DENGUE and DENGUE HEMORRHAGIC FEVER

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Dengue fever also known as breakbone fever, is an infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle  and joint pains, and a characteristic morbilliform  skin rash. In a small proportion of cases the disease develops to the life-threatening dengue hemorrhagic fever and dengue shock syndrome.
Dengue is transmitted by several species of mosquito within the Aedes genus, principally A. aegypti. The virus exists in four different types; infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type is believed to increase the risk of severe complications. As there is no vaccine, prevention is sought by reducing the habitat and the number of mosquitoes and limiting exposure to bites.
People infected with dengue virus are commonly asymptomatic  or only have mild symptoms such as an uncomplicated fever.[1]Others have more severe illness, and in a small proportion it is life-threatening.The incubation period ranges from 3–14 days, but most often it is 4–7 days.
The febrile phase involves high fevers, frequently over 40 °C (104 °F) and is associated with generalized pain and a headache; this usually lasts two to seven days.Flushed skin and some small red spots called petechiae, which are caused by broken capillaries, may occur at this point,as may some mild bleeding from mucous membranes of the mouth and nose.
The critical phase, if it occurs, follows the resolution of the high fever and typically lasts one to two days.During this phase there may be significant fluid accumulation in the chest and abdominal cavity due to increased capillary permeability and leakage. This leads to depletion of fluid from the circulation and decreased blood supply to vital organs.During this phase, organ dysfunction and severe bleeding may occur.Shock and hemorrhage occur in less than 5% of all cases of dengue.


Congenital Malformations

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Congenital malformation is a condition which is present at the time of birth which varies from the standard presentation.
About 3% of newborns have a "major physical anomaly", meaning a physical anomaly that has cosmetic or functional significance.
The cause of 40-60% of congenital anomalies in humans is unknown.For 20-25% of anomalies there seems to be a "multifactorial" cause, meaning a complex interaction of multiple minor genetic anomalies with environmental risk factors. Another 10-13% of anomalies have a purely environmental cause (e.g. infections, illness, or drug abuse in the mother). Only 12-25% of anomalies have a purely genetic cause. Of these, the majority are chromosomal anomalies.
Genetic causes of congenital anomalies include inheritance of abnormal genes from the parents, as well as new mutations in one of the germ cells that gave rise to the fetus.
Environmental causes of congenital anomalies are referred to as teratogenic. These are generally problems with the mother's environment. Teratogens can include dietary deficiencies, toxins, or infections. For example, dietary deficiency of maternal folic acid is associated with spina bifida. Ingestion of harmful substances by the mother (e.g., alcohol, mercury, or prescription drugs such as phenytoin) can cause recognizable combinations of birth defects.
A limb anomaly is called a dysmelia. These include all forms of limbs anomalies, such as amelia, ectrodactyly, phocomelia, polymelia, polydactyly, syndactyly, polysyndactyly, oligodactyly, brachydactyly, achondroplasia, congenital aplasia or hypoplasia, amniotic band syndrome, and cleidocranial dysostosis.
Congenital anomalies of the heart include patent ductus arteriosus, atrial septal defect, ventricular septal defect, and tetralogy of fallot. Helen Taussig has been a major force in research on congenital anomalies of the heart.Congenital anomalies of the nervous system include neural tube defects such as spina bifida, meningocele, meningomyelocele, encephalocele and anencephaly. Other congenital anomalies of the nervous system include the Arnold-Chiari malformation, the Dandy-Walker malformation, hydrocephalus, microencephaly, megencephaly, lissencephaly, polymicrogyria, holoprosencephaly, and agenesis of the corpus callosum.
Congenital anomalies of the gastrointestinal system include numerous forms of stenosis and atresia, and imperforate.


Community-acquired Pneumonia

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Community-acquired pneumonia (CAP) is defined as an acute infection of the lung parenchyma accompanied by symptoms of acute illness, which is not acquired in hospitals or other long-term care facilities.One of the most common infectious diseases in the world.
12/1,000/year, about 600,000 hospitalization cases per year (in the U.S.).
The 6th leading cause of death in the U.S. (7th in Taiwan).
The most common cause of death due to infectious disease

Pathology
Primarily involve the interstitium or the alveoli.
Lobar pneumonia
bronchopneumonia
Necrotizing pneumonia
Lung abscess

Clinical Manifestations
Typical presentation
Cough (>90%)
Sudden onset of fever (80%)
SOB (66%)
Sputum production (66%)
Pleuritic pain (50%)
Signs of pulmonary consolidation (dullness, increased fremitus, egophony, bronchial breatathing sound, rales)

Atypical presentation
More gradual onset
Dry cough
Extrapulmonary symptoms
Legionella-CNS, heart, liver, GI and GU
M.pneumoniae- upper RT, GI, skin
The point that extrapulmonary organ involvement  separate atypical from typical pneumonia cannot be overemphasized!
Prompt and accurate diagnosis of CAP is important, since it is the only acute respiratory tract infection in which delayed  antibiotic treatment has been associated with increased risk of death.


Nonatherosclerotic Arterial Syndromes

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Polyarteritis Nodosa
More common in adult males
Spares the arterioles, capillaries, venules and glomeruli
Associated with hepatitis B antigenemia
Kidney (most frequently affected): 85%
Multiple intrarenal aneurysms
Aneurysms may thrombose and disappear
Appear in new locations

Clinical Manifestation
Abdominal pain
Systemic hypertension
Anorexia and weight loss
Abdominal distention
Hematemesis, melena
Jaundice
Painless hematuria
Peripheral neuropathy
Tender subcutaneous nodules
Gangrene of fingers and toes

Buerger’s Disease
The histopathological findings vary according to the duration of the disease. The findings are most likely to be diagnostic in the acute phase of the disease
The hallmark of the acute-phase lesion is an occlusive, highly cellular, inflammatory thrombus, with less inflammation in the walls of the blood vessels. Polymorphonuclear leukocytes, microabscesses, and multinucleated giant cells may be present

First reported by von Viniwalter in 1879 but first detailed description in 1908 by Leo Buerger.

Neonatal Congenital Heart Disease

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Congenital heart disease (CHD) affects ~1% of newborn infants and
accounts for ~10% of all congenital anomalies. Factors that ? risk for CHD include
maternal diabetes mellitus, familial presence of genetic syndromes (e.g., Noonan
syndrome), history of previous infant with CHD, and genetic factors that are just now
starting to be identified. The most common types of CHD are ventricular septal defect,
pulmonic stenosis, endocardial cushion defect, atrial septal defect and tetralogy of Fallot.
Although some infants with CHD do not have signs or symptoms in the newborn period,
others will need immediate intervention because of the severity of their disease. The
following discussion of CHD is not exhaustive. It is intended as a guide to the initial
management (diagnostic and therapeutic) of infants presenting with clinical findings
indicative or suggestive of CHD.


Amblyopia

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Unilateral or less commonly, bilateral reduction  of best corrected visual  acuity that can not be attributed directly to the effect of any structural abnormality of the eye or the posterior visual pathway. Defect of central vision
Resulting from one of following:
Strabismus
Anisometropia or high bilateral refractive  error (Isoametropia)
Visual deprivation

Prevalence: 2%-4% in the North American population
Commonly unilateral
Nearly all amblyopic visual loss is preventable or reversible with timely detection and appropriate intervention.
Children with amblyopia or at risk for amblyopia should be identified at a young age when the prognosis for successful treatment is best.
Role of screening is important
Amblyopia is primarily a defect of central vision.
There is a critical period for sensitivity in developing amblyopia.
The time necessary  for amblyopia to occur during critical period is shorter for stimulus deprivation than for strabismus or anisometropia.

Neurophysiology:
Cells of the primary visual cortex can completely lose their innate ability or show significant  functional  deficiencies
Abnormalities also occur in neurons in the lateral geniculate body
Evidence concerning involvement at the retinal level remains inconclusive

Classification:
Strabismus Amblyopia
Anisometropia  Amblyopia
Amblyopia Due to bilateral high refractive error (isometropia)
Deprivation  Amblyopia

Diagnosis
Characteristics of vision alone cannot be used to reliably differentiated amblyopia from other form of visual loss.
The crowding phenomenon is typical for amblyopia but not uniformly demonstrable.
Afferent pupillary defect are Characteristic of optic nerve disease but occasiinally appear to be present with amblyopia
Multiple assessment using a variety of tests or performed on different occasions are sometime required to make a final judgment concerning the presence and severity of amblyopia.

Binocular  fixation pattern:
It is a test for estimating the relative level of vision in the tow eyes for children with strabismus who are under the age of about 3.
This test is quite sensitive for detecting amblyopia but results can be falsely positive.
Showing a strong preference when sision is equal or nearly equal in the tow eyes, particularly with small angle strabismic deviations.

The modified Snellen technique directly measures acuity in children 3-6 years old.
Often, however, only isolated letters can be used, which may lead to under estimated amblyopia visual loss.
Croding bar may help alleviate this problem.

Treatment
Treatment of amblyopia  involves the following steps:
Eliminating (if possible) any obstacle to vision such as a cataract
Correcting refractive error
Forcing use of the poorer eye by limiting use of the better eye.

Eosinophilic Pneumonia

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Eosinophilic pneumonia – infiltration of lung parenchyma by eosinophilsEosinophil – a PMN that has granules that release major basic protein, eosinophil cationic protein, eosinophil-derived neurotoxin, eosinophilic peroxidase, arachidonic acid products, ROS
Pro-inflammatory cell that purported to attack parasites
Maturation regulated by IL-5 (differentiaion of eosinophil precursors), IL-3, and GM-CSF
Activation:  Eosinophils circulate in blood for 1 day, before being attracted into target tissues
Adhesion, attraction, diapedesis, chemotaxis
Helper T cells also regulate its activity, and it interacts with other myeloid cells (mast cells, fibroblasts, platelets, etc)

Characteristics
Cough, dyspnea, chest pain
Systemic sxs – fatigue, malaise, f/c/ns
PE – wheezing, crackles
CBC – eosinophilia ; elevated ESR
CXR – bilateral infiltrates
CT scan – ground glass opacity and/or consolidation
**BAL

eosinophilic pneumonia can be caused by:
Parasites
other infections (fungi, yeast)
ABPA
Drugs (esp NSAIDS and abx), toxin, radiation

Other lung dz assoc with eosinophilia:
Organizing pna, asthma, interstitial pna, lung transplant, langerhans cell granulomatosis, sarcoid, paraneoplastic eosinophilic pneumonia

Causes
Often there is no cause…
Idiopathic Eosinophilic Pneumonia
Chronic  vs.  Acute
Churg-Strauss syndrome
Hypereosinophilic syndrome
(all other organs can have eosinophilic infiltration too…ie esophagitis, vasculitis, fasciitis)

The eyes are frequently involved in diseases affecting the rest of the body
Ocular manifestations in certain multisystem disorders may offer a diagnostic clue
Sometime the eye involvement may be subtle enough to avoid detection unless the clinicians knows to look for it.

CORNEA RELATED TO SYSTEMIC DISEASES

DISEASES OF THE SKIN AND MUCOUS MEMBRANES
Atopic dermatitis, cicatricial pemphigoid, epidermolysis bullosa, erythema multiforme
DISORDERS OF COLLAGEN METABOLISM
Ehlers-Danlos syndrome, Marfan syndrome
COLLAGEN DISEASES
Dermatomyositis, periarteritis nodosa,rheumatoid arthritis, SLE
METABOLIC DISEASES
Amyloidosis, cystinosis, glycogen storage disease, gout, hyperlipidemia

CATARACT RELATED TO SYSTEMIC DISEASES
METABOLIC AND NUTRITION DISEASES
Aminoaciduria, diabetes mellitus, galactosemia, hypoparathyroidism, hypothyroidism, Wilson’s disease
INFECTIOUS DISEASES
Congenital HSV, syphylis, CMV, rubella
TOXIC SUBSTANCES

RETINA RELATED TO SYSTEMIC DISEASES
CARDIOVASCULAR DISEASES
Aortic arch syndrome, hypertension and toxaemia
of pregnancy, occlusive vascular disease
COLLAGEN DISEASES
Dermatomyosistis, periarteritis nodosa, SLE, temporal
arteritis, Wegener granulomatosis
ENDOCRINE DISEASES
Diabetes mellitus, Cushing syndrome,
hyperthyroidism, hypothyroidism, hypoparathyroidism
DISEASES OF THE SKIN AND MUCOUS MEMBRANES
Pseudoxanthoma elasticum
GASTROINTESTINAL AND NUTRITIONAL DISEASES
Regional enteritis, vitamin A deficiency
HEMATOLOGIC DISEASES
Anaemias, leukemias, sickle cell disease, thrombocytopenia
INFECTIOUS DISEASES
Candida retinitis, parasites, viral infections, tuberculosis, HIV, HSV, HZV, CMV
PHAKOMATOSES
METABOLIC DISEASES

THYROID EYE DISEASE (Graves’ ophthalmopathy)
The diagnosis may not be obvious, although it is quite common!
The severity of the eye changes does not always relate to the severity of the endocrine problem
It is not known why some patients with thyroid imbalance have eye features and others do not
The link is immunological, though the details are unclear
Often the eye features develop out of phase with the thyroid

PATHOGENESIS OF THYROID EYE DISEASE
The disease is not completely understood
The existing knowledge suggests that the disease is likely to be
autoimmune in origin and linked to autoimmune thyroid disease
Cigarette smoking is commoner among patients with Graves’
disease and smokers have a more severe ophthalmopathy
Orbital fibroblasts synthesize more glycosaminoglycans when
cultured under hypoxic conditions.
Glycosaminoglycans attract water ? swelling of extraocular
muscles
Infiltration of orbital tissue by immune cells ant their activation, with
subsequent cytokine release leads to local cell proliferation

OPHTHALMIC PROBLEMES IN NEUROLOGICAL DISORDERS
Multiple sclerosis -Optic (ON) neuritis is the most common manifestation (usually unilateral, but may be bilateral) and the presenting feature in about 25% of MS patients
About 60% of patients in the 20-40 years age group who present with ON will subsequently develop evidence of systemic demyelinisation!

Stroke - Homonymous hemianopia is the commonest finding
Often not recognized by the patient
Lesion within the optic path behind the chiasm (usually in the radiation passing through temporal and parietal areas to the occipital cortex)
Occlusion of the vertebrobasilar circulation may cause bilateral cortical lesions and marked visual disability
Many patients have reading difficulties

Intracranial tumors
Benign intracranial hypertension
Facial palsy

Congenital Viral Infections

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Rubella
Characteristics of Rubella
Member of the togavirus family
ssRNA positive-sense enveloped virus
Icosahedral capsid
Spread by respiratory droplets and transplacental.
In the prevaccination era, 80% of women were already infected by childbearing age.

Risks of rubella infection during pregnancy
Preconception        minimal risk                           
0-12 weeks           100% risk of fetus being congenitally infected resulting in major  congenital abnormalities.Spontaneous abortion occurs in 20% of cases.            
13-16 weeks          deafness and retinopathy 15%           
after 16 weeks       normal  development, slight risk of  deafness and retinopathy

Cytomegalovirus
Member of the herpesvirus
Icosahedral virus
Lipoprotein envelope, derived from the nuclear membrane
Genome: linear, ds DNA
Replicate in the nucleus
Single serotype
Humans are the natural hosts
Giant cell formation (Cytomegalo)

Primary  infection  usually asymptomatic. Virus  then  becomes latent and is reactivated from time to time.
Transmitted  by  infected saliva, breast  milk,  sexually, transplacental and through infected blood and organ transplantation.
60% of the population eventually become infected. In some developing countries, the figure is up to 95%.

Neonatal Herpes Simplex
The baby is usually infected perinatally during passage through the birth canal.
Premature rupturing of the membranes is a well recognized risk factor.
The risk of perinatal transmission is greatest when there is a florid primary infection in the mother.
There is an appreciably smaller risk from recurrent lesions in the mother, probably because of the lower viral load and the presence of specific antibody. 
The baby may also be infected from other sources such as oral lesions from the mother or a herpetic whitlow in a nurse.

Niemann-Pick Disease

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Condition involving the breakdown and use of fats and cholesterol in the body
Harmful amounts of lipids accumulate in the spleen, liver, lungs, bone marrow, and brain
Autosomal recessive pattern of inheritance (two copies of the gene must be present)
Four variants: A, B, C1, and C2
Clinical feature include: severe liver disease, breathing difficulties, developmental delay, seizures, increased muscle tone, lack of coordination, problems feeding, and inability to move eyes vertically.
No treatment

Types A and B: mutated SMPD1 gene
SMPD gene carries instructions for cells to produce, sphingomyelinase, which processes lipids.
Mutations lead to deficiency of sphingomyelinase and accumulations of cholesterol and lipids.
Types C1 and C2: mutated NCP1 or NCP2 gene
NCP1 gene produces a protein involved in the movement of cholesterol and lipids within a cell.
May be a cholesterol pump, which is why its mutation leads to the buildup of lipids and cholesterol in the cell membrane.
Plays a critical role in regulation of intracellular cholesterol trafficking
NCP2 gene produces protein that binds and transports cholesterol (not fully understood).

NCP1 v. NCP2 Gene
95% of patients have mutations in the NPC1 gene
Mapped at chromosome 18q11
NPC1 encodes a 1278 amino acid glycoprotein with 13 transmembrane domains.
Remainder of patients have mutations in the NPC2 gene (or HE1 gene)
Mapped at chromosome 14q24.3
Encodes a small soluble lysosomal protein involved in cholesterol binding.
Both genes have identical biochemical patterns suggesting that the two proteins function together in cellular transport of cholesterol, glycolipids, etc.
Work together to facilitate the intracellular transport of lipids from the lysosome to other cellular sites.
Their precise functions and relationship remain unclear and are currently the subject of intense investigation.


Acute Appendicitis

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The incidence of appendectomy appears to be declining due to more accurate preoperative diagnosis.
Despite newer imaging techniques, acute appendicitis can be very difficult to diagnose.

Acute appendicitis is thought to begin with obstruction of the lumen
Obstruction can result from food matter, adhesions, or lymphoid hyperplasia
Mucosal secretions continue to increase intraluminal pressure
Eventually the pressure exceeds capillary perfusion pressure and venous and lymphatic drainage are obstructed.
With vascular compromise, epithelial mucosa breaks down and bacterial invasion by bowel flora occurs.
Increased pressure also leads to arterial stasis and tissue infarction
End result is perforation and spillage of infected appendiceal contents into the peritoneum
Initial luminal distention triggers visceral afferent pain fibers, which enter at the 10th thoracic vertebral level.
This pain is generally vague and poorly localized.
Pain is typically felt in the periumbilical or epigastric area.
As inflammation continues, the serosa and adjacent structures become inflamed
This triggers somatic pain fibers, innervating the peritoneal structures.
Typically causing pain in the RLQ
The change in stimulation form visceral to somatic pain fibers explains the classic migration of pain in the periumbilical area to the RLQ seen with acute appendicitis.
In some males, retroileal appendicitis can irritate the ureter and cause testicular pain.
Pelvic appendix may irritate the bladder or rectum causing suprapubic pain, pain with urination, or feeling the need to defecate
Multiple anatomic variations explain the difficulty in diagnosing appendicitis.


Anterior ischemic optic neuropathy

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Anterior ischemic optic neuropathy (AION) is a medical condition involving loss of vision due to damage to the optic nerve  from insufficient blood supply. AION is generally divided into two types: arteritic AION (or AAION) and non-arteritic AION (NAION or simply AION). AAION is due to temporal arteritis (also called giant cell arteritis), an inflammatory disease of big-sized blood vessels that occurs especially with advancing age. In contrast, NAION results from the coincidence of cardiovascular risk factors in a patient with "crowded" optic discs. Non-arteritic AION is more common than AAION and usually occurs in a slightly younger group than AAION.NAION typically presents suddenly and upon awakening. The patient notes seeing poorly in one eye. Vision in that eye is obscured by a dark shadow, often involving just the upper or lower half of vision, usually the area towards the nose. There is no pain. Since arteritic AION is similar in presentation to non-arteritic AION, patients over the age of 50 diagnosed with NAION must be evaluated to exclude AAION (symptoms: painful jaw muscle spasms, scalp tenderness, unintentional weight loss, fatigue, myalgias and loss of appetite).


Seizures

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An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain".Seizure types are organized according to whether the source of the seizure within the brain is localized (partial or focal onset seizures) or distributed (generalized seizures). Partial seizures are further divided on the extent to which consciousness is affected (simple partial seizures and complex partial seizures). If consciousness is unaffected, then it is a simple partial seizure; otherwise it is a complex partial seizure. A partial seizure may spread within the brain—a process known as secondary generalization. Generalized seizures are divided according to the effect on the body, but all involve loss of consciousness. These include absence, myoclonic, clonic, tonic, tonic–clonic, and atonic seizures. The signs and symptoms of seizures vary depending on the type.Seizures may cause involuntary changes in body movement or function, sensation, awareness, or behavior. Seizures are often associated with a sudden and involuntary contraction of a group of muscles and loss of consciousness. However, a seizure can also be as subtle as a fleeting numbness of a part of the body, a brief or long term loss of memory, visual changes, sensing/discharging of an unpleasant odor, a strange epigastric sensation, or a sensation of fear and total state of confusion. A seizure can last from a few seconds to status epilepticus, a continuous group of seizures that is often life-threatening without immediate intervention. Therefore seizures are typically classified as motor, sensory, autonomic, emotional  or cognitive. After the active portion of a seizure, there is typically a period referred to as postictal before a normal level of consciousness returns.
In some cases, the full onset of a seizure event is preceded by some of the sensations described above, called vertiginous epilepsy. These sensations can serve as a warning to that a generalized tonic–clonic seizure is about to occur. These warning sensations are cumulatively called an aura and are due to a focal seizure.
It is important to distinguish primary epileptic seizures from secondary causes. Blood tests, lumbar puncture or toxicology screening can be helpful in specific circumstances suggestive of an underlying cause like alcohol or benzodiazepine withdrawal, meningitis or drug overdose, but there is insufficient evidence to support their routine use in the work-up of an adult with an apparently unprovoked first seizure.

Tonsillitis

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Sore throat and temperatureMembrane over the tonsils and enlarged and sore lymph glands
General symptoms (headache, abdominal pain particularly in children, nausea, and vomiting)
rapid onset of symptoms
Cough and rhinitis are evidence against group A streptococcal  infection
Aetiology of tonsillitis
significant causative agents:
beta-haemolytic streptococci (groups A, C and G)
adenoviruses
Epstein-Barr virus
other causative agents:
various bacteria and viruses which are rare and with little significance on treatment

Diagnosis of tonsillitis
Group A streptococcal infection cannot be reliably diagnosed on clinical symptoms and findings
Antibiotic treatment should be based on isolation of beta-haemolytic streptococci from the throat
The main bacteriological investigation is a throat swab (the only acceptable one during an epidemic)
Use of “on the spot” testing methods is justifiable only if results are available whilst the patient waits
a positive “on the spot” test result is reliable – a negative one should be counterchecked by bacterial culture

Antimicrobial therapy of tonsillitis
First choice:
    Penicillin V 1-1.5 mega units twice daily for 10 days (more relapses with shorter treatment period (A))
Second choice:
first generation cephalosporins (cefalexin 750 mg twice daily or cefadroxil 1g daily) or
procaine penicillin 1.2 – 1.5 mega units daily
    for 10 days
macrolides – with caution (if local resistance patterns accept their use or they are indicated by sensitivity testing)

Dural Arteriovenous malformation

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Plexiform arteriovenous fistulae with the nidus of AV shunting totally within the dural leaflet.Fed by pachymeningeal arteries or dural branches of brain or scalp arteries.
Drained by adjacent dural sinuses, or retrograde through leptomeningeal veins. 

DAVM Pathoanatomy and Pathophysiology
Venous hypertension in dural leaflet
Dural sinus outflow restriction/occlusion
Retrograde (leptomeningeal) venous drainage
Secondary sequelae of parenchymal venous hypertension

DAVM Pathoetiology
Sinus occlusion (congenital or acquired)
Trauma (blunt, penetrating, surgical)
Hypercoagulable states (including neoplasia, inflammation, etc…)

DAVM Natural History
Clinical presentation related to lesion location
Aggressive symptoms (hemorrhage, focal neurologic deficits, seizures, etc.) solely related to leptomeningeal venous

drainage
Progression, spontaneous resolution highly unpredictable (cavernous sinus DAVMs notable for spontaneous resolution)

DAVM Management Strategies
Expectant and
symptomatic treatment--
surveillance for progression,
aggressive features
Transarterial embolization-- palliative, preparatory, definitive (slow polymerization)
Transvenous embolization-- pathologic segment
Surgery-- disconnection of leptomeningeal venous drainage, coagulation/excision/isolation of pathologic dural leaflet/sinus segment
Stereotactic Radiosurgery-- 18-24 months delayed effect (interval risk)

Vasculitis Review

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Vasculitis: Inflammation of blood vessels causing vessel and tissue damage
Classification is according to the Chapel Hill Consensus Conference of 1994
Large-vessel vasculitides
Medium-vessel vasculitides
Small-vessel vasculitides (many)
ANCA-associated
Non-ANCA-associated (many)

Large Vessel Vasculitides
Giant cell arteritis (formerly called temporal arteritis)
Takayasu’s arteritis
Distinguished only by age of pt > or < 50 yo
Both involve the aorta and its primary branches

Medium Vessel Vasculitides
Polyarteritis nodosa (PAN)
Buerger’s = Thromboangiitis obliterans
Kawasaki’s disease = Mucocutaneous LN syndrome

Small Vessel Vasculitides
ANCA-associated
Wegener’s granulomatosis (WG)
Churg-Strauss syndrome (CSS)
Microscopic polyangiitis (MPA) – no granulomas
Drug-induced ANCA vasculitis
Idiopathic

Non-ANCA-associated
Infectious (Hep B, Hep C, HIV, Parvo, CMV, EBV)
CVD-related (RA, SLE, Bechet’s, Sjogren’s)
Drug-related (cutaneous leukocytoclastic angiitis)
Henoch-Schonlein Purpura (HSP) – IgA deposits
Goodpasture’s disease
Cryoglobulinemia
IBD-related
Urticarial vasculitis
Paraneoplastic vasculitis

Retropharyngeal abscesses(RPA) are most commonly seen in infants and young children.It is an abscess located in the tissues in the back of the throat behind the posterior pharyngeal wall (the retropharyngeal space). Because RPA's typically occur in deep tissue, they are difficult to diagnose by physical examination alone.
RPA is usually caused by a bacterial infection originating from the nasopharynx, tonsils, sinuses, adenoids or middle ear. Any Upper Respiratory Infection (URI) can be a cause. RPA can also result from a direct infection due to penetrating injury or a foreign body.
Symptoms may include stiff neck (limited neck mobility or torticollis), some form of palpable neck pain , malaise, difficulty swallowing, fever, stridor, drooling, or enlarged cervical lymph nodes.RPA can lead to airway obstruction or sepsis  - both life-threatening emergencies.Fatalities normally occur from patients not receiving treatment immediately and suffocating prior to knowing that anything serious was wrong. CT is the definitive diagnostic test.X ray of the neck 80% of the time shows swelling of the retropharyngeal space. If the retropharyngeal space is more than half of the size of the C2 vertebra, it may indicate retropharyngeal abscess.
RPA's frequently require surgical intervention. A tonsillectomy approach is typically used to access/drain the abscess, and the outcome is usually positive. In complex cases, tracheotomy may be required to prevent upper airway obstruction caused by edema in the neck.Antibiotics are also given.


Childhood Stroke

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The cause of stroke in children is unknown in one-third of cases.  The most common reported risk factors for stroke in children include cardiac disorders, sickle cell disease, coagulation disorders, arterial dissection, moya moya, infection, and other rare genetic disorders.Cardiac disorders  are the most common cause of ischemic stroke in children and account for up to 50% of strokes in case series. The risk of stroke in children with congenital heart disease is related to the abnormality, diagnostic and surgical procedures, and associated genetic or acquired factors that predispose children to thrombosis. Cardiac disorders can lead to the development of intracardiac thrombi that may embolize to the brain or can lead to thrombosis in cyanotic patients with anemia.
Blood disorders  are the second most common cause of stroke in children.  Several blood disorders associated with stroke in children include:
    *Sickle cell disease is the most common cause of stroke in African American children. The recurrence risk for this group is very high.
    *Coagulation disorders can lead to a tendency to clot or hemorrhage.  The risk of stroke seems to be greatest among children who have a combination of genetic factors. Multiple factors are associated with a heightened risk of thrombosis and recurrence.
Vascular Disorders -  23% of children with arterial ischemic stroke in one study
    *Moya-Moya disease is a chronic non-inflammatory occlusive intracranial vasculopathy of unknown cause. 
    *Arterial dissection, a common cause of stroke in children, is usually due to trauma.

Causes of Hemorrhagic Stroke in a child
Vascular malformations, blood disorders and malignancy  have been identified as risk factors in children who have a hemorrhagic stroke.
    *Vascular malformations, including arteriovenous malformations (AVMs), aneurysms, and cavernous malformations are the most common risk factors for children with hemorrhagic stroke.
    *Blood disorders, including thrombocytopenia, leukemia, SCD, and coagulopathies have been identified in some children with hemorrhagic stroke.  Acquired thrombocytopenia and coagulopathies were the most common blood risk factors in one report.
    *Intracranial tumors, including medulloblastomas and primitive neuroectodermal tumors, have been identified in cases of children who have a hemorrhagic stroke.


Zollinger-Ellison Syndrome (Gastrinoma)

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Zollinger–Ellison syndrome is a triad of gastric acid hypersecretion, severe peptic ulceration, and non-beta cell islet tumor of pancreas (gastrinoma). In this syndrome increased levels of the hormone gastrin are produced, causing the stomach  to produce excess hydrochloric acid. Often the cause is a tumor (gastrinoma) of the duodenum or pancreas producing the hormone gastrin. Gastrin then causes an excessive production of acid which can lead to peptic ulcers in almost 95% of patients.Gastrinomas may occur as single tumors or as multiple, small tumors. About one-half to two-thirds of single gastrinomas are malignant tumors that most commonly spread to the liver and lymph nodes near the pancreas and small bowel. Nearly 25 percent of patients with gastrinomas have multiple tumors as part of a condition called multiple endocrine neoplasia type I (MEN I). MEN I patients have tumors in their pituitary gland and parathyroid glands in addition to tumors of the pancreas.Clinical suspicion of Zollinger–Ellison syndrome may be aroused when the above symptoms prove resistant to treatment, when the symptoms are especially suggestive of the syndrome, or endoscopy is suggestive. The diagnosis of Zollinger–Ellison syndrome is made by several laboratory tests and imaging studies.
    * Secretin stimulation test, which measures evoked gastrin levels
    * Fasting gastrin levels, on at least three separate occasions
    * Gastric acid secretion and pH

Proton pump inhibitors  (such as omeprazole  and lansoprazole) and histamine H2-receptor antagonists (such as famotidine and ranitidine) are used to slow down acid secretion. Cure is only possible if the tumors are surgically removed, or treated with chemotherapy.

Severe sepsis – defined by the presence of both infection and a systemic inflammatory response which produce organ failure 750,000 Americans suffer from it each year
It has a High mortality rate
Incidence is rising and is expected to exceed 1 million cases by 2010

Physiologic Derangements Occurring in Severe Sepsis
Overproduction of inflammatory mediators
IL-1, IL-6, TNF
Unopposed microthrombi formation
Result – organ damage
Low oxygen perfusion to major organs
Cytokine-induced apoptosis

General Facts about Protein C
Made by the liver and circulates as a zymogen
Activated by thrombomodulin receptor
Protein C levels are drastically reduced in states of sepsis
Thrombomodulin receptor down regulation occurs in severe sepsis

Mechanism of Action for rhAPC
Drastically reduces production of thrombin
Reduces levels of PAI-1, enhancing tPA’s actions
Anti-inflammatory mechanisms
Reduces cytokine elaboration
Decreases oxidative damage to endothelial cells
Blocks endothelial cell apoptosis

Contraindications
Active internal bleeding
Hx of hemorrhagic stroke in last 3 mths
Hx of intracranial/ intraspinal surgery or severe head trauma in last 2 mths
Trauma with increased risk of life-threatening bleeding
Epidural catheter
Intracranial neoplasm
Mass lesion
Cerebral herniation

GOALS OF FRACTURE TREATMENT
Restore the patient to optimal functional state
Prevent fracture and soft-tissue complications
Get the fracture to heal, and in a position which will produce optimal functional recovery
Rehabilitate the patient as early as possible

HOW FRACTURES HEAL
In nature
 Regeneration vs repair
 Three phases of healing by callus
 Rapid process, rehabilitation slow, low risk
With operative intervention (reduction + compression)
 Primary bone healing
 Slow process, rehabilitation rapid, high risk
With operative intervention (nailing or external fixation)
 Healing by callus
 Rapid process, rehabilitation rapid, lesser risk

TREATING THE FRACTURE
Does the fracture require reduction?
 Is it displaced?
 Does it need to be reduced? (e.g. clavicle, ribs, MT’s)

How accurate a reduction do we need?
 alignment without angulation (closed reduction - e.g. wrist)
 anatomic (open reduction - e.g. adult forearm )

How are we going to hold the reduction?
 Semi-rigid (Plaster)
 Rigid (Internal fixation)

What treatment plan will we follow?
 When can the patient load the injured limb?
 When can the patient be allowed to move the joints?
 How long will we have to immobilise the fracture for?


Trigerminal Neuralgia

Posted by e-Medical PPT

Trigeminal neuralgia is a neuropathic disorder characterized by episodes of intense pain in the face, originating from the trigeminal nerve. One, two, or all three branches of the nerve may be affected. The disorder is characterized by episodes of intense facial pain that last from a few seconds to several minutes or hours. The episodes of intense pain may occur paroxysmally. To describe the pain sensation, patients may describe a trigger area on the face so sensitive that touching or even air currents can trigger an episode; however, in many patients the pain is generated spontaneously without any apparent stimulation. It affects lifestyle as it can be triggered by common activities such as eating, talking, shaving and brushing teeth. Wind, high pitched sounds, loud noises such as concerts or crowds, chewing, and talking can aggravate the condition in many patients.
There is also a variant of trigeminal neuralgia called atypical trigeminal neuralgia. This variant is also called "trigeminal neuralgia, type 2",based on a recent classification of facial pain. In some cases of atypical trigeminal neuralgia the sufferer experiences a severe, relentless underlying pain similar to a migraine in addition to the stabbing shock-like pains.
Several theories exist to explain the possible causes of this pain syndrome. It was once believed that the nerve was compressed in the opening from the inside to the outside of the skull; but newer leading research indicates that it is an enlarged blood vessel - possibly the superior cerebellar artery - compressing or throbbing against the microvasculature of the trigeminal nerve near its connection with the pons. Such a compression can injure the nerve's protective myelin sheath and cause erratic and hyperactive functioning of the nerve. This can lead to pain attacks at the slightest stimulation of any area served by the nerve as well as hinder the nerve's ability to shut off the pain signals after the stimulation ends.
Anticonvulsants are a common treatment strategy for trigeminal neuralgia. Carbamazepine is the first line drug; second line drugs include baclofen, lamotrigine, oxcarbazepine, phenytoin, gabapentin, and sodium valproate. Uncontrolled trials have suggested that clonazepam and lidocaine may be effective.Low doses of some antidepressants such as amitriptyline are thought to be effective in treating neuropathic pain.


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