Cerebral Palsy ✅ Flashcards Preview

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Flashcards in Cerebral Palsy ✅ Deck (73)
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1
Q

How do upper motor neuron lesions usually present?

A

Hypertonia

2
Q

What is the most common disabling condition in children with hypertonia?

A

Cerebral palsy

3
Q

What are the most disabling types of CP?

A

Spastic and dystonic types

4
Q

What is lost in spastic and dystonic types of CP?

A

There is a loss of the usual balance of excitatory and inhibitory muscle control

5
Q

What is CP?

A

A descriptive term which has been defined as ‘a group of permanent disorders of movement and posture causing activity limitation that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain’

6
Q

What are the motor disorders of CP often accompanied by?

A
  • Disturbances of sensation, perception, cognition, communication and behaviour
  • Epilepsy
  • Secondary musculoskeletal disorders
7
Q

Are children with CP always hypertonic?

A

No

8
Q

What are the four main clinical types of CP?

A
  • Spastic
  • Dystonic
  • Ataxic
  • Choreo-athetoid
9
Q

What characterises spastic CP?

A

A velocity dependent increase in tonic stretch receptors

10
Q

How must spasticity be assessed in spastic CP?

A

Must be dynamic

11
Q

What is the spasticity described as in spastic CP?

A

‘Clasp knife’

12
Q

What characterises dystonic CP?

A

Spasm and sustained contraction of muscles, leading to abnormal posturing

13
Q

What can dystonic CP lead to over time?

A

Contractures

14
Q

What is dystonic CP often described as feeling like?

A

Lead pipe rigidity

15
Q

What characterises ataxic CP?

A

Uncoordinated movements linked to a disturbed sense of balance and depth perception

16
Q

What characterises choreo-athetoid CP?

A

Hyperkinesia (excess of involuntary movements), which are often writhing in nature

17
Q

What % of cases of CP are unilateral spastic?

A

25%

18
Q

What areas of the brain are most commonly affected in unilateral spastic CP?

A

Infarction within the distribution of middle cerebral artery (left MCA distribution more commonly affected than right)

19
Q

What are the potential causes of unilateral spastic CP?

A
  • Intrapartum asphyxia
  • Ischaemia (stroke) in late third trimester
  • Intraventricular haemorrhage related to prematurity
20
Q

What % of cases of CP are bilateral spastic?

A

55%

21
Q

What is the more common type of bilateral spastic CP?

A

Roughly equal proportions diplegia to quadriplegia

22
Q

What area of the brain is most commonly affected in bilateral spastic CP?

A
  • Bilateral cerebral hemisphere infarction

- Cerebral dysgenesis

23
Q

What are the most common causes of bilateral spastic CP?

A
  • Genetic
  • Infections in early pregnancy, e.g. CMV, toxoplasmosis
  • Vascular accidents/malformations
24
Q

What are the less common causes of bilateral spastic CP?

A
  • Neonatal meningitis or metabolic insult

- Postnatal causes

25
Q

What % of cases of CP are dyskinetic?

A

15%

26
Q

What area of the brain is most commonly affected in dyskinetic CP?

A

Discrete gliotic lesions in the putamina and thalami

27
Q

What are the potential causes of dyskinetic CP?

A
  • Acute profound asphyxia in the late third trimester or intrapartum
  • Bilirubin encephalopathy
28
Q

What are some causes of intrapartum asphyxia?

A
  • Cord prolapse
  • Antepartum haemorrhage
  • Uterine rupture
29
Q

What % of cases of CP are ataxic?

A

5%

30
Q

What are the most common causes of ataxic CP?

A
  • Abnormal development of cerebellum

- Dysmorphic syndromes

31
Q

What are the less common causes of ataxic CP?

A
  • Postnatal infection or trauma
32
Q

Do children with CP always fit into one category?

A

No, they often have a mixed picture of movements

33
Q

What is the Gross Motor Function Classification System used for?

A

To describe the functional ability of a child’s gross motor skills

34
Q

What other conditions can mimic CP?

A
  • Spinal cord tumours
  • Channelopathies
  • Sandifer syndrome
  • MECP2 duplication
  • Congenital dopa-responsive disorders
  • Genetic spastic paraplegia
  • Some metabolic conditions
  • Ataxia telangiectasia
35
Q

Give 2 examples of metabolic conditions that can mimic CP?

A
  • GLUT1 deficiency

- Glutaric aciduria type 1

36
Q

When does particular care need to be taken in the diagnosis of CP to check there is no underlying cause?

A
  • When there is a family history, to ensure not an underlying inheritable cause
  • When child presents with ‘ataxic cerebral palsy’
37
Q

What is required to meet a child with CP’s complex needs?

A

MDT approach

38
Q

What are the potential sites of action of drugs that manage spasticity?

A
  • Motor cortex
  • Spinal cord
  • Muscle
39
Q

What kind of drug is diazepam?

A

Gamma-aminobutyric acid (GABA) agonist

40
Q

What is GABA?

A

The principal inhibitory neurotransmitter regulating neuronal excitability in the nervous system

41
Q

What does GABA have a direct effect on?

A

Muscle tone

42
Q

What is the result of GABA acting centrally?

A

It relieves spasticity and muscle spasm, but has additional effects of sedation and acts as an anxiolytic

43
Q

What can long-term use of GABA lead to?

A

Dependency

44
Q

What is short term use of GABA useful for?

A

Painful spasms, e.g. after surgery, or to break cycles of distress and increasing spasticity

45
Q

What kind of drug is baclofen?

A

A GABA agonist

46
Q

At what level does baclofen inhibit neuronal transmission?

A

At a spinal level

47
Q

What is the main adverse effect of baclofen?

A

Sedation

48
Q

Is sedation a significant side effect of baclofen?

A

Yes, it often limits its use

49
Q

Why are high doses of baclofen often needed?

A

Because its passage into the CSF when given orally is poor

50
Q

How can the dose requirement of baclofen be reduced?

A

By using intrathecally

51
Q

How is baclofen given intrathecally?

A

Via a surgically implanted continuous-delivery pump

52
Q

What is the advantage of giving baclofen intrathecally?

A

Only a tiny fraction of the equivalent oral dose needs to be given, which allows greater efficacy with fewer adverse effects

53
Q

What kind of drug is tizanidine?

A

An alpha-2 adrenergic receptor agonist

54
Q

Where does tizanidine act?

A

At the spinal level

55
Q

Who is tizanidine particularly useful in?

A

Children who are severely disabled by CP, and in those with night-time spasms

56
Q

Why is tizanidine useful in night-time spasms?

A

As it commonly has a sedative effect

57
Q

How does botulinum toxin A work?

A

By chemically denervating the muscle, allowing the muscle to relax and thus improving function and cosmesis in some cases

58
Q

How does botulinum toxin A act?

A

By cleaving synaptosomal-associated protein (SNAP-25)

59
Q

What is SNAP-25?

A

A cytoplasmic protein which aids in the process of attaching the synaptic vesicle to the pre-synaptic membrane

60
Q

What is the effect of cleaving SNAP-25?

A

It stops the release of acetylcholine at the synapse, and blocks neurotransmission

61
Q

What happens to the effects of botulinum toxin A over time?

A

Gradually wear off over 3-6 months

62
Q

Why do the effects of botulinum toxin A gradually wear off?

A

Because the myelin sheath retracts and new terminals are made, which form contacts with the myocyte to resume neurotransmission

63
Q

How does dantrolene work on spasticity and spasms?

A

By affecting calcium uptake into skeletal muscles and decreasing free intracellular calcium concentration

64
Q

Is sedation a problem with dantrolene?

A

Less so than other drugs used in CP

65
Q

Why should dantrolene be caused cautiously?

A

It can cause hepatic dysfunction and blood dyscrasias

66
Q

What non-drug treatment may be used for spasticity?

A

Selective dorsal rhizotomy (SDR)

67
Q

When is SDR particularly used in treating spasticity in CP?

A

In more mobile groups of children with CP (GMFCS levels 2-3)

68
Q

What happens in SDR?

A

Surgical procedure to divide some of the lumbar sensory nerve roots

69
Q

Why does dividing lumbar sensory nerve roots in SDR improve spasticity?

A

It interrupt the sensory-motor reflex arc responsible for increased muscle tone

70
Q

What should pre-op assessment for SDR include?

A

Bladder assessment

71
Q

Why is bladder assessment required prior to SDR?

A

Due to the risk of affecting continence

72
Q

What is the limitation of SDR?

A

The child’s general level of gross motor function unlikely to change significantly

73
Q

What is the benefit of SDR?

A

May be improvements in quality of gait, and improved comfort and ability to tolerate splints and postural management programmes