Cerebral Palsy Recent Advances in Treatment

The functional priorities of a person with CP are, in order of importance, communication, activities of daily living, mobility in the environment, and walking. 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. 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.

The secondary abnormalities are best characterised as growth disorders. 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. In conditions such as spastic diplegia, both remodeling of foetal bone alignment and future modelling 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. 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. Hence, to an orthopaedic surgeon, CP is essentially a 'short muscle disease.'

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. 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. 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. 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. 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 orthopaedic 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.

Many of the treatments introduced for spasticity and other aspects of CP were inadequately evaluated when first introduced and have become enshrined in clinical practice without benefit of acceptable evidence of efficacy and effectiveness. Over the last 15 years, valid and reliable outcome measures have been developed for many relevant aspects of CP ranging from electomechanical torque measures of spasticity and instrumented gait analysis and energy assessment to measures of functional ability and quality of life.

Oral muscle relaxants

·         The benefits of drugs like Baclofen are severely limited by side effects ( drowsiness, unsteadiness or short-term memory deficit) when administered orally.

·         The poor lipid solubility means that the drug reaches the target tissue in very low concentrations.

Phenol (3–7%)& Alcohol (45–100%)

·         Produce selective denervation when injected into motor nerves or muscles

·         Because diffusion of both is limited, the area of effective denervation extends just a few millimetres from the injection site

·         Duration of denervation: 3–6 months (alcohol), 4–8 months (phenol)

·         Only for motor nerves such as the obturator nerve and musculocutaneous nerve

·         Rarely used these days

·         Side effects: pain on injection, non-selective protein denaturation, possible permanent muscle fibrosis, dysaesthesias lasting for several weeks

Botulinum Toxin-A injection

Botulinum toxin injections cause a focal, dose-dependant, reversible chemodenervation of muscle. It is sometimes used to buy time in a child deemed too young for surgery (2-4 years) and works best for localised Gastrocnemius spasticity.

Problems:

·         Expensive

·         Temporary (lasting about 3-6 months)

·         Can only delay (and not usually prevent) SEMLARASS

·         Ineffective in the presence of contractures or lever arm disease (femoral/tibial torsion, planovalgus feet, hip subluxation/dislocation)

·         Reported complications: Muscle soreness, pain on injection, rash, fatigue, excessive weakness, Influenza-like symptoms, infection, allergic reaction, Subacromial Impingement Syndrome, Mediastinitis, Rapid Osteoporosis

·         Pathetic quality of life: stress of repeated injections, plasters and physiotherapy throughout childhood

·         Antibody formation correlated with secondary nonresponse

·         High Discontinuation Rates: 76% after an initially good response according to a study in the west, where finance was not a consideration

Recent Concerns

·         Toxin acts by weakening muscle and not by addressing spasticity

·         Long term deleterious effects on muscle growth and function

Dangerous complications reported recently leading to FDA issuing a warning in February 2008 against its use in CP 

·         Permanent paralysis

·         Respiratory paralysis and dysphagia

·         Generalised muscle weakness

·         Death

 

Occupational / Physical 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. Another aspect of OT is the 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. However, the latest policy statement from the American Academy of Cerebral Palsy & Developmental Medicine (AACP&DM), in 2001, concludes that the long-term benefits of therapy are marginal and not measurable. 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 usually preferred to solid A.F.O. in ambulatory children.

Selective Dorsal Rhizotomy

This neurosurgical operation involves a laminoplasty from L1 to S1 and section of 20% to 40% of the dorsal nerve rootlets.

Selection criteria:

·         Pure spasticity

·         Good selective motor control

·         Adequate underlying muscle strength

·         Age 4 years to 7 years

·         Diagnosis of spastic diplegia due to prematurity

Problems:

·         Adverse long-term effects (sensory disturbance, bladder dysfunction, scoliosis, lordosis, hip dislocations and foot deformities)

·         Validity of the root tissue selection process is questionable

·         Uncontrolled clinical results have not been replicated by controlled trials

·         L oss of antigravity stability and worsening of motor function

·         Cannot be used in children with contractures and lever arm disease or upper limb involvement

·         Over 70% will still need Orthopaedic Surgery. SDR frequently accelerates the need for Orthopaedic Surgery

·         Irreversible

·         The same holds good for other neurosurgical procedures, e.g., neurectomies and fasciculotomies

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.

Problems:

·         Exorbitantly expensive

·         Invasive and associated with life-threatening complications, e.g., neurological injuries due to catheter tip dislodgement, intradural infection and fibrosis , etc.

·         Rapidly progressing scoliosis

·         R eplacement of tube and refilling of pump require multiple risky operations

·         A cts predominantly on the lower limbs

Conventional Orthopaedic Surgery

Problems:

·         Lengthening of monoarticular (muscles that cross only one joint) muscles or tendons (adductor brevis, iliopsoas, tendoachilles) leading to loss of antigravity action and severe weakness

·         Over lengthening of tendons common

·         Muscle transfers (Eggers) leading to reverse deformity, e.g., genu recurvatum

·         Does not help the severely involved: quadriplegics, athetoid, dystonia

·         Joint fusions (Grice fusion): degeneration of surrounding joints

·         Lever arm dysfunction rarely corrected simultaneously or early enough: recurrence of contractures

·         Cannot control spasticity, produce reciprocal movements to facilitate antigravity muscles, and improve functional skills and voluntary movement of the hand

What's new in the management of CP?

SEMLARASS or Single Event Multilevel Lever Arm Restoration and Anti Spasticity Surgery include the following components:

·         Single event : all surgeries are usually completed under a single anaesthetic, requiring only one hospital admission and one period of rehabilitation

·         Multilevel : all the affected regions and all orthopaedic deformities (soft tissue and bony) are corrected simultaneously in view of interdependence of joints

·         Lever arm restoration : simultaneous correction of hip subluxation, femoral anteversion, tibial torsion, hindfoot valgus to improve the direction of pull of muscles

·         Anti spasticity : myofascial surgical releases to reduce spasticity

 

SEMLARASS was conceptualised by Dr. Deepak Sharan at RECOUP, Bangalore , India , in 2000.

The unique features of SEMLARASS include:

·         Operating between the ages of 4 years to 8 years (preferably), to avoid joint decompensation and over lengthening of tendons that happen due to continued usage of deformed joints. We consider modalities used to postpone SEMLARASS like Botulinum Toxin, Casting or SDR harmful to the child's eventual outcome because of development of over lengthened tendons and joint decompensation.

·         Minimally invasive procedures using image intensifier that do not require large skin incisions and consequent risk of blood loss and infection

·         Use of External Fixators that do not require a second operation for removal

·         All bony operations done to restore deformed lever arms are extra-articular (not involving joints) to allow for the maximum growth potential of children's bones

·         Simultaneous lever arm restoration is essential for spasticity and contracture correction as well as to reduce chances of recurrence of deformities and repeat surgery at a later stage

·         Tendon lengthening is avoided to reduce weakness

·         The surgery is followed by a supervised and intensive protocol based rehabilitation developed at RECOUP.

 

SEMLARASS draws its origin from 2 prevalent concepts in the surgical treatment of CP:

1.      Orthopaedic Selective Spasticity Control Surgery (OSSCS), developed by Dr. Takashi Matsuo ( Tokyo , Japan ) based on the principle that multiarticular muscles, which have less antigravity activity, are hyperactive in CP. Therefore, spasticity and athetotic movements can be controlled by releasing them selectively. The monoarticular muscles, which have antigravity activity and are responsible for maintaining an upright posture, are carefully preserved. Hence, there is no loss of antigravity activity or muscle weakness and no loss of sensation and stereognosis.

2.      Correction of lever arm dysfunction (e.g., hip subluxation, increased femoral anteversion, tibial torsion and hindfoot valgus) as proposed by Dr. James Gage from Minnesota , USA .

In the majority of CP patients, SEMLARASS is necessary to correct contractures, correct bony deformities, and re-balance abnormal muscle forces producing gait deviations.

SEMLARASS offers correction of all orthopaedic deformities (soft tissue and bony) in one session, requiring only one hospital admission and one period of rehabilitation. OSSCS is based on the concept that the multiarticular muscles, which have less antigravity activity, are hyperactive in CP. Therefore, spasticity and athetotic movements can be controlled by releasing them selectively. The monoarticular muscles, which have antigravity activity and are responsible for maintaining an upright posture, 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. With the availability of OSSCS, w e can now control spasticity of the neck, shoulder, elbow, forearm, wrist, fingers, thumb, extensor pattern of the trunk, paralytic scoliosis, hip, knee and foot, and therefore can facilitate the stability of the neck, trunk, shoulder and elbow and of the lower extremities, and can activate skills of the hand. Control of the abnormal postural reflex can be accomplished and alternation such as reciprocal movement and cross-patterned movement of the extremities is also facilitated. More stable postures such as sitting and standing, and stable transfers such as crawling and gait, by facilitating activity of the antigravity muscles, can be achieved.

SEMLARASS avoids most of the problems associated with SDR, ITB and Conventional Orthopaedic Surgery. The advantages of performing all the procedures under a single anaesthetic include avoidance of additional pain and inconvenience, repeated costly hospitalisations, and need for the child to complete more than one postoperative rehabilitation programme. This also eliminates multiple periods of functional regression that normally follow each surgical procedure. Precise correction, stable fixation and early mobilisation are essential for a good outcome.

We have been performing SEMLARASS since the year 2000 (over 10,000 surgeries in 600 patients from all over India and other countries, including over 100 patients from Kerala): Spastic diplegia 65%; Spastic hemiplegia 20%; Spastic quadriplegia 15%; Spastic or mixed 75%; athetoid 20%; dystonia 5%. Follow up 1 year to 8 years (mean 4.5 years). Improved functional results were recorded in almost all patients using Instrumented Computerised Gait Analysis (available at RECOUP, Bangalore since 2007) , video gait recording, observational gait analysis, Gross Motor Function Classification System and other functional scales. 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 SEMLARASS, even selected cases of spastic quadriplegia and athetoid CP can be improved functionally. Traditionally, these children have been bed-bound with an abysmal quality of life. After SEMLARASS, significant improvements may be noted in head control, sitting and standing balance, and limited ambulation. Mental retardation is not a contraindication for surgery. A major advantage of SEMLARASS 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. Physical therapy for strengthening muscles is more effective once spasticity is reduced. Functional strength training (Suspended treadmill training, suspended bicycle training, therapeutic swimming and horse back riding (hippotherapy) are useful modalities in this situation (all are available exclusively in Bangalore ). 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.

The postoperative rehabilitation following SEMLARASS is intensive and protocol based, and requires dedicated and skilled physical therapy for at least 2 years. Functional improvement is slow and steady and can continue for 2 years or more.

Ideal age for surgery

It is very important to emphasise the ideal age for surgery: 4-8 years. The child develops a mature gait pattern by the age of 4 or 5 years and is better able to cooperate with the intensive 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 and adults. Unstable lever arm disease must be operated irrespective of age if there is to be any hope of preserving ambulation. We have seen cases of ruptured tendoachilles due to forcible muscle stretching by physiotherapists in the presence of contractures, necessitating an emergency multi level SEMLARASS! 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 SEMLARASS, studies using instrumented gait analysis have shown significant improvement in gait, energy efficiency, appearance, and function.

Conclusion

Currently, a well-planned and executed SEMLARASS , 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. Indeed, a programme for treating CP that fails to make SEMLARASS available to its patients deprives them of one of the most effective treatment aids. However, this is like a double-edged sword: SEMLARASS should be done only at tertiary level centers by highly experienced surgeons who have received the appropriate training in centers of excellence.