👶 Cerebral Palsy (CP): Classification, Pathophysiology, and Rehab

Cerebral Palsy (CP) is the most common motor disability in childhood. It is a non-progressive brain lesion occurring during the developing brain period (prenatal, perinatal, or postnatal). While the injury is stable, the clinical manifestations of movement and posture change significantly as the child grows.

1. 📊 Classification of Cerebral Palsy

A. Based on Movement Disorder (Physiopathology)

Type	Site of Damage	Movement Quality	Key Features
Spastic CP (75–85%)	Cerebral Cortex (UMN damage)	Stiffness, exaggerated reflexes.	Hypertonia, scissoring gait, toe walking.
Dyskinetic CP (6%)	Basal Ganglia	Involuntary, uncontrolled, sustained/intermittent movements.	Athetoid (writhing), Dystonic (rigid posturing). Fluctuation in tone.
Ataxic CP (6%)	Cerebellum	Uncoordinated, clumsy, imprecise movements.	Wide-based gait, intention tremor, hypotonia.
Mixed CP	Multiple sites	Combination of features (most commonly Spastic + Dyskinetic).	Most complex management due to mixed tone.

B. Based on Topographical Distribution

This describes which limbs are most affected by the disorder:

• Hemiplegia: One side of the body (arm and leg).
• Diplegia: Primarily the lower limbs are affected, with the upper limbs less involved or spared.
• Quadriplegia/Tetraplegia: All four limbs are involved equally or severely.

C. Functional Level (GMFCS)

The Gross Motor Function Classification System (GMFCS) is the primary tool for communicating functional capacity and predicting future mobility for CP patients.

GMFCS Levels (I–V):

• Level I: Walks without limitations, runs and jumps.
• Level III: Walks using an assistive device (crutches/walker) indoors; may use a wheelchair for distance.
• Level V: Severely limited voluntary control; transported in a manual wheelchair.

2. 👶 Etiology: Risk Factors and Timing of Injury

The timing of the brain insult determines the specific pathology:

• Prenatal (75%):
  • Prematurity & Low Birth Weight (highest risk factors).
  • Maternal Infections (e.g., TORCH complex: Toxoplasmosis, Others (Syphilis, HIV), Rubella, Cytomegalovirus, Herpes Simplex).
  • Placental insufficiency or Intrauterine growth restriction.
• Perinatal (6%): Birth Asphyxia or complicated labor (historically overemphasized).
• Postnatal (Up to 10%): Severe Jaundice (Kernicterus), Meningitis/Encephalitis, or early childhood Head Injury/Stroke.

3. 🚩 Clinical Features and Associated Problems

A. Motor Signs and Reflexes

• Delayed Milestones: Failure to achieve sitting balance, crawling, or walking at expected ages.
• Abnormal Tone & Postures: Scissoring of legs (adductor hypertonia), persistent toe walking (gastrocnemius spasticity).
• Primitive Reflexes: Persistence of reflexes that should integrate (disappear) by 6 months, such as ATNR (Asymmetrical Tonic Neck Reflex), STNR (Symmetrical Tonic Neck Reflex), and TLR (Tonic Labyrinthine Reflex).
• Gait Abnormalities: Scissoring Gait (legs cross due to adductor spasticity), Crouched Gait (hip/knee flexion, ankle dorsiflexion).

B. Associated Problems (Crucial for QoL)

CP is not just a motor disorder; associated problems affect comprehensive management:

• Cognitive Impairment: Present in about 50% of cases.
• Epilepsy/Seizures: Occur in up to 40% of patients.
• Speech and Feeding: Dysarthria (speech difficulty), oral motor dysfunction leading to drooling and aspiration risk.
• Orthopedic: Hip Dislocation (due to strong, tight hip flexors/adductors overwhelming weak abductors) and progressive Scoliosis.
• Vision and Hearing Impairment.

4. 📋 Physiotherapy Assessment Tools

Assessment must be holistic, dynamic, and use standardized, validated scales:

• Functional Level: GMFCS (for prognosis/planning).
• Gross Motor Capacity: GMFM (Gross Motor Function Measure) $\rightarrow$ Quantifies change in motor function over time.
• Tone: Modified Ashworth Scale (MAS) for spasticity grading.
• Activities of Daily Living (ADLs): Pediatric Evaluation of Disability Inventory (PEDI).
• Reflexes: Assessment of primitive reflexes (ATNR, STNR, TLR) and pathological reflexes (Babinski).

5. 🛠️ Physiotherapy Management: Type-Specific Interventions

A. Early Intervention (Ages 0–2: Neuroplasticity Window)

• Goal: Facilitation of normal movement patterns and preventing the establishment of abnormal posture/tone.
• Key Interventions: Handling and Positioning (e.g., proper seating, side-lying to inhibit tonic reflexes). Neuro-Developmental Treatment (NDT)/Bobath: Facilitation of head/trunk control, transitions, and weight-bearing.
• Stretching: Gentle, sustained stretching to counteract early contractures.

B. Spastic CP Management (Most Common)

Focus: Inhibition of hypertonia, alignment, and strengthening of weak antagonists.

• Contracture Prevention: Serial Casting (to gain long-term passive range, especially in the Achilles tendon), Night Splints (AFOs).
• Weight-Bearing: Promotes bone density, reduces extensor tone, and provides proprioceptive input (e.g., standing frames, partial weight-bearing).
• Gait: Task-oriented training emphasizing proper heel strike, hip extension, and balance.
• Orthotics: AFOs (Solid or Ground Reaction) to prevent toe-walking (equinus) and stabilize the foot. SWASH brace (Standing, Walking, and Sitting Hip) for hip adduction/scissoring control.

C. Dyskinetic CP Management (Basal Ganglia Lesion)

Focus: Stability and damping involuntary movement.

• Co-Contraction Training: Improving joint stability.
• Relaxation and Rhythmic Movement: Slow, rhythmic exercises and hydrotherapy.
• Weighted Devices: Using weighted vests or utensils to reduce the amplitude of involuntary movements (ataxia/athetosis).
• Postural Stability: Training against gravity in mid-range positions.

D. Advanced Techniques

• Constraint-Induced Movement Therapy (CIMT): Highly effective for Hemiplegic CP to increase use and function of the affected upper limb.
• Hydrotherapy: Warm water facilitates relaxation and movement due to buoyancy.
• FES (Functional Electrical Stimulation): Can be used to improve gait mechanics (e.g., activate tibialis anterior to manage foot drop).

6. 🩹 Medical and Surgical Interventions

A. Medical Management

• Botulinum Toxin Injections (Botox): Temporarily reduces focal spasticity (e.g., gastrocnemius, hamstrings) to allow for stretching/casting to be more effective.
• Intrathecal Baclofen Pump (ITB): Delivers Baclofen directly to the spinal cord for generalized, severe spasticity.
• Anti-spasticity Drugs: Oral Baclofen, Diazepam, Tizanidine.

B. Surgical Management

• Selective Dorsal Rhizotomy (SDR): Cutting select sensory nerve rootlets to permanently reduce severe spasticity (mainly L2–S2) in ambulatory Spastic Diplegia.
• Orthopedic Surgery: Tendon Lengthening (e.g., Achilles, Hamstrings), Muscle Transfers, and corrective osteotomies for hip subluxation/dislocation and scoliosis.

7. 📈 Prognosis and Functional Outlook

While the CP injury is static, prognosis is dynamic and depends heavily on functional milestones:

• Ambulation Prediction: If a child with CP achieves independent sitting by age 2 years, they have a high probability ($\sim 80\%$) of achieving independent walking (GMFCS I–III).
• Severity: GMFCS Level V patients require lifelong assistance and non-ambulatory management (seating, respiratory care).
• Non-Progressive, but Changing: The brain damage is static, but secondary musculoskeletal problems (scoliosis, hip dislocation) and progressive functional decline can occur if management is not consistent throughout growth.

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🎓 Academic Short Notes and Viva Prep

• Definition of CP: Non-progressive disorder of movement/posture due to injury to the developing brain.
• Types of CP: Spastic (UMN/Cortex), Dyskinetic (Basal Ganglia), Ataxic (Cerebellum).
• Primitive Reflexes (ATNR/STNR/TLR): Persistence interferes with normal motor development (e.g., STNR prevents quadruped crawling).
• Physiotherapy in Spastic Diplegia: Focus on stretching hip flexors/adductors/gastroc, strengthening hip extensors/abductors, and using AFOs/Serial Casting.
• Role of Orthotics: Prevent secondary deformities, improve stability (AFO, dynamic splints), and enhance gait efficiency.

❓ Frequently Asked Questions (FAQs)

Q: What is the main neurological problem causing Dyskinetic CP?

A: Dyskinetic CP results from damage to the Basal Ganglia (which controls movement tone and initiation), leading to involuntary movements (athetosis, dystonia) and highly fluctuating muscle tone, unlike the sustained hypertonia of spastic CP.

Q: What does a persistent Asymmetrical Tonic Neck Reflex (ATNR) interfere with?

A: The ATNR (fencing posture) interferes with midline activities, bringing the hands to the mouth, bilateral hand use, and rolling. If persistent, the child cannot easily roll or feed themselves.

Q: Why is hip dislocation a common orthopedic complication in severe CP?

A: Hip dislocation occurs due to the strong, unopposed pull of hypertonic hip flexors and adductors (spasticity) overpowering the weaker hip abductors and extensors. This imbalance gradually pulls the femoral head out of the socket.

Q: What is the window of opportunity for early intervention in CP?

A: The first two years of life are considered the critical window. During this time, the brain is highly plastic, meaning intensive, targeted physiotherapy (like NDT or high-repetition functional training) can maximize functional gains and potentially reorganize surviving neural pathways.

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🎯 10 Practice MCQs for Cerebral Palsy Exam

Q1. Spastic Cerebral Palsy is primarily caused by damage to the:

Answer: A). Spastic CP is due to Upper Motor Neuron (UMN) damage originating in the motor cortex.

Q2. Which feature is most characteristic of Spastic Diplegia?

Answer: B). Diplegia means legs are more involved than arms. Scissoring is due to adductor spasticity.

Q3. A child with CP is classified as GMFCS Level V. This indicates:

Answer: B). Level V is the most severe functional category (Non-ambulatory).

Q4. The clinical goal of Serial Casting in spastic CP is to:

Answer: B). Serial casting uses prolonged stretch over time to remodel muscle and connective tissue length, correcting fixed contractures.

Q5. Persistent presence of the Symmetrical Tonic Neck Reflex (STNR) would interfere primarily with which activity?

Answer: B). Head flexion causes arm flexion/leg extension, and head extension causes arm extension/leg flexion. This makes hands-and-knees (quadruped) movement impossible.

Q6. Which intervention is best suited for managing Ataxic CP symptoms like poor balance and intention tremor?

Answer: B). Ataxic CP involves cerebellar damage; management focuses on stability, coordination (Frenkel), and damping movement amplitude.

Q7. The prognosis for achieving walking is high if a child with CP achieves this milestone by age 2 years:

Answer: C). Independent sitting by age 2 is the single strongest predictor of potential for ambulation (GMFCS I–III).

Q8. The surgical procedure that involves selectively cutting sensory nerve rootlets to permanently reduce severe lower limb spasticity is:

Answer: B). SDR targets the afferent loop of the stretch reflex, providing lasting spasticity reduction in carefully selected candidates (often spastic diplegia).

Q9. In a child with Hemiplegic CP, CIMT requires restricting the unaffected arm. This technique primarily relies on which principle of neurological recovery?

Answer: B). By forcing the use of the affected limb, CIMT drives neuroplasticity by overcoming the learned compensatory strategy of ignoring the weaker side.

Q10. The infectious cause of CP that is characterized by high levels of unconjugated bilirubin causing brain damage (kernicterus) is:

Answer: B). Uncontrolled hyperbilirubinemia can cross the blood-brain barrier and deposit in the basal ganglia, typically leading to Dyskinetic CP.

📚 Important Academic References

• Novak, I., et al. (2020). Clinical practice guideline for the diagnosis and management of cerebral palsy. Developmental Medicine & Child Neurology, 62(3), 296–305. (Current clinical guidelines).
• Palisano, R., et al. (1997). Development and reliability of a system to classify gross motor function in children with cerebral palsy. Developmental Medicine & Child Neurology, 39(4), 214–223. (The GMFCS).
• O’Sullivan, S. B., & Schmitz, T. J. (2019). Physical Rehabilitation (7th ed.). F.A. Davis Company. (For NDT, assessment, and general management).
• Tscharnuter, I. (2018). Neurodevelopmental treatment. In The Pediatric Guide to Physical Therapy. Springer. (NDT principles).