Asymmetrical Onset of Leg Amyotrophic Diplegia (LAD): A Case Report

Abstract

Progressive muscular atrophy (PMA) comprises approximately 10% of patients with motor neuron disease (MND). Some of the patients presenting initially as PMA will develop when followed over time upper motor neuron findings leading to the diagnosis of ALS. True PMA cases represent a pure lower motor neuron presentation of sporadic motor neuron disease and are in a spectrum with ALS and PLS. While PMA typically affects both the arms and legs, some patients have predominantly upper extremity involvement and others may have selective leg weakness referred to respectively as brachial amyotrophic diplegia (BAD) 1,2 and leg amyotrophic diplegia (LAD).3 These cases of progressive muscle atrophy remain restricted to a body region for extended periods. These are considered slow regional variants of motor neuron disease. LAD is a leg onset variant of progressive muscular atrophy (PMA). LAD weakness is confined to the legs for at least 2 years, and there are no upper motor neuron signs.4
A LMN syndrome confined to legs LAD was first described by Pierre Marie and his student Patrikios in 1918 and was known as the pseudopolyneuritic variant of ALS, the Marie-Patrikios form, or the peroneal form of ALS.
Here is another case of LAD for the neuromuscular literature.