Introduction 

Definition of Cerebral Palsy (CP) 

The commonest cause of childhood disabilities is CP, which is not a single entity but rather a group of neurological conditions in which there are lifelong body movement and posture disorders. 

It results from nonprogressive events (doesn't continue to happen or worsen with time) that lead to brain damage around the time of birth. Such events include brain malformations, reduced oxygen delivery to the brain, infection, trauma and stroke happening most of the time during pregnancy but can also be during or after birth.¹ ​

Symptoms 

The clinical features of CP vary from person to person and can change over time. It alters the function of a small area of the body or the whole body depending on the part of the brain affected. The features of CP are: 

• Delay in child motor development like head support, sitting and walking when compared to his peers 
• Muscles are too floppy or stiff (spastic) affecting posture and mobility 
• Weak arm and leg muscles 
• Body shaking 
• Clumsy movement due to loss of muscle coordination² ​

How common is CP? 

Nearly 1 child in every 500 has CP. This number can even be higher in certain groups such as premature babies meaning infants born before completing 37 weeks of pregnancy and infants born weighing less than 1.5 kg.¹ ​ 

Importance of pain management in CP 

Pain is the most common coexisting condition with CP.³​​ Studies estimated that around 30% of children and 70% of adults with CP do experience pain from various causes.⁴ It has a great influence on the quality of life of the affected individuals and their families and negatively impacts their participation in physical and daily activities, including school and sleep.^5,6 ​

Doctors under-recognise and under-treat pain in CP patients due to the following challenges: 

• Difficulties in communication and reporting pain by the child or adult with CP
• Pain comes from unrecognised multiple areas in the body
• Differences of mental processes and physical abilities of affected individuals
• Doctors face limitations in pain assessment tools⁴ ​

Therefore, pain recognition and relief using various forms of intervention is essential to improve the conditions of CP patients and  elevate their quality of life.⁶ ​

Understanding Pain in Cerebral Palsy 

Pain is described as an unpleasant and annoying sensation or emotion that associates a potential tissue damage and is classified based on its timing into acute or chronic. 

Acute pain in CP 

It happens for a short duration of time and usually happens as a result of a medical procedure or a treatment intervention that can in turn increase the muscle spasm and further worsen the initial pain. 

Chronic pain in CP 

Chronic pain in CP is categorised into primary or secondary. 

Chronic primary pain 

In chronic primary pain, there is no identifiable cause or explanation for the condition, and pain on itself constitutes the main problem. An example of primary pains is headaches which include migraine and tension headaches that are considered common among people with CP. 

Chronic secondary pain 

In chronic secondary pain,  pain is a consequence of another health condition and encompasses the most common types of pain encountered by individuals with CP such as: 

1. Musculoskeletal pain

It is the most common type of pain and results from muscle spasm and spasticity. When a muscle contracts,  the blood coming to supply it with oxygen is cut,  causing a painful sensation that can consequently increase the spasms keeping the cycle going on and on. 

Spasticity and muscle weakness cause contracture deformity which is a stiffness of the muscles and tissues around the joints,  limiting its range of movement and causing pain. It tends to worsen with time if not dealt with properly. Spasticity and contracture both cause disturbances in joint alignment especially in weight-bearing areas like the hips, knees and the back. Ankle and foot deformities are also very common. 

Another condition which contributes to musculoskeletal pain is osteoporosis in which the decreased use of bones results in weakness, degeneration and increased likelihood of fractures. Both osteoporosis and fractures cause pain with varying degrees. 

2. Visceral pain 

Pain and abdominal symptoms are experienced by the majority of individuals with CP and results from conditions like: 

• Heart pain and acid reflux 
• Constipation 
• Abdominal pain, the cause of which is not fully understood 

3. Face and mouth pain 

Teeth grinding or clenching is common in CP and leads to jaw disorders and results in: 

• Headache 
• Mouth biting leading to ulcerations  

4. Neuropathic pain 

 A persistent or occasional pain brought by a defect in the nerve fibres responsible for pain sensation. It can also be triggered by some stimuli like touch and cold objects. It can be presented in the form of: 

• Burning sensation 
• Squeezing sensation 
• Pricking sensation 

5. Pain after surgery 

Surgery is sometimes required to improve mobility and to relieve pain, however, it can  also lead to pain in the affected area like the back and knees.⁷ ​

6. Pressure ulcers (bedsores) 

Immobility results in skin changes caused by the continuous pressure of the skin especially at the areas on bony prominences that can ulcerate,  bleed or become infected.⁸ ​

Pain recognition and assessment 

Although pain is a significant symptom in CP it continues to be underrecognized and undertreated, therefore, several pain assessment tools were developed for the clinicians and health providers to aid in the process. These tools vary in their effectiveness and their suitability to the addressed condition and healthcare specialists should be aware of this information when choosing the appropriate tool for their patients.⁹ ​

What are the features that communicate pain in a child with impaired verbal interaction? 

Some features may help the caregivers to detect pain in children and adults with CP who are not able to communicate their sensations : 

• Crying and moaning 
• Teeth clenching and altered facial expressions 
• Irritability 
• Sleep disturbances  
• Increased stiffness, arching back and fist clenching 
• Sweating, tears and pallor 
• Breath-holding¹⁰​

Pain Management Strategies 

Importance of a team approach  

It is important to note that multiple teams of different specialities should participate in the process in order to manage CP effectively and to achieve the best outcomes possible. They include: 

• Physicians like neurologists and orthopaedists 
• Nurses  
• Physical therapists   
• Occupational therapists 
• Behavioural health specialists 
• Social workers¹ ​

The teams collaborate with each other to put a management plan specifically tailored to the patient. 

Non-pharmacological interventions  

Physical and occupational therapies have a significant role in the treatment of CP. They aid in improving movement and reducing spasticity which in turn helps in relieving pain. It involves performing stretching exercises, massages and using aids and adaptive devices to help facilitate body mobility.  

Pharmacological treatments 

Drugs used to reduce pain intensity like painkillers or to relieve spasticity like: 

• Botulinum neurotoxin A injections (Botox):

Botox is a well-known treatment option for pain management in CP. It reduces deformity and stiffness. It is given intramuscularly and can be started in as young as 18-month-old children. 

• Systemic anti-spasticity drugs such as:  
  • Baclofen 
  • Diazepam 
  • Anti seizure medications  

However, they have many reported side-effects like dizziness, drowsiness and confusion and their effect is usually short-lived. 

Surgical and invasive interventions 

Interventions are reserved for the more complicated cases after attempting the less invasive approaches.  

• Intrathecal baclofen therapy  

A pump is surgically introduced through the skin to access the canal of the spinal cord to deliver the muscle relaxant Baclofen.  

• Selective dorsal rhizotomy 

This is a procedure intended to reduce spasticity in which the surgeon cuts selected nerve fibres in the spinal cord to cut the stimulus pathway causing the abnormal muscle activity. 

Other treatment options

Treating other causes of pain not related to spasticity if identified like constipation and bedsores. And surgical correction of the deformities.^1,11 ​

Summary

Cerebral palsy (CP), a disorder of movement and posture is one of the most encountered neurological conditions that manifest in childhood and persists throughout life. It leads to significant pain capable of impacting the daily life of the affected individual most of the time,  and the family that requires a multidisciplinary approach. This is used to formulate a personalised plan utilising non-pharmacological and pharmacological interventions and sometimes surgical procedures.