Paeds X

Question 2

What are the different classifications of cerebral palsy? [4]

Describe their features [4]

Where do each of the above have damage that causes them? [4]

Answer 2

Classification
Spastic:
- hypertonia (increased tone) and reduced function resulting from damage to upper motor neurones

Dyskinetic:
- problems controlling muscle tone, with hypertonia and hypotonia, causing athetoid movements and oro-motor problems.
- This is the result of damage to the basal ganglia.

Ataxic:
- problems with coordinated movement resulting from damage to the cerebellum

Mixed:
- a mix of spastic, dyskinetic and/or ataxic features

Question 3

You can gain a lot of information about a child from their gait:

Hemiplegic / diplegic gait: indicates an [] lesion
Broad based gait / ataxic gait: indicates a [] lesion
High stepping gait: indicates foot drop or a [] lesion
Waddling gait: indicates pelvic muscle weakness due to []
Antalgic gait (limp): indicates localised []

Answer 3

Hemiplegic / diplegic gait: indicates an upper motor neurone lesion

Broad based gait / ataxic gait: indicates a cerebellar lesion

High stepping gait: indicates foot drop or a lower motor neurone lesion

Waddling gait: indicates pelvic muscle weakness due to myopathy

Antalgic gait (limp): indicates localised pain

TOM TIP: Get used to assessing and recognising the patterns of upper and lower motor neurone lesions. Cerebral palsy is a perfect condition for examiners to bring to OSCEs, because signs are reliable and patients are stable. The differential diagnosis of an upper motor neurone lesion is acquired brain injury or a tumour.

Question 4

Patients with cerebral palsy may have a hemiplegic or diplegic gait. This gait is caused by [2] in the legs.

Answer 4

Patients with cerebral palsy may have a hemiplegic or diplegic gait. This gait is caused by increased muscle tone and spasticity in the legs.

Question 5

Mx for CP:
Paediatricians will regularly see the child to optimise their medications. This may involve: [3]

Answer 5

Muscle relaxants (e.g. baclofen) for muscle spasticity and contractures
Anti-epileptic drugs for seizures
Glycopyrronium bromide for excessive drooling

Question 6

What are the congenital causes of hydrocephalus? [1]

Describet the basic pathophysiology [1]

Answer 6

The most common cause of hydrocephalus is aqueductal stenosis, leading to insufficiency drainage of CSF.
- The cerebral aqueduct that connects the third and fourth ventricle is stenosed (narrowed).
- This blocks the normal flow of CSF out of the third ventricle, causing CSF to build up in the lateral and third ventricles.

Question 7

Describe the presentation of hydrocephalus in children [5]

Answer 7

The cranial bones in babies are not fused at the sutures until around 2 years of age. Therefore, the skull is able to expand to fit the cranial contents.
- When a baby has hydrocephalus it causes outward pressure on the cranial bones. Therefore, babies with hydrocephalus will have an enlarged and rapidly increasing head circumference (occipito-frontal circumference). Also:
- Bulging anterior fontanelle
- Poor feeding and vomiting
- Poor tone
- Sleepiness

Question 8

What is a key risk of VP shunt placement? [1]

Answer 8

Intraventricular haemorrhage during shunt related surgery

Question 9

What is the pathophysiology of DMD and BMD? [2]

Answer 9

Becker muscular dystrophy (BMD):
- X-linked recessive disorder resulting from mutations in the DMD gene, which encodes for the protein dystrophin used in muscle fibre stability.
- non-frameshift insertion in the dystrophin gene resulting in both binding sites being preserved leading to a milder form

Duchenne muscular dystrophy:
- Due to mutation in the gene encoding dystrophin
- frameshift mutation resulting in one or both of the binding sites are lost leading to a severe form

Question 10

Describe the cardiac [1], pulmonary [2] and cognitive features [2] of BMD

Answer 10

Cardiac Manifestations
* BMD frequently involves cardiac muscle leading to dilated cardiomyopathy.
* Patients may present with symptoms of heart failure such as dyspnoea, fatigue or fluid retention. Cardiac arrhythmias are also common.

Pulmonary Manifestations
* In later stages of BMD, patients may develop respiratory muscle weakness leading to impaired pulmonary function. Symptoms can include dyspnoea on exertion and recurrent respiratory infections.

Cognitive and Behavioural Features
* Though not as common, cognitive impairment and behavioural issues can be associated with BMD. These can include learning difficulties and attention deficit disorder.

Question 11

Describe the mx of BMD [1]

Answer 11

Corticosteroids:
- Prednisolone or Deflazacort are the first-line therapy to delay muscle weakness. Monitor for side effects including weight gain, osteoporosis and behavioural changes.

Question 12

Desribe the managment of BMD that would help with cardiac and pulmonary mx and other support that might be given [3]

Answer 12

Cardiac Management:
- Regular cardiac assessments should be conducted due to the high risk of cardiomyopathy.
- Angiotensin-converting enzyme inhibitors or beta-blockers may be used as prophylaxis against left ventricular dysfunction.
- Consideration should also be given to implantable cardioverter-defibrillators or cardiac resynchronisation therapy in patients with severe cardiac involvement.

Pulmonary Management:
- Pulmonary function tests should be conducted annually.
- Non-invasive ventilation may be necessary in later stages of the disease to manage hypoventilation during sleep.

Mobility and Physical Therapy:
- Physiotherapy is essential to maintain mobility and prevent contractures.
- Orthotic devices may provide additional support.

Nutritional Support:
- A dietitian should assess nutritional needs regularly due to the risk of dysphagia and weight loss. Gastrostomy feeding may become necessary in advanced stages.

Surgical Interventions:
- Spinal surgery may be required for progressive scoliosis while orthopaedic surgery can help manage contractures and fractures resulting from osteoporosis.

Question 13

Myotonic dystrophy is a genetic disorder that usually presents in adulthood. Typical features are [4]

Answer 13

Progressive muscle weakness
Prolonged muscle contractions
Cataracts
Cardiac arrhythmias

TOM TIP: The key feature of myotonic dystrophy to remember is the prolonged muscle contraction. This may present in exams with a patient that is unable to let go after shaking someones hand, or unable to release their grip on a doorknob after opening a door. When doing an upper limb neurological examination always shake the patients hand and observe for difficulty releasing their grip.

Question 14

Describe the muscular manifestations of myotonic dystrophy [3+]

Answer 14

Myotonia
* The hallmark feature of DM is delayed muscle relaxation following voluntary contraction or percussion, termed myotonia.
* Myotonia can be generalized or focal, affecting the hands, tongue, facial muscles, or lower limbs.

Muscle Weakness
* Both DM1 and DM2 present with progressive muscular weakness; however, the distribution and severity may vary between subtypes.
* Distal Limb Weakness (DM1): In DM1 patients, distal limb weakness predominantly affects the flexor muscles of the fingers, wrists, and ankles. In advanced stages, proximal limb muscles may also be involved.
* Proximal Limb Weakness (DM2): Patients with DM2 typically exhibit proximal limb weakness affecting hip girdle muscles more than shoulder girdle muscles. The weakness pattern in DM2 often resembles that of limb-girdle muscular dystrophy.

Facial & Bulbar Weakness
* Facial muscle involvement in both subtypes may manifest as ptosis, facial diplegia, dysarthria, dysphagia or nasal regurgitation due to palatal insufficiency.

Question 15

The treatment of MD is a MDT approach.

In terms of pharmacotherapy, [] can be used for myotonia, but its use should be guided by a neurologist. Steroids are not recommended due to potential worsening of myotonia.

Answer 15

In terms of pharmacotherapy, Mexiletine can be used for myotonia, but its use should be guided by a neurologist. Steroids are not recommended due to potential worsening of myotonia.

Question 16

What is meant by plagiocephaly and brachycephaly? [1]

What are they a risk of ? [1]

Answer 16

Plagiocephaly and brachycephaly are very common conditions that cause abnormal head shapes in otherwise normal health babies.

• Plagio- translates as oblique, or slanted. Plagiocephaly refers to flattening of one area of the baby’s head.
• Brachy- translates as short. Brachycephaly refers to flattening at the back of the head, resulting in a short head from back to front.

Question 17

Why does plagiocephaly and brachycephaly typically occur? [1]

Answer 17

These conditions occur where a baby had a tendency to rest their head on a particular point
- resulting in the skull bones and sutures moulding with gravity to create an abnormal head shape. This is called positional plagiocephaly

Question 18

When investigating plagio / brachycephaly, which muscle should you look to see is shortened? [1] Why? [1]

Answer 18

Look for congenital muscular torticollis (CMT), which is a shortening of the sternocleidomastoid muscle on one side.
- This may be the reason the child always rests on one side of their head.
- Physiotherapy can help with movement exercises to treat the torticollis.

Question 19

What is meant by spinal muscular atrophy? [1]

How do patients typically present? [4]

Answer 19

Spinal muscular atrophy (SMA) is a rare autosomal recessive condition that causes a progressive loss of motor neurones, leading to progressive muscular weakness.
- Spinal muscular atrophy affects the lower motor neurones in the spinal cord.
- This means there will be lower motor neurone signs: such as fasciculations, reduced muscle bulk, reduced tone, reduced power and reduced or absent reflexes.

Question 20

There are four categories of spinal muscular atrophy that are numbered from most to least severe. Describe the difference between them [4]

SMA type [] is the most common type.

Answer 20

There are four categories of spinal muscular atrophy that are numbered from most to least severe. SMA type 2 is the most common type.

SMA type 1 has an onset in the first few months of life, usually progressing to death within 2 years.

SMA type 2 has an onset within the first 18 months. Most never walk, but survive into adulthood.

SMA type 3 has an onset after the first year of life. Most walk without support, but subsequently loose that ability. Respiratory muscles are less affected and life expectancy is close to normal.

SMA type 4 has an onset in the 20s. Most will retain the ability to walk short distances but require a wheelchair for mobility. Everyday tasks can lead to significant fatigue. Respiratory muscles and life expectancy are not affected.

Question 21

Describe the respiratory support that children with SMA type 1 may need [2]

Answer 21

Respiratory support with non-invasive ventilation may be required to prevent hypoventilation and respiratory failure, particularly during sleep.

Children with SMA type 1 may require a tracheostomy with mechanical ventilation, which can dramatically extend life by supporting failing respiratory muscles.

Question 22

What are key clinical features of allergic rhinitis? [2]

Answer 22

Swollen, red mucuosa & septum
Enlarged inferior turbinate (in chronic inflammation this will be white)

Question 23

How do nasal polyps present differently to allergic rhinitis when looking up nose? [1]

Answer 23

Question 24

Describe what is meant by the bi-phasic anaphylaxis reaction [2]

What increases the chance of it occurring? [[3]

Answer 24

After initial symptoms (and treatment), about 12 hours after the initial reaction, 2nd less severe reaction occurs

Increased chance if:
- needed multiple doses of adrenaline
- delay in adrenaline administration
- previous bi-phasic reaction

NB: quite rare,

Question 25

When do you give adrenaline to patients [3]

Answer 25

**Hx of anaphylaxis** **Minor reaction** but has **significant risk factor like asthma** **Reacted to traces of a food**

Question 26

Explain the three main ways to test for allergy? [3]

Answer 26

**Skin prick testing** - A drop of each allergen solution is placed at marked points along the patch of skin, along with a **water control and a histamine control.** A fresh needle is used to make a tiny break in the skin at the site of each allergen. **After 15 minutes, the size of the wheals to each allergen** are assessed and compared to the controls. **RAST testing** - RAST testing measures the total and allergen specific IgE quantities in the patient’s blood sample. **Food challenge testing** - The child is **gradually given increasing quantities of an allergen** to **assess the reaction** starting with almost non-existent quantities diluted further in other foods, for example mixing a small amount of peanut into a bar of chocolate. Children are monitored very closely after each exposure. This can be very helpful in excluding allergies for reassurance.

Question 27

What are skin prick and RAST testing specifically assessing? [1]

Answer 27

**Skin prick testing** and **RAST** **testing** assess **sensitisation** and NOT **allergy**. This is important, because it makes these tests notoriously unreliable and misleading.

Question 28

What is the gold standard investigation for dx allergy? [1]

Answer 28

**Food challenge testing** is the gold standard investigation for diagnosing allergy, however it requires a lot of time and resources and is only available in selected places.

Question 29

Describe when and how many samples of mast cell tryptase you should take [+]

Answer 29

Mast cell tryptase is one of the major proteins released during activation and degranulation **Immediate sample**: taken as soon as possible after onset. Should NOT delay treatment **Second sample:** taken at 1-2 hours after onset. Should be no later than 4 hours. Minimum required sample **Third sample:**taken at least 24 hours after onset. Often taken at follow-up allergy clinic. Acts as the baseline level

Question 30

Describe the treatment protocol in emergency anaphylaxis [4] ## Footnote NB in adults

Answer 30

ABCDE **1**. **IM adrenaline 1mg/ml (1:1000) in anterolateral aspect middle of thigh** **2.** **Establish airway & give high flow O2** **3**. **If no response - repeat IM adrenaline after 5 minutes** & **IV fluid bolus** **4. If no improvement after 2 doses of adrenaline - follow refractory algorithm**

Question 31

What are the doses for IM adrenaline for: Adults and children > 12 6-12 year olds 6 months - 6 years < 6 months

Answer 31

**Adult and child >12 years old:** - **500 micrograms IM (0.5 mL of 1mg/mL adrenaline)** **6-12 years old**: - **300 micrograms IM** (0.3 mL of 1mg/mL adrenaline) **6 months - 6 years:** - **150 micrograms IM** (0.15 mL of 1mg/mL adrenaline) **< 6 months:** - **100-150 micrograms IM** (0.1-0.15 mL of 1mg/mL adrenaline)

Question 32

How does adrenaline work to treat anaphylaxis? [2]

Answer 32

**Alpha-adrenergic receptors:** - causes vasoconstriction that reverses peripheral vasodilation and reduces tissue oedema **Beta-adrenergic receptors:** - causes bronchodilation, increases myocardial contractility and suppresses histamine/leukotriene release. Also inhibits mast cell activation

Question 33

How do you treat refractory anaphylaxis? [1]

Answer 33

The principal treatment is initiation of an **adrenaline infusion**. Repeated doses of intramuscular adrenaline should be given at 5 minute intervals whilst the intravenous infusion is being prepared and ongoing fluid resuscitation should be administered.

Question 34

**TOM TIP:** Remember to **measure mast cell tryptase** within **[] hours** of an **anaphylactic reaction**. This is a common exam question and also something that will impress senior colleagues if it is part of your management plan when managing children with anaphylaxis.

Answer 34

**TOM TIP**: Remember to **measure mast cell tryptase within 6 hours of an anaphylactic reaction**. This is a common exam question and also something that will impress senior colleagues if it is part of your management plan when managing children with anaphylaxis.

Question 35

The Resus Council UK recommend the following risk-stratified approach to discharge: fast-track discharge (after 2 hours of symptom resolution): [3] adequate supervision following discharge [2] minimum 12 hours after symptom resolution [6]

Answer 35

**fast-track discharge (after 2 hours of symptom resolution):** * good response to a single dose of adrenaline * complete resolution of symptoms * has been given an adrenaline auto-injector and trained how to use it **adequate supervision following discharge minimum 6 hours after symptom resolution**: * 2 doses of IM adrenaline needed, or * previous biphasic reaction **minimum 12 hours after symptom resolution**: * severe reaction requiring > 2 doses of IM adrenaline * patient has severe asthma * possibility of an ongoing reaction (e.g. slow-release medication) * patient presents late at night * patient in areas where access to emergency access care may be difficult * observation for at 12 hours following symptom resolution

Question 36

What is the difference between non-allergic rhinitis (NAR) and allergic rhinitis [1] How do they present differently? [2]

Answer 36

**NAR often presents similarly to allergic rhinitis**, but **lacks the immunoglobulin E (IgE) mediated response** seen in the latter. - Patients with **NAR** typically **experience chronic nasal symptoms including rhinorrhoea, congestion and sneezing**. - However, unlike allergic rhinitis, these symptoms are **NOT seasonal** and do **NOT respond well to antihistamines.**

Question 37

How do you manage allergic rhinitis? [4]

Answer 37

**allergen avoidance** **if the person has mild-to-moderate intermittent, or mild persistent symptoms:** * **oral or intranasal antihistamines**: Non-sedating antihistamines include **cetirizine, loratadine and fexofenadine** & Sedating antihistamines include **chlorphenamine (Piriton) and promethazine** **if the person has moderate-to-severe persistent symptoms, or initial drug treatment is ineffective:** * **intranasal corticosteroids** such as such as **fluticasone and mometasone** **a short course of oral corticosteroids are occasionally needed to cover important life events** there may be a role for short courses of **topical nasal decongestants** (e.g. oxymetazoline). - They should not be used for prolonged periods as increasing doses are required to achieve the same effect (tachyphylaxis) and rebound hypertrophy of the nasal mucosa (rhinitis medicamentosa) may occur upon withdrawal

Question 38

Describe the correct way to do nasal spray technique for allergic rhinitis? [4]

Answer 38

The aim when **administering** a nasal spray is to get a **good coating throughout the nasal passage**. **Hold the spray in the left hand when spraying into the right nostril and vice versa**. Aim to **spray slightly outward**, **away** from the **nasal septum**. **Do NOT sniff** at the **same time as spraying**, as this **sends the mist straight to the back of the throat**. The patient **should not taste the spray at the back of the throat.** If they do, that means it has gone too far.

Question 39

**[]** deficiency is the most common complement deficiency.

Answer 39

**C2 deficiency** is the most common complement deficiency.

Question 40

Describe what is meant by C1 Esterase Inhibitor Deficiency (Hereditary Angioedema) [3]

Answer 40

**Bradykinin** is part of the **inflammatory response** - It is **responsible for promoting blood vessel dilatation** and **increased vascular permeability, leading to angioedema** - Part of the **action of C1 esterase** is to **inhibit bradykinin.** - An **absence of C1 esterase causes intermittent angioedema** in response to **minor triggers**, such as viral **infections or stress,** or without any clear trigger at all. **Angioedema** often affects the **lips** or **face** but can occur anywhere on the body, including the **respiratory and gastrointestinal tract.** - The swelling can last several few days before self resolving. Angioedema can occur in the larynx and compromise the patients airway.

Question 41

**TOM TIP:** A key test for hereditary angioedema (C1 esterase inhibitor deficiency) is to check the levels of **[]** **[]** levels will be **high/low** in the condition. The exam question describe a patient with episodes of unexplained lip swelling and ask what test to perform. The answer is [] levels.

Answer 41

TOM TIP: A key test for hereditary angioedema (C1 esterase inhibitor deficiency) is to check the levels of **C4 (compliment 4).** **C4 levels** will be **low** in the **condition**. The exam question describe a patient with episodes of unexplained lip swelling and ask what test to perform. The answer is C4 levels.

Question 42

Describe the symptoms of hereditary angioedema

Answer 42

**attacks** may be proceeded by **painful macular rash** **painless, non-pruritic swelling of subcutaneous/submucosal tissues** - may affect upper airways, skin or abdominal organs (can occasionally present as abdominal pain due to visceral oedema) **urticaria** is NOT usually a feature

Question 43

How do you treat HAE? [2]

Answer 43

**IV C1-inhibitor concentrate** **fresh frozen plasma (FFP) if this is not available** ## Footnote NB: HAE does not respond to adrenaline, antihistamines, or glucocorticoids