process makes it possible to establish an accurate diagnosis.

Learn more about testing for ALS here.

Electromyography (EMG) and nerve conduction velocity (NCV) tests are important in diagnosing ALS. These electrodiagnostic tests are similar, but there are differences:

  • EMG tests: EMG tests involve inserting a needle electrode into the muscle. They measure the electrical activity of muscle fibers to detect the presence, location, and extent of any nerve and muscle issues.
  • NCV tests: NCV tests use electrode pads on the skin’s surface. They measure how well and quickly electrical signals travel through a nerve, which helps identify damage to the nerve fiber or the protective myelin sheath.

Learn more about EMG and NCV tests here.

Blood tests help doctors rule out other possible causes of symptoms, such as hyperparathyroidism, infections, or toxicities. Tests in a diagnostic work-up may include:

  • complete blood count (CBC)
  • comprehensive metabolic panel (CMP)
  • thyroid function tests
  • liver function tests
  • vitamin B12 level
  • calcium levels
  • c–reactive protein
  • creatine kinase

A spinal tap or lumbar puncture involves inserting a needle into the spine to collect cerebrospinal fluid (CSF). CSF is a clear fluid that surrounds the brain and spinal cord.

A spinal tap provides additional information about the person’s health. For example, it helps identify inflammatory conditions of the nervous system, such as MS. It can also help detect bacteria, fungi, and other organisms that cause brain or spinal cord infections.

Learn more about lumbar punctures here.

X-rays and magnetic resonance imaging (MRI) can help doctors detect bone and joint abnormalities that may cause similar symptoms to ALS.

An MRI is far more detailed than an X-ray. It provides a detailed picture of the spinal cord, the nerves, bones, and the connective tissues surrounding and protecting the spinal cord. It helps doctors identify pressure on the spinal cord or major nerves, tumors, and bony abnormalities that compress the nerves.

Doctors can request a small tissue sample, known as a biopsy, from a muscle for laboratory analysis. Repeating the test helps them identify degeneration that differs from other degenerative diseases. For instance, there are more severe changes in ALS over a shorter period, so doctors can differentiate it from MS or muscular dystrophy.

In ALS, muscle biopsies also show inflammation, atrophy of the nerve fibers, tissue death, and other abnormalities.

Neurological exams test reflexes, muscle strength, and other responses. Doctors repeat them regularly to assess whether symptoms such as muscle weakness, muscle wasting, and spasticity progressively worsen.

Reaching an ALS diagnosis can take considerable time, as many other conditions can mimic the symptoms. On average, it takes around 12 months.

Minimizing this delay is critical as there are medications that can delay ALS progression, and the sooner treatment begins, the better the outcome. Speeding the diagnostic process may also help families and caregivers plan for the future and make care decisions.

Therefore, seeking a second opinion from an ALS specialist with experience diagnosing and treating the disease is important. A person can make the most of their time with a specialist by researching and coming prepared to ask questions regarding symptoms, diagnostic tests, and treatment options.

Once the doctor has confirmed an ALS diagnosis and created a treatment plan, the person may want to talk with specialists about life planning, including:

  • long-term care for mobility needs
  • financial planning and insurance coverage
  • respite care for family members
  • nutrition and hydration options
  • social support for coping with the diagnosis and living with ALS

Having a strong support system can be invaluable following an ALS diagnosis. There are many resources to help individuals affected by ALS and their families, such as:

  • support groups
  • online forums
  • patient advocacy organizations

Getting an ALS diagnosis can be a challenging experience, but gathering information and speaking with specialists can help make the process less overwhelming.

There is currently no cure for ALS, and the symptoms tend to develop relatively quickly, progressing over 2 to 5 years after diagnosis. However, 1 in 5 people live for more than 5 years, and around 1 in 20 live for 20 years or more.

ALS is a serious condition that greatly impacts quality of life, but early diagnosis and prompt treatment can help individuals manage their disease.

Recently, researchers have also identified new ALS treatments and made advancements in existing treatments that may slow disease progression. This research provides hope for people living with ALS, helping them live longer and better lives.

Doctors find ALS challenging to diagnose, as many other conditions can mimic its symptoms. As such, it is a diagnosis of exclusion, meaning doctors must rule out other conditions before reaching an ALS diagnosis.

The diagnostic process involves a variety of tests, including neurological examinations, blood and urine tests, MRI scans, spinal taps, and biopsies to help confirm the presence of ALS. In addition, it is beneficial for people to seek a second opinion from an ALS specialist with experience diagnosing and treating the condition.

Currently, there is no cure for ALS, but medications can help manage the disease. Recent research provides additional hope for those living with the disease.