The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.

Intrauterine growth restriction refers to the failure of the fetus to grow in accordance with the weeks of gestation. There are two types of growth restriction, symmetrical and asymmetrical. Causes include various genetic abnormalities, fetal infections, maternal health conditions, etc. Risk factors for the development of IUGR include fetal echogenic bowel, maternal age above 40 years, low PAPP-A levels, maternal smoking or cocaine use, etc. Fetal echogenic bowel implies a brighter than usual fetal intestines on ultrasonography. It is a marker associated with trisomy 21, which is a cause of IUGR.

Risk factors for neonatal death and stillbirth (weak predictive value):- African American race- Advanced maternal age- History of fetal demise- Maternal infertility- History of small for gestational age infant- Small for gestational age infant- Obesity- Paternal age- Poverty and poor quality of careSo in this case the risk factor is the parental unemployment

E. coli accounts for the majority of UTI’s in children. If this child responds well to treatment and has no recurrence of his symptoms, then no form of imaging is required, as per NICE advice for children aged 6 months to 3 years. Had the child been less than 6 months of age, then a USS at 6 weeks would be necessary.Other options:- Pseudomonas causes atypical UTI. This warrants ultrasonography within the acute illness phase as it may reflect an underlying pathology and DMSA at 4-6 months.- Recurrent UTI is defined as two or more episodes of pyelonephritis OR 1 pyelonephritis and one cystitis OR 3 or more cystitis. It requires USS at six weeks and DMSA at 4-6 months.- Septicaemia is a sign of an atypical UTI. This requires USS within the acute illness as it may reflect an underlying pathology and DMSA at 4-6 months.- Unwell 48hrs post antibiotics is a sign of an atypical UTI. This requires USS within the acute illness as may reflect underlying pathology and DMSA at 4-6 months.

Sepsis can be described as a condition in which there is a dysregulated inflammatory response to an infection. In the case of neonates, sepsis can be life threatening and may present with respiratory distress more than 4 hours after birth, shock, seizures, and multi organ failure. Risk factors that further point to sepsis include prolonged rupture of maternal membranes for more than 24 hours before birth, a history of a maternal fever during labour, or parenteral antibiotic treatment given to the mother for a suspected or confirmed bacterial infection.

Treating persons infected with C. trachomatis prevents adverse reproductive health complications and continued sexual transmission, and treating their sex partners can prevent reinfection and infection of other partners. Treating pregnant women usually prevents transmission of C. trachomatis to neonates during birth. Chlamydia treatment should be provided promptly for all persons testing positive for infection. Treatment delays have been associated with complications (e.g. PID) in a limited proportion of women. To minimise disease transmission to sex partners, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen and resolution of symptoms if present. To minimise risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all of their sex partners are treated. Persons who receive a diagnosis of chlamydia should be tested for HIV, GC, and syphilis.

Based on the presentation, the child most probably is suffering from a refractive error.Astigmatism, myopia and high hypermetropia could all cause these symptoms. This child has difficulty in using vision for finer tasks such as reading. Mild to moderate refractive error would not impair the child’s ability to play or even watch television as for the child in question. Note: Refractive error is the most common treatable cause of reduced vision in children all over the world! Other options:- A congenital cataract is rare and retinal dystrophy is even rarer. – Amblyopia would suggest poor vision in only one eye, something that might not cause symptoms in this age group. – Parents or teachers would have probably noticed squint if it was present.

Familial/inherited short stature is the most likely and commonest factor resulting in short stature among the children. Klinefelter syndrome is characterised by tall stature, widely spaces nipples and infertility. Other factors include congenital heart disease, maternal deprivation and diabetes mellitus but these are the rare causes.

Not being able to form a sentence at the age of 18 months is quite normal. A combination of two words to form a sentence can be done by 2 years of age.

Patients with HIV have a deficiency of CD4 lymphocytes which are also known as helper T cells (Th). They are involved with antigen-specific responses as well as delayed-type hypersensitivity. The risk of developing P. jiroveci pneumonia is greatest with a CD4 count of 200 x 109/l or below.

Haemolytic Uremic Syndrome affects children and is characterised by abdominal pain, a purpuric rash over the body, generalized pallor, haematuria and bloody diarrhoea. There is always a history of preceding diarrhoea caused usually by E.coli and it affects the renal system causing haematuria and deranged renal function tests.

Prophylactic antibiotics should be given to the child to avoid infections and renal injury.

Prepubertal atrophic vaginitis is due to a lack of vaginal oestrogen. The pathophysiology behind prepubertal atrophic vaginitis:1.The proximity of the vagina to the anus2.Lack of oestrogen – leads to thinning of the vaginal mucosa3.Lack of pubic hair to protect the area4.Lack of labial fat pads

The thyroid gland is one of the first endocrine glands to develop, and is formed from the endoderm of the epithelial tissue of the primitive pharynx. The mature gland is functionally made up of follicles with colloid which contain the pro hormone thyroglobulin. Thyroid hormone is synthesised at a cellular level and is stored as thyroglobulin, before its release as thyroid hormone, a major modulator of metabolism. In between the follicular cells are parafollicular, or C-cells which secrete parathyroid hormone or calcitonin which are responsible for calcium regulation in the body.

The red reflex examination is an important part of the paediatric ocular assessment. The red reflex is abnormal in conditions like retinoblastoma, retinopathy of prematurity, cataract, and retinal detachment. Amblyopia is a cortical developmental disorder that results in defective visual inputs to both the eyes. The disorder occurs during the cortical plasticity stage of embryonic development. The red reflex is normal in this case since there is no hindrance to the reflection of light from the ocular media and fundus.

Umbilical vein catheterization utilizes the exposed umbilical stump in a neonate as a site for emergency central venous access up to 14 days old. Umbilical vein catheterization can provide a safe and effective route for intravenous delivery of medications and fluids during resuscitation.The indication for umbilical vein catheterization is when there is a need for IV access in a neonate for resuscitation, transfusions, or short-term venous access when otherwise unobtainable.

Precocious puberty is the attainment of normal pubertal biochemical and physical features at an abnormally earlier age. The age cut-offs commonly used to define precocious puberty are 8 years for females and 9 years for males. The onset of normal puberty is triggered by gonadotropic-releasing hormones from the hypothalamus.In most of the familial cases, the condition is transmitted by affected father. In boys, this makes up about 5% of the cases.Full adult height potential is not achieved in patients of precious puberty, although there is an advanced bone maturation.

Croup is the most common aetiology for hoarseness, cough, and onset of acute stridor in febrile children. Symptoms of coryza may be absent, mild, or marked. The vast majority of children with croup recover without consequences or sequelae.

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

The rational part of a teen’s brain isn’t fully developed until the age of 25 or so.In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.

Syphilis is an infectious venereal disease caused by the spirochete Treponema pallidum. Syphilis is transmissible by sexual contact with infectious lesions, from mother to foetus in utero, via blood product transfusion, and occasionally through breaks in the skin that come into contact with infectious lesions. If untreated, it progresses through 4 stages: primary, secondary, latent, and tertiary. Primary and secondary syphilis are easy to treat with a penicillin injection. Penicillin is one of the most widely used antibiotics and is usually effective in treating syphilis. People who are allergic to penicillin will likely be treated with a different antibiotic, such as:doxycyclineazithromycinceftriaxone

The clinical features and the presentation of this child and the MRI findings are highly suggestive of acute lymphoblastic leukaemia.Anaemia and neutropenia, with a borderline platelet count as well as the tumour infiltration on both femurs on the MRI scan, are suggestive of a widespread Marrow disorder. Based on the age of the patient, acute lymphoblastic leukaemia is more appropriate as it is more common than acute myeloid leukaemia in children and can present with bony pain in this age group.Other options:- Acute myeloid leukaemia: Although this is the most common leukaemia that is seen in adults, it rarely presents in children. – Ewing’s sarcoma: This would usually present in a more unilateral manner, and would only be associated with cytopenia if there was direct bone marrow involvement.- HIV infection: It would be very rare in this group. HIV infection can cause a wide array of signs and symptoms, but we are told that the MRI scan is highly suggestive of tumour infiltration, which would be uncommon in this condition. – Juvenile arthritis: It is much less common. There is also nothing to find on examination, such as swollen or painful joints, which would usually be seen in this condition.

The boy suffers from balanitis xerotica obliterans (BXO) which is surgically treated with circumcision and urethral calibration. In fact, the condition is the only true medical indication for circumcision.

Bleeding oesophageal varices secondary to portal hypertension can cause a massive gastrointestinal haemorrhage resulting in shock. Perforated ulcer is less likely in this age group. Mallory Weiss tear would not likely result in a massive haemorrhage. Aorto-intestinal fistula is more common in older patients with abdominal aneurysms. Boerhaave’s syndrome is a result of a ruptured oesophagus following excessive vomiting.

Crossover trials are characterized by the switching of study participants throughout the treatment groups, keeping a random order of switching. This randomization is important to determine any carry-over effect of different treatment modalities. The benefit of this study is the evaluation of the efficacy of various short-term treatment options for the relief of chronic conditions. The washout period is small in this type of study. Crossover studies are more efficient than the parallel studies, but they should be used according to the treatment options and outcomes.

Codman’s triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. The main causes for this sign are osteosarcoma, Ewing’s sarcoma, eumycetoma, and a subperiosteal abscess.

External oblique forms the outermost muscle of the three muscles comprising the anterolateral aspect of the abdominal wall. Its aponeurosis comprises the anterior wall of the inguinal canal.

An epidural hematoma occurs when there is bleeding between the dura mater (a tough fibrous layer of tissue between the brain and skull) and the skull bone. These occur when arteries are torn as a result of a blow to the head, and injury in the temple area is a common cause. Although the pattern of a lucid interval followed by later neurological symptoms is characteristic, only a minority of patients display this pattern of symptoms. Reported death rates from epidural hematoma vary widely, ranging from 5% to over 40%. Middle meningeal artery is frequently involved in such incidents.

Although initially thought to affect only boys, girls with DMD also have an estimated 10% chance of inheriting the condition. In girls, DMD may present with all or some clinical manifestations.

Cystinosis is a condition characterized by accumulation of the amino acid cystine (a building block of proteins) within cells. This condition is inherited in an autosomal recessive pattern.Excess cystine damages cells and often forms crystals that can build up and cause problems in many organs and tissues. The kidneys and eyes are especially vulnerable to damage| the muscles, thyroid, pancreas, and testes may also be affected.There are three distinct types of cystinosis. In order of decreasing severity, they are nephropathic cystinosis, intermediate cystinosis, and non-nephropathic or ocular cystinosis.Nephropathic cystinosis begins in infancy, causing poor growth and a particular type of kidney damage (renal Fanconi syndrome) in which certain molecules that should be reabsorbed into the bloodstream are instead eliminated in the urine. The kidney problems lead to the loss of important minerals, salts, fluids, and many other nutrients. The loss of nutrients impairs growth and may result in soft, bowed bones (hypophosphatemic rickets), especially in the legs. The nutrient imbalances in the body lead to increased urination, thirst, dehydration, and abnormally acidic blood (acidosis). By about the age of 2, cystine crystals may be present in the clear covering of the eye (cornea). The build-up of these crystals in the eye causes pain and an increased sensitivity to light (photophobia). Untreated children will experience complete kidney failure by about the age of 10. Other signs and symptoms that may occur in untreated people, especially after adolescence, include muscle deterioration, blindness, inability to swallow, diabetes, thyroid and nervous system problems, and an inability to father children (infertility) in affected men.The signs and symptoms of intermediate cystinosis are the same as nephropathic cystinosis, but they occur at a later age.