Symptoms and Diagnosis
The initial symptoms of ALS can be quite varied in different people. One person may have trouble grasping a pen or lifting a coffee cup, while another person may experience a change in vocal pitch when speaking. ALS is typically a disease that involves a gradual onset.
The rate at which ALS progresses can be quite variable from one person to another. Although the mean survival time with ALS is three to five years, many people live five, ten or more years. Symptoms can begin in the muscles that control speech and swallowing or in the hands, arms, legs or feet. Not all people with ALS experience the same symptoms or the same sequences or patterns of progression. However, progressive muscle weakness and paralysis are universally experienced.
Gradual onset, painless, progressive muscle weakness is the most common initial symptom in ALS. Other early symptoms vary but can include tripping, dropping things, abnormal fatigue of the arms and/or legs, slurred speech, muscle cramps and twitches, and/or uncontrollable periods of laughing or crying.
When the breathing muscles become affected, ultimately, people with the disease will need permanent ventilatory support to assist with breathing.
Since ALS attacks only motor neurons, the sense of sight, touch, hearing, taste and smell are not affected. For many people, muscles of the eyes and bladder are generally not affected.
ALS is a difficult disease to diagnose. There is no one test or procedure to ultimately establish the diagnosis of ALS. It is through a clinical examination and series of diagnostic tests, often ruling out other diseases that mimic ALS, that a diagnosis can be established. A comprehensive diagnostic workup includes most, if not all, of the following procedures:
- Electrodiagnostic tests including electomyography (EMG) and nerve conduction velocity (NCV)
- Blood and urine studies including high resolution serum protein electrophoresis, thyroid and parathyroid hormone levels and 24-hour urine collection for heavy metals
- Spinal tap
- X-rays, including magnetic resonance imaging (MRI)
- Myelogram of cervical spine
- Muscle and/or nerve biopsy
- A thorough neurological examination
For more information on the importance of a second opinion, click here.
These tests are done at the discretion of the physician, usually based on the results of other diagnostic tests and the physical examination. There are several diseases that have some of the same symptoms as ALS, and most of these conditions are treatable. It is for this reason that The ALS Association recommends that a person diagnosed with ALS seek a second opinion from an ALS expert - someone who diagnoses and treats many ALS patients and has training in this medical specialty. The ALS Association maintains a list of recognized experts in the field of ALS.