This facial neurological defict is because of the
brain stroke.
stroke can be thrombotic, embolic, hemorrhagic, hypoperfusion related etc and can affect one of the 3 central nervous system pathways like spinothalamic tract, corticospinal tract and dorsal column, symptoms include hemiplegia and muscle weakness of face, numbness, reduction in sensory and vibration sensation.
Usually unilateral, opposite side of the brain part affected.