Pseudopolyneuritic form of amyotrophic lateral sclerosis: Marie-Patrikios type

Introduction: Amyotrophic lateral sclerosis (ALS), also called motor neuron disease (MND), is a progressive, neurodegenerative, and inexorable disease that affects the neurons of the anterior horn of the spinal cord, as well as the lateral funiculus. A rare variant of ALS was first described in 1918 by Patrikios and Marie, called the pseudopolyneuritic form or Marie-Patrikios disease. It is characterized by an initial manifestation with melting of the feet, distal weakness of the muscles of the anterior compartment of the leg, and absence of the Achilles tendon reflex. We present an atypical case of ALS, marked by polyneuropathy and involvement of upper and lower motor neurons. Case Report: A 70-year-old man reported that approximately four years ago he started having pain in the thoracic region with subsequent paresis in the lower limbs. Initially, compressive myelopathy, transverse myelitis, and spastic paraparesis of various causes were thought to be the cause. However, the non-impairment of the superficial and deep sensibility, obviously, with absence of sensorial level, associated to the absence of specific imaging findings in the thoracic and lumbar spine, a normal complete laboratory, ruled out such hypotheses. Conclusion: We highlight that the pseudopolyneuritic form presented in this study has a better prognosis and survival rate when compared to other subtypes of ALS. Thus, a detailed investigation including physical, neurological, and electrophysiological examination is essential to establish the diagnosis and increase the scarce knowledge about this condition.