American Health Information Management Association (AHIMA) Certification Practice Exam

What is the appropriate ICD-9-CM diagnosis code for Lou Gehrig's disease?

1. 335.20

2. 334.8

3. 335.29

4. 335.2

The correct answer is: 335.20

The appropriate ICD-9-CM diagnosis code for Lou Gehrig's disease, which is medically known as amyotrophic lateral sclerosis (ALS), is correctly identified as 335.20. This code specifies "amyotrophic lateral sclerosis," which directly correlates with Lou Gehrig's disease, thereby designating it as the most suitable and accurate code for this condition. The additional codes presented do not apply to Lou Gehrig’s disease. For instance, the code 334.8 pertains to other specified disorders of the basal ganglia, while 335.29 is used for other specified degenerative diseases of the motor neuron. The code 335.2 itself refers to motor neuron disease, but it is not as specific as 335.20 for the particular diagnosis of ALS. Therefore, 335.20 is the most appropriate choice as it captures the disease accurately and specifically within the classification system.