**6. Motor function recovery**

Hemiplegia is the most paramount clinical feature, which is described as sided weakness of extremity, facial droop, and slurred speech. Motor function recovery follows stereotypic patterns. It initially develops flaccid hemiplegia during the acute phase. Depending on individual cases, however, flaccid hemiplegia evolves into spastic hemiplegia. It continues to evolve into spastic synergy. Typically, flexion synergy develops in hemiplegic upper extremity and extension synergy in the lower extremity. As the synergy fades, individual movement of joints emerges. The longer the length of time in flaccid hemiplegia, the poorer the prognosis of motor recovery. Motor recovery may stagnate at any phase and may skip phases. Another pattern is that proximal segment of extremity function recovers earlier than distal one. Many patients with stroke sustain typical stereotyped poor dexterity and hemiplegic gait because of residual distal extremity dysfunction. In order to facilitate motor recovery, comprehensive rehabilitation modalities, such as anti-spastic medications, orthotics, and therapeutic exercise are cooperated. Significant motor recovery usually occurs in the first three months after stroke. Further recovery may continue in the next three months but less extensive.

Brunnstrom stage describes the evolution of hemiplegia54. Flaccid paralyzed extremity is seen at stage 1; Mild spasticity is appreciated in the flaccid paralyzed extremity at stage 2; The spasticity increases and some self-activated synergic movement of the paralyzed extremity begins at stage 3; Dominant stereotyped self-activated synergic movement of the paralyzed extremity is more prominent at stage 4; decreasing synergic movement pattern with emerging individual movement of the paralyzed extremity is the hall mark of the stage 5; normal movement pattern is seen at stage 6. Not all paralyzed extremity evolves from stage 1 to 6. Depending on stroke severity and recovery potential, the stages may progress quickly or may be skipped. Generally speaking, hemiplegia with short or absent stage 1 has better recovery; the longer the stage 1, the worse prognosis; the lower stage, the poorer outcome, 11, 55-58.

In addition to Brunnstrom stage, motor function recovery tends to begin in the proximal segment and then to progress to the distal segments of the extremity. This tendency is common in both upper and lower extremity. Most of stroke patients are able to move their proximal segments of arms and legs at the time of discharge from inpatient rehabilitation. However, many stroke patients sustain significant paralysis of the distal segments of arm and leg. Because of this residual impairment, most stroke survivors have difficulties to be independent with ADLs and ambulation. Another common finding is that motor recovery of the lower extremity is better than that of the upper extremity. Why is motor recovery of the proximal segments and the lower extremity better than that of the distal segments and the lower extremity? It can be partially explained by topographic distribution in the brain (the cortex corresponding to hand is much larger than one to foot in the brain) and higher developmental hierarchy (hand function develops later than foot function). Compared to the proximal segments or foot function, more neurons and synapses are to be involved to maintain functions of the distal segments or hand.
