(a) Pathological “circle sign” of the right hand. The patient is unable to correctly oppose the tips of digits I and II due to weakness of flexor pollicis longus muscle and the flexor digitorum profundus muscle of the index finger, (b) Lüthy’s bottle sign. See the gap between the cup and the skin web due to weakness of thumb adduction, opposition, and flexion in median nerve lesion, (c) Normal neurography of the right median nerve, (d) Diffusion-weighted magnetic resonance imaging showing an acute infarction in the “hand knob” area of the left precentral gyrus.