Unilateral lingual paralysis after isolated unilateral infarction in the primary motor cortex

The crossed projections appear to dominate functionally, as evidenced by greater compound muscle action potential amplitudes and shorter onset latencies of contralateral responses when compared with the ipsilateral responses. 1 2 This case provides clinical evidence not only for functional dominance of the crossed corticobulbar projections to the tongue but also for the incapability of the unaffected hemisphere to use the uncrossed corticolingual projections, leading to lingual paralysis.