All subjects should participate in active rehabilitation. They will receive two physical and occupational therapy sessions per day. Post discharge, each participant should continue to receive rehabilitation therapy at least 3 days per week until the study completion.

GMFM (Gross Motor Function Measure) as a standardized measurement tool for assessing Gross Motor Function consisting of sub-scales; lying & rolling, sitting, crawling & kneeling, standing, walking, running & jumping (range: 0~100 , Higher value means better gross motor function). The investigators will report GMFM scores at each assessment time points.

Korean version of Bayley Scale of Infant Development-II (K-BSID-II) Motor Scales (higher value means better motor function: 0 - worst, 111 - best). The investigators will report K-BSID-II Motor Scale raw scores at each assessment time points.

WeeFIM (Functional Independence Measure for Children) measures functional independence in daily activities. WeeFIM contains 18 items and each item is ranked from complete dependence (scored as 1) to complete independence (scored as 7). The range is from 18 to 126 and higher scores mean more independent performance in daily activities. The investigators will report total WeeFIM scores measured at each assessment time points.

We will evaluate visual perception function with one of three measures: DTVP (Developmental Test of Visual Perception), MVPT (Motor-free Visual Perception Test), and VMI (Visual-Motor Integration, Visual Perception and Motor Coordination). All can be scored as percentile rank from 0 to 100. Higher values mean better visual perception ability

Summation of MMT (manual muscle strength test score): summated scores of the manual muscle strength test (zero=0, trace=1, poor=2, fair=3, good=4, normal=5) for flexors, extensors, abductors, and adductors of bilateral shoulder and hip joints; flexors and extensors of bilateral elbow, wrist, and knee; dorsiflexors and plantar flexors of the ankles (range: 0 ~ 160) Higher scores mean better muscle strength. Categories of outcome table will be summation of MMT scores measured at each assessment time point.

Pediatric Evaluation of Disability Inventory (PEDI) for assessing functional performance in daily activities in children (All values are adjusted and higher value means better functional performance, 0 - worst, 100 - best). We will report 2 scales and 3 domains of each scale: a Functional Skill Scale (FSS) and a Caregiver Assistance Scale (CAS) which are divided respectively into 3 domains: self care, mobility, and social function. Categories of outcome table will be each domain scores measured at each assessment time point.

Sequenced Language Scale for Infant (SELSI), Preschool Receptive-Expressive Language Scale (PRES) or Korean Western Aphasia Battery (K-WAB) will be used depending on age and function.