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

Paget disease is a localized disorder of bone remodelling that typically begins with excessive bone resorption followed by an increase in bone formation. This osteoclastic over activity followed by compensatory osteoblastic activity leads to a structurally disorganized mosaic of bone (woven bone), which is mechanically weaker, larger, less compact, more vascular, and more susceptible to fracture than normal adult lamellar bone.
Approximately 70-90% of persons with Paget disease are asymptomatic; however, a minority of affected individuals experience various symptoms, including the following:
– Bone pain (the most common symptom)
– Secondary osteoarthritis (when Paget disease occurs around a joint)
– Bony deformity (most commonly bowing of an extremity)
– Excessive warmth (due to hypervascularity)
– Neurologic complications (caused by the compression of neural tissues)
Measurement of serum alkaline phosphatase—in some cases, bone-specific alkaline phosphatase (BSAP)—can be useful in the diagnosis of Paget disease. Elevated levels of urinary markers, including hydroxyproline, deoxypyridinoline, C-telopeptide, and N -telopeptide, may help identify patients with Paget disease.
Serum calcium and phosphate levels should be within the reference range in patients with Paget disease.

NPV = TN / FN+TN

= TN (true negative) / FN+TN (false negative + true negative)

= Probability (patient not having disease when test is negative)

Memantine is an antagonist of the NMDA (N-Methyl-D-Aspartate)-receptor subtype of glutamate receptor. It is used to slow the neurotoxicity thought to be involved in Alzheimer’s disease and other neurodegenerative diseases.

Drug interactions:
When given concomitantly with other NMDA-receptor antagonists (e.g., ketamine, amantadine) increase the risk of psychosis.
Dopamine agonists, L-dopa, and anticholinergics enhance effects of memantine.
Antispasmodics (e.g., baclofen)  enhance effects, as memantine has some antispasmodic effects.
Drugs excreted by cationic transporters in the kidney (e.g. quinine, cimetidine, ranitidine) reduce excretion.

Common adverse effects include dizziness, headache, confusion, diarrhoea, and constipation.

Metabolic acidosis is associated with cocaine overdose.
In overdose, cocaine leads to agitation, tachycardia, hypertension, sweating, hallucinations, and finally convulsions.
Metabolic acidosis, hyperthermia, rhabdomyolysis, and ventricular arrhythmias also occur.
Chronic use may be associated with premature coronary artery disease, dilated cardiomyopathy, and increased risk of cerebral haemorrhage.
There are 3 stages for acute cocaine toxicity:
Stage I: CNS symptoms of headache, vertigo, pseudo hallucinations, hyperthermia, hypertension.
Stage II: increased deep tendon reflexes, tachypnoea, irregular breathing, hypertension.
Stage III: Areflexia, coma, fixed and dilated pupils, hypotension, ventricular fibrillation, apnoea, and respiratory failure.

Treatment:
– Airway, breathing, and circulation to be secured. The patient’s fever should be managed, and one should rule out hypoglycaemia as a cause of the neuropsychiatric symptoms.
– Cardiovascular toxicity and agitation are best-treated first-line with benzodiazepines to decrease CNS sympathetic outflow.
– The mixed beta/alpha blocker labetalol is safe and effective for treating concomitant cocaine-induced hypertension and tachycardia.
– Non-dihydropyridine calcium channels blockers such as diltiazem and verapamil have been shown to reduce hypertension reliably, but not tachycardia.
– Dihydropyridine agents such as nifedipine should be avoided, as reflex tachycardia may occur.
– The alpha-blocker phentolamine has been recommended but only treats alpha-mediated hypertension and not tachycardia.

The normal partial pressure reference values are:
– PaO2 more than 80 mmHg (11 kPa)
– PaCO2 less than 45 mmHg (6.0 kPa).
This patient has an elevated PaCO2 (7.4kPa)
Hypoxemia (PaO2 <8kPa) with hypercapnia (PaCO2 >6.0kPa).
The pH is also lower than 7.35 at 7.3

Type 2 respiratory failure is caused by inadequate alveolar ventilation; both oxygen and carbon dioxide are affected. Defined as the build-up of carbon dioxide levels (PaCO2) that has been generated by the body but cannot be eliminated. The underlying causes include:
– Increased airways resistance (chronic obstructive pulmonary disease, asthma, suffocation)
– Reduced breathing effort (drug effects, brain stem lesion, extreme obesity)
– A decrease in the area of the lung available for gas exchange (such as in chronic bronchitis)
– Neuromuscular problems (Guillain–Barré syndrome, motor neuron disease)
– Deformed (kyphoscoliosis), rigid (ankylosing spondylitis), or flail chest.

Mycoplasma infection causes cold autoimmune haemolytic anaemia (AIHA). The rest of the aforementioned options cause warm AIHA.

AIHA may be divided into ‘warm’ and ‘cold’ types, according to the temperature at which the antibodies best cause haemolysis. It is most commonly idiopathic but may be secondary to a lymphoproliferative disorder, infection, or drugs.

1. Warm AIHA:
In warm AIHA, the antibody (usually IgG) causes haemolysis best at body temperature and tends to occur in extravascular sites, for example, spleen. Management options include steroids, immunosuppression, and splenectomy. It is caused by autoimmune diseases such as SLE (rarely causes mixed-type AIHA), cancers such as lymphomas and CLL, and drugs such as methyldopa.

2. Cold AIHA:
The antibody in cold AIHA is usually IgM and causes haemolysis best at 4°C and occurs more commonly intravascularly. Features may include symptoms of Raynaud’s disease and acrocyanosis. Patients do not respond well to steroids. Cold AIHA is caused by cancers such as lymphomas, and infections such as mycoplasma and EBV.

This woman is receiving methotrexate, an immunosuppressant, to control her rheumatoid arthritis. In such immunocompromised patients, BNF suggests clarithromycin as first-line management.

The Hyperlipidaemia Effect: Pseudohyponatremia in Pancreatic Cancer; Patients who have disorders of cholestasis commonly present with volume depletion due to vomiting and poor oral intake, which, in turn, often leads to hypovolemic hyponatremia. It is less well known that disorders of cholestasis, including tumours of the hepatobiliary system, can be accompanied by hyperlipidaemia.

The patient has a recent history of bleeding peptic ulcer disease, which is an absolute contraindication for thrombolysis. So he should be offered primary angioplasty.

Methyldopa is the drug of first choice for the control of mild to moderate hypertension in pregnancy. Labetalol is also considered as a first line drug for hypertension in pregnancy. Calcium channel blockers and hydralazine are considered as second line drugs. Beta-blockers (except labetalol), angiotensin receptor blockers, angiotensin-converting enzyme inhibitors and thiazides are not recommended.

The normal partial pressure reference values are: oxygen PaO2 more than 80 mmHg (11 kPa), and carbon dioxide PaCO2 lesser than 45 mmHg (6.0 kPa).
This patient has an elevated PaCO2 of 6.8kPa which exceeds the normal value of less than 6.0kPa.
The pH is also lower than 7.35 at 7.32

In any patient with asthma, an increasing PaCO2 indicates severe airway obstruction that is leading to respiratory muscle fatigue and patient exhaustion.

According to the British Thoracic Society guidelines:
Indications for admission to intensive care or high-dependency units include
patients requiring ventilatory support and those with acute severe or life-threatening asthma who are failing to respond to therapy, as evidenced by:
• deteriorating PEF
• persisting or worsening hypoxia
• hypercapnia
• arterial blood gas analysis showing fall in pH or rising hydrogen concentration
• exhaustion, feeble respiration
• drowsiness, confusion, altered conscious state
• respiratory arrest

Transfer to ICU accompanied by a doctor prepared to intubate if:
• Deteriorating PEF, worsening or persisting hypoxia, or hypercapnia
• Exhaustion, altered consciousness
• Poor respiratory effort or respiratory arrest

A single dose of intravenous magnesium sulphate is safe and may improve lung function and reduce intubation rates in patients with acute severe asthma. Intravenous magnesium sulphate may also reduce hospital admissions in adults with acute asthma who have had little or no response to standard treatment.

Consider giving a single dose of intravenous magnesium sulphate to
patients with acute severe asthma (PEF <50% best or predicted) who have not had a good initial response to inhaled bronchodilator therapy.
Magnesium sulphate (1.2–2 g IV infusion over 20 minutes) should only be used following consultation with senior medical staff.

To differentiate ventricular tachycardia (VT) from supraventricular tachycardia (SVT) with aberrant conduction the following electrocardiographic features should be looked for:

Evidence of preceding atrial activity for SVT. Oesophageal leads are helpful if P waves are hidden in the QRS complex.
QRS duration more than 140 ms for VT.
QRS morphology: Features of QRS morphology that favour SVT are RBBB or triphasic patterns like rSR in V1 and qRS in V6. Monophasic pattern like R or qR in V1 and rS or QS in V6 or multiple morphology QRS complexes favour VT.
AV dissociation for VT.

The most common location for a duodenal ulcer bleed is the posterior duodenum (remember: posterior bleeds, anterior perforates). The perfusion to this area is most specifically from the posterior superior pancreaticoduodenal artery.

The anterior superior pancreaticoduodenal artery supplies the anterior region. The gastroepiploic artery supplies mostly the stomach. The splenic artery goes, obviously, toward the spleen, in the other direction. The gastroduodenal artery is a branch of the celiac artery, and it’s branches are the anterior superior pancreaticoduodenal artery and posterior superior pancreaticoduodenal artery.

RET (rearranged during transfection) is a receptor tyrosine kinase involved in the development of neural crest derived cell lineages, kidney, and male germ cells. Different human cancers, including papillary and medullary thyroid carcinomas, lung adenocarcinomas, and myeloproliferative disorders display gain-of-function mutations in RET.
In over 90% of cases, MEN2 syndromes are due to germline missense mutations of the RET gene.
Multiple endocrine neoplasias type 2 (MEN2) is an inherited disorder characterized by the development of medullary thyroid cancer (MTC), parathyroid tumours, and pheochromocytoma.

Pneumonia is the predominant clinical manifestation of Legionnaires disease (LD). After an incubation period of 2-10 days, patients typically develop the following nonspecific symptoms:
Fever
Weakness
Fatigue
Malaise
Myalgia
Chills

Respiratory symptoms may not be present initially but develop as the disease progresses. Almost all patients develop a cough, which is initially dry and non-productive, but may become productive, with purulent sputum and, (in rare cases) haemoptysis. Patients may experience chest pain.
Common GI symptoms include diarrhoea (watery and non bloody), nausea, vomiting, and abdominal pain.

Fever is typically present (98%). Temperatures exceeding 40°C occur in 20-60% of patients. Lung examination reveals rales and signs of consolidation late in the disease course.

Males are more than twice as likely as females to develop Legionnaires disease.

Age
Middle-aged and older adults have a high risk of developing Legionnaires disease while it is rare in young adults and children. Among children, more than one third of reported cases have occurred in infants younger than 1 year.

Situations suggesting Legionella disease:
-Gram stains of respiratory samples revealing many polymorphonuclear leukocytes with few or no organisms

-Hyponatremia

-Pneumonia with prominent extrapulmonary manifestations (e.g., diarrhoea, confusion, other neurologic symptoms)

Specific therapy includes antibiotics capable of achieving high intracellular concentrations (e.g., macrolides, quinolones, ketolides, tetracyclines, rifampicin).
Clarithromycin, a new macrolide antibiotic, is at least four times more active in vitro than erythromycin against Legionella pneumophila. In this study the safety and efficacy of orally administered clarithromycin (500 to 1,000 mg bid) in the treatment of Legionella pneumonia were evaluated.
Clarithromycin is a safe effective treatment for patients with severe chest infections due to Legionella pneumophila.

Ramipril is an ACE inhibitor that blocks the conversion of angiotensin I to angiotensin II as well as preventing the breakdown of bradykinin, leading to blood vessel dilatation and decreased blood pressure. However, bradykinin also causes smooth muscles in the lungs to contract, so the build-up of bradykinin is thought to cause the dry cough that is a common side-effect in patients that are on ACE inhibitors.

If a pleural effusion is present, a diagnostic thoracentesis may be performed and analysed for pH, lactate dehydrogenase, glucose levels, specific gravity, and cell count with differential. Pleural fluid may also be sent for Gram stain, culture, and sensitivity. Acid-fast bacillus testing may also be considered and the fluid may be sent for cytology if cancer is suspected.

The following findings are suggestive of an empyema or parapneumonic effusion that will likely need a chest tube or pigtail catheter for complete resolution:
-Grossly purulent pleural fluid
-pH level less than 7.2
-WBC count greater than 50,000 cells/µL (or polymorphonuclear leukocyte count of 1,000 IU/dL)
-Glucose level less than 60 mg/dL
-Lactate dehydrogenase level greater than 1,000 IU/mL
-Positive pleural fluid culture

The most often used golden criteria for empyema are pleural effusion with macroscopic presence of pus, a positive Gram stain or culture of pleural fluid, or a pleural fluid pH under 7.2 with normal peripheral blood ph.

The best answer is cytomegalovirus. The mother was infected during the pregnancy and the baby has developed cytomegalo-inclusion syndrome. Histologically, it is identified by viral particles surrounded by lysosomes.

The major delayed problem with radiotherapy is the development of secondary cancers. This risk begins to appear ten years after therapy.

Sitagliptin-induced pancreatitis can occur at any time after the initiation of therapy, even after several years. Patients taking sitagliptin who present with signs and symptoms of mild or severe pancreatitis should immediately discontinue sitagliptin and use an alternate medication regimen for control of type 2 diabetes.
In response to pancreatitis reported in post-marketing surveillance through the Adverse Event Reporting System (AERS), the FDA has issued revised prescribing information for sitagliptin stating that cases of acute pancreatitis have been reported with use, to monitor closely for signs and symptoms of pancreatitis, and to use sitagliptin with caution in patients with a history of pancreatitis.

Hemiballismus or hemiballism in its unilateral form is a very rare movement disorder. It is a type of chorea caused in most cases by a decrease in activity of the subthalamic nucleus of the basal ganglia, resulting in the appearance of flailing, ballistic, undesired movements of the limbs. Symptoms may decrease while the patient is asleep. Antidopaminergic agents (e.g. Haloperidol) are the mainstay of treatment.

The patients high morning blood sugar levels are suggestive to Somogyi Phenomenon which suggests that hypoglycaemia during the late evening induced by insulin could cause a counter regulatory hormone response that produces hyperglycaemia in the early morning.
Substitution of regular insulin with an immediate-acting insulin analogue, such as Humulin lispro, may be of some help.

The latest reserches say that simple tooth extraction in patients on warfarin treatment can be performed safely without high risk of bleeding, providing that the INR is equal to or less than 3.5 on the day of extraction. A close follow-up and monitoring of patients taking warfarin is mandatory after dental extraction.

Syringomyelia is a development of a cavity (syrinx) within the spinal cord. Signs and symptoms include loss of feeling, paralysis, weakness, and stiffness in the back, shoulders, and extremities. Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. Symptoms typically vary depending on the extent and, often more critically, on the location of the syrinx within the spinal cord.

Normal pressure hydrocephalus is a form of communicating hydrocephalus characterised by enlarged ventricles with normal opening pressure on lumbar puncture. For diagnostic purposes, a triad of urinary incontinence, gait abnormality and dementia is necessary. It is necessary to diagnose the condition early because it is reversible by placing a ventriculoperitoneal shunt. It is most common in patients aged more than 60 years.

Juvenile Onset Parkinson’s is an autosomal recessive condition that usually presents in late childhood to early adulthood, initially with gait disorders caused by lower limb dystonia that later develops to the more classical signs Parkinson’s.

Current guidelines recommend the use of ambrisentan, Bosentan (recommendation I, level of evidence A) and macitentan (I, B) in patients with PAH and WHO functional class II and III. In WHO functional class IV, the first-line drug is Epoprostenol and the recommendation for Endothelin receptor antagonists is weaker (IIb, C).

Behçet disease is a rare vasculitic disorder that is characterized by a triple-symptom complex of recurrent oral aphthous ulcers, genital ulcers, and uveitis. The systemic manifestations can be variable. Ocular disease has the greatest morbidity, followed by vascular disease generally from active vasculitis. Cutaneous manifestations can occur in up 75% of patients with Behcet disease and can range from acneiform lesions, to nodules and erythema nodosum. GI manifestations can be severe. Differentiating Behçet disease from active inflammatory bowel disease can be clinically difficult. Herpes would have ideally responded to acyclovir. Sarcoidosis does not have genital and oral ulcerations.

Prostate cancer is the most common primary tumour that metastasises to the bone.

Most common tumours causing bone metastasis (in descending order):
1. Prostate (32%)
2. Breast (22%)
3. Kidneys (16%)
4. Lungs
5. Thyroid

Most common sites of bone metastasis (in descending order):
1. Spine
2. Pelvis
3. Ribs
4. Skull
5. Long bones