Cerebral Palsy: Definition and Types

Cerebral Palsy Definition

• Cerebral palsy (CP) is a group of non-degenerating neurological disabilities.
• Caused by non-progressive damage to the brain before, during, or shortly after birth.
• It is a disorder of movement and posture.
• Manifestations are primarily motor with or without other associated deficits.
• Severity depends on the site and extent of the lesion.

Types of Cerebral Palsy

• Clinical classifications include Spastic, Dyskinetic, Hypotonic/Ataxic, and Mixed.
• Topographical classifications are Hemiplegia, Diplegia, Quadriplegia, Triplegia, Monoplegia, and Double hemiplegia.

Main Motor Problems of CP

• All types of cerebral palsy are characterized by Muscle tone abnormality (hypertonia & hypotonia).
• Released primitive reflexes.
• Delay in the development of normal postural reactions such as righting, equilibrium, and protective reactions.
• Delay gross and fine motor development.
• Musculoskeletal abnormality is common, such as contracture and deformity.

Typical Impairments of the Infant and Child with Hypertonia

• Decreased stiffness in neck and trunk.
• Increased stiffness in extremities, distal > proximal, which varies with type, extent, and location of the lesion.
• Difficulty grading between co-activation and reciprocal inhibition.
• Difficulty initiating certain muscle groups like hip flexors and triceps.
• Difficulty sustaining certain muscle groups such as thoracic extensors and abdominals.
• Difficulty terminating certain muscle groups, for example hip extensors, adductors, and internal rotators.
• Activation of muscles tends to be in small ranges.
• Difficulty with eccentric control, for example quadriceps.

Musculoskeletal System Impairments

• Limited range of motion of certain muscles from soft tissue shortening.
• Other muscles are over-lengthened and are the antagonists.
• Decreased ability to generate force in certain muscles especially in spastic muscles.
• Strength of poor grade.
• High risk for scoliosis.
• At risk for hip subluxation and/or dislocation.

Common Contracture Sites

• Elbow flexors
• Forearm pronators
• Wrist and fingers flexors
• Hip adductors and flexors
• Knee flexors
• Ankle planter flexors

Sensory/Perceptual System Impairments

• Decreased tactile and proprioceptive awareness.
• Difficulty discriminating different kinds of touch.
• Decreased kinesthesia throughout the body.
• Decreased vestibular registration.
• Decreased body awareness.

Gross and Fine Motor Impairments

• Limited independent mobility on the floor or in vertical.
• May use assistive device for mobility.
• Poor sitting balance with spastic quadriplegia.
• Poor higher-level balance skills.
• Decreased use of hands due to use for stability and for assistive device for mobility.
• Poor grasp and release and decreased in-hand manipulation with spastic quadriplegia.

Oral Motor Impairments

• Usually noted more with spastic quadriplegia.
• May have drooling and poor articulation.
• May have difficulty feeding.

Typical Impairments of the Infant and Child with Hypotonia

• Decreased stiffness throughout the trunk and extremities
• Inability to grade the level of stiffness necessary for functional activities
• Extension favored over flexion for function
• Difficulty co-activating for stability in trunk and in the extremities
• Muscle activity is initiated in phasic bursts for functional activity
• Great difficulty sustaining most muscle groups, especially abdominals and gluteals for proximal stability
• Poor eccentric control of certain muscles (i.e., quadriceps)

Musculoskeletal System Impairments in Hypotonia

• Joints tend to be hypermobile and the child relies on ligaments for stability
• Stability gained through end-range positioning
• Contractures develop secondary to positioning of the arms and legs. E.g. the pectorals, tensor fascia latae, or flexors of the hips and elbows

Sensory/Perceptual System Impairments in Hypotonia

• Difficulty with tactile and proprioceptive awareness which reqires greater input to receive sensory information
• Decreased kinesthesia and body awareness
• May seek increased sensory input, sometimes in unsafe situations
• Decreased ability to use both sides together as a wide base is used for stability

Gross and Fine Motor Impairments in Hypotonia

• Developmental milestones achieved later
• May skip creeping on hands and knees
• Uses “W” sitting for stability
• Lacks higher-level balance skills
• Uses end-range stability
• Lacks shoulder girdle stability and therefore distal strength
• Hands without arches
• Decreased bimanual skill and in-hand manipulation
• Decreased success with independent activities of daily living

Oral Motor Impairments in Hypotonia

• Decreased strength of oral motor muscles
• Breathy voice and short Phrases
• Decreased rotary chew ability

Typical Impairments of the Infant and Child with Dyskinesia

• Profound global decrease in stiffness, proximal > distal
• Difficulty with co-activation and reciprocal inhibition noted much more frequently
• Inability to grade initiation or sustaining of muscle activation
• Muscle termination tends to be passive
• Difficulty with eccentric control of muscles

Musculoskeletal System Impairments in Dyskinesia

• Significant asymmetry of the spine and hips
• Joints may be hypermobile
• Poor ability to generate force
• Significant hypermobility at C1 and C6-C7 with increasing age, resulting in possible spinal subluxation
• Frequent temporomandibular joint problems

Sensory/Perceptual System Impairments in Dyskinesia

• Vision used in upward gaze
• Decreased proprioception
• Poor body awareness
• Poor kinesthesia

Gross and Fine Motor Impairments in Dyskinesia

• Developmental milestones achieved later
• Limited floor mobility, great difficulty sitting on the floor
• Delayed acquisition of ambulation skills
• Use of “W” sitting for stability
• Difficulty using hands for tasks as they are used for stability in vertical and on the floor
• Decreased bimanual skill and in-hand manipulation
• Decreased success with independent activities of daily living

Oral Motor Impairments in Dyskinesia

• Poor articulation
• Breathy voice and short phrases
• Prone to temporomandibular joint impairments because of asymmetric use of the facial muscles
• Frequent drooling with poor lip closure

Typical Impairments of the Infant and Child with Ataxia

• Tends to have slight decrease in stiffness in trunk, sometimes in the limbs as well
• Poor grading of stiffness
• Poor damping, oscillations are of high frequency and low amplitude
• Difficulty timing and sequencing initiating, sustaining, and terminating muscle activation
• Decreased ability to grade co-activation and reciprocal inhibition
• Poor co-activation of trunk, hips, and shoulder girdles
• Difficulty generating force
• Tends to rest in end range and rely on ligaments for stability
• Relies on vision for balance and postural alignment
• Visual system with severe nystagmus
• Decreased visual perception
• Decreased proprioception throughout the body
• Increased latency in processing sensory information
• Severe postural insecurity; very fearful of movement

Gross Motor Impairments in Ataxia

• Uses a very wide base to move on the floor independently
• Keeps legs flexed in vertical to lower the center of gravity
• Development tends to be slower owing to poor balance in upright

Fine and Oral Motor Impairments in Ataxia

• Poor skills due to an inability to grade precise movements
• Difficulty with activities requiring dissociation of the arms (segmental)
• Difficulty with a variety of textures and tastes

Gait Patterns in CP

• Hemiplegic gait is characterized by several types

Hemiplegic Gait

• Type 1: Weak or paralyzed/silent dorsiflexors (= dropfoot)
• Type 2: Type 1 + triceps surae contracture
• Type 3: Type 2 + hamstrings and/or Rectus Femoris spasticity
• Type 4: Type 3 + spastic hip flexors and adductors

Type 1 Hemiplegia

• "Drop foot" is most clearly seen in the swing phase.
• There is no calf contracture.
• Management involves a leaf spring ankle foot orthosis.

Type 2 Hemiplegia

• The most common type in clinical practice.
• True equinus is noted in the stance phase of gait.
• There are sub-categories to type 2 hemiplegic gait
• Equinus plus neutral knee and neutral hip.
• Equinus plus recurvatum knee and extended hip.
• There is usually a variable degree of drop foot in swing.
• A pattern of true equinus can be seen through most of the stance phase.
• Management includes reducing calf spasticity, orthotic support, and lengthening of the calf.

Type 3 Hemiplegia

• The type is characterized by calf spasticity or contracture, impaired ankle dorsiflexion in swing, and a stiff flexed knee.
• Management is to reduce calf spasticity, lengthen the calf, and use solid or hinged AFO, or hamstring release.

Type 4 Hemiplegia

• Characterized by more marked proximal involvement.
• Marked asymmetry, including pelvic retraction.
• Equinus, flexed stiff knee, flexed hip, and anterior pelvic tilt are observed in the sagittal plane.
• Hip adduction occurs in the coronal plane, and internal rotation in the transverse plane.
• There is a high incidence of hip subluxation.
• Reduce calf spasticity, lengthening of the calf, solid or hinged AFO, and hamstring release are management strategies.

Diplegic Gait Patterns

• Torsional deformities of the long bones and foot deformities are frequently found in spastic diplegic CP
• The most common bony problems are medial femoral torsion, lateral tibial torsion with foot valgus and abduction.

Type 1 Diplegia - True Equinus

• The calf spasticity is frequently dominant resulting in a true equinus gait
• The ankle is in plantar flexion throughout stance and the hips and knees extended.
• Management involves reducing calf spasticity, using a hinged AFO, and lengthening of calf.

Type 2 Diplegia - Jump Gait

• The jump gait can present with or without a stiff knee.
• The condition is very commonly seen in children with diplegia who also have more proximal involvement.
• There is tightness of the hamstrings and hip flexors in addition to calf spasticity.
• An anterior pelvic tilt and an increased lumbar lordosis is present.
• There is often a stiff knee because of rectus femoris activity in the swing phase.
• Spasticity management, stretching, solid or higed AFO, and GR AFO are management strategies.

Type 3 Diplegia - Apparent Equinus

• This presents with or without a stiff knee gait.
• Equinus may gradually decrease as hip and knee flexion increase.
• There is frequently a stage of apparent equinus.
• The management is the same as type 2.

Type 4 Diplegia - Crouch Gait

• This presents with or without a stiff knee gait.
• The condition is defined as excessive dorsiflexion or calcaneus at the ankle in combination with excessive flexion at the knee and hip.
• It occurs in the more severe diplegic CP children.
• The commonest cause of crouch gait is isolated lengthening of the Achilles tendon in the younger child.

Ataxic Gait

• This gait pattern is characterized by instability.
• Results in a compensatory wider base of support and elevated, outreaching arm postures to improve balance during gait
• Unsteady, staggering
• Patients will not be able to walk from heel to toe or in a straight line

Choreiform Gait (Hyperkinetic Gait)

• This gait is seen with certain basal ganglia disorders
• The patient will display irregular, jerky, involuntary movements in all extremities.
• Dancing gait.