Paralytic disease occurs when the virus enters the central nervous system (CNS) and replicates in motor neurons within the spinal cord, brain stem, or motor cortex, resulting in the selective destruction of motor neurons leading to temporary or permanent paralysis.
Single pulse TMS can be used to activate specific regions of the primary motor cortex resulting in motor evoked potentials (MEPs) within the corresponding peripheral muscle [ 7].
Unilateral destruction of motor cortex resulted in behavioral deficits due to disruption of the corticospinal tract (CST), a part of the descending motor pathway.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective degeneration of motor neurons located in the spinal cord, brain stem, and motor cortex, resulting in progressive atrophy and paralysis of limb, bulbar, and respiratory muscles [ 1– 5].
This result is in accordance with (Saito et al., 2013) showing that efferent and afferent stimulation of the sensory-motor cortex results in ERD in the same frequency bands.
Strokes that affect the motor cortex may result in partial, or full, paralysis of the limbs.
This would reduce the net difference in activation between left and right motor cortex and thus result in a lower amplitude of the mirror view LRP compared with the direct view LRP.
As a consequence, we cannot exclude that frequencies higher than beta are involved in the coupling between the prefrontal areas and the primary motor cortex or that the results found are due to aliasing of higher frequencies, although the EEG results covering a bigger frequency range do point to the same frequencies, i.e., beta frequency.
We agree that the term sensorimotor is ambiguous, and that the primary somatosensory cortex (SI) could have distinct roles from the primary motor cortex (M1) in the results we present.
We hypothesize a trigger mechanism of cognitive activity with increasing beta rhythms generated in cognitively activated areas, spreading into the motor system, where resonance effects with intrinsic motor cortex frequencies can ultimately result in polyspikes and myoclonic jerks.
Because the effect of a direct injection should be more prominent than indirect spread or diffusion, false positive results of motor cortex injections are highly unlikely.
