Neurology Flashcards
Accurate description of Arnold Chiari malformation
Chiari II malformation
Spinal myelomeningocoele, beaker midbrain on neuroimaging and downward displacement of cerebellar vermis and tonsils
Which one of the following is most likely to increase risk of hepatoxicity due to sodium valproate
Polypharmacy
Benign partial epilepsy of childhood
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
Night terrors
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)
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:
- 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.
Haemorrhage between the aponeurosis and periosteum?
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.
Fluid between the periosteum and the scalp?
Caput succedaneum.
Localised oedematous swelling of the scalp which can cross suture lines. It is usually benign and resolves spontaneously.
Haemorrhage between the periosteum and the skull?
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
GEFS+
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.
An antagonist of AMPA receptors that has a long half-life.
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.
Anticonvulsant modulates neurotransmitter release by binding to synaptic vesicle protein (SV2A).
Levetiracetam
modulates neurotransmitter release at the synapse (it may inhibit neurotransmitter release). Levetiracetam also indirectly affects GABA transmission and inhibits N-type calcium channels.
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.
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.
MRI positive, medically refractory epilepsy
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.
Major and minor criteria for diagnosing encephalitis
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.
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?
Multiple café au lait macules.
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?
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)
Female teen on pyridostigmine for Myathesia Gravis, has pyelo. Why is Gentamicin contraindicated in this specific scenario?
Prolongs neuromuscular blockade.
Aminoglycoside abx impair neuromuscular transmission
Erb’s palsy
C4-6
IVH, more than 50% dilatation on head US
Grade III
Excessive intake of which of the following is implicated in idiopathic intracranial hypertension?
Vitamin A
What is the primary effect on alcohol on CNS
Activation of GABA receptors —> influx of Chlorise ions, hyperpolarises the cell.
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?
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.
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.
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.
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.
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.
