Nerve Conduction Testing and Electromyography, also referred to as NCV/EMG testing can help evaluate the peripheral nervous system in the diagnosis of conditions such as
Carpal Tunnel Syndrome
Motor Neuron Diseases such as ALS
This type of testing is not necessary for all patients but can be very helpful in your diagnosis and eventual treatment.
No special preparation is needed prior to your visit for NCV/EMG testing but it can be helpful to avoid heavy creams or lotions applied to the limbs being tested. The majority of patients say "it's not nearly as bad as I thought it was going to be!".
See the following video to see how it's done.