Neurology

Question 1

Accurate description of Arnold Chiari malformation

Answer 1

Chiari II malformation
Spinal myelomeningocoele, beaker midbrain on neuroimaging and downward displacement of cerebellar vermis and tonsils

Question 2

Which one of the following is most likely to increase risk of hepatoxicity due to sodium valproate

Answer 2

Polypharmacy

Question 3

Benign partial epilepsy of childhood

Answer 3

Begins 2-13yrs
Usually seizures occur when child is asleep
Partial motor seizures often beginning in the face. Generalised seizures are seen fairly often esp. younger kids

Gurgling/ guttural sound
Movement or jerk of tongue/ mouth
Myoclonic twitches one side of face
Drooling/ trouble swallowing
Numbness/ weakness side of tongue, lips, gums, cheeks
Trouble speaking

EEG centrotemporal spikes

Question 4

Night terrors

Answer 4

Non-Rem sleep arousal disorder. Form of parasomnia

Sudden, often dramatic arousal with facial expression, vocalisation and behaviour that express agitation and fear.

Tachycardia, diaphoresis, mydriasis and autonomic features.

Difficult to rouse, and fall back to sleep spontaneously after few minutes

Little/ no recall

Rare to have multiple episodes a night

18mo- peak 5-7yrs, resolve prior to adolescence

Trigger: stress, sleep deprivation, stimulants (neuroleptics, sedatives, antihistamines)

Question 5

You start a six-year-old boy with Duchenne muscular dystrophy on glucocorticoids because his gross motor skills have begun to plateau. Standard of care in this scenario:

Answer 5

• baseline ECG and echocardiogram is recommended by six years of age and should be repeated at least two yearly until 10 years of age, at which point annual surveillance is required. Review should be more frequent if signs or symptoms become apparent before the age of 10 years.
• An annual ophthalmology examination is required for boys on glucocorticoids because of the risk of cataracts and raised intra-ocular pressure.
• An annual DEXA scan is required at 3+ years or at commencement of glucocorticoids, then should be repeated annually for children on chronic glucocorticoids.
• Annual sitting spirometry is recommended for all ambulatory children six years and over. This is increased to six-monthly when a boy is no longer ambulant.

Question 6

Haemorrhage between the aponeurosis and periosteum?

Answer 6

Subgaleal haemorrhage.

rupture of the emissary veins which connect the scalp veins and the dural sinuses. The space between the aponeurosis and the periosteum is a potential space which can hold approximately 250ml of blood. Given that the average blood volume of a term newborn is 280ml, a subgaleal haemorrhage can lead to severe hypovolaemic shock and death. It can occur in uncomplicated vaginal deliveries but is more commonly associated with vacuum-assisted deliveries.

Question 7

Fluid between the periosteum and the scalp?

Answer 7

Caput succedaneum.
Localised oedematous swelling of the scalp which can cross suture lines. It is usually benign and resolves spontaneously.

Question 8

Haemorrhage between the periosteum and the skull?

Answer 8

Cephalhaematoma

vacuum-assisted deliveries but does not usually result in a large loss of blood volume because the haemorrhage is contained within the suture line

Question 9

GEFS+

Answer 9

Genetic epilepsy consisting of children who present with febrile convulsions early in infancy that, unlike typical febrile convulsions, persist beyond six years or are associated with multiple febrile seizures, generalised afebrile tonic clonic seizures, absences, myoclonic seizures and focal seizures.

The epilepsy typically resolves by mid-adolescence and is usually associated with an autosomal dominant inheritance pattern.

GEFS+ has been associated with SCN1B.

Question 10

An antagonist of AMPA receptors that has a long half-life.

Answer 10

Perampanel

PerAMPAnel is an antagonist of excitatory AMPA receptors. It is used to treat focal and generalised seizures. It has a long half-life of 105 hours. Side effects include psychiatric changes, including increased suicidality; dizziness, gait disturbance, somnolence, risk of falls and slurred speech. High doses can produce euphoria.

Question 11

Anticonvulsant modulates neurotransmitter release by binding to synaptic vesicle protein (SV2A).

Answer 11

Levetiracetam

modulates neurotransmitter release at the synapse (it may inhibit neurotransmitter release). Levetiracetam also indirectly affects GABA transmission and inhibits N-type calcium channels.

Question 12

Sodium channel blocker should be titrated very slowly as rapid up-titration, particularly in combination with sodium valproate, may result in a rash, or lead to Steven-Johnson’s syndrome.

Answer 12

Lamotrigine is a sodium channel blocker which is used in epilepsy and bipolar affective disorder. It is up-titrated slowly over 6 weeks to 3 months and is not a good anticonvulsant to use in an acute setting. It can be used in combination with sodium valproate for a synergistic effect, however this does increase the risk of a lamotrigine related rash.

Question 13

MRI positive, medically refractory epilepsy

Answer 13

Epilepsy surgery for MRI positive, medically refractory epilepsy has a success rate of about 70%. This remains the case for MRI positive epilepsy which is bilateral or generalised on EEG. This means that about 70% of children are seizure-free following epilepsy surgery and do not require anti-epileptic treatment. About 30% of children still require anti-epileptic treatment following epilepsy surgery and a number of these require multi-drug treatment.

Question 14

Major and minor criteria for diagnosing encephalitis

Answer 14

Major Criterion (required):

Patients presenting to medical attention with altered mental status (defined as decreased or altered level of consciousness, lethargy or personality change) lasting ≥24 h with no alternative cause identified.

Minor Criteria (2 required for possible encephalitis; ≥3 required for probable or confirmed encephalitis):
- Documented fever ≥38 degrees within the 72 h before or after presentation
- Generalized or partial seizures not fully attributable to a pre-existing seizure disorder
- New onset of focal neurologic findings
- CSF WBC count ≥5/cubic mm
- Abnormality of brain parenchyma on neuro-imaging suggestive of encephalitis that is either new from prior studies or appears acute in onset
- Abnormality on electroencephalography that is consistent with encephalitis and not attributable to another cause.

Question 15

You review a 15-month-old girl whose father has a diagnosis of neurofibromatosis type 1 (NF1). Her

parents want to know if she is affected. If she is affected, which feature is most likely to be present?

Answer 15

Multiple café au lait macules.

Question 16

A 22-month-old child presents refusing to weight bear. He is happy when lying flat on his back, but he becomes upset when is pulled to sit. He becomes irritable when his nappy is changed. On examination he has full range of movement of his hips and knees, and his lower limb examination is unremarkable. A plain X-ray of his knee, hip and spine are normal. CRP is raised to 48 and he has a WCC of 27. Which of the following is the most likely diagnosis?

Answer 16

Discitis (note epidural abscess rare in children)

Discitis is inflammation of the intervertebral disc is a rare condition. Disc biopsy is not necessary for diagnosis, but if it is done then >80% grow bacteria (usually staph aureus). This typically occurs between 4 and 10 years of age and the lower lumbar discs most commonly affected.

This is difficult to diagnose in young children and it usually presents with gradual onset of irritability and back pain, limp or refusal to crawl or walk. The child is systemically well but can have a low grade fever. It can present with abdo pain +/- vomiting. Symptoms are usually present for a few weeks prior to diagnosis.

On examination, you may not refusal to bend forward, percussion tenderness over the involved spine, hip pain and stiffness, loss of lumbar lordosis, neurologic findings (weakness, decreased reflexes), ileus.

If there are fever and acute signs, then think osteomyelitis rather than discitis.

Investigations:

Blood culture
WCC (generally normal)
ESR (generally elevated)
Xray - narrowing of intervertebral space, destruction of adjacent vertebral end plates, herniation of nucleus pulpous
Bone scan - diagnostic but may be normal early in illness
MRI - imaging of choice, shows extent of inflammation, involvement of disc and adjacent vertebral end plates
Management:

IV antibiotics until clinical improvement
Cover for Staph aureus and Kingella kingae (e.g. clindamycin, vancomycin) and a third generation cephalosporin (e.g. cefotaxime, ceftriaxone)

Question 17

Female teen on pyridostigmine for Myathesia Gravis, has pyelo. Why is Gentamicin contraindicated in this specific scenario?

Answer 17

Prolongs neuromuscular blockade.
Aminoglycoside abx impair neuromuscular transmission

Question 18

Erb’s palsy

Answer 18

C4-6

Question 19

IVH, more than 50% dilatation on head US

Answer 19

Grade III

Question 20

Excessive intake of which of the following is implicated in idiopathic intracranial hypertension?

Answer 20

Vitamin A

Question 21

What is the primary effect on alcohol on CNS

Answer 21

Activation of GABA receptors —> influx of Chlorise ions, hyperpolarises the cell.

Question 22

A three-day-old baby presents with respiratory distress and difficulty feeding. Her head circumference is 38cm, she has no abnormalities on respiratory or cardiac examination, and her echocardiogram is normal. A cranial ultrasound is performed and she is found to have a Vein of Galen malformation.

What is the ideal treatment for this infant?

Answer 22

Vein of Galen malformations are intracranial arteriovenous shunts located in the midline. They consist of feeding arteries (choroidal arteries and anterior cerebral artery) that drain into a large venous pouch (the precursor to the vein of Galen). Neonates usually present with symptoms of high output cardiac failure (shortness of breath, difficulties feeding, failure to thrive, sweating, weight loss) due to the elevated preload on the right side of the heart. Some infants will also have a large head circumference and prominent veins on the face or scalp.

The ideal treatment option is to manage heart failure symptomatically until the baby is around five-six months of age as the embolization procedure (closing the malformation with glue) is technically less difficult to perform at this age.

Immediate embolization may be required if the baby has severe heart failure, neurological deficits or seizures.

Question 23

The cerebral cortex is made up of a number of layers. In the motor cortex one of these layers contains giant pyramidal cells whose axons travel through the internal capsule to the brainstem and spinal cord to form the corticospinal tract.

Answer 23

The majority of the cerebral cortex is composed of six cortical layers:

I - the molecular layer
II - the external granular layer
III - the external pyramidal layer
IV - the internal granular layer
V - the internal pyramidal layer
VI - the multiform layer

Giant pyramidal cells (Betz cells) are found in the primary motor cortex in layer V and the axons of these cells form the corticospinal tract.

Question 24

An 8-year-old boy with headache and visual disturbance. The headache is preceded by an aura. Changes on his EEG are seen when he closes his eyes.

Answer 24

Gastaut syndrome can be mistaken for migraine but has EEG changes similar to Panayiotopoulos syndrome. Unlike Panayiotopoulos syndrome, seizures occur during the day and EEG changes are activated by eye closure.

Question 25

ADEM

Answer 25

monophasic, immune-mediated demyelinating disorder that can follow immunisations or more often infections including rubeola, rubella, varicella, herpes zoster, mumps, Mycoplasma pneumoniae, or, more commonly, other non-specific upper respiratory tract infections. Antecedent or presenting features include fever, lethargy, vomiting, weakness, ataxia, headache, seizures, and other systemic signs, and patients often progress to have delirium, coma, myelopathy, and focal neurologic signs.

Question 26

Acute vestibular neuritis

Answer 26

Vestibular neuritis, also known as vestibular neuronitis and labyrinthitis, represents an acute, spontaneous, peripheral vestibular ailment, characterised by the rapid onset of severe vertigo with nausea, vomiting, and gait instability.

Spontaneous vestibular nystagmus that is unilateral, horizontal, or horizontal-torsional, that is suppressed with visual fixation, and that does not change direction with gaze.

The fast phase of nystagmus beats away from the affected side. In pure vestibular neuritis, auditory function is preserved; when this syndrome is combined with unilateral hearing loss, it is called labyrinthitis. It is a benign disorder, self-limited, and associated with a complete recovery in most patients.

Question 27

Cerebellar ataxia

Answer 27

Primarily in children aged 1-3 years and is a diagnosis of exclusion.

Onset is sudden with truncal ataxia that can be so severe that the child is unable to sit or stand. Vomiting may occur initially, but fever and nuchal rigidity are absent. Horizontal nystagmus is evident in ~50% of cases and, if the child is able to speak dysarthria may be impressive.

Question 28

Menière’s disease

Answer 28

disorder of the inner ear that can affect hearing and balance to a varying degree. It is characterised by episodes of vertigo and tinnitus, and progressive hearing loss, usually in one ear. The so-called “classic Ménière’s” is considered to have the following four symptoms: periodic episodes of rotary vertigo; fluctuating, progressive, unilateral or bilateral hearing loss, usually in lower frequencies; unilateral or bilateral tinnitus; a sensation of fullness or pressure in one or both ears.

Question 29

unilateral facial nerve swelling involving the frontalis

Answer 29

Bells palsy is associated with hypertension and so blood pressure should be checked. It is a lower motor neurone lesion.

Femoral pulses because there is an association with coarctation of the aorta and otoscopy because acute media can cause a lower motor neurone facial palsy. Otoscopy would also reveal lesions consistent with Ramsay-Hunt syndrome (reactivation of VZV causing a vesicular eruption with facial nerve palsy).

Question 30

Lennox-Gastaut syndrome

Answer 30

slow spike and wave on EEG
Lennox-Gastaut syndrome has diffuse <2.5-Hz generalised sharp-and-slow wave discharges and paroxysms of fast activity. Atypical absence epilepsy may also demonstrate diffuse <2.5-Hz generalized sharp-and-slow wave discharges. Alternatively, absence seizures are differentiated by 3-Hz generalised spike-and-slow wave, often with repetitive trains of discharges, and especially during hyperventilation

Question 31

Hypsarrhytmia on EEG

Answer 31

Infantile spasms demonstrate hypsarrhythmia and multifocal spikes and sharp waves. Importantly, in clinical practice, there is no clear normal background activity. Hence, infantile spasms can be ruled out with some assuredness in an infant that has a normal EEG despite not exhibiting spasms at the time of recording.

Question 32

Bilateral centrotemporal spikes and sharp waves

Answer 32

Landau-Kleffner syndrome
Childhood epilepsy with centrotemporal spikes or benign rolandic epilepsy is classically associated with centrotemporal large-amplitude spikes or sharp waves, with accentuation in sleep. However, this is not an option here. Landau-Kleffner syndrome shows unilateral or bilateral temporal-parietal or centrotemporal spikes and sharp waves with fields that spread to apparent generalised spike wave pattern and becomes almost continuous when asleep (hence status epilepticus). Epileptic encephalopathy with continuous spikes and waves during sleep (CSWS) can also demonstrate this EEG feature. CSWS requires regression in two or more domains (as opposed to Landau-Kleffner which presents as language regression/aphasia). Finally, centrotemporal spikes can be a genetic trait in a typically developing child.

Question 33

Neurofibromatois criteria

Answer 33

In neurofibromatosis patient have café au lait spots. Up to 30% have pectus excavatum. And an ejection systolic murmur could be coarctation of the aorta, which is associated with NF.

The diagnostic criteria are (2 of the following are required):
Six or more café-au-lait spots or hyperpigmented macules >5mm in diameter in pre-pubertal children and 15mm post-pubertal
Axillary or inguinal freckles (>2 freckles)
Two or more typical neurofibromas or one plexiform neurofibroma
Optic nerve glioma
Two or more iris hamartomas (Lisch nodules), often identified only through slit-lamp examination by an ophthalmologist
Sphenoid dysplasia or typical long-bone abnormalities such as pseudarthrosis
First-degree relative (e.g. mother, father, sister, brother) with NF1