Correlation is a bivariate analysis that measures the strength of association between two variables and the direction of the relationship.Pearson r correlation: Pearson r correlation is the most widely used correlation statistic to measure the degree of the relationship between linearly related variables. Pearson’s correlation coefficient is the test that measures the statistical relationship, or association, between two continuous variables. It is known as the best method of measuring the association between variables of interest because it is based on the method of covariance. It gives information about the magnitude of the association, or correlation, as well as the direction of the relationship.The non-parametric Spearman or Kendall rank correlation coefficient is used if neither variable has a normal distribution or the sample size is small (i.e. <20).

Measles and chickenpox are spread by droplets. Thus, patients should be isolated. Rheumatic fever and post-streptococcal glomerulonephritis are immune mediated diseases that don’t require isolation. Herpetic gingivostomatitis spreads by direct transmission of infected secretions to the stratified squamous epithelium. HSP is not an infectious disease.

Retinopathy of prematurity affects infants born early, and is due to the abnormal growth of retinal vasculature as opposed to vascular occlusion often see in adults. Though most babies with ROP can see normally, the most significant complication of ROP Is retinal detachment which can lead to blindness. Other structures in the eye such as the optic nerve or the fovea however, are not affected. Children may develop nystagmus as a result of poor sight in the affected eye(s).

Based on the clinical scenario provided, the most probable nerve injured in this patient would be the trochlear nerve. The trochlear nerve has a relatively long intracranial course, and this makes it vulnerable to injury in head trauma. Head trauma is the most frequent cause of acute fourth nerve palsy. A 4th nerve palsy is the most common cause of vertical diplopia. The diplopia is at its worst when the eye looks medially which it usually does as part of the accommodation reflex when walking downstairs.

Marfan syndrome is a disorder that affects the connective tissue found throughout the body, Marfan syndrome can affect many systems, often causing abnormalities in the heart, blood vessels, eyes, bones, and joints. The two primary features of Marfan syndrome are vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes and aortic root disease, leading to aneurysmal dilatation, aortic regurgitation and dissection is the main cause of morbidity and mortality in Marfan syndrome.

A drooping eyelid is called ptosis or blepharoptosis. In ptosis, the upper eyelid falls to a position that is lower than normal. Severe ptosis may cover part or all of the pupil and interfere with vision, resulting in amblyopia.Visual development in a child can be permanently impaired when there is deprivation of visual stimulation or when the oculomotor function is impaired. Congenital ptosis can represent both these components

Absence epilepsy is the most common type of generalized childhood epilepsies. It is mainly idiopathic, but 10-40% of the cases have a positive family history. It is characterized by frequent absence seizures and periods of unconsciousness. The hallmark of absence epilepsy on EEG is the bilaterally synchronous 2–4 Hz spike and wave discharges (SWDs). The average age of onset is around 4-8 years, being more prevalent among girls. Treatment resistance is not common.

Chédiak–Higashi syndrome is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

The clinical picture suggests that the child is severely dehydrated. IV fluid bolus then IV maintenance fluids is the correct option.

The umbilical cord that connects the fetus to the placenta is about 50cm long. This tissue consists of the body stalk and vitelline duct. The former containing the allantoic diverticulum and the umbilical vessels. The latter contains the connection linking the digestive tube and the yolk sac. This cord is wrapped by stratum of ectoderm and gelatinous tissue or jelly of Wharton. The right umbilical vein plus the vitelline vessels and ducts disappear and this at birth the cord has three vessels which are the umbilical vein and two umbilical arteries.

The Meckel’s diverticulum is a vestigial remnant of the omphalomesenteric duct. This structure is also referred to as the vitelline and contains two types of ectopic tissue, namely| gastric and pancreatic.

The clinical picture suggests a vitamin K deficiency haemorrhagic disease of the new-born and requires IV vitamin K and fresh frozen plasma. This usually presents with gastrointestinal bleeding, bleeding from the umbilical stump and bruising after 2–7 days.

Adhesion formation might be reduced by minimally invasive surgical techniques and the use of adhesion barriers. Non-operative treatment is effective in most patients with ASBO. Contraindications for non-operative treatment include peritonitis, strangulation, and ischemia. When the adhesive aetiology of obstruction is unsure, or when contraindications for non-operative management might be present, CT is the diagnostic technique of choice. The principles of non-operative treatment are nil per os, naso-gastric, or long-tube decompression, and intravenous supplementation with fluids and electrolytes. When operative treatment is required, a laparoscopic approach may be beneficial for selected cases of simple ASBO.

Cranial nerve XI is also known as the accessory nerve. The accessory nerve innervates the trapezius muscle which retracts the scapula. The upper and lower fibres act together to also upwardly rotate it.

Apgar is a quick test performed on a baby at 1 and 5 minutes after birth. The 1-minute score determines how well the baby tolerated the birthing process. The 5-minute score tells the health care provider how well the baby is doing outside the mother’s womb. More specifically, five components are assessed and these are the appearance (A), the pulse (P), the grimace (G), the activity (A) and the respiration (R). A normal APGAR score is considered to be 10 points, 2 points given for each normal component. In this case, 1 point is given for the appearance due to the bluish extremities, 2 points are given for the pulse which is higher than 100 bpm, 1 point is given for the grimacing, 2 points are given for the activity due to the good muscle tone and 1 point is given for the respiration due to gasping. Total score is 7 points.

Foreign body aspiration (FBA) commonly occurs in children aged 1–3 years. FBA typically presents with sudden onset of coughing and choking, followed by stridor and dyspnoea. Obstruction of the larynx or trachea is a potentially life-threatening situation that causes severe respiratory distress, cyanosis, and suffocation. Most commonly, the foreign body (FB) becomes lodged in the main and intermediate bronchi| approx. 60% of FB are located in the right main bronchus due to the more vertical orientation compared to the left main bronchus. Reduced breath sounds on the one side only would not be explained by a tracheal obstruction as it would cause reduced breath sounds bilaterally and a more severe clinical picture.

Based on the clinical scenario, the patient has features suggestive of acute otitis externa, which can be managed with topic antibiotics.Otitis externa:It can be classified as acute (< 3 weeks) or chronic (> 3 months). Frequent exposure to water, e.g. swimming, is a risk factor for the condition. Itching, pain, hearing loss and discharge are common complaints. Examination demonstrates oedema of the external auditory canal with discharge. Pain may be elicited on the movement of the tragus or pinna. First-line treatment is with topical drops/sprays for one week. Acidic preparations such as 2% acetic acid, antibiotic or combined antibiotic and corticosteroid preparations may be used (1% hydrocortisone and 0.3% gentamicin). Acetic acid can be used as the first-line treatment for mild cases without discharge or hearing impairment. On selecting an appropriate topical preparation remember that topical aminoglycosides are contraindicated if the tympanic membrane is perforated and that chloramphenicol ear drops cause contact dermatitis in approximately 10% of people. Clinoquinol, a combination of antibacterial and antifungal, may be preferred over aminoglycoside containing preparations due to the theoretical lower risk of ototoxicity and dermatitis. However, there is no clear evidence to support the use of one topical preparation over another.Other options:- Admit for IV antibiotics: First line management is with analgesia and topical antibiotic or combined antibiotic and corticosteroid preparations. Thus, IV antibiotics is not an appropriate action.- Oral antibiotics: Oral antibiotics like flucloxacillin or erythromycin are considered only for severe infections such as the spread of cellulitis beyond the ear canal. – Reassurance is not sufficient to treat these patients. They require topic antibiotic therapy.- Referral to ENT: Should be considered only in case of treatment failure. ENT referral can also be considered if there is cellulitis extending past the margin of the external ear canal, extreme pain or extensive swelling and discharge likely to require suction or the insertion of an ear wick. Urgent ENT referral is reserved for suspected cases of malignant otitis externa (with the extension of the condition into the adjacent bone and spreading osteomyelitis).

Amniotic fluid is the protective liquid that surrounds the fetus in utero. It prevents the fetus from injury, protects the umbilical cord from compression, and provides necessary nutrients and a medium for growth and movement. Amniotic fluid originates from the maternal plasma initially, but by 16th week of gestation, fetal kidneys start making urine which contributes to further production of the amniotic fluid. Amniotic fluid contains a number of chemical substances including hormones, tumour markers, nutrients, electrolytes, and immunoglobulins. Main substances found in amniotic fluid include carbohydrates, proteins, lipids, lactoferrin, insulin-like growth factor, granulocyte colony-stimulating factor, erythropoietin, etc. Interleukin-1 is not a component of AF.

The patient has bloody diarrhoea that sounds like a food poisoning in the clinical scenario. Campylobacter is the most common cause of this in the United Kingdom. This is then followed by Salmonella and Shigella. The symptoms are usually self limiting. This is more likely to be bacterial from the food than a viral gastroenteritis.

Answer: Beta 2 transferrin assayBeta-2-transferrin is a protein found only in CSF and perilymph. Since 1979, beta-2-transferrin has been used extensively by otolaryngologists in the diagnosis of CSF rhinorrhoea and skull-base cerebrospinal fluid fistulas. With sensitivity of 94% – 100%, and specificity of 98% – 100%, this assay has become the gold standard in detection of CSF leakage. CSF rhinorrhoea is characterized by clear or xanthochromic watery rhinorrhoea that may not become apparent until nasal packing is removed.

The level of statistical significance is often expressed as a p-value between 0 and 1. The smaller the p-value, the stronger the evidence that you should reject the null hypothesis.A p-value less than 0.05 (typically ≤ 0.05) is statistically significant. It indicates strong evidence against the null hypothesis, as there is less than a 5% probability the null is correct (and the results are random). Therefore, we reject the null hypothesis, and accept the alternative hypothesis.However, this does not mean that there is a 95% probability that the research hypothesis is true. The p-value is conditional upon the null hypothesis being true is unrelated to the truth or falsity of the research hypothesis.A lower p-value is sometimes interpreted as meaning there is a stronger relationship between two variables. However, statistical significance means that it is unlikely that the null hypothesis is true (less than 5%).To understand the strength of the difference between two groups (control vs. experimental) a researcher needs to calculate the effect size.

The main result of a correlation is called the correlation coefficient (or r). It ranges from -1.0 to +1.0. The closer r is to +1 or -1, the more closely the two variables are related.If r is close to 0, it means there is no relationship between the variables. If r is positive, it means that as one variable gets larger the other gets larger. If r is negative it means that as one gets larger, the other gets smaller (often called an inverse correlation).

Answer: LaparoscopyThe diagnostic accuracy of laparoscopy for impalpable testis is well recognized. Approximately 20% of undescended testes are truly impalpable, and laparoscopy is actually regarded as the gold standard for their localization| none of the currently available imaging techniques (ultrasound, computerized tomography, or magnetic resonance imaging) has proven to be 100% reliable in predicting the presence or absence of a testis.In this respect, not only can laparoscopy be considered the most reliable tool to provide information on the location of the testis but also to confirm its absence.Undescended testes in boys is a very common congenital abnormality in which one or both testes does not reach the bottom of the scrotum prior to birth. The incidence of the condition is 3–5% among all boys at birth, and decreases to 0.8–1% after 6 months of age.Males with undescended testes have a lower sperm count, poorer quality sperm, and lower fertility rate, compared to males whose testicles descend normally| the rate of subfertility increases with bilateral involvement and increasing age at the time of orchidopexy.

Cranial nerve II (CN II or optic nerve) runs along the midline of the ventral surface of the brain and conveys visual information from the retina of each eye to the corresponding region of the primary visual cortex. The right half of the visual field of both eyes is processed by the left half of the retina, while the right half of the retina processes the left half of the visual field. These retinal ganglion cells project myelinated axons, carrying CN II sensory afferent fibres, through the optic chiasm, where optic nerve fibres from the nasal half of each retina decussate to the contralateral side of the brain for processing. After passing through the optic chiasm, the optic nerve becomes the optic tract that synapses to the lateral geniculate nucleus (LGN) of the thalamus and subsequently projects optic radiations to the primary visual cortex (V1) of the occipital lobe. The optic tract also projects to the superior colliculus, pretectal nuclei, and suprachiasmatic nuclei. This part of the optic pathway serves the important light reflex.Due to the anatomical location of the optic chiasm superior to the pituitary gland, a suprasellar extension of a pituitary macroadenoma will lead to compression of the optic nerve fibres decussating at the optic chiasm. Impingement of these nerves prevents visual information from the temporal visual fields of each eye from reaching the processing centres in the brain, leading to peripheral vision loss

Biliary atresia is a rare condition that causes obstructive jaundice. Without surgical treatment, e.g. Roux-en-Y, Kasai procedure or liver transplantation, death is likely by 2 years of age. The aetiology of biliary atresia is unknown. Theories suggest a multitude of etiological and causative factors that are both genetic and acquired.The other conditions do not cause a conjugated hyperbilirubinemia.

Cystic fibrosis is an autosomal recessive inherited disorder that affects the lungs or the pancreas. In the case of an affected child whose parents do not have the disorder but carry one copy of the mutated gene, each sibling has a 50% chance of being a carrier of the disease. They can inherit one copy of the gene from each parent. There is a 25 % chance that the child may inherit both mutated genes and be homozygous for the trait.

Based on the presentation, the patient is probably a case of Crohn’s disease. The first-line treatment of Crohn’s disease is exclusive enteral nutrition.Exclusive enteral nutrition (EEN)This involves drinking a protein-based formula exclusively for 6–8 weeks. It has been shown to have superior mucosal healing when compared with steroids. Furthermore, it is nutritionally advantageous when compared to steroids and does not have the side-effect profile of steroids.Other options:- Intravenous steroids: This is the first-line treatment for ulcerative colitis (UC) or Crohn’s disease if there is rectal disease (which is not the case here). Side-effects include adrenal suppression, behavioural effects, osteopenia and changes in adipose tissue distribution.- Oral steroids: This can be used if EEN is not possible. However, the side-effect profile is less favourable and is not as effective concerning mucosal healing.- Parental nutrition and surgery: They may be occasionally required in severe cases that have failed first-line therapy.

Due to malaria’s incubation period being between 7 and 30 days, malaria prophylaxis cannot provide a patient with confirmed protection. Prophylaxis treatment also often fails. The symptoms such as neck stiffness, fever, and vomiting are also consistent with the cerebral malaria diagnosis.

The age of the patient and the presence of immature white blood cells are suggestive of leukaemia. Hodgkin’s disease is unlikely in this age group and it usually presents with lymphadenopathy. In HIV, immature white blood cells are not present in the blood.

Von Willebrand disease (VWD), a congenital bleeding disorder caused by deficient or defective plasma von Willebrand factor (VWF), may only become apparent on haemostatic challenge, and bleeding history may become more apparent with increasing age. Type 1 VWD (,30% of VWD) typically manifests as mild mucocutaneous bleeding. Type 2 VWD accounts for approximately 60% of VWD. Type 2 subtypes include: Type 2A, which usually manifests as mild-to-moderate mucocutaneous bleeding| Type 2B, which typically manifests as mild-to-moderate mucocutaneous bleeding that can include thrombocytopenia that worsens in certain circumstances| Type 2M, which typically manifests as mild-moderate mucocutaneous bleeding| Type 2N, which can manifest as excessive bleeding with surgery and mimics mild haemophilia A. Type 3 VWD (<10% of VWD) manifests with severe mucocutaneous and musculoskeletal bleeding.