Saccular aneurysms, also known as berry aneurysms, appear as a round outpouching and are the most common form of cerebral aneurysm. They are a congenital intracranial defect, and haemorrhage can occur at any age, but is most common between the ages of 40-65 years. A second rupture (rebleeding) sometimes occurs, most often within about 7 days of the first bleed.

The glossopharyngeal nerve, known as the ninth cranial nerve (CN IX), is a mixed nerve that carries afferent sensory and efferent motor information. The glossopharyngeal nerve has five distinct general functions:
– The branchial motor (special visceral efferent), supplies the stylopharyngeus muscle.
– The visceral motor (general visceral efferent), provides parasympathetic innervation of the parotid gland via the otic ganglion.
– The visceral sensory (general visceral afferent), carries visceral sensory information from the carotid sinus and carotid body.
– The general sensory (general somatic afferent), provides general sensory information from the inner surface of the tympanic membrane, upper pharynx (GVA), and the posterior one-third of the tongue.
– The visceral afferent (special visceral afferent), provides taste sensation from the posterior one-third of the tongue, including the circumvallate papillae.

Insulin is produced by the beta-cells of the islets of Langerhans in the pancreas. Its actions include:
– promoting uptake of glucose into cells
– glycogen synthesis (glycogenesis)
– protein synthesis
– stimulation of lipogenesis (fat formation).
– driving potassium into cells – used to treat hyperkaelamia.
Parathyroid hormone and activated vitamin D are the principal hormones involved in calcium/phosphate metabolism, rather than insulin.

Carbon tetrachloride (CCl4) is a common agent used in the dry cleaning industry and is thought to cause the formation of free radicals. It causes rapid breakdown of the endoplasmic reticulum due to decomposition of lipids and severe liver cell injury. Within less than 30 mins, hepatic protein synthesis declines, lipid export is reduced due to lack of apoprotein and there is an influx of calcium and cell death.

Weakening of pulse with inhalation and strengthening with exhalation is known as pulsus paradoxus. This represents an exaggeration of the normal variation of the pulse in relation to respiration. It indicates conditions such as cardiac tamponade and lung disease. The paradox refers to the auscultation of extra cardiac beats on inspiration, as compared to the pulse. Due to a decrease in blood pressure, the radial pulse becomes impalpable along with an increase in jugular venous pressure height (Kussmaul sign). Normal systolic blood pressure variation (with respiration) is considered to be >10 mmHg. It is >100 mmHg in Pulsus paradoxus. It is also predictive of the severity of cardiac tamponade.

Initially, all tibial shaft fractures should be stabilized with a long posterior splint with the knee in 10-15° of flexion and the ankle flexed at 90°
Closed fractures with minimal displacement or stable reduction may be treated nonoperatively with a long leg cast, but cast application should be delayed for 3-5 days to allow early swelling to diminish. The cast should extend from the midthigh to the metatarsal heads, with the ankle at 90° of flexion and the knee extended. The cast increases tibial stability and can decrease pain and swelling.
Despite proper casting techniques and adequate follow-up, not all nonoperatively treated tibial shaft fractures heal successfully.
Operative fixation is required when fractures are unstable. Surgical options include plating, external fixation, intramedullary nailing, and, in some cases, amputation.
Intramedullary nailing with locking screws (see the image below) has become the treatment of choice for most tibial shaft fractures. The prevalence of non-union and malunion is greatly decreased in comparison with the other methods of fixation. Patients are also able to return to low-impact activities much sooner than they can with the other treatments.

The sternal angle is the site for identification of the second rib as the second rib is attached to the sternum at this point.

Staphylococcus aureus is the most pathogenic species and is implicated in a variety of infections.  S. aureus can be identified due to its production of coagulase. The staphylococcal enzyme coagulase will cause inoculated citrated rabbit plasma to gel or coagulate. The coagulase converts soluble fibrinogen in the plasma into insoluble fibrin.

Answer: Acute subdural haematoma

An acute subdural haematoma (SDH) is a clot of blood that develops between the surface of the brain and the dura mater, the brain’s tough outer covering, usually due to stretching and tearing of veins on the brain’s surface. These veins rupture when a head injury suddenly jolts or shakes the brain.
Traumatic acute SDHs are among the most lethal of all head injuries. Associated with more severe generalized brain injury, they often occur with cerebral contusions.
SDHs are seen in 10 percent to 20 percent of all traumatic brain injury cases and occur in up to 30 percent of fatal injuries.
Diagnosis:

SDHs are best diagnosed by computed tomography (CT) scan. They appear as a dense, crescent-shaped mass over a portion of the brain’s surface.
Most patients with acute SDHs have low Glasgow Coma Scale (GCS) scores on admission to the hospital.

Acute traumatic subdural haematoma often results from falls, violence, or motor vehicle accidents. Suspect acute subdural haematoma whenever the patient has experienced moderately severe to severe blunt head trauma. The clinical presentation depends on the location of the lesion and the rate at which it develops. Often, patients are rendered comatose at the time of the injury. A subset of patients remain conscious; others deteriorate in a delayed fashion as the haematoma expands.
A GCS score less than 15 after blunt head trauma in a patient with no intoxicating substance use (or impaired mental status baseline) warrants consideration of an urgent CT scan. Search for any focal neurologic deficits or signs of increased ICP. Any abnormality of mental status that cannot be explained completely by alcohol intoxication or the presence of another mind-altering substance should increase suspicion of subdural hematoma in the patient with blunt head trauma.

The clinical presentation of a patient with an acute subdural haematoma depends on the size of the hematoma and the degree of any associated parenchymal brain injury. Symptoms associated with acute subdural haematoma include the following:

Headache

Nausea

Confusion

Personality change

Decreased level of consciousness

Speech difficulties

Other change in mental status

Impaired vision or double vision

Weakness

On noncontrast CT scan, an acute subdural haematoma appears as a hyperdense (white), crescent-shaped mass between the inner table of the skull and the surface of the cerebral hemisphere.

Answer: Measurement of faecal calprotectin

Based on Rome criteria, this patient has Irritable Bowel Syndrome (IBS). Irritable bowel syndrome (IBS) is a group of symptoms—including abdominal pain and changes in the pattern of bowel movements without any evidence of underlying damage. These symptoms occur over a long time, often years. It has been classified into four main types depending on whether diarrhoea is common or constipation is common, or both are common, or neither occurs very often (IBS-D, IBS-C, IBS-M, or IBS-U respectively). IBS negatively affects quality of life and may result in missed school or work. Disorders such as anxiety, major depression, and chronic fatigue syndrome are common among people with IBS.

The recommendations for physicians are to minimize the use of medical investigations. Rome criteria are usually used. They allow the diagnosis to be based only on symptoms, but no criteria based solely on symptoms is sufficiently accurate to diagnose IBS. Worrisome features include onset at greater than 50 years of age, weight loss, blood in the stool, iron-deficiency anaemia, or a family history of colon cancer, celiac disease, or inflammatory bowel disease. The criteria for selecting tests and investigations also depends on the level of available medical resources.

Rome criteria
The Rome IV criteria includes recurrent abdominal pain, on average, at least 1 day/week in the last 3 months, associated with two or more of the following criteria:

Related to defecation
Associated with a change in frequency of stool
Associated with a change in form (appearance) of stool.
Physicians may choose to use one of these guidelines or may simply choose to rely on their own anecdotal experience with past patients. The algorithm may include additional tests to guard against misdiagnosis of other diseases as IBS. Such red flag symptoms may include weight loss, gastrointestinal bleeding, anaemia, or nocturnal symptoms. However, red flag conditions may not always contribute to accuracy in diagnosis; for instance, as many as 31% of people with IBS have blood in their stool, many possibly from hemorrhoidal bleeding.

The diagnostic algorithm identifies a name that can be applied to the person’s condition based on the combination of symptoms of diarrhoea, abdominal pain, and constipation. For example, the statement 50% of returning travellers had developed functional diarrhoea while 25% had developed IBS would mean half the travellers had diarrhoea while a quarter had diarrhoea with abdominal pain. While some researchers believe this categorization system will help physicians understand IBS, others have questioned the value of the system and suggested all people with IBS have the same underlying disease but with different symptoms

The main diseases that cause an increased excretion of faecal calprotectin are inflammatory bowel diseases, coeliac disease, infectious colitis, necrotizing enterocolitis, intestinal cystic fibrosis and colorectal cancer.

Although a relatively new test, faecal calprotectin is regularly used as indicator for inflammatory bowel diseases (IBD) during treatment and as diagnostic marker. IBD are a group of conditions that cause a pathological inflammation of the bowel wall. Crohn’s disease and ulcerative colitis are the principal types of inflammatory bowel disease. Inflammatory processes result in an influx of neutrophils into the bowel lumen. Since calprotectin comprises as much as 60% of the soluble protein content of the cytosol of neutrophils, it can serve as a marker for the level of intestinal inflammation. Measurement of faecal calprotectin has been shown to be strongly correlated with 111-indium-labelled leucocytes – considered the gold standard measurement of intestinal inflammation. Levels of faecal calprotectin are usually normal in patients with irritable bowel syndrome (IBS). In untreated coeliac disease, concentration levels of faecal calprotectin correlate with the degree of intestinal mucosal lesion and normalize with a gluten-free diet.

Faecal calprotectin is measured using immunochemical techniques such as ELISA or immunochromatographic assays. The antibodies used in these assays target specific epitopes of the calprotectin molecule.

Gallbladder ultrasonography should be considered if the patient has recurrent dyspepsia or characteristic postprandial pain.

Abdominal computed tomography (CT) scanning is appropriate to screen for tumours, obstruction, and pancreatic disease if these are diagnostic possibilities.

CT and magnetic resonance (MR) enterography or wireless capsule endoscopy are employed if red flags exist to suggest enteritis (small bowel inflammation) or a tumour.

Colonoscopy is appropriate if alarm symptoms are present and in patients who otherwise qualify for screening colonoscopy.

Factor XI is also known as plasma thromboplastin and is one of the enzymes of the coagulation cascade. It is produced in the liver and is a serine protease. It is activated by factor XIIa, thrombin and by itself. Deficiency of factor XI causes the rare type of haemophilia C. Low levels of factor XI also occur in other disease states, including Noonan syndrome. High levels of factor XI have been seen in thrombosis.

Nephrotic syndrome is a disorder in which the glomeruli have been damaged, characterized by:
– Proteinuria (>3.5 g per 1.73 m2 body surface area per day, or > 40 mg per square meter body surface area per hour in children)
– Hypoalbuminemia (< 2,5 g/dl)
– Hyperlipidaemia, and oedema (generalized anasarca).

The lateral geniculate nucleus (LGN) of the thalamus is the primary processor of visual information in the central nervous system. The LGN receives information directly from the retina and sends projections directly to the primary visual cortex. The LGN likely helps the visual system focus its attention on the most important information.

The blood supply to the hip joint is from two main arteries, the medial circumflex femoral and lateral circumflex femoral arteries. These are branches of the deep artery of the thigh, which itself is a branch of the femoral artery. There is contribution of blood supply from the inferior gluteals, foveal and obturator arteries.

Folliculitis is the inflammation of the hair follicles. It is usually caused by Staphylococcus infection.

Clostridioides difficile (formerly Clostridium difficile) colitis results from a disturbance of the normal bacterial flora of the colon, colonization by C difficile, and the release of toxins that cause mucosal inflammation and damage. Antibiotic therapy is the key factor that alters the colonic flora. C difficile infection (CDI) occurs primarily in hospitalized patients.
The diagnosis of C difficile colitis should be suspected in any patient with diarrhoea who has received antibiotics within the previous 3 months, has been recently hospitalized, and/or has an occurrence of diarrhoea within 48 hours or more after hospitalization. In addition, C difficile can be a cause of diarrhoea in community dwellers without previous hospitalization or antibiotic exposure

The following recommendations on Clostridium difficile infection (CDI) were released on February 2018 by the Infectious Diseases Society of America (ISDA) and Society for Healthcare Epidemiology of America (SHEA).
Diagnosis (adults)
Patients with unexplained and new-onset ≥3 unformed stools in 24 hours are the preferred target population for testing for CDI.
Use a stool toxin test as part of a multistep algorithm (i.e., glutamate dehydrogenase [GDH] plus toxin; GDH plus toxin, arbitrated by nucleic acid amplification test [NAAT]; or NAAT plus toxin) rather than NAAT alone for all specimens when there are no pre-agreed institutional criteria for patient stool submission.
Use NAAT alone or a multistep algorithm for testing (i.e., GDH plus toxin; GDH plus toxin, arbitrated by NAAT; or NAAT plus toxin) rather than a toxin test alone when there are pre-agreed institutional criteria for patient stool submission.
Do not perform repeat testing (within 7 days) during the same episode of diarrhoea and do not test stool from asymptomatic patients, except for epidemiologic studies

The characteristic morphological features of hyaline degeneration is ground-glass, pinking staining cytoplasm with an intact cell membrane. The accumulation of lipids, calcium salts, lipofuscin and an amorphous cytoplasm with an intact cell membrane are all characteristically found in different situations.
Pyknotic nucleus and orphan Annie eye nucleus are not seen in hyaline degeneration.

Answer: 13

Eye Opening Response
Spontaneous–open with blinking at baseline – 4 points
Opens to verbal command, speech, or shout – 3 points
Opens to pain, not applied to face – 2 point
None – 1 point

Verbal Response
Oriented – 5 points
Confused conversation, but able to answer questions – 4 points
Inappropriate responses, words discernible – 3 points
Incomprehensible speech – 2 points
None – 1 point

Motor Response
Obeys commands for movement – 6 points
Purposeful movement to painful stimulus – 5 points
Withdraws from pain – 4 points
Abnormal (spastic) flexion, decorticate posture – 3 points
Extensor (rigid) response, decerebrate posture – 2 points
None – 1 point

He is seen to be disorientated despite opening his eyes in response to speech and being able to talk. He is also able to obey motor commands. His score is therefore 13: 3 for eye opening response, 4 for verbal response and 6 for motor response.

Steps involved in leukocyte arrival and function include:
1. margination: cells migrate from the centre to the periphery of the vessel.
2. rolling: selectins are upregulated on the vessel walls.
3. adhesion: upregulation of the adhesion molecules ICAM and VCAM on the endothelium interact with integrins on the leukocytes. Interaction of these results in adhesion.
4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product.
5. phagocytosis: engulfing the offending substance/cell.

Small-cell lung carcinoma (SCLC) is a type of highly malignant cancer that most commonly arises within the lung. SCLC usually metastasizes widely very early on in the natural history of the tumour, and in nearly all cases responds dramatically to chemotherapy and/or radiotherapy. Surgery has no role in the treatment of this disease.

The ST segment lies between the QRS complex and the T-wave. The normal duration of the ST segment is 0.08 s. ST-segment elevation or depression may indicate myocardial ischaemia or infarction.

Vomiting usually results in hypokalaemia, and hyponatremia would least likely occur as a result of it. Hyponatremia is a common postoperative finding among patients and hence serum sodium must be carefully monitored. Addison disease, SIADH, diuretic therapy can all cause hyponatremia.

A calculus in the ureter, if less than 5mm in diameter is likely to pass spontaneously. However, a larger calculus irritates the ureter and may become lodged, leading to hydroureter and/or hydronephrosis. Likely sites where the calculus might get lodged, include pelviureteric junction, distal ureter at the level of iliac vessels and the vesicoureteric junction. An obstruction can result in reduced glomerular filtration. There can be deterioration in renal function due to hydronephrosis and a raised glomerular pressure, leading to poor renal blood flow. Permanent renal dysfunction usually takes about 4 weeks to occur. Secondary infection can also occur in chronic obstruction.

The aqueous humour is a transparent, watery fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary epithelium and fills both the anterior and the posterior chambers of the eye. It maintains the intraocular pressure and inflates the globe of the eye. It is this hydrostatic pressure which keeps the eyeball in a roughly spherical shape and keeps the walls of the eyeball taut. It provides nutrition (e.g. amino acids and glucose) for the avascular ocular tissues; posterior cornea, trabecular meshwork, lens, and anterior vitreous. It may serve to transport ascorbate into the anterior segment to act as an antioxidant agent. The presence of immunoglobulins indicate its role in immune response to defend against pathogens.

Excessively high levels of prolactin in the blood is called hyperprolactinaemia. Normally, prolactin levels are less than 580 mIU/l in females and less than 450 mIU/l in men. The biologically inactive macroprolactin can lead to a false high reading. However, the patient remains asymptomatic. Dopamine down-regulates prolactin whereas oestrogen upregulates it. Hyperprolactinaemia can be caused due to lack of inhibition (compression of pituitary stalk or low dopamine levels), or increased production due to a pituitary adenoma (prolactinoma). Either of these causes can lead to a prolactin level of 1000-5000 mIU/l. However, levels more than 5000mIU/l are usually associated due to an adenoma and >100,000 mIU/l are seen in macroadenomas (tumours < 1cm in diameter). Increased prolactin causes increased dopamine release from the arcuate nucleus of hypothalamus. This increased dopamine in turn, inhibits the GnRH (Gonadotrophin Releasing Hormone) thus blocking gonadal steroidogenesis resulting in the symptoms of hyperprolactinaemia. In women, it includes hypoestrogenism, anovulatory infertility, decreased or irregular menstruation or complete amenorrhoea. It can even cause production of breast milk, loss of libido, vaginal dryness and osteoporosis. In men, the symptoms include impotence, decreased libido, erectile dysfunction and infertility. In men, treatment can be delayed due to late diagnosis as they have no reliable indicator such as menstruation that might indicate a problem. Most of the male patients seek help only when headaches and visual defects start to surface.

Achalasia is an oesophageal motility disorder where inappropriate contractions in the oesophagus lead to reduced peristalsis and failure of the lower oesophageal sphincter to relax properly in response to swallowing. Classical triad of symptoms include dysphagia to fluids followed by solids, chest pain and regurgitation of undigested food. Other symptoms include belching, hiccups, weight loss and cough. Diagnosis is by:
– X-ray with a barium swallow or oesophagography : narrowing at the gastroesophageal junction (‘bird/parrot beak’ or ‘rat tail’ appearance) and various degrees of mega-oesophagus (oesophageal dilatation) as the oesophagus is gradually stretched by retained food. Effectiveness of treatment can be measured with a 5-minute timed barium swallow.
– Manometry – probe measures the pressure waves in different parts of oesophagus and stomach while swallowing.
– Endoscopy
– CT scan to exclude other causes like malignancy
– Pathological examination showing defect in the nerves which control oesophageal motility (myenteric plexus).
In Chagas disease, there is destruction of ganglion cells by Trypanosoma cruzi.

Breast implants are mainly: saline-filled and silicone gel-filled. Complications include haematoma, fluid collections, infection at the surgical site, pain, wrinkling, asymmetric appearance, wound dehiscence and thinning of the breast tissue.

Alpha-1 antitrypsin (A1AT) deficiency is a condition characterised by the lack of a protein that protects the lungs and liver from damage, called alpha1-antytripsin. The main complications of this condition are liver diseases such as cirrhosis and chronic hepatitis, due to accumulation of abnormal alpha 1-antytripsin and emphysema due to loss of the proteolytic protection of the lungs.

The facial muscles generally originate from the facial bones and attach to the skin, in the same plane as the platysma muscle. They are all innervated by cranial nerve VII (the facial nerve). The occipitofrontalis muscle consists of two parts: The occipital belly, near the occipital bone, and the frontal belly, near the frontal bone.

Atrophy is characterised by the breakdown of intracellular components along with organelles and packing them into vacuoles known as autophagic vacuoles. This is an adaptive response that separates the damaged cellular structures from the rest of the cells.