Dr Odirichi Andrew – paediatric specialty doctor with input from Dr Shachi Buch – consultant community paediatrician.

I remember learning about cerebral palsy (CP) as a medical student; it was certainly one of those topics that required an added clinical exposure to grasp. Not until I started working in paediatrics did I fully encounter how this disorder presents.

You may be wondering what cerebral palsy is all about, what causes it and how it is managed; this article is here to simplify cerebral palsy! Now let’s get started!

Definition

I’ve got this easy definition of cerebral palsy which has stuck with me – Cerebral palsy (CP) is a neurological disorder of POSTURE and MOVEMENT that occurs to due to a NON-PROGRESSIVE injury to the developing BRAIN.  

International experts thought that this definition certainly did not encompass the heterogenous nature, functional problems, and associated complications, hence, a broader definition was agreed.

‘Cerebral Palsy describes a group of permanent disorders of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or immature brain. The motor disorders of CP are often accompanied by disturbances of sensation, perception, cognition, communication, and behaviour, by epilepsy, and by secondary musculoskeletal problems’.

How many people are affected?

According to NICE, the number of people with CP (prevalence) is 2.0 to 3.5 per 1000 live birth. This number may be different depending on location. It is estimated that 35% of infants born before 26 weeks of gestation (premature) develop CP. The prevalence is also more in multiple pregnancies. 

What causes cerebral palsy?

As you would already imagine, an insult to the brain antenatally, perinatally, and postnatally can result in cerebral palsy.

Antenatal and perinatal causes include:

• Hypoxic ischemic injury
• Intrauterine infections
• Congenital abnormalities
• Maternal trauma

Postnatal causes are:

• Stroke
• Trauma
• Hypoxic events
• Meningitis
• Kernicterus

Risk factors are:

Prematurity

Multiple pregnancy

Assisted reproduction techniques.

Medical conditions in mother such as thyroid disorders, pre-eclampsia

Toxins and chemicals

Genetic susceptibility

These conditions act alone or in combination with other factors to increase the chances of injury occurring in the developing brain. For instance, assisted reproduction may lead to multiple pregnancy which could result in preterm birth that may be complicated by periventricular leukomalacia (PVL) or intraventricular haemorrhage (IVH). It is important to say that sometimes the cause of the CP may remain unknown.

How does CP occur?

In both preterm and term infants, hypoxia, and inflammatory/infective events interplay to cause CP. The water shed area is commonly affected; this is an area in the brain with end arterial supply and is at greater risk of hypo-perfusion. In the preterm, the area is around the ventricles while in term infants it may be in different areas on the cortex.

Preterm infants   – The risk of cerebral palsy is inversely related to the gestational age and birthweight. Preterm infants often have periventricular leukomalacia (PVL), intraventricular haemorrhage and bronchopulmonary dysplasia which predispose to cerebral palsy. Periventricular leukomalacia refers to damage to the white matter around the ventricles. The white matter is responsible for transmitting information between nerve cells and within the brain cells. In the preterm infant, the periventricular white matter is susceptible to hypoxic/ischemic damage due to immature cerebral blood flow autoregulation. Ischemia with or without infection results in cytokine release, oxidative stress, and excitotoxicity, which are toxic to the brain cells. PVL is the most common risk factor for CP in preterm; IVH cause CP on its own or together with PVL.

Term infants – Perinatal hypoxic ischemic injury often involving the basal ganglia and the thalamic region of the brain is the commoner pattern seen in term infants unlike in preterm infants. Hypoxic injury results in mitochondrial failure, increased intracellular calcium and the production of reactive oxygen and nitrogen species. These in addition to excitotoxic injury from excessive glutamate results in death of neuronal cells.

The cascade of events that occur following hypoxic-ischemic episodes, inflammation and infection in the brain are the factors for development of CP.

Classification

Cerebral palsy classification is often used to signpost health care professionals and carers to the severity and type of the symptoms to help provide care commensurate to the needs of those who have CP. 

Classification according to distribution

1. Monoplegia – affecting one limb.
2. Hemiplegia – affecting one side of the body 
3. Diplegia – lower limbs are more affected than upper limbs.
4. Triplegia – three limbs are affected.
5. Quadriplegia – all limbs are affected.

Some authors have begun to use the terms unilateral or bilateral cerebral palsy in which case monoplegic and hemiplegic CP are classed as unilateral while diplegia, triplegia and quadriplegia CP are classed as bilateral.

Classification according to motor impairment

• Spastic type 
• Dyskinetic type
• Ataxic type

Classification of functionality

The gross motor functional classification system (GMFCS) is commonly used to stratify the mobility of patients with CP. Other classification of functionality exists. 

Don’t be put off by GMFCS levels, I will give you a clue on how to learn it. 

Level I – nearly normal only some problems with speed/coordination

level II – as good as level I but needs wheeled mobility for long distances.

Level III – needs handheld mobility device plus wheeled mobility for long distances.

Level IV – needs wheeled mobility in most settings.

Level V – severely impaired ability to move. Needs wheeled mobility in all settings.

Clinical features

Overview

1. Abnormal primitive reflexes – the earliest sign of CP is persistence of reflexes, failure to develop expected reflex for age or exaggeration of existing reflex. 
2. Abnormal tone and posture – Hypertonia is common, but they may have normal or reduced tone or even changing tone. Fisting may also be noted.
3. Developmental delay – development assessment is a useful screen to predict CP especially in the presence of more than one motor delays. Look out for the following threshold for abnormal development.
4. hand preference before 12 months
5. Persistent fisting after 4 months of development
6. Sitting without support by 9 months.
7. Tightness of the legs or scissoring between 6 and 12 months (not being able to take leg to the mouth)
8. Head lag after 4 months of age
9. Constant asymmetrical posturing and movements beyond 4 months of age

Description of motor presentation

• Spasticity – Spasticity is increased muscle resistance to passive movement. Spastic CP have mainly upper motor neurone signs which includes hyperreflexia, extensor plantar response and clonus. Spastic CP may present as spastic diplegia, spastic quadriplegia or spastic hemiplegia. See classification above and figure 1-2.
• Dyskinesis – This is an abnormal involuntary movement of the muscles. They may present as dystonia, chorea or athetosis.
• Ataxia – In ataxia, there is impairment of voluntary movement and speech coordination resulting in unsteadiness and broad-based gait. There may be discoordination of speech manifesting as slurred or explosive speech.
• Others 
• It reasonable to note here that the above motor presentation in CP overlap and this may change as the child grows into adolescence and adulthood. This should not be a source of confusion but rather the child’s motor phenotype should be documented periodically as they evolve. There may be mixed presentation where a child has more than one motor feature with no feature predominating. For example, spastic and dyskinetic features co-existing. 
• Sometimes hypotonic CP may be described. Individuals with hypotonic CP may have truncal hypotonia with or without spasticity. This term is not widely used.

Co-morbidities and complications

• Neurologic – epilepsy, microcephaly, sleep disturbances, oro-facial dyspraxia
• Speech disorders – dysarthria, aphasia, speech delay
• Gastrointestinal – constipation, drooling, feeding difficulties, growth failure, gastroesophageal reflux, bowel incontinence, abdominal pain.
• Pulmonary – obstructive sleep apnea, restrictive lung disease, recurrent aspiration, dysphagia, chronic lung disease.
• Visual and hearing problems
• Oral health – tooth decay, tooth malalignment
• Sleep issues
• Genitourinary – urinary tract infections, incontinence, neurogenic bladder
• Vision – strabismus, refractive errors, optic nerve atrophy, cataract, cortical impairment, visual field defects
• Endocrine – delayed or precocious puberty
• Skin – decubitus ulcers
• Cognition and behaviour – anxiety, depression, ADHD, learning difficulties.
• Musculoskeletal – osteopenia, scoliosis, contractures, hip dislocation, hip dysplasia, hip subluxation, limb deformities
• Chronic pain

Diagnosis

Cerebral Palsy is a clinical diagnosis.

1. There is increased suspicion of CP if there are features such as developmental delay, abnormal tone, or posture.
2. History of perinatal asphyxia, prematurity, prolonged NICU admission, neonatal seizures, and infections.
3. Investigations – Neuroimaging, metabolic and genetic testing supports or rules out the diagnosis of CP.
4. Magnetic resonance imaging
5. Cranial ultrasound scan
6. Genetic testing
7. Metabolic testing

Differential diagnosis

Neurodegenerative, Metabolic and some genetic disorder can present like CP. 

Consider differential diagnosis to CP if there is regression of milestones, progression in the symptoms, family history of consanguinity, uneventful or term pregnancy, predominant muscle weakness, symptoms worsened by childhood illness or prolonged recovery from childhood illness.

Treatment 

Since we are unable to change the damage that have occurred in the brain, the treatment of CP is often channelled towards controlling the symptoms and complications. 

The goals of treatment are individualised, set to promote independence and preserve function as much as possible with the participation of parents or carers. Approach to management is largely holistic, touching on all areas such as medical, social, psychologic, community-related, and educational needs of the child. 

Interventions are commenced as soon as a diagnosis of CP is suspected to maximise function and reduce disability. The modalities of management are chosen from the less invasive to the most invasive. 

A multidisciplinary team manages a specific aspect of the patient’s problem coordinated by the community paediatrician

Symptom	Treatment goal	Non pharmacologic	Pharmacologic	Invasive/surgery
Spasticity	Minimise motor impairment, comfort, improve function	Physiotherapy, Occupational therapy, Orthotics and mobility equipment	Baclofen, Benzodiazepines (Diazepam), Muscle relaxants (Tizanidine), Dantrolene	Botulinum toxin A injection, Intrathecal baclofen pumps Selective dorsal Rhizotomy
Dystonia	As in spasticity	As in spasticity	Dopamine agonist (Carbidopa/levodopa), Antihistamines/anticholinergics (Trihexyphenidyl), Dopamine depletors (tetrabenazine), Muscle relaxants (Tizanidine), Benzodiazepine (Diazepam, clonazepam), Baclofen, Anti-seizure agents (carbamazepine, gabapentin)	Deep brain stimulation
Scoliosis	Encourage growth, improve lung function	Spinal bracing, moulded wheelchair		Scoliosis surgery (spinal rods, spinal fusion)
Hip disorders -subluxation, dislocation, and dysplasia	Reduce disability and pain, comfort	Screening for hip disorders by routine clinical examination and radiological assessment, Abduction braces		Surgery- Femoral and pelvic osteotomies, soft tissue release
Contractures and joint deformities	Reduce disability and improve function	Serial casting		Muscle/tendon surgeries such as tendon release, tendon lengthening and tendon transfer. Bone surgeries e.g osteotomy, hemiepiphysiodesis
Epilepsy	Reduce disability		Anti-seizure agents	Vagal nerve stimulation, hemispherectomy
Nutrition/ feeding difficulties	Improve nutritional state and growth. Avoid aspiration	Growth and nutritional status assessment, Food supplementation		Nasogastric tube feeding, Gastrostomy
Communication	Complement communication deficits	Speech and language assessment Communication aids, sign language, voice input devices
Drooling	Prevent aspiration, improve quality of life	Behavioural therapy	Anticholinergics (hyoscine, glycopyrrolate)	Botulinum toxin injection of salivary gland , Salivary gland surgery (excision/ligation)
Bone density problems	Prevent bone demineralisation and pathologic fracture	Weight bearing programs	Calcium and vitamin D supplementation, Bisphosphonates for severe cases
Sleep problems	Improve quality of life	Sleep hygiene, carer education, Sleep specialist	Melatonin, Identify and treat underlying cause such as obstructive sleep apnea, reflux, spasticity
Skin care	Prevent skin breakdown and pressure sores	Positioning and frequent turning, Pressure support devices, Regular skin assessment. Assessment of braces and devices for fitting, Prevent wound contamination	Pain killers, treat infection, wound management
Chronic pain	Improve quality of life, comfort	Identify and treat underlying cause such as constipation, reflux, hip disorders	Pain relief

Hey! This table is by no means exhaustive. Children with cerebral palsy may require intervention for other problems related or unrelated to their condition. If the problem is anticipated or present, they should be referred to the appropriate MDT member.

Take home points

Cerebral palsy is a non-progressive neurologic disorder with diverse presentation and comorbidities. Diagnosis is suspected by a history of prematurity or perinatal events, developmental delay, or abnormal tone/posture; imaging modalities supports or excludes the diagnosis of CP. Management is aimed at maximising function, managing comorbidities, and reducing complications.