1. A healthcare worker sustained a needle stick injury from a known HIV
seropositive patient not taking antiretroviral therapy.
Assuming the healthcare worker is HIV seronegative, which of the following is
the risk of transmission?
A. 1/300
B. ⅓
C. 1/3000
D. 1/30000
E. 1/30
Answer: A
Explanation:
Key learning points
Immunology
● The risk of developing HIV from a seropositive patient not taking antiretroviral
therapy following a needlestick injury is 1/300
Explanation
This is an estimated risk based on retrospective case-control studies.
Evaluating risk is important when counselling a patient and deciding when to offer
post-exposure prophylaxis.
2. What is the most common finding in Cheyne-Stokes breathing?
A. Pilocytic astrocytoma
B. Heart failure
C. Liver failure
, D. Renal failure
E. Stroke
Answer: B
Explanation: Key learning points
Neurology
● Two-thirds of cases of Cheyne-Stokes breathing appear to have heart failure.
Explanation
Two-thirds of cases of Cheyne-Stokes breathing appear to have heart failure.
Treatment of this can result in improvement of the breathing disorder.
Stroke and metabolic dysfunction can also result in Cheyne-Stokes apnoea but are
not as common as heart failure.
Cheyne-Stokes is a type of central sleep apnoea in which there is loss of chest and
abdominal movements and crescendo-decrescendo breathing in a repetitive fashion.
Treatments include diuretics and non-invasive ventilation.
It is seen in end of life care but also during sleep apneoa.
References
https://www.sleepfoundation.org/sleep-apnea/cheyne-stokes-respirations#:~:text=Ch
eyne%2DStokes%20respirations%20are%20a,breath%20at%20all%2C%20called%
20apneas.
,3. A 70-year-old lady presents to the Emergency Department at 2 am complaining of
acute onset of severe bilateral headache, right upper and lower limb weakness,
nausea, vomiting, and breathlessness. Computed tomography of the head shows no
intracranial pathology.
Blood investigations show a haemoglobin of 50 g/L, a platelet count of 2 × 109/L and
no renal impairment. Clotting screen, including fibrinogen, is normal. Blood film
examination shows extensive red cell fragments and confirms genuine
thrombocytopenia.
Which is the most probable underlying pathophysiology?
A. Evans syndrome
B. Thrombotic thrombocytopenic purpura (TTP)
C. Disseminated intravascular coagulation (DIC)
D. Acute ischaemic stroke
E. Haemolytic uraemic syndrome (HUS)
Answer:B
Key learning points
Haematology
● TTP is characterised by thrombocytopenia, MAHA, and fluctuating
neurological signs, rarely also with renal impairment and fever, and is
treated with urgent plasma exchange.
Explanation
Thrombotic thrombocytopenic purpura (TTP) is a medical emergency,
originally defined as a classic pentad of:
● thrombocytopenia
● MAHA (microangiopathic haemolytic anaemia)
● neurological signs which tend to be fluctuating
● renal impairment, and
● fever.
, Fever and renal impairment, although described as part of the classical
pentad, are usually absent in the acute presentation.
Evans syndrome, the combination of autoimmune haemolytic anaemia and
thrombocytopenia only, does not cause multisystem symptoms, and DIC is
excluded by the normal clotting screen and fibrinogen.
Although an ischaemic stroke is evident in this case, it is the platelet
activation and resulting ischaemia from the TTP which is the underlying
pathophysiological mechanism in play rather than a primary CVA.
Thrombotic thrombocytopenic purpura should be considered a medical
emergency, and the initial diagnosis should be made on clinical history,
examination and routine laboratory testing and blood film. To avoid early
mortality, treatment with plasma exchange should be commenced on the day
of the presentation as soon as possible.
4. A 45-year-old man has a history of progressive weakness for five weeks. He
had particular difficulty getting out of the bath.
On examination there was severe truncal and proximal limb weakness, without
wasting or fasciculation.
Tendon reflexes, plantar responses and sensation were all normal.
The vital capacity was 1.8L.
What is the most likely diagnosis?
A. Gullain barre syndrome
B. Syringobulbia
C. Cervical myelitis
seropositive patient not taking antiretroviral therapy.
Assuming the healthcare worker is HIV seronegative, which of the following is
the risk of transmission?
A. 1/300
B. ⅓
C. 1/3000
D. 1/30000
E. 1/30
Answer: A
Explanation:
Key learning points
Immunology
● The risk of developing HIV from a seropositive patient not taking antiretroviral
therapy following a needlestick injury is 1/300
Explanation
This is an estimated risk based on retrospective case-control studies.
Evaluating risk is important when counselling a patient and deciding when to offer
post-exposure prophylaxis.
2. What is the most common finding in Cheyne-Stokes breathing?
A. Pilocytic astrocytoma
B. Heart failure
C. Liver failure
, D. Renal failure
E. Stroke
Answer: B
Explanation: Key learning points
Neurology
● Two-thirds of cases of Cheyne-Stokes breathing appear to have heart failure.
Explanation
Two-thirds of cases of Cheyne-Stokes breathing appear to have heart failure.
Treatment of this can result in improvement of the breathing disorder.
Stroke and metabolic dysfunction can also result in Cheyne-Stokes apnoea but are
not as common as heart failure.
Cheyne-Stokes is a type of central sleep apnoea in which there is loss of chest and
abdominal movements and crescendo-decrescendo breathing in a repetitive fashion.
Treatments include diuretics and non-invasive ventilation.
It is seen in end of life care but also during sleep apneoa.
References
https://www.sleepfoundation.org/sleep-apnea/cheyne-stokes-respirations#:~:text=Ch
eyne%2DStokes%20respirations%20are%20a,breath%20at%20all%2C%20called%
20apneas.
,3. A 70-year-old lady presents to the Emergency Department at 2 am complaining of
acute onset of severe bilateral headache, right upper and lower limb weakness,
nausea, vomiting, and breathlessness. Computed tomography of the head shows no
intracranial pathology.
Blood investigations show a haemoglobin of 50 g/L, a platelet count of 2 × 109/L and
no renal impairment. Clotting screen, including fibrinogen, is normal. Blood film
examination shows extensive red cell fragments and confirms genuine
thrombocytopenia.
Which is the most probable underlying pathophysiology?
A. Evans syndrome
B. Thrombotic thrombocytopenic purpura (TTP)
C. Disseminated intravascular coagulation (DIC)
D. Acute ischaemic stroke
E. Haemolytic uraemic syndrome (HUS)
Answer:B
Key learning points
Haematology
● TTP is characterised by thrombocytopenia, MAHA, and fluctuating
neurological signs, rarely also with renal impairment and fever, and is
treated with urgent plasma exchange.
Explanation
Thrombotic thrombocytopenic purpura (TTP) is a medical emergency,
originally defined as a classic pentad of:
● thrombocytopenia
● MAHA (microangiopathic haemolytic anaemia)
● neurological signs which tend to be fluctuating
● renal impairment, and
● fever.
, Fever and renal impairment, although described as part of the classical
pentad, are usually absent in the acute presentation.
Evans syndrome, the combination of autoimmune haemolytic anaemia and
thrombocytopenia only, does not cause multisystem symptoms, and DIC is
excluded by the normal clotting screen and fibrinogen.
Although an ischaemic stroke is evident in this case, it is the platelet
activation and resulting ischaemia from the TTP which is the underlying
pathophysiological mechanism in play rather than a primary CVA.
Thrombotic thrombocytopenic purpura should be considered a medical
emergency, and the initial diagnosis should be made on clinical history,
examination and routine laboratory testing and blood film. To avoid early
mortality, treatment with plasma exchange should be commenced on the day
of the presentation as soon as possible.
4. A 45-year-old man has a history of progressive weakness for five weeks. He
had particular difficulty getting out of the bath.
On examination there was severe truncal and proximal limb weakness, without
wasting or fasciculation.
Tendon reflexes, plantar responses and sensation were all normal.
The vital capacity was 1.8L.
What is the most likely diagnosis?
A. Gullain barre syndrome
B. Syringobulbia
C. Cervical myelitis
