Which ONE of the following features of pseudoseizures is LEAST helpful in differentiating it from a true seizure?
Answer: C: A true generalised seizure may cause a high AG metabolic acidosis (lactic acidosis). In pseudoseizures this acidosis is not usually present. Serum prolactin level may be elevated in a true seizure up to 60 minutes from the time of cessation of seizure activity, but this is not a feature in a pseudoseizure. Abrupt onset and termination is a feature of true seizures, but in pseudo seizures the onset may be gradual over several minutes and the seizures happen in the presence of witnesses only. Unlike in generalised seizures the seizure activity in the limbs may be asymmetrical and alternating from one limb to the other.
Reference:
Regarding a first seizure in a 36-year-old man with human immunodeficiency virus (HIV) infection, all of the following statements are correct EXCEPT:
Answer: B: In the majority of HIV-infected patients who present with a seizure a cause cannot be identified. In the others the most common causes of seizures are:
Other causes include:
Once raised intracranial pressure is ruled out with clinical examination and with a head CT, an LP should be performed. A contrast head CT or MRI should be done because a non-contrast CT may miss a small mass lesion due to cerebral toxoplasmosis or tumour in these patients.
Regarding the diagnosis of Guillain-Barré syndrome in a 10-year-old child, which ONE of the following statements is TRUE?
Answer: B: Guillain-Barré syndrome (GBS) is a rare presentation to the ED, but diagnosis is important because it can lead to life-threatening respiratory failure in one-third of patients. The typical features are progressive, relative symmetrical and global (both proximal and distal) weakness. Loss of deep tendon reflexes is usually an early part of the illness. However, in one variant (acute motor axonal neuropathy) reflexes may be retained. At least three variants of the disease have been described. In the Miller Fisher variant, there is areflexia with no or less severe weakness, ataxia and ophthalmoplegia. Assessment for respiratory failure is important in the ED as this is not usually associated with dyspnoea. Measurement of vital capacity is essential to determine the time for intubation. About 75% of patients have a preceding respiratory and gastrointestinal infection. Established associated infections are Campylobacter jejuni, Epstein-Barr virus (EBV), CMV, mycoplasma and HIV. One-third of the patients have antibodies for C. jejuni, and therefore serological testing for C. jejuni can confirm the diagnosis in a suspected case. CSF examination with a lumbar puncture in patients with GBS typically shows a high protein but <10 × 106 /L cells, and these are mainly mononuclear cells. When the cell count is more than 50 x 106 /L GBS is unlikely and other diagnoses should be considered.
References:
A 10-year-old child with a ventriculoperitoneal shunt presents to the ED with increasing headache, nausea, vomiting and unsteady gait that has developed over the past 48 hours.
Which ONE of the following statements is correct regarding his initial management?
Answer: D: The most common complication of CSF shunts (including common ventriculoperitoneal shunts) is shunt malfunction. This can be due to: proximal or distal obstruction of the shunt; mechanical causes such as fracture or disconnection of the tubing, migration and misplacement of the end of the tubing; overdrainage of the CSF; non-drainable CSF loculations in the ventricles; and pseudocyst formation at the drainage site in the abdomen. Although the valve chamber or reservoir can be located and compressed to assess its filling to determine the potential obstruction, this is known to be unreliable to exclude shunt obstruction, therefore further imaging is indicated. Although shunt series X-rays may detect the above mentioned mechanical causes, even in combination with a head CT, shunt malfunction cannot safely be ruled out in the ED. Therefore input from neurosurgery will be required. Shunt infection may coexist with features for shunt obstruction. Fever and meningism may not be present and lumbar puncture findings are unreliable for diagnosis. Neurosurgical referral for shunt tap for microbiological testing is indicated.
Regarding the diagnosis of botulism in infancy, which ONE of the following statements is TRUE?
Answer: B: Infant botulism is a rare presentation but has been reported in Australasian hospitals. Because of the rarity of the condition and the less overt nature of clinical features, the diagnosis is often delayed. Infant botulism results from systemic absorption of Clostridium botulinum toxin released from the spores of bacteria colonizing the intestinal tract. It has been reported that infants who live close to construction sites (where soil contains spores) or who are given contaminated honey are more at risk of developing this illness. There is no associated fever or altered level of consciousness in these infants who usually present during 6 weeks to 9 months of age. The presentation is a descending paralysis with poor sucking, poor swallowing, ptosis and lack of facial expression. Infants may be hypotonic and may progress to symmetrical paralysis with respiratory failure.
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