Recent advances in management of cerebral palsy
http://www.100md.com
《美国医学杂志》
Department of Pediatric Orthopaedics and Rehabilitation, Bangalore Children's Hospital, Bangalore, India
Abstract
Recent advances in clinical research have increased our understanding of causal pathways, opportunities for primary prevention, and the value of specific intervention strategies in the management of Cerebral Palsy (CP). Despite the increasing popularity of newer treatment alternatives, e.g., Botulinum Toxin and Intrathecal Baclofen, single event multilevel Orthopaedic bony and soft tissue surgery, in the context of a multi-disciplinary rehabilitation team, remains a vital component in the overall management plan. A meticulous clinical examination, augmented in some cases by instrumented gait analysis, allows for a comprehensive treatment plan addressing the entire extremity. This paper provides a critical review of the currently available treatment modalities
Keywords: Cerebral palsy; Spasticity; Management, Orthopedic surgery
The usual medical advice currently given in India to parents of children with Cerebral Palsy (CP) is one of the following:
1.CP is incurable: so don't waste money on treatment.
2.Unsubstantiated but well publicized complementary modalities claiming to "cure the brain without side-effects", e.g., homeopathy, ayurvedic or biochemic pills, or oil massage.
3.Refer to physiotherapist for some perfunctory stretches or to NGOs for social management (e.g., vocational training, residential care) and physicians take no further active role in treatment.
Very few centers exist in India that provide a dedicated, trained and qualified multidisciplinary team comprising of Developmental Pediatrician, Pediatric Orthopedic Surgeon, Pediatric Neurologist or Neurosurgeon, Physiotherapist, Occupational Therapist and Orthotist. Each of these specialists offers a unique perspective that enhances the development of a comprehensive evaluation and treatment program for each individual patient. Multidisciplinary CP clinics allow for the frequent comprehensive follow-up of children with CP while decreasing the need for patient travel.[1]
The natural history of untreated CP is one of progressive deterioration. It has been shown that without intervention, detrimental changes in gait and function will occur over time span as short as 1.5 years.[2],[3] During adolescent growth spurt, many patients gain substantial weight, their gait worsens and become wheelchair bound.
Principles of Treatment
CP cannot be cured. The goals of management should be to use appropriate combinations of interventions ( e.g., developmental, physical, medical, surgical, chemical, and technical modalities) to promote function, to prevent secondary impairments and, to increase the child's developmental capabilities.[1]
The functional priorities of a person with CP are, in order of importance, communication, activities of daily living, mobility in the environment, and walking.[4] Medical professionals must remember that the patient and family have only a certain amount of time and energy to devote to these priorities and to various aspects of treatment.
Gross motor function in CP is related to the degree of involvement, which in turn is a manifestation of the site and severity of the central nervous system (C.N.S.) lesion. This primary injury to the C.N.S. produces "positive" features such as spasticity, hyper-reflexia and co-contraction, and "negative" features including weakness, loss of selective motor control, sensory deficits and poor balance.[5] Clinicians have traditionally focused more on the positive features because it is possible to treat spasticity, but it is the negative features, which determine when or if a child will walk.[5]
The secondary abnormalities are essentially growth disorders.[6] They develop over time in a growing child. Growth of bone occurs via epiphyseal plates, but it is the joint reaction forces acting on these bones that determine their ultimate shape. If those forces are correct, the final shape of the bone will be correct. If the forces are distorted, the final shape of the bone will be distorted.[6] In conditions such as spastic diplegia, both remodeling of foetal bone alignment and future modeling of bone, as it grows, are abnormal. Hence, deformities such as increased femoral anteversion, external tibial torsion, talipes equinovalgus (with mid-foot break) and hip subluxation are common and are called lever arm disease. Muscles work most efficiently on rigid bony levers which are in the line of gait progression. Maldirected or bent levers reduce the effectiveness of muscle action.[6] The conditions for normal muscle growth, on the other hand, are regular stretching of relaxed muscle under physiological loading. In children with CP, the skeletal muscle does not relax during activity because of spasticity and these children have greatly reduced levels of activity because of weakness and poor balance.[5]
Tertiary abnormalities are those compensations that the individual uses to circumvent the primary and secondary abnormalities of gait. An example is circumduction gait in co-spasticity of hamstrings and rectus femoris, caused by abduction of hips in order to clear the ground. These coping responses must be carefully identified and left alone.[6]
The secondary abnormalities are amenable to treatment, whereas, with the exception of spasticity, the primary abnormalities are difficult to alter. Hence, the basis of treatment of CP lies in analysing the pathology, and determining which portions of it can be corrected and which cannot.[6]
The following modalities are attempted to treat inadequate muscle growth: passive stretch, night splinting, physical therapy, botulinum toxin injections, phenol/alcohol injections, and orthopaedic surgery and/ or spasticity reduction.[6] For treatment of spasticity in children younger than 4 years and adolescents in the midst of their growth spurt, physical therapy, inhibitory casts, orthotics, or botulinum toxin injections are preferred. Global spasticity management is the choice between 4 to 7 years.[6] Selective Dorsal Rhizotomy (SDR) may be employed for pure spasticity; while mixed patterns and spasticity, not fulfilling the selection criteria of SDR, may respond to Intrathecal Baclofen (ITB).
Contractures and lever arm disease can be corrected only by orthopedic surgery, but minor deformities may be managed by bracing. Extrapyramidal symptoms, deficient selective motor control and abnormal balance mechanisms are presently incurable and are the major limiting factors in management.[6]
Oral Muscle Relaxants
The benefits of drugs like diazepam, baclofen, and dantrolene are severely limited by side effects (e.g., lethargy, irritability, and impaired cognitive skills) when administered orally.[7] The poor lipid solubility means that the drug reaches the target tissue in very low concentrations.
Phenol
It is a focal, temporary neurolytic injection but is rarely used now because of availability of Botulinum toxin and the fact that it is more painful. It can only be used for motor nerves such as the obturator nerve and musculocutaneous nerve.[8]
Botulinum Toxin-A injection
Botulinum toxin injections cause a focal, dose-dependant, reversible chemodenervation of muscle.[9] However, it is exorbitantly expensive, temporary (lasting about 3-6 months) and can only delay (and not usually prevent) orthopedic surgery.[5] It is ineffective in the presence of contractures or lever arm disease, and its role in the overall management of a lifelong disorder like CP is still being explored.[9] The patient who could benefit most from this treatment is one who is hypertonic, either spastic or dystonic, whose abnormal muscle tone is interfering with function or who is expected to develop joint contrature with growth because of this abnormal tone.[9] Further, this "ideal patient" will have no more than two or three muscles that require treatment at any one time in order to accomplish the objectives. Patients with fixed contracture on the static examination may respond to a combination of serial casting and botulinum toxin injections.[9] In our experience, patients younger than 4 yrs without fixed contracture respond most favorably to treatment with Botulinum Toxin.
Occupational/Physical Therapy
Physical therapy is aimed at improving infant-caregiver interaction, giving family support, supplying resources, and parental education, as well as at promoting motor and developmental skills. Occupational Therapy (OT) focuses on the development of skills necessary for the performance of activities of daily living. These include play, self-care activities such as dressing, grooming and feeding, and fine motor tasks such as drawing and writing. OT also addresses cognitive and perceptual disabilities, especially in the visual-motor area, and adaptation of equipment and seating to allow better upper extremity use and to promote functional independence. Neurodevelopmental Therapy and Sensory Integration are specialized techniques used by the therapists to achieve these goals. The common principles in many therapies include development of sequence learning, normalization of tone, training of normal movement patterns, inhibition of abnormal patterns, and prevention of deformity. In general, since a child learns motor control in a cephalocaudal direction, the therapist will work in the same way, first trying to establish trunk control and then working toward control of the lower extremities.[10] However, the latest policy statement from the American Academy of Cerebral Palsy and Developmental Medicine concludes that the long-term benefits of Neurodevelopmental Therapy are marginal and not measurable.[11] Except for an immediate improvement in the range of motion of joints, no other functional parameters showed any long-term improvement. A child with mild CP shows improvement with therapy, whereas the more severe cases progressively develop contractures and lever arm disease around the age of 4-7 years, after which, no further improvement occurs with continuing therapy.
Orthosis
The traditional metal and leather caliper (HKAFO) has no place in the modern management of CP. Newer lightweight, thermoplastic materials and the use of orthoses only below the knee is the order of the day. A functional and dynamic design like articulated ankle foot orthosis (A.F.O.), ground reaction A.F.O. or posterior leaf spring A.F.O. is preferred to solid A.F.O. in ambulatory children.[12]
Hippotherapy (Horseback Riding Therapy)
Hippotherapy has been shown to improve gross motor function (tone, ROM, strength, coordination, and balance) in children with CP, which may reduce the degree of motor disability.[13] Hippotherapy offers many potential cognitive, physical, and emotional benefits. We have noted satisfactory results with Hippotherapy in Bangalore, especially in post-surgical rehabilitation.
Selective Dorsal Rhizotomy (SDR)
This neurosurgical operation involves a laminoplasty from L1 to S1 and section of 20% to 40% of the dorsal nerve rootlets. The selection criteria includes pure spasticity, good selective motor control, adequate underlying muscle strength, age 4 years to 7 years, and diagnosis of spastic diplegia due to prematurity.[5] The early enthusiasm with this procedure has been tempered with concerns about long-term effects (scoliosis, lordosis, hip dislocations and foot deformities), questions about the validity of the root tissue selection process, and recognition that uncontrolled clinical results have not been replicated by controlled trials.[14] Recent meta analyses suggest that the decision whether or not to perform SDR depends on whether or not an anticipated mean GMFM change score increment of 4 percentage points above the amount of change with non-invasive care justifies the time, effort, and risk involved.[14] Most children who undergo SDR will also need to undergo orthopaedic surgery later.
Intrathecal Baclofen
An implanted, battery-driven, microprocessor-controlled pump administers small quantities of Baclofen into the subarachnoid space and has a role in severe spastic quadriplegia.[5],[8] This too is exorbitantly expensive, invasive and associated with life-threatening complications, e.g., neurological injuries due to catheter tip dislodgement, infection, etc. Rapidly progressing scoliosis has already been reported.[5],[8] Both SDR and ITB act predominantly on the lower limbs.
What is New in the Management of CP
Advances in research are increasing our understanding of causal pathways, opportunities for primary prevention, and the value of specific intervention strategies.[1]
In the past decade, two remarkable advances have occurred in the management of CP:
1.The use of instrumented gait analysis to aid decision-making regarding single event multilevel surgery and to study its outcome.[6]
2.Orthopedic Selective Spasticity Control Surgery (OSSCS) devised by a Japanese Orthopaedic Surgeon, Takashi Matsuo.[15]
After these developments, most orthopaedic operations done in the past are now considered inappropriate and harmful. The functional results have improved as well, very dramatically in most cases. Yet, the same out-dated operations (originally devised for polio) continue to be performed at many centers in India, after which a child frequently deteriorates functionally. Orthopaedic surgery in India is largely discredited because of inappropriate case selection, wrong operations or operations at the wrong level performed by surgeons who have received little training in either assessment or the technique of these operations.
The importance of meticulous assessment lies in the fact that over 30 muscles are involved in taking a single step. The surgeon needs to identify exactly which muscle(s) are causing functional problems because, lengthening the wrong muscles will make the child much worse.[16] All procedures have to be done in one anesthetic episode because most muscles involved in CP are bi-articular and correcting deformities at one joint leaving the neighboring joint alone will not work.[5],[6] Unfortunately, the effects of these operations are irreversible and the surgeon gets only one chance to hit the bull's eye.[6] Also, bony deformities, e.g., increased femoral anteversion, external tibial torsion and talipes equinovalgus need to be corrected at the same time as contracture releases, otherwise recurrence of contractures is inevitable.
It is now evident, after the advent of computerized gait analysis, that what was called scissoring gait in the past is actually due to spasticity of medial hamstrings and frequently increased femoral anteversion ("pseudoadduction)." Adductor tenotomy and obturator neurectomy in this situation will convert an assisted ambulator into a non-ambulator because of denervation of adductor brevis (an important hip flexor), besides producing an abduction deformity of hips.[18] It in the absence of instrumented gait analysis in India, pattern recognition may help inform clinicians where to look for associated spasticity or contracture and not to focus on a single problem or anatomical level.
The commonest clinical scenario is that of a child with spastic diplegia who walks on the toes. The immediate response of many surgeons is to perform Z lengthening of the tendoachilles, a simple procedure that takes only a few minutes to perform, but the functional effects to the child may be devastating and permanent. Most children with spastic diplegia have hip and knee flexion contractures and tiptoe in order to shift the center of gravity close to the body. It is uncommon to encounter a true tendoachilles contracture in diplegics and inappropriate lengthening of tendoachilles in the presence of hip and knee contractures inevitably leads to a persistent crouch at the knee and an unstable calcaneus deformity; this is because of excessive dorsiflexion and loss of power at the ankle which cannot be braced nor salvaged surgically.[18]
Another important fact is that the prevalence of hip displacement is approximately 1% in spastic hempiplegia, 5% in spastic diplegia and 35-55% in spastic quadriplegia.[17] Hip displacement in quadriplegia is usually silent in the early stages and is usually missed by carers and pediatricians who may be focused on more obvious issues such as feeding difficulties or management of seizures. An important goal of management of spastic quadriplegia should be early detection of hip abnormality by x-ray screening and referral for simple, soft tissue surgery to prevent dislocation.[16] Once a painful, fixed dislocation has taken place, the results of major salvage surgery are at best indifferent and unpredictable.[18]
Single event multilevel surgery refers to the correction of all orthopedic deformities (soft tissue and bony) in one session, requiring only one hospital admission and one period of rehabilitation.[16] OSSCS is based on the concept that the multiarticular muscles, which have less antigravity activity, are hyperactive in CP.[15] Therefore, spasticity and athetotic movements can be controlled by releasing them selectively. The monoarticular muscles which have antigravity activity are carefully preserved. Hence, there is no loss of antigravity activity (muscle weakness) and no loss of sensation and stereognosis. There is also no increase in the occurrence of dislocations and deformities. OSSCS avoids most of the problems associated with SDR and ITB.[15] The advantages of performing all the procedures under a single anesthetic include avoidance of additional pain and inconvenience, repeated costly hospitalizations, and need for the child to complete more than one postoperative rehabilitation programs. Precise correction, stable fixation and early mobilization, along with expert pain relief, are essential for a good outcome.[16]
Surgical lengthening of fixed contractures at the hips, knees, or ankles can allow the child to keep the mass of the head and upper trunk over the base of support. This may allow independent ambulation without crutches if the child's equilibrium reactions are adequate.[8] The goals of the patient, the family, the therapist, and the surgeon must be discussed openly because the expectations of the child's family at times may be unrealistic.[16]
In Bangalore, we have been performing single event multilevel OSSCS (over 100 cases from all over India and other countries) according to current International recommendations for the past 4 years and the functional results have been very encouraging. Several children have now achieved near normalcy of gait. Video recordings before and after surgery and an opportunity to meet/speak to parents of operated children are routinely made available to parents when they are considering this surgery. With the availability of OSSCS, even selected cases of spastic quadriplegia and athetoid CP can be improved functionally. Traditionally, these children have been bed-bound with a pathetic quality of life. After surgery, significant improvements may be noted in head control and sitting balance. Mental retardation is not a contraindication for surgery. A major advantage of successful surgical rehabilitation that has been noted is an all round acceleration of other functions thereafter, e.g., learning, speech, behaviour, etc. Decreased spasticity allows the child to have greater range of motion, less spastic response to stretch, and better potential to develop and use voluntary activity during gait.[5] Physical therapy for strengthening muscles is more effective once spasticity is reduced. The traditional view was that muscle strengthening was neither possible nor desirable in CP because it might increase spasticity. Recent research has shown that muscle strength can be reliably measured in children with CP, and that those who participate in strengthening programmes demonstrate increases in muscle power and improvements in function.[5]
Ideal Age for Surgery
It is very important to emphasize the ideal age for surgery: 4-6 years for lower limbs and 6-8 years for upper limbs. The preschool-age child is most likely to suffer recurrence of contractures during continued growth.[18] The child develops a mature gait pattern by the age of 4 or 5 years and is better able to cooperate with a post-operative physiotherapy programme. Once this window of opportunity is lost (usually due to reluctance of physiotherapists to let go or the insistence of the family in exploring non-operative options at any cost) and complex decompensated joint pathology has developed, the results of operation are less gratifying, though functional improvements still occur in older children. Unstable lever arm disease must be operated irrespective of age if there is to be any hope of preserving ambulation.[5] We have seen cases of ruptured tendoachilles due to forcible muscle stretching by physiotherapists in the presence of contractures, necessitating an emergency multi level OSSCS! A common misconception is that as long as the child is somehow able to walk, surgery should be avoided. The problem is that co-spasticity of muscles acting across the joints and the development of deformities makes the gait laborious, energy consuming and inefficient. After OSSCS, studies using instrumented gait analysis have shown significant improvement in gait, energy efficiency, appearance, and function.[15]
Conclusion
Currently, a well-planned and executed single event multilevel OSSCS, in the context of a multi-disciplinary team, provides the child with CP with the only hope for a dramatic, predictable and lasting functional improvement. However, this is like a double-edged sword: surgery should be done only at tertiary level centers by highly experienced surgeons who have received the appropriate training in centers of excellence (usually outside India).
References
1. Rosenbaum P. Cerebral palsy: what parents and doctors want to know. BMJ 2003; 326: 970-974.
2. Johnson DC, Damiano DL, Abel MF. The evolution of gait in childhood and adolescent cerebral palsy. J Pediatr Orthop 1997; 17: 392-396.
3. Bell KJ, Ounpuu S, DeLuca PA et al. Natural progression of gait in children with cerebral palsy. J Pediatr Orthop 2002; 22: 677-682.
4. Bleck EE. Orthopedic Management in Cerebral Palsy . Oxford; MacKeith Press, 1987.
5. Graham HK, Selber P. Musculoskeletal aspects of cerebral palsy. J Bone Joint Surg (Br) 2003; 85-B: 157-166.
6. Gage JR, Novacheck TF. An update on the treatment of gait problems in cerebral palsy. J Pediatr Orthop 2001; 10: 265-274
7. Badell A. The effects of medications that reduce spasticity in the management of spastic cerebral palsy. J Neuro Rehab 1991; 5(Suppl 1): S13-S14.
8. Gormley ME Jr, Krach LE, Piccini L. Spasticity management of the child with spastic quadriplegia. Eur J Neurol 1998; 5(Suppl 5): S127-S135.
9. Russman BS, Tilton A, Gormley ME Jr. Cerebral palsy: A rational approach to a treatment protocol and the role of botulinum toxin in treatment. Muscle Nerve 1997; 20 (suppl 6): S1-S13.
10. Bobath B, Bobath K. The Neuro-development Treatment. In Scrutton D, ed. Management of the Motor Disorders of Children with Cerebral Palsy . Philadelphia; Lippincott, 1984; 6-18.
11. Butler C, Darrah J. Effects of neurodevelopmental treatment (NDT) for cerebral palsy: an AACPDM evidence report. Dev Med Child Neurol 2001; 43: 778-790.
12. Romkes J, Brunner. Comparison of a dynamic and a hinged ankle-foot orthosis by gait analysis in patients with hemiplegic cerebral palsy. Gait and Posture 2002; 15: 18-24.
13. Sterba JA, Rogers BT, France AP, Vokes DA. Horseback riding in children with cerebral palsy: effect on gross motor function. Developmental Medicine and Child Neurology 2002; 44: 301-308.
14. McLaughlin J, Bjornson K, Temkin N et al. Selective dorsal rhizotomy: meta-analysis of three randomized controlled trials. Dev Med Child Neurol 2002; 44: 17-25
15. Matsuo T. Cerebral palsy: spasticity-control and orthopaedics. An introduction to orthopaedic selective spasticity-control surgery (OSSCS). Soufusha, Tokyo; 2002.
16. Karol LA. Surgical Management of the Lower Extremity in Ambulatory Children With Cerebral Palsy. J Am Acad Orthop Surg 2004; 12: 196-203.
17. Renshaw TS, Green NE, Griffin PP, Root L. Cerebral palsy: Orthopaedic management. Instr Course Lect 1996; 45: 475-490.
18. Flynn JM, Miller F. Management of hip disorders in patients with cerebral palsy. J Am Acad Orthop Surg 2002; 10: 198-209.(Sharan Deepak)
Abstract
Recent advances in clinical research have increased our understanding of causal pathways, opportunities for primary prevention, and the value of specific intervention strategies in the management of Cerebral Palsy (CP). Despite the increasing popularity of newer treatment alternatives, e.g., Botulinum Toxin and Intrathecal Baclofen, single event multilevel Orthopaedic bony and soft tissue surgery, in the context of a multi-disciplinary rehabilitation team, remains a vital component in the overall management plan. A meticulous clinical examination, augmented in some cases by instrumented gait analysis, allows for a comprehensive treatment plan addressing the entire extremity. This paper provides a critical review of the currently available treatment modalities
Keywords: Cerebral palsy; Spasticity; Management, Orthopedic surgery
The usual medical advice currently given in India to parents of children with Cerebral Palsy (CP) is one of the following:
1.CP is incurable: so don't waste money on treatment.
2.Unsubstantiated but well publicized complementary modalities claiming to "cure the brain without side-effects", e.g., homeopathy, ayurvedic or biochemic pills, or oil massage.
3.Refer to physiotherapist for some perfunctory stretches or to NGOs for social management (e.g., vocational training, residential care) and physicians take no further active role in treatment.
Very few centers exist in India that provide a dedicated, trained and qualified multidisciplinary team comprising of Developmental Pediatrician, Pediatric Orthopedic Surgeon, Pediatric Neurologist or Neurosurgeon, Physiotherapist, Occupational Therapist and Orthotist. Each of these specialists offers a unique perspective that enhances the development of a comprehensive evaluation and treatment program for each individual patient. Multidisciplinary CP clinics allow for the frequent comprehensive follow-up of children with CP while decreasing the need for patient travel.[1]
The natural history of untreated CP is one of progressive deterioration. It has been shown that without intervention, detrimental changes in gait and function will occur over time span as short as 1.5 years.[2],[3] During adolescent growth spurt, many patients gain substantial weight, their gait worsens and become wheelchair bound.
Principles of Treatment
CP cannot be cured. The goals of management should be to use appropriate combinations of interventions ( e.g., developmental, physical, medical, surgical, chemical, and technical modalities) to promote function, to prevent secondary impairments and, to increase the child's developmental capabilities.[1]
The functional priorities of a person with CP are, in order of importance, communication, activities of daily living, mobility in the environment, and walking.[4] Medical professionals must remember that the patient and family have only a certain amount of time and energy to devote to these priorities and to various aspects of treatment.
Gross motor function in CP is related to the degree of involvement, which in turn is a manifestation of the site and severity of the central nervous system (C.N.S.) lesion. This primary injury to the C.N.S. produces "positive" features such as spasticity, hyper-reflexia and co-contraction, and "negative" features including weakness, loss of selective motor control, sensory deficits and poor balance.[5] Clinicians have traditionally focused more on the positive features because it is possible to treat spasticity, but it is the negative features, which determine when or if a child will walk.[5]
The secondary abnormalities are essentially growth disorders.[6] They develop over time in a growing child. Growth of bone occurs via epiphyseal plates, but it is the joint reaction forces acting on these bones that determine their ultimate shape. If those forces are correct, the final shape of the bone will be correct. If the forces are distorted, the final shape of the bone will be distorted.[6] In conditions such as spastic diplegia, both remodeling of foetal bone alignment and future modeling of bone, as it grows, are abnormal. Hence, deformities such as increased femoral anteversion, external tibial torsion, talipes equinovalgus (with mid-foot break) and hip subluxation are common and are called lever arm disease. Muscles work most efficiently on rigid bony levers which are in the line of gait progression. Maldirected or bent levers reduce the effectiveness of muscle action.[6] The conditions for normal muscle growth, on the other hand, are regular stretching of relaxed muscle under physiological loading. In children with CP, the skeletal muscle does not relax during activity because of spasticity and these children have greatly reduced levels of activity because of weakness and poor balance.[5]
Tertiary abnormalities are those compensations that the individual uses to circumvent the primary and secondary abnormalities of gait. An example is circumduction gait in co-spasticity of hamstrings and rectus femoris, caused by abduction of hips in order to clear the ground. These coping responses must be carefully identified and left alone.[6]
The secondary abnormalities are amenable to treatment, whereas, with the exception of spasticity, the primary abnormalities are difficult to alter. Hence, the basis of treatment of CP lies in analysing the pathology, and determining which portions of it can be corrected and which cannot.[6]
The following modalities are attempted to treat inadequate muscle growth: passive stretch, night splinting, physical therapy, botulinum toxin injections, phenol/alcohol injections, and orthopaedic surgery and/ or spasticity reduction.[6] For treatment of spasticity in children younger than 4 years and adolescents in the midst of their growth spurt, physical therapy, inhibitory casts, orthotics, or botulinum toxin injections are preferred. Global spasticity management is the choice between 4 to 7 years.[6] Selective Dorsal Rhizotomy (SDR) may be employed for pure spasticity; while mixed patterns and spasticity, not fulfilling the selection criteria of SDR, may respond to Intrathecal Baclofen (ITB).
Contractures and lever arm disease can be corrected only by orthopedic surgery, but minor deformities may be managed by bracing. Extrapyramidal symptoms, deficient selective motor control and abnormal balance mechanisms are presently incurable and are the major limiting factors in management.[6]
Oral Muscle Relaxants
The benefits of drugs like diazepam, baclofen, and dantrolene are severely limited by side effects (e.g., lethargy, irritability, and impaired cognitive skills) when administered orally.[7] The poor lipid solubility means that the drug reaches the target tissue in very low concentrations.
Phenol
It is a focal, temporary neurolytic injection but is rarely used now because of availability of Botulinum toxin and the fact that it is more painful. It can only be used for motor nerves such as the obturator nerve and musculocutaneous nerve.[8]
Botulinum Toxin-A injection
Botulinum toxin injections cause a focal, dose-dependant, reversible chemodenervation of muscle.[9] However, it is exorbitantly expensive, temporary (lasting about 3-6 months) and can only delay (and not usually prevent) orthopedic surgery.[5] It is ineffective in the presence of contractures or lever arm disease, and its role in the overall management of a lifelong disorder like CP is still being explored.[9] The patient who could benefit most from this treatment is one who is hypertonic, either spastic or dystonic, whose abnormal muscle tone is interfering with function or who is expected to develop joint contrature with growth because of this abnormal tone.[9] Further, this "ideal patient" will have no more than two or three muscles that require treatment at any one time in order to accomplish the objectives. Patients with fixed contracture on the static examination may respond to a combination of serial casting and botulinum toxin injections.[9] In our experience, patients younger than 4 yrs without fixed contracture respond most favorably to treatment with Botulinum Toxin.
Occupational/Physical Therapy
Physical therapy is aimed at improving infant-caregiver interaction, giving family support, supplying resources, and parental education, as well as at promoting motor and developmental skills. Occupational Therapy (OT) focuses on the development of skills necessary for the performance of activities of daily living. These include play, self-care activities such as dressing, grooming and feeding, and fine motor tasks such as drawing and writing. OT also addresses cognitive and perceptual disabilities, especially in the visual-motor area, and adaptation of equipment and seating to allow better upper extremity use and to promote functional independence. Neurodevelopmental Therapy and Sensory Integration are specialized techniques used by the therapists to achieve these goals. The common principles in many therapies include development of sequence learning, normalization of tone, training of normal movement patterns, inhibition of abnormal patterns, and prevention of deformity. In general, since a child learns motor control in a cephalocaudal direction, the therapist will work in the same way, first trying to establish trunk control and then working toward control of the lower extremities.[10] However, the latest policy statement from the American Academy of Cerebral Palsy and Developmental Medicine concludes that the long-term benefits of Neurodevelopmental Therapy are marginal and not measurable.[11] Except for an immediate improvement in the range of motion of joints, no other functional parameters showed any long-term improvement. A child with mild CP shows improvement with therapy, whereas the more severe cases progressively develop contractures and lever arm disease around the age of 4-7 years, after which, no further improvement occurs with continuing therapy.
Orthosis
The traditional metal and leather caliper (HKAFO) has no place in the modern management of CP. Newer lightweight, thermoplastic materials and the use of orthoses only below the knee is the order of the day. A functional and dynamic design like articulated ankle foot orthosis (A.F.O.), ground reaction A.F.O. or posterior leaf spring A.F.O. is preferred to solid A.F.O. in ambulatory children.[12]
Hippotherapy (Horseback Riding Therapy)
Hippotherapy has been shown to improve gross motor function (tone, ROM, strength, coordination, and balance) in children with CP, which may reduce the degree of motor disability.[13] Hippotherapy offers many potential cognitive, physical, and emotional benefits. We have noted satisfactory results with Hippotherapy in Bangalore, especially in post-surgical rehabilitation.
Selective Dorsal Rhizotomy (SDR)
This neurosurgical operation involves a laminoplasty from L1 to S1 and section of 20% to 40% of the dorsal nerve rootlets. The selection criteria includes pure spasticity, good selective motor control, adequate underlying muscle strength, age 4 years to 7 years, and diagnosis of spastic diplegia due to prematurity.[5] The early enthusiasm with this procedure has been tempered with concerns about long-term effects (scoliosis, lordosis, hip dislocations and foot deformities), questions about the validity of the root tissue selection process, and recognition that uncontrolled clinical results have not been replicated by controlled trials.[14] Recent meta analyses suggest that the decision whether or not to perform SDR depends on whether or not an anticipated mean GMFM change score increment of 4 percentage points above the amount of change with non-invasive care justifies the time, effort, and risk involved.[14] Most children who undergo SDR will also need to undergo orthopaedic surgery later.
Intrathecal Baclofen
An implanted, battery-driven, microprocessor-controlled pump administers small quantities of Baclofen into the subarachnoid space and has a role in severe spastic quadriplegia.[5],[8] This too is exorbitantly expensive, invasive and associated with life-threatening complications, e.g., neurological injuries due to catheter tip dislodgement, infection, etc. Rapidly progressing scoliosis has already been reported.[5],[8] Both SDR and ITB act predominantly on the lower limbs.
What is New in the Management of CP
Advances in research are increasing our understanding of causal pathways, opportunities for primary prevention, and the value of specific intervention strategies.[1]
In the past decade, two remarkable advances have occurred in the management of CP:
1.The use of instrumented gait analysis to aid decision-making regarding single event multilevel surgery and to study its outcome.[6]
2.Orthopedic Selective Spasticity Control Surgery (OSSCS) devised by a Japanese Orthopaedic Surgeon, Takashi Matsuo.[15]
After these developments, most orthopaedic operations done in the past are now considered inappropriate and harmful. The functional results have improved as well, very dramatically in most cases. Yet, the same out-dated operations (originally devised for polio) continue to be performed at many centers in India, after which a child frequently deteriorates functionally. Orthopaedic surgery in India is largely discredited because of inappropriate case selection, wrong operations or operations at the wrong level performed by surgeons who have received little training in either assessment or the technique of these operations.
The importance of meticulous assessment lies in the fact that over 30 muscles are involved in taking a single step. The surgeon needs to identify exactly which muscle(s) are causing functional problems because, lengthening the wrong muscles will make the child much worse.[16] All procedures have to be done in one anesthetic episode because most muscles involved in CP are bi-articular and correcting deformities at one joint leaving the neighboring joint alone will not work.[5],[6] Unfortunately, the effects of these operations are irreversible and the surgeon gets only one chance to hit the bull's eye.[6] Also, bony deformities, e.g., increased femoral anteversion, external tibial torsion and talipes equinovalgus need to be corrected at the same time as contracture releases, otherwise recurrence of contractures is inevitable.
It is now evident, after the advent of computerized gait analysis, that what was called scissoring gait in the past is actually due to spasticity of medial hamstrings and frequently increased femoral anteversion ("pseudoadduction)." Adductor tenotomy and obturator neurectomy in this situation will convert an assisted ambulator into a non-ambulator because of denervation of adductor brevis (an important hip flexor), besides producing an abduction deformity of hips.[18] It in the absence of instrumented gait analysis in India, pattern recognition may help inform clinicians where to look for associated spasticity or contracture and not to focus on a single problem or anatomical level.
The commonest clinical scenario is that of a child with spastic diplegia who walks on the toes. The immediate response of many surgeons is to perform Z lengthening of the tendoachilles, a simple procedure that takes only a few minutes to perform, but the functional effects to the child may be devastating and permanent. Most children with spastic diplegia have hip and knee flexion contractures and tiptoe in order to shift the center of gravity close to the body. It is uncommon to encounter a true tendoachilles contracture in diplegics and inappropriate lengthening of tendoachilles in the presence of hip and knee contractures inevitably leads to a persistent crouch at the knee and an unstable calcaneus deformity; this is because of excessive dorsiflexion and loss of power at the ankle which cannot be braced nor salvaged surgically.[18]
Another important fact is that the prevalence of hip displacement is approximately 1% in spastic hempiplegia, 5% in spastic diplegia and 35-55% in spastic quadriplegia.[17] Hip displacement in quadriplegia is usually silent in the early stages and is usually missed by carers and pediatricians who may be focused on more obvious issues such as feeding difficulties or management of seizures. An important goal of management of spastic quadriplegia should be early detection of hip abnormality by x-ray screening and referral for simple, soft tissue surgery to prevent dislocation.[16] Once a painful, fixed dislocation has taken place, the results of major salvage surgery are at best indifferent and unpredictable.[18]
Single event multilevel surgery refers to the correction of all orthopedic deformities (soft tissue and bony) in one session, requiring only one hospital admission and one period of rehabilitation.[16] OSSCS is based on the concept that the multiarticular muscles, which have less antigravity activity, are hyperactive in CP.[15] Therefore, spasticity and athetotic movements can be controlled by releasing them selectively. The monoarticular muscles which have antigravity activity are carefully preserved. Hence, there is no loss of antigravity activity (muscle weakness) and no loss of sensation and stereognosis. There is also no increase in the occurrence of dislocations and deformities. OSSCS avoids most of the problems associated with SDR and ITB.[15] The advantages of performing all the procedures under a single anesthetic include avoidance of additional pain and inconvenience, repeated costly hospitalizations, and need for the child to complete more than one postoperative rehabilitation programs. Precise correction, stable fixation and early mobilization, along with expert pain relief, are essential for a good outcome.[16]
Surgical lengthening of fixed contractures at the hips, knees, or ankles can allow the child to keep the mass of the head and upper trunk over the base of support. This may allow independent ambulation without crutches if the child's equilibrium reactions are adequate.[8] The goals of the patient, the family, the therapist, and the surgeon must be discussed openly because the expectations of the child's family at times may be unrealistic.[16]
In Bangalore, we have been performing single event multilevel OSSCS (over 100 cases from all over India and other countries) according to current International recommendations for the past 4 years and the functional results have been very encouraging. Several children have now achieved near normalcy of gait. Video recordings before and after surgery and an opportunity to meet/speak to parents of operated children are routinely made available to parents when they are considering this surgery. With the availability of OSSCS, even selected cases of spastic quadriplegia and athetoid CP can be improved functionally. Traditionally, these children have been bed-bound with a pathetic quality of life. After surgery, significant improvements may be noted in head control and sitting balance. Mental retardation is not a contraindication for surgery. A major advantage of successful surgical rehabilitation that has been noted is an all round acceleration of other functions thereafter, e.g., learning, speech, behaviour, etc. Decreased spasticity allows the child to have greater range of motion, less spastic response to stretch, and better potential to develop and use voluntary activity during gait.[5] Physical therapy for strengthening muscles is more effective once spasticity is reduced. The traditional view was that muscle strengthening was neither possible nor desirable in CP because it might increase spasticity. Recent research has shown that muscle strength can be reliably measured in children with CP, and that those who participate in strengthening programmes demonstrate increases in muscle power and improvements in function.[5]
Ideal Age for Surgery
It is very important to emphasize the ideal age for surgery: 4-6 years for lower limbs and 6-8 years for upper limbs. The preschool-age child is most likely to suffer recurrence of contractures during continued growth.[18] The child develops a mature gait pattern by the age of 4 or 5 years and is better able to cooperate with a post-operative physiotherapy programme. Once this window of opportunity is lost (usually due to reluctance of physiotherapists to let go or the insistence of the family in exploring non-operative options at any cost) and complex decompensated joint pathology has developed, the results of operation are less gratifying, though functional improvements still occur in older children. Unstable lever arm disease must be operated irrespective of age if there is to be any hope of preserving ambulation.[5] We have seen cases of ruptured tendoachilles due to forcible muscle stretching by physiotherapists in the presence of contractures, necessitating an emergency multi level OSSCS! A common misconception is that as long as the child is somehow able to walk, surgery should be avoided. The problem is that co-spasticity of muscles acting across the joints and the development of deformities makes the gait laborious, energy consuming and inefficient. After OSSCS, studies using instrumented gait analysis have shown significant improvement in gait, energy efficiency, appearance, and function.[15]
Conclusion
Currently, a well-planned and executed single event multilevel OSSCS, in the context of a multi-disciplinary team, provides the child with CP with the only hope for a dramatic, predictable and lasting functional improvement. However, this is like a double-edged sword: surgery should be done only at tertiary level centers by highly experienced surgeons who have received the appropriate training in centers of excellence (usually outside India).
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