Week 2: CP and Neurodevelopmental Disorders

Palsy

• Comes from the same Greek root as paralysis.

• Muscle weakness or paralysis.

• Examples:

  • Bell’s palsy: weakness in muscles of face.

  • “Shaking palsy”: Parkinson’s.

  • Bulbar palsy: difficulty swallowing, talking.

Cerebral Palsy (CP)

• Most common movement disorder in children, affecting about 1 in 500 births.

• Not a single condition but a group of disorders.

• Types:

  • Spastic cerebral palsy (70-80%).

  • Dyskinetic cerebral palsy (10-20%), also known as athetoid.

  • Ataxic cerebral palsy (5-10%).

  • Hypotonic (3%).

  • Mixed.

• Each person’s experience of CP is unique.

Aetiology of CP

• CP is a brain injury or developmental disorder.

• 90% of cases are congenital.

• 10% are acquired during the first year of life.

• Root causes are often unknown, but risk factors include:

  • Oxygen deprivation during birth.

  • Pre-term birth.

  • Genetics (minor factor).

  • Twin births.

  • Low socioeconomic status.

  • Low birth weight (foetal growth restriction).

  • Maternal infection (e.g., rubella, herpes simplex).

  • Perinatal stroke (in the baby).

Pathophysiology of CP

• Involves white matter injury.

• Healthy brain development:

  • Homeostatic microglia.

  • Oligodendrocyte precursor cells (OPCs) mature into myelinating oligodendrocytes.

  • Normal myelination leads to healthy motor and cognitive function.

• Perinatal brain injury:

  • Hypomyelination.

  • Pro-inflammatory microglia.

  • Leads to cognitive, sensory, and motor deficits, resulting in cerebral palsy.

Site of Injury and Types of CP

• The site of brain injury determines the type of CP:

  • Motor cortex damage: Spastic CP.

  • Basal ganglia damage: Dyskinetic CP.

  • Cerebellum damage: Ataxic CP.

Spastic CP

• Damage to white matter from the motor cortex (upper motor neurons).

• Characterized by hypertonia (stiffness).

• Types:

  • Diplegia: mainly legs affected.

  • Hemiplegia: one side of the body affected.

  • Quadraplegia: all four limbs affected.

• Can affect other parts of the body, causing problems swallowing and speaking, as well as vision problems.

• Diplegia often presents with a characteristic “scissoring gait”.

Dyskinetic CP

• Damage to the basal ganglia (brain regions involved in regulating motor function).

• Types of movements:

  • Athetosis: slow, writhing movements.

  • Chorea: hyperkinetic symptoms – “dance-like” involuntary and irregular movements.

  • Dystonia: repetitive and twisted movements/abnormal postures.

Ataxic CP

• Damage to the cerebellum.

• Causes problems with coordination and balance.

Other Problems Associated with CP

• About half of people with CP have an intellectual disability (20% severe).

• Intellectual disability is NOT caused by CP itself; both conditions usually result from the same injurious factor (e.g., maternal infection).

• Seizures.

• Bone and joint problems:

  • Arthritis due to abnormal gait.

  • Fragile bones due to lower exercise.

• Curvature of the spine (hemiplegia, use of mobility aids).

• Chronic pain, possibly linked to bone/joint problems, GI tract issues, contractures.

Treatment for CP

• No cure!

• Management focuses on improving quality of life:

  • Physiotherapy: exercises to improve strength and range of movement (prevent contractures).

  • Speech and language therapy: communication, swallowing.

  • Assistive technologies/mobility aids.

  • Muscle relaxants: e.g., diazepam, baclofen, botox.

  • Surgery:

    • Musculoskeletal.

    • Selective dorsal rhizotomy.

  • Pain relief medication.

  • Anticonvulsant medication.

Prevention of CP

• Hypothermia treatment for traumatic birth/hypoxia during birth.

• Not applicable to pre-term babies.

Genetic Neurodevelopmental Disorders

• Williams syndrome: deletion of 27 genes on chromosome 7.

• Angelman syndrome: deletion of the UBE3A gene on maternal chromosome 15.

• Prader-Willi syndrome: deletion of a cluster of genes on paternal chromosome 15.

• All are complex syndromes affecting the development of the nervous system.

Williams Syndrome

• Characteristic appearance.

• Abnormalities in the frontal cortex and cerebellum lead to difficulties in motor tasks.

• Abnormalities in the parietal cortex lead to difficulties in visual-spatial tasks.

• “Cocktail party personalities” (highly verbal relative to cognitive abilities).

• Exaggerated fear response (non-social).

• Differences in size and response of the amygdala.

Angelman Syndrome

• Characteristic appearance.

• Seizures.

• Ataxia.

• Learning difficulties.

• Uncontrolled laughter.

• Brain regions affected:

  • Hippocampus: cognitive deficits (learning, memory).

  • Cortex, Cerebellum: motor deficits.

Prader-Willi Syndrome

• Characteristic appearance.

• Many have (mild) cognitive deficits.

• Spoken language is often poor, but reading and comprehension are better.

• Good at visual organization (jigsaw puzzles).

• Insatiable appetite (leading to obesity and diabetes risk).

• Underdevelopment of:

  • Regions of basal ganglia. - refine voluntary movments

  • Amygdala.

  • Hippocampus.

  • Hypothalamus. - homeostasis

  • Cerebellum. - balance, coordination, motor movement

Labradors

• Variant of POMC may be the cause of obesity in Labrador retrievers.