The clinical picture is characteristic of retinal detachment, which should be treated immediately to prevent permanent loss of vision. Scleral buckling is a surgical procedure used to repair a retinal detachment, where the surgeon attaches a piece of silicone or a sponge onto the white of the eye at the spot of a retinal tear pushing the sclera toward the retinal tear or break, promoting repair. Signs of detachment include an increase in the number of eye floaters, flashes of light in the field of vision, and reduced peripheral vision.

The clinical effect and toxicity of MgSO4 can be linked to its concentration in plasma. A concentration of 1.8 to 3.0 mmol/L has been suggested for treatment of eclamptic convulsions. Maternal toxicity is rare when MgSO4 is carefully administered and monitored. The first warning of impending toxicity in the mother is loss of the patellar reflex at plasma concentrations between 3.5 and 5 mmol/L. Respiratory paralysis occurs at 5 to 6.5 mmol/L. Cardiac conduction is altered at greater than 7.5 mmol/L, and cardiac arrest can be expected when concentrations of magnesium exceed 12.5 mmol/L. Careful attention to the monitoring guidelines can prevent toxicity. Deep tendon reflexes, respiratory rate, urine output and serum concentrations are the most commonly monitored parameters.

Phrenic nerve palsy causing hemidiaphragm paralysis is a very uncommon feature of thoracic aortic aneurysm.

Thoracic aortic aneurysms are usually asymptomatic however chest pain is most commonly reported symptom. Left hemidiaphragm paralysis, because of left phrenic nerve palsy, is a very rare presentation of thoracic aortic aneurysm.
Thoracic aortic aneurysm may present atypical symptoms such as dysphagia due to compression of the oesophagus; hoarseness due to vocal cord paralysis or compression of the recurrent laryngeal nerve; superior vena cava syndrome due to compression of the superior vena cava; cough, dyspnoea or both due to tracheal compression; haemoptysis due to rupture of the aneurysm into a bronchus; and shock due to rupture of the aneurysm.
Common causes of phrenic nerve palsy include malignancy such as bronchogenic carcinoma, as well as mediastinal and neck tumours. Phrenic nerve palsy can also occur due to a penetrating injury or due to iatrogenic causes arising, for example, during cardiac surgery and central venous catheterization. Many cases or phrenic nerve palsy are idiopathic.

Beckwith-Wiedemann syndrome is a inherited condition associated with organomegaly, macroglossia, abdominal wall defects, Wilm’s tumour and neonatal hypoglycaemia. Wilm’s tumour is a kidney cancer that usually occurs in children. The causes are unknown, however, risk factors include race and family history. Of note, Wilm’s tumour can occur as part of the following syndromes: WAGR syndrome, Denys-Drash syndrome, and Beckwith-Wiedmann syndrome and not the other listed options in this question.

Triptans are specific 5-HT1 agonists used in the acute treatment of migraine. They are generally used as first-line therapy in combination with an NSAID or paracetamol.

The most likely diagnosis is Wernicke’s encephalopathy. This presents in a long time alcoholic from vitamin BI deficiency. Symptoms include confusion and confabulation, oculomotor symptoms/signs, and ataxia.

This is a classical picture of graft versus host disease (GVHD) following bone marrow transplant. Acute GVHD occurs in the first 100 days post transplant with chronic GVHD occurring 100-300 days after transplant. GVHD is graded according to the Seattle system, and each organ involved is scored (skin, liver, and gut).

The standard initial treatment in the acute setting is high-dose methylprednisolone started immediately. If there is no response, a more intensive immunosuppressive agent such as alemtuzumab or antilymphocyte globulin is needed.

Beta blockers and calcium channel blockers have proven prognostic benefits. Nitrates don’t have any proven prognostic benefits. A statin is indicated for a patient with angina and cholesterol level of 5.5 to 8.5 to prevent risk of myocardial infarction. So the preferred combination from the given answers is beta blocker + statin.

COPD is commonly associated with progressive hypoxemia. Oxygen administration reduces mortality rates in patients with advanced COPD because of the favourable effects on pulmonary hemodynamics.

Long-term oxygen therapy improves survival 2-fold or more in hypoxemic patients with COPD, according to 2 landmark trials, the British Medical Research Council (MRC) study and the US National Heart, Lung and Blood Institute’s Nocturnal Oxygen Therapy Trial (NOTT). Hypoxemia is defined as PaO2 (partial pressure of oxygen in arterial blood) of less than 55 mm Hg or oxygen saturation of less than 90%. Oxygen was used for 15-19 hours per day.

Therefore, specialists recommend long-term oxygen therapy for patients with a PaO2 of less than 55 mm Hg, a PaO2 of less than 59 mm Hg with evidence of polycythaemia, or cor pulmonale. Patients should be evaluated after 1-3 months after initiating therapy, because some patients may not require long-term oxygen.

All of the aforementioned listed tumours, except brain tumours, can metastasise to lungs and produce the typical CXR picture consisting of hilar lymphadenopathy with either diffuse multinodular shadows resembling miliary disease or multiple large well-defined masses (canon balls). Occasionally, cavitation or calcification may also be seen.

Most brain tumours, however, do not metastasise. Some, derived form neural elements, do so but in these cases, intraparenchymal metastases generally precede distant haematogenous spread.

Arthrocentesis should usually be done when there is a suspicion of pseudogout or septic arthritis as in this case which leads to an early diagnosis and prompt treatment. Polarized microscopy demonstrates weakly positively birefringent rhomboid crystals which are blue when parallel to light and yellow when perpendicular to light. Elevated serum uric acid levels that cause gout are usually found after large consumption of alcohol or meat, or post surgery. Autoimmune diseases like SLE, RA etc require an autoimmune screen.

Among the above statements, gastric lavage and normal saline IV infusion are the two appropriate interventions for a patient of acute lithium toxicity.

Activated charcoal is not effective after lithium overdose, although gastric lavage should be considered if patients present within 6–8 h.
Where levels are above 3 mmol/l, the use of normal saline to induce diuresis should be considered, although careful monitoring of fluid balance is necessary.
Where levels of lithium are above 4 mmol/l, dialysis is often required. Haemodialysis is preferred, but in a facility where haemodialysis is not possible, peritoneal dialysis may be considered.
Patients should not be discharged until they are asymptomatic and have a serum lithium level less than 1.5 mEq/L.

Ankylosing spondylitis (spondylarthritis) is a chronic inflammatory disease of the axial skeleton that leads to partial or even complete fusion and rigidity of the spine. Males are disproportionately affected and upwards of 90% of patients are positive for the HLA-B27 genotype, which predisposes to the disease. The most characteristic early finding is pain and stiffness in the neck and lower back, caused by inflammation of the vertebral column and the sacroiliac joints. The pain typically improves with activity and is especially prominent at night. Other articular findings include tenderness to percussion and displacement of the sacroiliac joints (Mennell’s sign), as well as limited spine mobility, which can progress to restrictive pulmonary disease.
The most common extra-articular manifestation is acute, unilateral anterior uveitis. Diagnosis is primarily based on symptoms and x-ray of the sacroiliac joints, with HLA-B27 testing and MRI reserved for inconclusive cases. There is no curative treatment, but regular physiotherapy can slow progression of the disease. Additionally, NSAIDs and/or tumour necrosis factor-α inhibitors may improve symptoms. In severe cases, surgery may be considered to improve quality of life. The spine adopts a bamboo shape, not lordosis. The pain usually improves as the day progresses. leg raise test causes pain in cases of meningitis etc not in this case.

The farmer has most likely ingested an organophosphate insecticide.
Organophosphorus compounds are used widely as:
• Insecticides – Malathion, parathion, diazinon, dichlorvos
• Nerve gases – Soman, sarin, tabun, VX
• Ophthalmic agents – Echothiophate
• Antihelmintics – Trichlorfon
• Herbicides – merphos
• Industrial chemical (plasticizer) – Tricresyl phosphate
Signs and symptoms of Organophosphorus Poisoning (OPP) can be classified as:
• Muscarinic effects:
o Cardiovascular – Bradycardia, hypotension
o Respiratory – Rhinorrhoea, bronchorrhea, bronchospasm, cough, severe respiratory distress
o Gastrointestinal – Hypersalivation, nausea and vomiting, abdominal pain, diarrhoea, faecal incontinence
o Genitourinary – Incontinence
o Ocular – Blurred vision, miosis
o Glands – Increased lacrimation, diaphoresis
• Nicotinic effects:
o Muscle fasciculation, weakness, cramping, diaphragmatic failure, and autonomic side effects include: hypertension, tachycardia, and mydriasis.
• Central nervous system (CNS) effects:
o Anxiety, emotional lability, restlessness, confusion, ataxia, tremors, seizures, coma, apnoea
Mainstay Treatment:
• Decontamination
• Securing Airway, Breathing and Circulation
• Atropine
• Pralidoxime
• Benzodiazepines

The type of significance test used depends on whether the data is parametric (can be measured, usually normally distributed) or non-parametric.
Parametric tests:
Student’s t-test – paired or unpaired*
Pearson’s product-moment coefficient – correlation

Non-parametric tests:
Mann-Whitney U test – unpaired data
Wilcoxon signed-rank test – compares two sets of observations on a single sample
chi-squared test – used to compare proportions or percentages
Spearman, Kendall rank – correlation.

The outcome measured is not normally distributed, i.e. it is non-parametric. This excludes the Student’s t-tests. We are not comparing percentages/proportions so the chi-squared test is excluded. The Mann–Whitney U test is a nonparametric test of the null hypothesis that it is equally likely that a randomly selected value from one sample will be less than or greater than a randomly selected value from a second sample.
This test can be used to investigate whether two independent samples were selected from populations having the same distribution.

Sleep paralysis is a temporary inability to move or speak that occurs when you’re waking up or falling asleep. Paralysis is often accompanied by hallucinations

REM is a stage of sleep when the brain is very active and dreams often occur. The body is unable to move, apart from the eyes and muscles used in breathing, possibly to stop the person from acting out the dreams and hurting himself.

It’s not clear why REM sleep can sometimes occur while one is awake, but it has been associated with:
-not getting enough sleep (sleep deprivation or insomnia)
-irregular sleeping patterns – for example, because of shift work or jet lag
-narcolepsy – a long-term condition that causes a person to suddenly fall asleep at inappropriate times
-a family history of sleep paralysis
-sleeping on one’s back

T. gondii infection in immunocompetent people is usually asymptomatic. It can present as fits in patients with AIDs, who are immunosuppressed. Additionally, infection in the first trimester of pregnancy is very harmful. Congenital toxoplasmosis presents with intracranial calcifications, classically. It can also present with hydrocephalus, microcephaly, blindness, petechiae. Siramycin is the drug of choice to try to prevent vertical transmission from mother to baby. It is typically gotten from cat faeces or raw/undercooked meat, not raw eggs (raw eggs: think salmonella).

Hepatorenal syndrome is renal vasoconstriction that cannot overcome the effects of splanchnic vasodilation. Vasoactive mediators cause this splanchnic vasodilation, reducing SVR, which is sensed by the juxtaglomerular apparatus, activating the RAAS system, leading to renal vasoconstriction. However, the overall splanchnic vasodilation effect is greater than this renal vasoconstriction effect.

The cardiovascular effects of β-adrenoceptor block result from reduction of the sympathetic drive which includes reduced heart rate (automaticity) and reduced myocardial contractility (rate of rise of pressure in the ventricle). This will lead to reduced cardiac output and an overall fall in oxygen consumption.

According to the updated GMC guidelines, patient safety is more important than anything else, thus the correct thing to do is inform your colleague’s employing body.

Methemoglobinemia is a rare condition in which the haemoglobin iron is in oxidized or ferric state (Fe3+) and cannot reversibly bind oxygen. Normally, the conversion of ferrous form of iron (Fe2+) to its ferric form (Fe3+) is regulated by NADH methaemoglobin reductase, which results in the reduction of methaemoglobin to haemoglobin. Disruption in the enzyme leads to increased methaemoglobin in the blood. There is tissue hypoxia as Fe3+ cannot bind oxygen, and hence the oxygen-haemoglobin dissociation curve is shifted to the left.

Methemoglobinemia can occur due to congenital or acquired causes. Congenital causes include haemoglobin variants such as HbM and HbH, and deficiency of NADH methaemoglobin reductase. Acquired causes are drugs (e.g. sulphonamides, nitrates, dapsone, sodium nitroprusside, and primaquine) and chemicals (such as aniline dyes).

The features of methemoglobinemia are cyanosis, dyspnoea, anxiety, headache, severe acidosis, arrhythmias, seizures, and loss of consciousness. Patients have normal pO2 but oxygen saturation is decreased. Moreover, presence of chocolate-brown coloured arterial blood (colour does not change with addition of O2) and brown urine also point towards the diagnosis of methemoglobinemia.

Northern blotting’s purpose is to measure the size and amount of RNA transcribed from a specific gene of interest.

Arterial ischemia ulcers present with many of the symptoms observed in this patient: ulcer on the lower extremities, pain, swelling, yellow sores, a punched-out appearance, the foot turning red when dangling from a bed. Smoking a lot is also known to be a causative factor here. This type of ulcer develops due to damage to the arteries caused by a lack of blood flow to the tissue – they are also deep wounds. Venous ischemic ulcers usually form in the knee or inner ankle area as opposed to the foot.

Specificity (negative in health)
The ability of a test to correctly classify an individual as disease- free is called the test′s specificity. [Table 2]

Specificity = d / b+d

= d (true negative) / b+d (true negative + false positive)

= Probability of being test negative when disease absent.

Example: One hundred persons with normal angles (diagnosed by ′gold standard′: gonioscopy) are examined by peripheral angle chamber depth examination. Eighty-five persons had normal peripheral angle chamber depth [Table 3]. The specificity of the peripheral angle chamber depth examination to PACG is therefore –

85 / 100 = 85%.

The incubation periods of disorders is extremely important to diagnose, treat, prevent or attenuate a disease.

• Chickenpox: 7-21 days.
• Whooping cough: 10-14 days.
• Hand, foot and mouth disease: 2-6 days.
• German measles: 14-21 days.
• Mumps: 14-18 days.

Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs. It rarely presents before age 40 and various patterns of disease are recognised, including amyotrophic lateral sclerosis, progressive muscular atrophy and bulbar palsy.
Non-invasive ventilation (usually BIPAP) is used at night, with studies having shown a survival benefit of around 7 months. Riluzole prevents stimulation of glutamate receptors, used mainly in amyotrophic lateral sclerosis and has been shown to prolong life by about 3 months.

Clozapine can cause neutropenia or agranulocytosis.

Clozapine is an atypical antipsychotic used in the treatment of schizophrenia, and in patients who are intolerant to, or unresponsive to other antipsychotics.

It is a weak D2-receptor and D1-receptor blocking activity, with noradrenolytic, anticholinergic, and antihistaminic properties.

Many antipsychotic drugs can occasionally cause bone marrow depression, but agranulocytosis is particularly associated with clozapine.

Other side effects include:
Hypotension, tachycardia
Fever, sedation, seizures (with high doses)
Appetite increase
Constipation
Heartburn
Weight gain
Extrapyramidal symptoms
Agranulocytosis
Neuroleptic malignant syndrome

An overall concordance rate in monozygotic twins was documented to be 25% as compared to dizygotic twins with 3%. First degree relatives have a chance of around 3% of developing the disease. Caucasians show an increase frequency of HLA-B8. The Japanese lupus patients had a stronger association with HLA-DR2.

The chance of two carriers of a recessive gene having a child that is homozygous for that disease (that is both genes are transmitted to the child) is 25%. Therefore, the chances of this couple having a child with CF are 25%(1/4) x 1/20 = 1/80.

The diagnosis is Refsum’s disease. This is an autosomal recessive disorder that causes a sensorimotor peripheral neuropathy. It is caused by defective alpha oxidation of phytanic acid leading to its accumulation in tissues. Cardiac conduction abnormalities and cardiomyopathies may also occur.
Epiphyseal dysplasia causes a characteristic shortening of the fourth toe. Serum phytanic acid levels are elevated. Treatment is by dietary restriction of foods containing phytanic acid (dairy products, fish, beef and lamb).