How is ALS Diagnosed?

Diagnosing ALS can be a difficult process, since the initial symptoms presented are very subtle, differently manifested in several patients, and overlapping with some other neuromuscular conditions. In this article, we will familiarize you with the strategies and steps employed by healthcare professionals to diagnose ALS.

ALS Diagnosis: Initial Presentation

1. Initial Symptoms
   The patient presented often begins showing symptoms of muscle weakness and twitching. This causes the healthcare professional to consider a series of possible neuromuscular conditions.
2. Medical History
   A thorough review of the patient’s medical history is in order to determine whether the symptoms presented could be a result of any conditions to which the patient is genetically predisposed.
3. Physical examination
   Physical examination is conducted to assess any consistent patterns of the patient’s neurological decline. 

How Is ALS Diagnosed: Electromyogram (EMG) and Nerve Conduction Study (NCS)

Electromyogram (EMG)

A determinative test in the ALS diagnostic process is EMG, as it evaluates the electrical activity of muscles. The healthcare worker inserts needle electrodes into muscles to record electrical activity and identify abnormalities, suggesting possible ALS. 

Nerve Conduction Study (NCS)

A brief electrical shock is applied to the skin over the area with nerves that are being evaluated. The NCS assesses the speed and strength of signals traveling between neurons and muscles to assess whether a nerve impairment is contributing to muscle weakness.

Eliminating Similarly Presenting Conditions

Healthcare providers use several diagnostic methods not specific for ALS patients to rule out other conditions presenting similarly to ALS, such as herniated disks or spinal tumors. ALS candidates may undergo tests such as Magnetic Resonance Imaging (MRI), blood and urine tests, and even muscle biopsy.

The El Escorial Criteria

This specific criteria was designed by the World Federation of Neurology, and it serves as a standardized guideline for ALS diagnosis. They categorize diagnoses into possible, probable, or definite ALS based on clinical observations and test results to help finalize the patient’s diagnosis.

Diagnosing ALS is a long and complicated process, however, with the right diagnosis, the patient can receive proper treatment offered by several healthcare professionals.

Credits:
ALS Symptoms and Diagnosis
The Role Of Electromyography Tests in ALS
Diagnosis Of ALS