Understanding ALS Diagnosis: Tests, Symptoms, and Key Procedures

Amyotrophic Lateral Sclerosis (ALS), also commonly known as Lou Gehrig’s disease, is a gradual neurodegenerative disease which causes the nerve cells in the brain to deteriorate. Initially impacting the arms and legs or having changes in speech, ALS disease causes extreme muscle distress and severely affects mobility, speech, swallowing, breathing, and muscle control, leading to progressive physical disability. Let’s take a closer look at the process of ALS diagnosis, highlighting the tests, symptoms, and key procedures. 

What Is ALS and Why Is Diagnosis Important?

ALS is a brutal neurodegenerative disease that gradually strips away the ability to eat, speak, move, and breathe, casting a dark shadow with its fatal prognosis.

Overview of Amyotrophic Lateral Sclerosis (ALS):

ALS disease can have a debilitating impact on physical health by damaging the motor neurons in the brain and spinal cord, which manage voluntary movements and muscle control (balancing relaxation and contraction). ALS causes progressive deterioration and death of these motor neurons, thereby causing the brain to cease the initiation and controlling of muscle movement. This impacts the ability of the person living with ALS (pALS) to chew, swallow, speak, and breathe.

ALS symptoms appear gradually, and manifestation of symptoms can vary from person to person. Initially, ALS often begins with muscle twitching, which could appear as difficulty grabbing a pencil, lifting a water bottle, or changes in speech. This leads to progressive weakness in limbs, trouble swallowing, and difficulty in speech. The average life expectancy for people living with ALS is typically between 2 – 5 years after diagnosis, but some may live for  5 – 10 years or longer, depending on the progression of the disease. 

The Importance of Early and Accurate ALS Diagnosis

In many cases, people living with ALS are diagnosed after the disease has progressed to advanced stages. This often means they experience functional impairment and may miss the opportunity to benefit from treatment that could potentially improve their life expectancy of ALS. Although there are no specific diagnostic tests, ALS diagnosis typically follows a certain process, based on clinical symptoms and comprehensive evaluation to enable early intervention. 

According to studies in the U.S., the duration from the first ALS symptom to a confirmed ALS diagnosis takes about 11 - 15 months. This timeline includes a process of elimination, with a minimum of 3 - 4 consultations with different healthcare professionals, which may include orthopedic surgeons, spinal specialists, chiropractors, and neurologists, which eventually lead to an ALS specialist. With timely ALS diagnosis, there is a higher quantity of healthy motor neurons in the spinal cord and brain, providing a window of time to modify ALS disease progression with experimental drugs and other novel treatment options. With early ALS diagnosis, people living with ALS tend to maintain better motor function, while the underlying cause of the disease is investigated. Early intervention also supports caregivers and families by easing some financial and emotional burden. 

Common Symptoms Leading to ALS Diagnosis

Although ALS diagnosis can take significant time, documenting and evaluating the early symptoms can accelerate the treatment process. 

Signs and Symptoms of ALS

Generally, ALS symptoms may differ among individual cases, based on the nerve cells impacted. It often begins with muscle weakness which progressively worsens, leading to a complete loss of mobility as the disease progresses through its stages. Some of the early signs and symptoms of ALS are as follows:

• Difficulty walking or doing routine activities.

• Stumbling and falling during movement.

• Experiencing weakness in the feet, legs or ankles.

• Weakness in the arms or hands, causing clumsiness.

• Difficulty swallowing and slurred speech. 

• Changes in thinking and behavioral patterns.

• Lack of control while laughing, yawning, or crying. 

• Muscle cramps and muscle twitching, especially in the arms, shoulders, feet, and tongue. 

Early symptoms of ALS can sometimes be isolated to the feet, legs, hands, or arms. As the different stages of ALS progress, it starts affecting other organs in the body. ALS continues to worsen, eventually leading to an inability to do basic activities such as chewing, breathing, and speaking. The disease is so brutal that the person living with ALS can be paralyzed at advanced stages. 

ALS symptoms leading to ALS diagnosis (PC: ALS News Today)

When to Seek Medical Evaluation for ALS Symptoms

If you are experiencing consistent muscle weakness, cramps, unusual exhaustion, or frequent dropping of objects during physical activity, it is important to seek medical evaluation. Prompt evaluation is critical to early ALS diagnosis, which may allow pALS to benefit from treatment, to ensure timely interventions for ALS treatment with required drugs or medication and other forms of therapy. The gradual progression of ALS disease may aggravate conditions with worsening symptoms, causing progressive muscle atrophy, extreme muscle distress, and weakness. If you, or someone you know, is experiencing muscle weakness, difficulty with everyday tasks, or changes in speech or ability to eat,  please seek medical evaluation. 

Next steps after ALS diagnosis (PC: ALS News Today)

Tests for ALS Diagnosis

ALS diagnosis can be a difficult process, as early symptoms can resemble other neurodegenerative diseases. The following tests may be given as part of a comprehensive medical evaluation for early ALS diagnosis are:

Electromyography 

This test involves inserting a thin needle through the skin into specific muscles. Electromyography predicts ALS diagnosis by documenting the movement of muscles during contraction and relaxation. The records can help determine if the person has any nerve or muscle damage, as well as the specific location and intensity. 

Nerve conduction study

Nerve conduction study evaluates the ability of the nerves to issue signals to the muscles, helping to determine nerve conditions within different organs. ALS diagnosis can be confirmed with prevalent nerve damage. Generally, both electromyography and nerve conduction study are conducted together with samples from limb,  bulbar, and thoracic locations. 

MRI

Magnetic Resonance Imaging (MRI) scans offer intricately detailed and structured images of the spinal cord and the brain. With advanced MRI techniques, such as diffusion tensor imaging (DTI), it is possible to analyze very miniscule changes, such as white matter integrity, particularly in the corticospinal tract. This test may detect ALS diagnosis even before the other clinical signs. The MRI can detect tumors in the spinal cord, presence of herniated disks in the neck, and other changes in the body which indicate ALS symptoms or other neurodegenerative diseases.

Blood and urine testing

With a series of blood and urine tests, it is possible to rule out other conditions which share common ALS symptoms. ALS diagnosis can be detected through blood tests which show high levels of neurofilament light (NfL). The rise in NfL levels implies rapid degeneration of the neurons, making it a valuable biomarker for diagnosis of ALS disease.

Spinal tap

The spinal tap, or lumbar punction test involves extracting spinal fluid for laboratory testing. During the test, a small needle is inserted between two bones situated in the lower back, and spinal fluid is collected through the needle. Usually, the cerebrospinal fluid (CSF) of people living with ALS does not contain specific abnormalities that confirm ALS diagnosis. The CSF usually appears normal or has minimal changes, so lumbar puncture or spinal tap cannot directly confirm ALS disease, but examining CSF can indicate other conditions or diseases which are similar to the ALS disease. Test results can vary, sometimes showing a rise in protein concentration or an increase in albumin or IgG levels, which suggests a potential blood-brain barrier damage in ALS disease. 

Nerve and muscle biopsy

Nerve and muscle biopsies are not recommended for preliminary ALS diagnosis, but can help in the process of eliminating other conditions. During the procedure, small pieces of nerve/muscle tissue are collected for further laboratory analysis. These tests are generally ordered when clinicians suspect a muscle or nerve disorder, particularly with unusual weakness, pain or high levels of creatine kinase (CK). 

Genetic testing

Genetic testing plays a crucial role in ALS diagnosis, as it can identify mutations linked to familial ALS. The test involves collecting a blood sample and analyzing it using techniques, such as next-generation sequencing, which allows for the  simultaneous analysis of multiple genes related to ALS. The key genes tested for ALS diagnosis include C9orf72, SOD1, FUS, and TARDBP, and some other genes may be examined, according to clinical assessment, family history and ethnicity. 

Conclusion 

ALS is a brutal neurodegenerative disease which impacts voluntary movement and muscle mobility of the person, with gradual onset varying according to the intensity of the deteriorating neurons. The progression of the ALS disease can vary across individuals, and symptoms of ALS may manifest differently according to the different stages of ALS. ALS diagnosis is a complex process, which often involves a combination of different tests, from clinical evaluation, neurological tests, and other lab assessments. Early and accurate diagnosis is essential for timely intervention, effective management, and improved quality of life for people with ALS. Digital biomarkers studied by EverythingALS aim to simplify the diagnostic process, potentially enabling earlier intervention and improved outcomes.