Influence of Visual Dependence on Inter-Segmental Coordination during Upright Stance in Cerebral Palsy.

The presence of visual dependence as an influential factor on the development of functional stability in ambulatory individuals with cerebral palsy (CP) was studied in 22 adults with spastic bilateral CP, 11 of whom were considered visually dependent, and 18 healthy adults. Participants stood upright during pitch plane disturbances of the visual field and support surface. Intersegmental coordination behaviors were assessed by fitting trajectories of adjacent body segments to an ellipse. Mixed-model repeated measures ANOVAs were performed on ellipse orientation angle and area. Dissimilar stabilizing strategies adopted by the two groups with CP imply that visual dependence impacts postural control. Postural reorganization in response to visual flow in all groups indicates that we cannot ignore perceptual aspects of postural control when designing therapeutic interventions.

Visual dependence affects postural sway responses to continuous visual field motion in individuals with cerebral palsy.

The current study aimed to explore the impact of visual dependence on sensorimotor coupling of postural sway and visual motion in adults and teens with spastic cerebral palsy (CP). We hypothesized that individuals with CP would exhibit greater magnitudes of sway than healthy individuals, and the presence of visual dependence (VD) would produce instability in the direction of visual motion. Participants stood in a virtual environment in which the visual scene remained static or continuously rotated 30 degree/second in pitch-up or pitch-down. Increased center of pressure and center of mass responses were observed in the direction of visual scene motion in those with CP. Those with VD exhibited reduced frequency responses in anterior-posterior direction than those who were visually independent. VD suggests deficient sensorimotor integration that could contribute to postural instability and reduced motor function. Individuals with CP who are visually dependent may benefit from more sensory focused rehabilitation strategies. ABBREVIATIONS: AP, anterior-posterior; CP, cerebral palsy; COM, center of mass; COP, center of pressure; MDF, median frequency; ML, mediolateral; PD, pitch down (nose down) rotation; PU, pitch up (nose up) rotation; RFT, rod and frame test; RMS, root mean square; SLP, slope of the fitted line; TD, typical development; VD, visual dependence; VI, visual independence; VOR, vestibulo-ocular reflex; VPI, visual perceptual impairment.

Postural responses of adults with cerebral palsy to combined base of support and visual field rotation.

We employed a virtual environment to examine the postural behaviors of adults with cerebral palsy (CP). Four adults with CP (22-32 years) and nine healthy adults (21-27 years) were tested with a Rod and Frame protocol. They then stood quietly on a platform within a three-wall virtual environment. The platform was either kept stationary or tilted 3(°) into dorsiflexion in the dark or with pitch up and down visual field rotations at 30(°)/s and 45(°)/s. While the visual field rotated, the platform was held tilted for 30 s and then slowly returned to a neutral position over 30 s. Center of pressure (CoP) was recorded and center of mass (CoM) as well as trunk and ankle angles were calculated. Electromyography (EMG) responses of the ankle and the hip muscles were recorded and analyzed using wavelets. Larger angular deviations from vertical and horizontal in the Rod and Frame test indicated that adults with CP were more visually dependent than healthy adults. Adults with CP had difficulty maintaining balance when standing on a stationary platform during pitch upward rotation of the visual scene. When the platform was tilted during visual field rotations, adults with CP took longer to stabilize their posture and had larger CoM oscillations than when in the dark. The inability to compensate for busy visual environments could impede maintenance of functional locomotion in adults with CP. Employing a visual field stimulus for assessment and training of postural behaviors would be more meaningful than testing in the dark.

The relationship between spasticity and muscle volume of the knee extensors in children with cerebral palsy.

PURPOSE: The purpose of this study was to examine the relationship between spasticity and muscle volume in children with cerebral palsy (CP), using isokinetic dynamometry and magnetic resonance imaging. METHODS: A retrospective sample of 8 children with diplegic CP was analyzed. One set of 10 passive knee flexion movements was completed at a velocity of 180° per second with concurrent surface electromyography of the medial hamstrings (MH) and vastus lateralis (VL) to assess knee extensor spasticity. Magnetic resonance imaging was used to measure maximum cross-sectional area and muscle volume of the quadriceps femoris. RESULTS: The quadriceps femoris muscle volume was positively correlated with MH reflex activity, VL reflex activity, MH/VL co-contraction, and peak knee extensor passive torque (P < .05). CONCLUSION: The present findings suggest that higher levels of knee extensor muscle spasticity are associated with greater quadriceps muscle volume in children with spastic diplegic CP.

Muscle changes following cycling and/or electrical stimulation in pediatric spinal cord injury.

OBJECTIVE: To determine the effect of cycling, electrical stimulation, or both, on thigh muscle volume and stimulated muscle strength in children with spinal cord injury (SCI). DESIGN: Randomized controlled trial. SETTING: Children's hospital specializing in pediatric SCI. PARTICIPANTS: Children (N=30; ages, 5-13y) with chronic SCI. INTERVENTIONS: Children were randomly assigned to 1 of 3 interventions: functional electrical stimulation cycling (FESC), passive cycling (PC), and noncycling, electrically stimulated exercise (ES). Each group exercised for 1 hour, 3 times per week for 6 months at home. MAIN OUTCOME MEASURES: Preintervention and postintervention, children underwent magnetic resonance imaging to assess muscle volume, and electrically stimulated isometric muscle strength testing with the use of a computerized dynamometer. Data were analyzed via analyses of covariance (ANCOVA) with baseline measures as covariates. Within-group changes were assessed via paired t tests. RESULTS: All 30 children completed the training. Muscle volume data were complete for 24 children (8 FESC, 8 PC, 8 ES) and stimulated strength data for 27 children (9 per group). Per ANCOVA, there were differences between groups (P<.05) for quadriceps muscle volume and stimulated strength, with the ES group having greater changes in volume and the FESC group having greater changes in strength. Within-group analyses showed increased quadriceps volume and strength for the FESC group and increased quadriceps volume for the ES group. CONCLUSIONS: Children receiving either electrically stimulated exercise experienced changes in muscle size, stimulated strength, or both. These changes may decrease their risk of cardiovascular disease, insulin resistance, glucose intolerance, and type 2 diabetes. CLINICAL TRIALS REGISTRATION NUMBER: NCT00245726.

Effects of a supported speed treadmill training exercise program on impairment and function for children with cerebral palsy.

AIM: To compare the effects of a supported speed treadmill training exercise program (SSTTEP) with exercise on spasticity, strength, motor control, gait spatiotemporal parameters, gross motor skills, and physical function. METHOD: Twenty-six children (14 males, 12 females; mean age 9y 6mo, SD 2y 2mo) with spastic cerebral palsy (CP; diplegia, n=12; triplegia, n=2; quadriplegia n=12; Gross Motor Function Classification System levels II-IV) were randomly assigned to the SSTTEP or exercise (strengthening) group. After a twice daily, 2-week induction, children continued the intervention at home 5 days a week for 10 weeks. Data collected at baseline, after 12-weeks' intervention, and 4 weeks after the intervention stopped included spasticity, motor control, and strength; gait spatiotemporal parameters; Gross Motor Function Measure (GMFM); and Pediatric Outcomes Data Collection Instrument (PODCI). RESULTS: Gait speed, cadence, and PODCI global scores improved, with no difference between groups. No significant changes were seen in spasticity, strength, motor control, GMFM scores, or PODCI transfers and mobility. Post-hoc testing showed that gains in gait speed and PODCI global scores were maintained in the SSTTEP group after withdrawal of the intervention. INTERPRETATION: Although our hypothesis that the SSTTEP group would have better outcomes was not supported, results are encouraging as children in both groups showed changes in function and gait. Only the SSTTEP group maintained gains after withdrawal of intervention.

Continuous visual field motion impacts the postural responses of older and younger women during and after support surface tilt.

The effect of continuous visual flow on the ability to regain and maintain postural orientation was examined. Fourteen young (20-39 years old) and 14 older women (60-79 years old) stood quietly during 3° (30°/s) dorsiflexion tilt of the support surface combined with 30° and 45°/s upward or downward pitch rotations of the visual field. The support surface was held tilted for 30 s and then returned to neutral over a 30-s period while the visual field continued to rotate. Segmental displacement and bilateral tibialis anterior and gastrocnemius muscle EMG responses were recorded. Continuous wavelet transforms were calculated for each muscle EMG response. An instantaneous mean frequency curve (IMNF) of muscle activity, center of mass (COM), center of pressure (COP), and angular excursion at the hip and ankle were used in a functional principal component analysis (fPCA). Functional component weights were calculated and compared with mixed model repeated measures ANOVAs. The fPCA revealed greatest mathematical differences in COM and COP responses between groups or conditions during the period that the platform transitioned from the sustained tilt to a return to neutral position. Muscle EMG responses differed most in the period following support surface tilt indicating that muscle activity increased to support stabilization against the visual flow. Older women exhibited significantly larger COM and COP responses in the direction of visual field motion and less muscle modulation when the platform returned to neutral than younger women. Results on a Rod and Frame test indicated that older women were significantly more visually dependent than the younger women. We concluded that a stiffer body combined with heightened visual sensitivity in older women critically interferes with their ability to counteract posturally destabilizing environments.

Trunk and hip muscle activity in early walkers with and without cerebral palsy--a frequency analysis.

Poor control of postural muscles is a primary impairment in cerebral palsy (CP), yet core trunk and hip muscle activity has not been thoroughly investigated. Frequency analysis of electromyographic (EMG) signals provides insight about the intensity and pattern of muscle activation, correlates with functional measures in CP, and is sensitive to change after intervention. The objective of this study was to investigate differences in trunk and hip muscle activation frequency in children with CP compared to children with similar amounts of walking experience and typical development (TD). EMG data from 31 children (15 with CP, 16 with TD) were recorded from 16 trunk and hip muscles bilaterally. A time-frequency pattern was generated using the continuous wavelet transform and instantaneous mean frequency (IMNF) was calculated at each interval of the gait cycle. Functional principal component analysis (PCA) revealed that IMNF was significantly higher in the CP group throughout the gait cycle for all muscles. Additionally, stride-to-stride variability was higher in the CP group. This evidence demonstrated altered patterns of trunk and hip muscle activation in CP, including increased rates of motor unit firing, increased number of recruited motor units, and/or decreased synchrony of motor units. These altered muscle activation patterns likely contribute to muscle fatigue and decreased biomechanical efficiency in children with CP.

Trunk and hip muscle activation patterns are different during walking in young children with and without cerebral palsy.

BACKGROUND: Poor control of postural muscles is a primary impairment in people with cerebral palsy (CP). OBJECTIVE: The purpose of this study was to investigate differences in the timing characteristics of trunk and hip muscle activity during walking in young children with CP compared with children with typical development (TD). METHODS: Thirty-one children (16 with TD, 15 with CP) with an average of 28.5 months of walking experience participated in this observational study. Electromyographic data were collected from 16 trunk and hip muscles as participants walked at a self-selected pace. A custom-written computer program determined onset and offset of activity. Activation and coactivation data were analyzed for group differences. RESULTS: The children with CP had greater total activation and coactivation for all muscles except the external oblique muscle and differences in the timing of activation for all muscles compared with the TD group. The implications of the observed muscle activation patterns are discussed in reference to existing postural control literature. LIMITATIONS: The potential influence of recording activity from adjacent deep trunk muscles is discussed, as well as the influence of the use of an assistive device by some children with CP. CONCLUSIONS: Young children with CP demonstrate excessive, nonreciprocal trunk and hip muscle activation during walking compared with children with TD. Future studies should investigate the efficacy of treatments to reduce excessive muscle activity and improve coordination of postural muscles in CP.

Relationship between age and spasticity in children with diplegic cerebral palsy.

OBJECTIVE: To examine the relationship between passive torque, reflex activity, co-contraction, and age during the assessment of spasticity of knee flexors and extensors in children with spastic diplegic cerebral palsy (CP). DESIGN: Retrospective. SETTING: Pediatric orthopedic hospital. PARTICIPANTS: Children (N=36) with spastic diplegic CP. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Spasticity of the knee flexors and knee extensors (as measured by peak passive torque, mean passive torque, reflex activity of the medial hamstrings, reflex activity of vastus lateralis, and co-contraction) was assessed during passive movements completed using an isokinetic dynamometer with concurrent electromyography. RESULTS: A significant positive relationship was found between age and mean knee flexor passive torque (P<.05), while a significant negative relationship was found between age and mean percentage of the range of motion with co-contraction (P<.05). CONCLUSIONS: Our results suggest that passive stiffness may play a larger role in spasticity than reflex activity as children with spastic diplegic CP age. Additional research is needed to determine whether subject age could influence the effectiveness of interventions, such as serial casting or botulinum toxin, for spasticity in children with spastic diplegic CP.

Variability and symmetry of gait in early walkers with and without bilateral cerebral palsy.

PURPOSE: Investigating gait characteristics during the early stages of walking in CP may contribute to the understanding of the development of impaired gait. The objective of this study was to investigate differences in the variability and symmetry of spatiotemporal gait characteristics during the early years of walking in children with bilateral spastic CP compared to children with similar amounts of walking experience and typical development (TD). METHODS: The spatiotemporal gait parameters of 31 children (15 with spastic CP, 16 with TD) who had an average of 28.5 (18.1 SD) months of walking experience were collected using an instrumented walkway. RESULTS: All primary spatiotemporal parameters were reduced in the CP group, who also demonstrated greater stride-to-stride variability, compared to the TD group. There were no statistically significant differences in side-to-side symmetry between groups. IMPLICATIONS: Clinical trials investigating gait interventions during the early years of walking in children with CP should be conducted to determine if treatment can reduce the functional limitations that are present during the emergence of walking skills. Further investigation should examine variability and symmetry in the kinematics, kinetics, and muscle activity patterns of early walkers with CP, and the effect of treatment on the variability and symmetry of walking characteristics.

Age and electromyographic frequency alterations during walking in children with cerebral palsy.

The use of surface electromyography (sEMG) recorded during ambulation has provided valuable insight into motor development and changes with age in the pediatric population. However, no studies have reported sEMG differences with age in the children with cerebral palsy (CP). In this study, data from 50 children were divided retrospectively into four groups, representing either an older (above the age of seven years) or younger (below the age of seven years) age group with either typical development (TD) or CP. Data were analyzed from 16 children in the younger age group with TD, and eight in the older age group with TD. Data were also available from 14 in the younger age group with CP, and 12 in the older age group with CP. SEMG signals from the rectus femoris (RF) and medial hamstring (MH) were analyzed using wavelet techniques to examine time-frequency content. RF muscle activity was statistically different between all groups (p<0.001), with an elevated instantaneous mean frequency (IMNF) in the older TD group than the younger TD group, an elevated IMNF in the younger CP group than the older CP group, and elevated IMNF in both CP groups compared to both TD groups. Activity for the MH muscle followed the same pattern except for the CP young and old group comparison, which indicated no difference. The results indicate that differences in neuromuscular activation exist between younger and older groups of children with both TD and CP, and may provide new insight into muscle activity pattern changes during the development of walking.

A randomized controlled trial on the effects of cycling with and without electrical stimulation on cardiorespiratory and vascular health in children with spinal cord injury.

OBJECTIVE: To examine the cardiorespiratory/vascular effects of cycling with and without functional electrical stimulation (FES) in children with spinal cord injury (SCI). DESIGN: Randomized controlled trial. SETTING: Pediatric referral hospital. PARTICIPANTS: Children with SCI (N=30), ages 5 to 13 years, with injury levels from C4 to T11, and American Spinal Injury Association grades A, B, or C. INTERVENTIONS: Children were randomly assigned to 1 of 3 groups: FES leg cycling exercise, passive leg cycling, or noncycling control group receiving electrical stimulation therapy. After receiving instruction on the use of the equipment, children exercised for 1 hour 3 times per week for 6 months at home with parental supervision. MAIN OUTCOME MEASURES: Oxygen uptake (Vo(2)) during an incremental arm ergometry test, resting heart rate, forced vital capacity, and a fasting lipid profile. RESULTS: There were no differences (P>.05) between groups after 6 months of exercise when comparing pre- and postvalues. However, there were differences between groups for some variables when examining percent change. The FES cycling group showed an improvement (P=.035) in Vo(2) (16.2%+/-25.0%) as compared with the passive cycling group (-28.7%+/-29.1%). For lipid levels, the electrical stimulation-only group showed declines (P=.032) in cholesterol levels (-17.1%+/-8.5%) as compared with the FES cycling group (4.4%+/-20.4%). CONCLUSIONS: Cycling with FES led to gains in Vo(2), whereas electrical stimulation alone led to improvements in cholesterol.

Use of the Teager-Kaiser Energy operator for muscle activity detection in children.

The purpose of this study was to demonstrate the usefulness of the Teager-Kaiser Energy (TKE) operator to assess surface electromyographic (sEMG) activity from the hip and trunk muscles during pediatric gait in children with and without cerebral palsy (CP). Muscle activity was recorded from the trapezius, erector spinae, rectus abdominus, external oblique, gluteus maximus and medius, rectus femoris, and semitendinosus bilaterally in ten children with typical development (TD) and five children with CP ages 44.4 +/- 18.6 months. Duration of muscle activity was calculated as a percentage of the gait cycle, and compared to two common onset detection methods, a standard deviation (SD) amplitude threshold method, and the visual inspection from two raters (R1, R2). Relative and absolute agreement was determined using intraclass correlation coefficients (ICCs) and Bland-Altman plots. Of the two automated methods, the TKE method demonstrated better agreement with visual inspection (0.45-0.89) than the SD (0.11-0.76) method. The Bland-Altman plots indicated a smaller bias and 95% confidence interval for the TKE method in comparison to the raters (TKE to R1: -5, 113%; TKE to R2: 4, 95%; SD to R1: -24, 170%; SD to R2: -15, 151%). The use of the TKE operator may better detect sEMG activity in children than the standard amplitude method.

Impact of cycling on hip subluxation in children with spinal cord injury.

BACKGROUND: Hip subluxation is common in children with spinal cord injury, especially in those younger than 10 years. The effects of standing with functional electrical stimulation (FES) on hip subluxation have been studied in these children. However, FES cycling is now available to children with spinal cord injury, but the effect of this intervention on hip subluxation has not been studied. METHODS: Hip migration indices were measured before and after a 6-month program of FES cycling, passive cycling, or electrical stimulation exercise without cycling performed 3 times per week. During cycling, children were positioned to avoid hip adduction and internal rotation to decrease potential stress on the hip. RESULTS: There were no changes in the hip migration indices for children in any group after participating in the study. CONCLUSIONS: These findings suggest that the 3 interventions used in this study may be safe for the hip, provided that the hips are positioned to avoid adduction and internal rotation while cycling. LEVEL OF EVIDENCE: Randomized controlled trial, level 2.

Incidental findings during functional magnetic resonance imaging: ethical and procedural issues.

Incidental findings during fMRI: ethical and procedural issues.This purpose of this report was to describe the discovery of an incidental finding during functional magnetic resonance imaging in a child of typical development. During the completion of a functional magnetic resonance imaging protocol, an abnormality was noted by a board-certified neuroradiologist that was identified as a benign developmental arachnoid pouch. Significant ethical concerns were apparent with the discovery of an incidental finding, which included how to address the likelihood of incidental findings in the consent and assent process, how to disclose the incidental findings to the subject's parents and primary care provider, and how to minimize subject and parental anxiety.

The effects of a shank guide on cycling biomechanics of an adolescent with cerebral palsy: a single-case study.

OBJECTIVE: To examine 3-dimensional lower-extremity joint kinematics and muscle activity during cycling with and without a shank guide for a single subject with spastic diplegic cerebral palsy (CP). DESIGN: Single case. SETTING: Pediatric referral hospital. PARTICIPANT: A 13-year-old adolescent with spastic diplegic CP and limited ambulation abilities. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Kinematic data were collected for 6 joint motions and electromyographic data for 7 muscles during 10- to 15-second trials. Average variability in the kinematic curves was calculated, and kinematic and electromyographic data were analyzed descriptively. RESULTS: With the guide, the subject cycled at 40.1+/-2.0 rpm compared with 13.7+/-4.0 rpm without it. In addition, there was less variability in the kinematic curves (P=.03) and muscles tended to turn on sooner and off later. These results indicate that this subject could cycle faster with the guide, which is desirable for cardiovascular health, and that there was a possible increase in motor control due to reduced needs to control excessive joint motions. CONCLUSIONS: Based on these findings, a shank guide may allow some people with CP to cycle faster and provide improved joint kinematics.

Roles of reflex activity and co-contraction during assessments of spasticity of the knee flexor and knee extensor muscles in children with cerebral palsy and different functional levels.

BACKGROUND AND PURPOSE: Spasticity is a common impairment in children with cerebral palsy (CP). The purpose of this study was to examine differences in passive resistive torque, reflex activity, coactivation, and reciprocal facilitation during assessments of the spasticity of knee flexor and knee extensor muscles in children with CP and different levels of functional ability. SUBJECTS: Study participants were 20 children with CP and 10 children with typical development (TD). The 20 children with CP were equally divided into 2 groups: 10 children classified in Gross Motor Function Classification Scale (GMFCS) level I and 10 children classified in GMFCS level III. METHODS: One set of 10 passive movements between 25 and 90 degrees of knee flexion and one set of 10 passive movements between 90 and 25 degrees of knee flexion were completed with an isokinetic dynamometer at 15 degrees /s, 90 degrees /s, and 180 degrees /s and concurrent surface electromyography of the vastus lateralis and medial hamstring muscles. RESULTS: Children in the GMFCS level III group demonstrated significantly more peak knee flexor torque with passive movements at 180 degrees /s than children with TD. Children in the GMFCS level I and level III groups demonstrated significantly more repetitions with medial hamstring muscle activity, vastus lateralis muscle activity, and co-contraction than children with TD during the assessment of knee flexor spasticity at a velocity of 180 degrees /s. DISCUSSION AND CONCLUSION: Children with CP and more impaired functional mobility may demonstrate more knee flexor spasticity and reflex activity, as measured by isokinetic dynamometry, than children with TD. However, the finding of increased reflex activity with no increase in torque in the GMFCS I group in a comparison with the TD group suggests that reflex activity may play a less prominent role in spasticity.

Examination of spasticity of the knee flexors and knee extensors using isokinetic dynamometry with electromyography and clinical scales in children with spinal cord injury.

BACKGROUND/OBJECTIVE: To examine the role of reflex activity in spasticity and the relationship between peak passive torque, Ashworth Scale (AS), and Spasm Frequency Scale (SFS) of the knee flexors and extensors during the measurement of spasticity using an isokinetic dynamometer in children with spinal cord injury (SCI). METHODS: Eighteen children with chronic SCI and 10 children of typical development (TD) participated. One set of 10 passive movements was completed using an isokinetic dynamometer at 15, 90, and 180 degrees per second (deg/s) while surface electromyographic data were collected from the vastus lateralis (VL) and medial hamstrings (MH). Spasticity was clinically assessed using the AS and SFS. RESULTS: There were no significant differences in peak passive torque of the knee flexors and extensors at any velocity for children with SCI compared to children with TD. Children with TD demonstrated significantly more reflex activity of the MH during the assessment of knee flexor spasticity at all movement velocities than did children with SCI. Children with TD demonstrated significantly more reflex activity of the VL during the assessment of knee-extensor spasticity with movements at 180 deg/s. The relationship between peak passive torque, AS, and SFS was significant during movements at a velocity of 90 deg/s only. CONCLUSIONS: The role of increased reflexes in spasticity needs further examination. Isokinetic dynamometry may be measuring a different aspect of spasticity than the AS and SFS do in children with SCI.

Outcomes of a home cycling program using functional electrical stimulation or passive motion for children with spinal cord injury: a case series.

BACKGROUND/OBJECTIVE: Children with spinal cord injury (SCI) are at risk for musculoskeletal and cardiovascular complications. Stationary cycling using functional electrical stimulation (FES) or passive motion has been suggested to address these complications. The purpose of this case series is to report the outcomes of a 6-month at-home cycling program for 4 children with SCI. METHODS: Two children cycled with FES and 2 cycled passively at home for 1 hour, 3 times per week. OUTCOME MEASURES: Data collected included bone mineral density of the left femoral neck, distal femur, and proximal tibia; quadriceps and hamstring muscle volume; stimulated quadriceps and hamstring muscle strength; a fasting lipid profile; and heart rate and oxygen consumption during incremental upper extremity ergometry testing. RESULTS: The 2 children cycling with FES and 1 child cycling passively exhibited improved bone mineral density, muscle volume, stimulated quadriceps strength, and lower resting heart rate. For the second child cycling passively, few changes were realized. Overall, the lipid results were inconsistent, with some positive and some negative changes seen. CONCLUSIONS: This case series suggests that cycling with or without FES may have positive health benefits and was a practical home exercise option for these children with SCI.