Amyotrophic lateral sclerosis (ALS) is a clinically heterogeneous disease and presents with varying degrees of upper motor and lower motor neuron involvement. In certain cases, diagnosis can be challenging even for an experienced neurologist. Electrophysiology supplements the physical examination for detection of lower motor neuron involvement and is combined with the neurological examination to diagnose ALS and define the degree of diagnostic certainty: possible, probable, or definite ALS. Traditionally, neuroimaging has played a role in excluding other diseases that can present with both upper motor and lower motor neuron signs (eg, a high cervical spinal cord lesion or a syrinx).
Foerster BR, Feldman EL. A Brighter Future for Patients With Amyotrophic Lateral Sclerosis Through Imaging?. JAMA Neurol. 2014;71(5):539-540. doi:10.1001/jamaneurol.2014.66