How is ALS diagnosed?

The diagnosis of ALS often comes after the exclusion of all other conditions to explain symptoms. While there is no single definitive test for ALS, specialists will often diagnose it after evidence of both upper and lower neuron signs in a single limb. Specialists will also go through a patient's medical history to look for the presence of other symptoms that may be associated with ALS.

Specialists will likely conduct multiple tests that can be used to rule out other diseases to help establish an ALS diagnosis.

Who gets ALS?

Each year, over 5,600 people in the United States are diagnosed with ALS. It is estimated that as many as 30,000 people in the US have the disease today.

The cause of ALS is unknown, though it is believed that genetics play some role in whether or not someone develops the disease. Up to 10% of cases are attributed to genetics and can be documented through family history.

There are three classifications of ALS that have been identified, with only one being directly tied to genetics.

1. Sporadic – the most common form of ALS diagnosed in the United States, making up 90 to 95% of all cases
2. Familial – can be traced through family history with multiple members diagnosed, and accounts for only 5 to 10% of all cases
3. Guamanian – a cluster of ALS that was diagnosed in Guam and the Trust Territories of the Pacific in the 1950's

In families where there is a history of ALS, there is as high as a 50% chance that other family members will inherit the gene mutation and eventually develop the disease.

Statistically, men are more likely to develop ALS than women. It has been shown that ALS is 20% more common in men than in women. However, the incidence of ALS becomes more equal between the genders with increased age. ALS Care Database information has shown that of patients diagnosed with ALS, 60% are men and 93% are Caucasian.