What is the difference between a diagnosis and a prognosis?

The diagnosis involves identifying and confirming ALS based on symptoms, a neurological examination, and diagnostic tests, particularly electromyography (EMG), electroneurography, cerebrospinal fluid analysis, and MRI. These procedures help rule out other neurological disorders as possible causes of the symptoms and confirm the diagnosis of ALS.

The prognosis, on the other hand, provides an assessment of the expected course of the disease. It takes into account factors such as the ALS phenotype (including the site of symptom onset), the rate of progression (ALS progression rate (ALSPR)), and individual measurement parameters, particularly body weight and respiratory parameters. In ALS, the prognosis helps patients, their families, and the treatment team anticipate future symptoms and plan supportive measures in advance. Although diagnosis and prognosis are closely linked, they represent different aspects of ALS treatment.