Week 3 - B - Neuromuscular disorders - cerebral palsy (spastic, dyskinetic, ataxis) and spina bifida

Question 1

Neuromuscular disorders occur due to abnormal or deficient motor neurone signals to skeletal muscle - Where between the brain and muscle may this defect occur?

Answer 1

The neuromuscular disorder may occur due to a defect in either the brain, spinal cord, peripheral nerve, neuromuscular junction or muscle

Question 2

There are many causes of neuromuscular disease - we talk more on it in our neurology notes. These flashcards will discuss a few common paediatric disorders What does an upper motor neruone defect present as? What does a lower motor neurone defect present as?

Answer 2

Upper motor neruone (Brain and spinal cord) - gives rise to weakness, spasticity (velocity dependent increased tone), hyperreflexia, and extensor plantar response (Babinski sign) Lower motor neurone (affecting anterior horn cells, nerve roots or peripheral nerve) - gives rise to weakness, reduced tone and hypo-or areflexia

Question 3

What is cerebral palsy? * when is the onset * when does the insult to the brain take place

Answer 3

Cerebral palsy is a chronic neuromuscular disorder with onset before 2-3 years of age due to an insult to the immature brain before, during or after birth

Question 4

What are the different causes of cerebral palsy?

Answer 4

Causes include * Genetic problems * Brain malformation * Intrauterine infection in early pregnancy * Prematurity * Intra-cranial haemorrhage * Hypoxia during birth * Meningitis Only 1 in 10 cases are due to problems during labour (contrary to popular belief) whilst often there is no identifiable cause or explanation.

Question 5

The expression of the disease and its severity are variable depending on the area of the brain affected What can the presenting features of cerebral palsy range from?

Answer 5

Presenting features range from mild symptoms and signs limited to one limb to total body involvement with profound learning difficulties and delayed milestones

Question 6

What are the different types of cerebral palsy? Which type is most common?

Answer 6

Cerebral palsy types * Spastic - most common approx 80% of CP * Dyskinetic (athetoid) * Ataxic * Mixed

Question 7

Which area is affected in spastic cerebral palsy? What are the features of spastic cerebral palsy?

Answer 7

Spastic cerebral palsy suggests a pyramidal lesion - affecting the motor cortex, upper motor neruones or coritcopsinal tracts Results in weakness and spasticity which may worsen as the child grows

Question 8

Spastic cerebral palsy can affect * one limb - is this usually arm or leg? * one ipsilateral upper and lower limb * symmetrical limbs only * all 4 limbs usually with learning difficulties What are each of these known as and which is most common?

Answer 8

Spastic cerebral palsy one limb - monoplegic - usually arm that is affected one ispilateral upper and lower limb - hemiplegic - most common symmetrical limbs only - diplegic (specifically paraplegic if affecting the legs only) all 4 limbs - quadriplegic

Question 9

Which area is affected in dyskinetic cerebral palsy? What are are the presenting features?

Answer 9

Dyskinetic cerebral palsy - extrapyramidal motor system is affected here - basal ganglia Presenting features - uncontrolled unwanted movements, poor movememnt flow/posture

Question 10

Which area is affected by ataxis cerebral palsy? What are the presenting features?

Answer 10

Ataxic cerebral palsy is also extrapyramidal affecting the cerebrllum-uncommon They present with shaky movements, loss of balance and coordination and proprioception DASHING (dysdiadokinesis, ataxic gait, slurred speech, hypotonia, intention tremor, nystagmus, gait (broad based)

Question 11

Some up again the 4 types of cerebral palsy and the areas of the brain affected

Answer 11

* Spastic cerebral palsy - affected the motor cortex, UMNs or corticospinal tracts * Dyskinetic cerebral palsy - affected the basal ganglia * Ataxic cerebral palsy - affected the cerebellum * Mixed cerebral palsy - mix

Question 12

How does spina bifida occur When does it arise?

Answer 12

Spina bifida is a congenital disorder where the two halves of the posterior vertebral arch fail to fuse It is likley to occur within the first 6 weeks of gestation

Question 13

What is the mildest form of spina bifida and what may seen on gross examination that indicates this?

Answer 13

Spina bifida occulta is the mildest form, there is incomplete fusion of the posterior vertebral body but no protrusion of any spinal contents - a small tuft of hair may be seen in the skin overlying the defect

Question 14

In its more severe form, spina bifida cystica, the contents of the vertebral canal herniate through the defect What are the two types of spina bifida cystica? Which is usually associated with neruoological sequelae?

Answer 14

Spina bifida meningocele - herniation of the meninges alone - no neurological sequelae Spinal bifida myelomeningocele - herniation of the meninges with the spinal cord or cauda equina - usually has a neurological deficit (motor and sensory) below the lesion and most will never function independently.

Question 15

What is the treatment of spina bfida cystica?

Answer 15

With spina bifida cystica the defect is usually closed with 48 hours of birth (to prevent drying or infection)

Question 16

What region of the back does spina bifida normally occur in? Name to drugs not given in pregnancy as they can predispose to spina bifida?

Answer 16

Spina bifida normally occurs in the lumbar region of the back Spina bifida is linked to reduced folate levels therefore avoid drugs that cause this * Methotrexate and trimethoprim both inhibit dihydrofolate reductase - this reduces folic acid synthesis * stop methotrexate 3 months before trying for a baby

Question 17

Which trimesters of pregnancy should trimethoprim not be given in for a UTI and what should be given instead?

Answer 17

Do not give trimethorpim in the first and second trimesters Give nitrofurantoin instead