Premium
The motor cortex and amyotrophic lateral sclerosis
Author(s) -
Eisen Andrew,
Weber Markus
Publication year - 2001
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.1042
Subject(s) - amyotrophic lateral sclerosis , neuroscience , excitotoxicity , anterior horn cell , degeneration (medical) , motor cortex , primary motor cortex , pyramidal tracts , anatomy , biology , medicine , pathology , glutamate receptor , biochemistry , stimulation , receptor , disease
On theoretical grounds, abnormalities of the motor cortex in patients with amyotrophic lateral sclerosis (ALS) could lead to anterograde (“dying‐forward”) transneuronal degeneration of the anterior horn cells as suggested by Charcot. Conversely, retrograde (“dying‐back”) degeneration of the corticospinal tracts could affect the motor cortex. Evidence derived from clinical, neuropathological, static, and functional imaging, and physiological studies, favors the occurrence of anterograde degeneration. It is hypothesized that transneuronal degeneration in ALS is an active excitotoxic process in which live but dysfunctional corticomotoneurons, originating in the primary motor cortex, drive the anterior horn cell into metabolic deficit. When this is marked, it will result in more rapid and widespread loss of lower motor neurons. In contrast, slow loss of corticomotoneurons, as occurs in primary lateral sclerosis (PLS), precludes excitotoxic drive and is incompatible with anterograde degeneration. Preservation of slow‐conducting non‐M1 direct pathways in PLS is not associated with excitotoxicity, and anterior horn cells survive for long periods of time. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 564–573, 2001