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Selective dorsal rhizotomy in cerebral palsy: quantitative outcome assessment using principal component analysis of gait
276
Gait and Posture
1995;
3: No 4
a
statistical significance of alterations in gait pattern. Patients were compared with normal controls, preoperatively and 6 to 12 months postoperatively. Large differences in gait patterns were readily identified when comparing patients with normal children. Further, even when clinical assessment and evaluation of video recordings were ambiguous, gait pattern quantification often demonstrated statistically significant changes toward more normal gait patterns following rhizotomy. Preliminary results comparing the benefits of rhizotomy in younger versus old children are presented. In general our observations suggest that the statistical reliability and resolution of gait outcome assessments are considerably improved by the present method of quantification. Refereoce 1 Mah C D, Hulliger M, LeeR G, O’CallaghanI. Quantitative analysisof humanmovementsynergies:constructive pattern analysisfor gait. J Motor Behav 1994; 26: 83-102.
bar (LJ level, a more complete reduction of spasticity in the hip flexors would occur, and functional outcome would be improved. Study Objective
The purpose of this study was to evaluate the effects of L1 vs. L2 SDR on the gait patterns of children with spastic CP. Design
A retrospective study of previous patients and prospective collection of patients who underwent pre and post-operative gait analysis prior to and following SDR. All SDR procedures were performed by a single surgeon at either Gillette Children’s Hospital or the Shriners Hospital for Crippled Children Twin Cities Unit. Postoperative gait analysis data was collected on average 12 months following SDR. Patients
The effects of L1 vs. L2 selective dorsal rbizotomy on gait in children with cerebral palsy
J L Stout, A4 E Dunn, J R Gage, L 0 Johnson Gillette Children’s Hospital, Motion Analysis Laboratory, 200 East University Ave, St. Paul, MN 55101, USA; Shriners Hospital for Crippled Children Twin Cities Unit, Minneapolis, MN, USA Problem
Selective Dorsal Rhizotomy (SDR) is a procedure used frequently to manage spasticity for children with cerebral palsy (CP). As originally described and typically performed, the procedure extends proximally to the second lumbar (L2) nerve roots for its tone reducing effects. However, the spasticity of children with CP
often includes the hip flexor muscle group which has innervation above the L, level. If the procedure included evaluation and transection of rootlets at the first lum-
Gait analysis data from fourteen children (28 sides) who underwent SDR including the L, nerve root and 8 children (16 sides) with SDR including the L2 level as the most proximal root were evaluated. All children were independent ambulators at the time of gait analysis both before and after SDR. All children had a diagnosis of spastic cerebral palsy. The average age pre-rhizotomy was 8+3 years (L,) and 9+5 years (L2). Measurementsand main results
Linear gait parameters (step length and velocity), kinematics and metabolic oxygen consumption were evaluated pre and post SDR for each group. Both groups demonstrated improvements in step length (17% L,, 34% L2) and velocity (19.4% L,, 23.2% L2). Metabolic oxygen consumption improved an average of 30% in both groups, reflecting decreased energy expenditure.
Abstracts
Differences were noted in the kinematic data between the L, and L2 groups at the pelvis and hip post SDR. The Lt group displayed a decrease in the mean pelvic tilt of 2”. The L2 group exhibited an increase in mean pelvic tilt of 2”. Overall range of pelvic motion in the sagittal plane decreased 3” in the Li group and 4” in the L2 group. No difference was noted in the total hip range of motion for either group. Maximum hip extension in terminal stance improved an average of 5” (L,) and 3” (L2). Conclusions
Differences related to the level of SDR are measured on kinematic data at the hip and pelvis, with greater improvement in mean pelvic tilt and terminal stance hip extension in the L, group. This is believed to be caused by a more complete reduction of hip flexor spasticity by inclusion of the L, nerve root during the SDR procedure. Different mechanisms may underlie spastic diplegic gait H Darwish. M Hulliger, T Myles
Alberta Children’s Hospital and the University Calgary, Calgary, Alberta, Canada
of
Increasing use of Selective Dorsal Rhizotomy (SDR) for children with spastic cerebral palsy has occurred following publication of recommendations for careful selection of candidates most likely to benefit. Absence of signs of extrapyramidal disorder, and the presence of such classic features of ‘spasticity’ as the ‘clasp knife response’ to joint manipulation, and clonus, are critical to proper selection. Although ambulatory children with a spastic diplegic gait clearly have co-contraction of muscles during ambulation with flexion at hips, knees, and ankles and adduction at the thighs, two groups can be identified. Group I have classic signs of ‘spasticity’ and Group II do not show velocity dependent muscle contraction (clasp knife response on passive joint movement) nor clonus. Although both groups may have improved outcome to SDR both the intra-operative EMG responses to dorsal root stimulation and the type and degree of improvement after SDR are different. The intra-operative EMG shows lower stimulus intensity to obtain responses and greater contralateral diffusion of muscle responses which also outlast the stimulus train in group II. We conclude these two groups of children have different mechanisms underlying their ‘spastic gait’. Rotulinum Toxin A and gastrocnemius tension and length characteristics N Eames, R Baker, S MC Neill, A Cosgrove, K Graham, H Cowie, T Taylor, A Hill
The Gait Analysis Laboratory, Musgrave Park Hospital, Belfast, Northern Ireland; The Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland
277
Botulinum neurotoxin type A was first used in the early 1970s by Scott [l] for the correction of strabismus in humans. The toxin is now a well accepted means of treating certain ocular and facial spasms [2]. Cosgrove [3] studying the role of intramuscular botulinum toxin in ambulatory children with cerebral palsy found that botulinum toxin objectively reduced spasticity and improved ambulatory status while yielding improvements in kinematics at knee and ankle joints. The muscles of these patients frequently display an increase in the resting tone and an exaggeration of the stretch reflex 3. Using a trigonometric formula calculating gastrocnemius length from measured knee flexion and foot dorsiflexion angles during VICON gait analysis, the effects of the toxin on the characteristics of the muscle are being observed in a prospective trial. Ambulatory children with dynamic equinus contractures undergo pre injection gait analysis. Gastrocnemius is injected using a standardised technique and patients are reviewed with post injection gait analysis at 2 weeks and then monthly intervals as the toxins effect reduces. Gastrocnemius length and tension characteristics are therefore defined throughout the duration of the toxins effect. In this paper the increase in functional muscle length of gastrocnemius post injection in responders is described. As well as discussing the comparison between normal tension and length curves and those for spastic muscles, the effective alteration in tension and length characteristics post injection will be described. References
Scott A B, Rosenbaum A, Collins C C. Pharmacological weakening of extraocular muscles. Invest Opthalmol Vis Sci 1973; 12, 924-927.
Savino P J, Malon M. Botulinurn toxin therapy. Neur Clin 1991; 9: 205-224.
Cosgrove A P, Carry I S, Graham H K. Botulinum toxin in the management of the lower limb in cerebral palsy. Dev Med Child Neurol 1994; 36: 386-396. Estimating gastrocnemius length from joint rotation measurements N Eames, R Baker, A Cosgrove
The Gait Analysis Laboratory, Musgrave Park Hospital, Belfast, Northern Ireland; The Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland The gastrocnemius musculo-tendinous unit is frequently affected in children with cerebral palsy and consequently is subject to lengthening procedures or other therapeutic approaches such as Botulinum toxin therapy. Gait analysis allows assessment of these patients but most available systems are limited to any changes in joint angles that may occur. We have developed a mathematical model [l] which may be applied to the joint rotation data to allow estimation of gastrocnemius length through the gait cycle. The formula is at present in use in the evaluation of patients under going surgical tendo achilles lengthening and Botulinum toxin therapy.
Gait and Posture
1995;
3: No 4
a
statistical significance of alterations in gait pattern. Patients were compared with normal controls, preoperatively and 6 to 12 months postoperatively. Large differences in gait patterns were readily identified when comparing patients with normal children. Further, even when clinical assessment and evaluation of video recordings were ambiguous, gait pattern quantification often demonstrated statistically significant changes toward more normal gait patterns following rhizotomy. Preliminary results comparing the benefits of rhizotomy in younger versus old children are presented. In general our observations suggest that the statistical reliability and resolution of gait outcome assessments are considerably improved by the present method of quantification. Refereoce 1 Mah C D, Hulliger M, LeeR G, O’CallaghanI. Quantitative analysisof humanmovementsynergies:constructive pattern analysisfor gait. J Motor Behav 1994; 26: 83-102.
bar (LJ level, a more complete reduction of spasticity in the hip flexors would occur, and functional outcome would be improved. Study Objective
The purpose of this study was to evaluate the effects of L1 vs. L2 SDR on the gait patterns of children with spastic CP. Design
A retrospective study of previous patients and prospective collection of patients who underwent pre and post-operative gait analysis prior to and following SDR. All SDR procedures were performed by a single surgeon at either Gillette Children’s Hospital or the Shriners Hospital for Crippled Children Twin Cities Unit. Postoperative gait analysis data was collected on average 12 months following SDR. Patients
The effects of L1 vs. L2 selective dorsal rbizotomy on gait in children with cerebral palsy
J L Stout, A4 E Dunn, J R Gage, L 0 Johnson Gillette Children’s Hospital, Motion Analysis Laboratory, 200 East University Ave, St. Paul, MN 55101, USA; Shriners Hospital for Crippled Children Twin Cities Unit, Minneapolis, MN, USA Problem
Selective Dorsal Rhizotomy (SDR) is a procedure used frequently to manage spasticity for children with cerebral palsy (CP). As originally described and typically performed, the procedure extends proximally to the second lumbar (L2) nerve roots for its tone reducing effects. However, the spasticity of children with CP
often includes the hip flexor muscle group which has innervation above the L, level. If the procedure included evaluation and transection of rootlets at the first lum-
Gait analysis data from fourteen children (28 sides) who underwent SDR including the L, nerve root and 8 children (16 sides) with SDR including the L2 level as the most proximal root were evaluated. All children were independent ambulators at the time of gait analysis both before and after SDR. All children had a diagnosis of spastic cerebral palsy. The average age pre-rhizotomy was 8+3 years (L,) and 9+5 years (L2). Measurementsand main results
Linear gait parameters (step length and velocity), kinematics and metabolic oxygen consumption were evaluated pre and post SDR for each group. Both groups demonstrated improvements in step length (17% L,, 34% L2) and velocity (19.4% L,, 23.2% L2). Metabolic oxygen consumption improved an average of 30% in both groups, reflecting decreased energy expenditure.
Abstracts
Differences were noted in the kinematic data between the L, and L2 groups at the pelvis and hip post SDR. The Lt group displayed a decrease in the mean pelvic tilt of 2”. The L2 group exhibited an increase in mean pelvic tilt of 2”. Overall range of pelvic motion in the sagittal plane decreased 3” in the Li group and 4” in the L2 group. No difference was noted in the total hip range of motion for either group. Maximum hip extension in terminal stance improved an average of 5” (L,) and 3” (L2). Conclusions
Differences related to the level of SDR are measured on kinematic data at the hip and pelvis, with greater improvement in mean pelvic tilt and terminal stance hip extension in the L, group. This is believed to be caused by a more complete reduction of hip flexor spasticity by inclusion of the L, nerve root during the SDR procedure. Different mechanisms may underlie spastic diplegic gait H Darwish. M Hulliger, T Myles
Alberta Children’s Hospital and the University Calgary, Calgary, Alberta, Canada
of
Increasing use of Selective Dorsal Rhizotomy (SDR) for children with spastic cerebral palsy has occurred following publication of recommendations for careful selection of candidates most likely to benefit. Absence of signs of extrapyramidal disorder, and the presence of such classic features of ‘spasticity’ as the ‘clasp knife response’ to joint manipulation, and clonus, are critical to proper selection. Although ambulatory children with a spastic diplegic gait clearly have co-contraction of muscles during ambulation with flexion at hips, knees, and ankles and adduction at the thighs, two groups can be identified. Group I have classic signs of ‘spasticity’ and Group II do not show velocity dependent muscle contraction (clasp knife response on passive joint movement) nor clonus. Although both groups may have improved outcome to SDR both the intra-operative EMG responses to dorsal root stimulation and the type and degree of improvement after SDR are different. The intra-operative EMG shows lower stimulus intensity to obtain responses and greater contralateral diffusion of muscle responses which also outlast the stimulus train in group II. We conclude these two groups of children have different mechanisms underlying their ‘spastic gait’. Rotulinum Toxin A and gastrocnemius tension and length characteristics N Eames, R Baker, S MC Neill, A Cosgrove, K Graham, H Cowie, T Taylor, A Hill
The Gait Analysis Laboratory, Musgrave Park Hospital, Belfast, Northern Ireland; The Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland
277
Botulinum neurotoxin type A was first used in the early 1970s by Scott [l] for the correction of strabismus in humans. The toxin is now a well accepted means of treating certain ocular and facial spasms [2]. Cosgrove [3] studying the role of intramuscular botulinum toxin in ambulatory children with cerebral palsy found that botulinum toxin objectively reduced spasticity and improved ambulatory status while yielding improvements in kinematics at knee and ankle joints. The muscles of these patients frequently display an increase in the resting tone and an exaggeration of the stretch reflex 3. Using a trigonometric formula calculating gastrocnemius length from measured knee flexion and foot dorsiflexion angles during VICON gait analysis, the effects of the toxin on the characteristics of the muscle are being observed in a prospective trial. Ambulatory children with dynamic equinus contractures undergo pre injection gait analysis. Gastrocnemius is injected using a standardised technique and patients are reviewed with post injection gait analysis at 2 weeks and then monthly intervals as the toxins effect reduces. Gastrocnemius length and tension characteristics are therefore defined throughout the duration of the toxins effect. In this paper the increase in functional muscle length of gastrocnemius post injection in responders is described. As well as discussing the comparison between normal tension and length curves and those for spastic muscles, the effective alteration in tension and length characteristics post injection will be described. References
Scott A B, Rosenbaum A, Collins C C. Pharmacological weakening of extraocular muscles. Invest Opthalmol Vis Sci 1973; 12, 924-927.
Savino P J, Malon M. Botulinurn toxin therapy. Neur Clin 1991; 9: 205-224.
Cosgrove A P, Carry I S, Graham H K. Botulinum toxin in the management of the lower limb in cerebral palsy. Dev Med Child Neurol 1994; 36: 386-396. Estimating gastrocnemius length from joint rotation measurements N Eames, R Baker, A Cosgrove
The Gait Analysis Laboratory, Musgrave Park Hospital, Belfast, Northern Ireland; The Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland The gastrocnemius musculo-tendinous unit is frequently affected in children with cerebral palsy and consequently is subject to lengthening procedures or other therapeutic approaches such as Botulinum toxin therapy. Gait analysis allows assessment of these patients but most available systems are limited to any changes in joint angles that may occur. We have developed a mathematical model [l] which may be applied to the joint rotation data to allow estimation of gastrocnemius length through the gait cycle. The formula is at present in use in the evaluation of patients under going surgical tendo achilles lengthening and Botulinum toxin therapy.