AMYOTROPHIC-LATERAL-SCLEROSIS WITH MARKED NEUROLOGICAL ASYMMETRY - CLINICOPATHOLOGICAL STUDY

We attempted to correlate the marked neurological asymmetry observed i n two amyotrophic lateral sclerosis patients with their histopathologi cal lesions. Patient 1, a 52-year-old man, developed dysarthria and dy sphagia, followed by muscle weakness in the left arm and then of the l eft leg. Patient 2, a 44-year-old man, developed muscle weakness in th e left hand, left leg, tongue with left-sided predominance, right hand and right leg in that order of progression. Both patients exhibited m oderate to marked left-sided predominant involvement of the lower moto r neuron system, accompanied by retained or hyperactive deep tendon re flexes on the left side in the early stage of their illness. Most of t he asymmetry in the lower motor neuron system involvement persisted un til the death of the patients. Histopathological examinations, includi ng semiquantitative analysis, revealed that both patients exhibited le ft-sided predominant degeneration of the lower motor neuron system at those spinal cord levels where the neurological asymmetry was of a mod erate to marked degree. In addition left-sided predominant degeneratio n of the lateral corticospinal tracts was seen in both patients and ri ght-sided predominant involvement of Betz cells in the leg area of the motor cortex of patient 1. This pattern of both the neurological and histopathological asymmetry suggested the probable existence of an int imate somatotopically related linkage between the upper motor neuron s ystem degeneration and lower motor neuron system degeneration in both patients.