Property:Explanation
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The hallmark of rotator cuff injuries is the combination of pain that accompanies shoulder weakness. The patient in this vignette has injured his infraspinatus muscle as a result of large rotational forces during pitching. The infraspinatus muscle is a rotator cuff muscle that is responsible for lateral rotation of the arm. It is innervated by the suprascapular nerve, which originates from the superior trunk of the brachial plexus (C5-C6). Injuries to the infraspinatus muscle and tendon are common among individuals who perform pitching sports. Although injury to the muscle is immediate, pain becomes more apparent when the muscle activity rests a few hours following the initial insult. Because the infraspinatus muscle is responsible for lateral rotation exclusively, attempt to laterally rotate the arm against resistance typically elicits pain on physical examination. In contrast, other maneuvers that do not involve lateral rotation of the arm do not cause contraction of the infraspinatus muscle and thus do not elicit pain. MRI of the shoulder is often required to confirm the suspicion of infraspinatus muscle or tendon injury.
The rotator cuff is composed of 4 muscles: Subscapularis, Infraspinatus, Teres minor, Suprascapularis (SITS). When patients are suspected to have rotator cuff injuries, provocative testing may be performed to further localize the injury. Although rotator cuff injuries often require MRI to identify the location of the injury, clinical tests may be helpful to evaluate for specific rotator cuff injuries:
* Empty can test: Patient pushes against physician resistance while arm in 90 degree abduction with thumb pointing down. Pain suggests tear to the supraspinatus muscle or tendon.<br>
* Full can test: Patient pushes against physician resistance while arm abducted 45-90 degrees and shoulder externally rotated. Pain suggests tear to the supraspinatus muscle or tendon.<br>
* Neer's test: Patient places the arm in forced flexion with arm in full pronation. Pain suggests subacromial impingement due to pinching under the coracoacromial arch.<br>
* Hawkin's test: Patient elevates the arm forward to 90 degrees while internally rotating the shoulder. Pain suggests subacromial impingement or rotator cuff tendonitis.<br>
* Drop-arm test: Patient passively abducts involved shoulder, then slowly lowers the arm to the waist. Sudden arm drop suggests supraspinatus injury.<br>
* Cross-arm test: Patient raises arm to 90 degrees and adducts forcibly the acromion into distal end of clavicle. Pain suggests acromioclavicular joint involvement.<br><br/>
'''Educational Objective:''' The infraspinatus is a muscle of the rotator cuff that is responsible for lateral rotation of the arm. Injuries of the infraspiantus muscle and its tendon are common among baseball pitchers.<br/>
'''References:''' Woodward TW, Best TM. The painful shoulder: part I. clinical evaluation. Am Fam Physician. 2000;61(10):3079-88.<br>
First Aid 2014 page 411
Panic disorder is an anxiety disorder characterized by episodes or attacks of fear that are associated with other somatic and cognitive symptoms. Panic disorder features a sudden unexpected onset and spontaneous resolution. It commonly affects young women before the age of 25 years. Patients may be otherwise healthy with no past medical history or risk factors, and they tend to have an unremarkable physical examination in the physician's clinic while not experiencing an attack. Common manifestations of panic attacks include symptoms of multiple organ systems and anatomic locations, such as chest pain, palpitations, dyspnea, bolus sensation and choking sensation, abdominal pains, feeling of unreality and impending doom, numbness of the extremities, diaphoresis, hot flashes, chills, and shaking. During an attack, physical examination may only be remarkable for tachycardia and tachypnea. Panic disorder may significantly affect a patient' quality of life; and patients are often too afraid of experiencing future attacks. The diagnosis of panic disorder necessitates that the patient experiences symptoms for more than 1 month.
Acutely, patients may be administered benzodiazepines to relieve the anxiety. However, benzodiazepines are not adequate long-term therapeutic options due to the risk of dependence. Thus, the mainstay of long-term pharmacological therapy for patients with panic disorder is selective serotonin reuptake inhibitors (SSRI), such as paroxetine. Although SSRI may require a few weeks to demonstrate efficacy, the majority of patients eventually report significant improvement with SSRI administration. Other non-pharmacological approaches include regular exercise, sufficient sleep, and avoidance of stimulants, alcohol, and caffeine intake.<br/>
'''Educational Objective:''' Panic disorder is an anxiety disorder characterized by episodes or attacks of fear that are associated with other somatic and cognitive symptoms. For the diagnosis to be made, the symptoms should persist for at least 1 month. The mainstay of long-term pharmacological therapy for patients with panic disorder is selective serotonin reuptake inhibitors (SSRI)<br/>
'''References:''' Kircanski K, Craske MG, Epstein AM, et al. Subtypes of panic attacks: a critical review of the empirical literature. Depress Anxiety. 2009;26(10):878-87.<br>
First Aid 2014 page 508
This patient has dyslipidemia coupled with a history of diabetes mellitus which increases her risk for coronary artery disease. Low HDL cholesterol has been linked to poor cardiovascular outcomes.
According to ATP III guidelines, the primary target in a patient with low HDL cholesterol (less than 40 mg/dl) is achieving the LDL goal i.e. LDL-C<130 mg/dl for this patient. LDL-C can be calculated using the formula:
LDL-C = Total cholesterol – HDL-C – Triglyceride/5
LDL-C = 239 mg/dl.
The next step in the management of this patient is by addressing the high LDL cholesterol with a statin, which has been proven to be the most effective in lowering serum LDL cholesterol.
<table cellpadding="3" cellspacing="0" border="1" align="center">
<tr>
<td bgcolor="#cccccc">'''Risk Category'''
</td>
<td bgcolor="#cccccc">'''Non-HDL Goal (mg/dl)'''
</td>
<td bgcolor="#cccccc">'''LDL Goal (mg/dl)'''
</td>
</tr>
<tr>
<td>0 to 1 CHD risk factor
</td>
<td><190
</td>
<td><160
</td>
</tr>
<tr>
<td>2 or more CHD risk factors (10-year risk for CHD ≤20%)
</td>
<td><160
</td>
<td><130
</td>
</tr>
<tr>
<td>CHD and CHD risk equivalent (10-year risk for CHD >20%)
</td>
<td><130
</td>
<td><100
</td>
</tr>
</table>
'''Educational Objective''': In a patient with dyslipidemia and a CHD risk equivalent (diabetes mellitus), the following represents the management plan according to the ATP III guidelines:
1) LDL cholesterol is the primary target. This is best achieved with statins.
2) If the serum triglyceride is between 200 and 499 mg/dl, then achieve non-HDL cholesterol goal first. Non-HDL cholesterol is calculated by subtracting HDL-C from the total cholesterol i.e. Non-HDL-C = TC – HDL-C. Non-HDL cholesterol is the summation of VLDL and LDL.
Source: http://www.wikidoc.org/index.php/High_density_lipoprotein_medical_therapy<br/>
'''Educational Objective:''' <br/>
'''References:'''
Dandy-Walker malformation (DWM) is a heterogeneous group of disorders characterized by the triad: hydrocephalus, partial or complete absence of the cerebellar vermis, and posterior fossa cyst with enlargement of the 4th ventricle. DWM has multiple modes of transmission, including autosomal dominant, autosomal recessive, and X-linked recessive transmission. Although the disease may be isolated, it may be part of a malformation syndrome such as Meckel syndrome, Joubert syndrome, G syndrome, CDG syndrome, and Aicardi syndrome. DWM is also associated with congenital heart disease, cleft lip/palate, and classically, neural tube defects including spina bifida. In the vignette, the patient is most likely diagnosed with DWM with associated spina bifida. Patients with DWM usually present within the first year of life with neurological complaints, such as convulsions, or failure to meet developmental milestones. Dandy-Walker malformation is most commonly caused by the agenesis of the cerebellar vermis. Agenesis is defined as an error in organ morphogenesis that results in absence of both primordial tissue.<br/>
'''Educational Objective:''' Dandy-Walker is characterized by agenesis of cerebellar vermis. Agenesis is defined as absence of organ due to absence of primordial tissue.<br/>
'''References:''' First Aid 2014 page 445 +
HIV protease, a product of the HIV ''Pol'' gene is an important component of the HIV life-cycle that cleaves synthesized polyproteins into structural and functional protein products. Without HIV protease, virions would be unable to mature. HIV protease inhibitors (PI) act by inhibiting this enzyme and stopping peptide cleavage. HAART therapy usually consists of a triple regimen including at least 2 nucleoside reverse transcriptase inhibitors (NRTIs) combined with one of the following: PI, integrase inhibitor, or non-nucleoside reverse transcriptase inhibitors (NNRTI). PI monotherapy is associated with mutations in the HIV genome leading to resistance to the medication. The mutation should occur in the Pol gene in order to create an HIV protease resistant to PI.<br/>
'''Educational Objective:''' HIV protease is targeted by protease inhibitors with resistance conferred by mutation in the Pol gene coding for a new HIV protease.<br/>
'''References:''' Molla A, Korneyeva M, Gao Q, et al. Ordered accumulation of mutations in HIV protease confers resistance to ritonavir. Nat Med. 1996;2(7):760-6. +
Seventy to eighty percent of patients with blunt renal trauma are successfully treated nonsurgically. Bed rest may reduce the likelihood of secondary hemorrhage; antibiotics may reduce the chance of development of infection in a perirenal hematoma. Fever, increasing leukocytosis, evidence of secondary hemorrhage, and persistent or increasing pain and tenderness in the region of the kidney are the indicators of failure of conservative treatment.
'''Educational Objective:'''
Conservative treatment with bed rest and antibiotics is indicated in patients with blunt renal trauma. Failure of the conservative treatment may indicate the necessity for a surgical intervention.<br/>
'''Educational Objective:''' <br/>
'''References:''' +
Barrett's esophagus is a form of glandular metaplasia, defined as loss of the normal non-keratinized stratified squamous epithelium of the distal esophagus. Instead, the epithelium is replaced by abnormal glandular columnar epithelium which resembles that of the duodenum. Barrett's esophagus is a premalignant lesion among the majority of patients with esophageal adenocarcinoma. The definitive diagnosis of Barrett's esophagus is based on endoscopic biopsy of the distal esophagus. Barrett's esophagus is a clinical concern due to its predisposition to adenocarcinoma of the esophagus. Barrett's esophagus is a common complication of long-standing gastroesophageal reflux disease (GERD). In addition to GERD and GERD symptoms, the most important risk factors for the development of Barrett's esophagus include obesity, advanced age, male sex, and white race. Patients with Barrett's esophagus are approximately 30-40 times more likely to develop esophageal adenocarcinoma compared to patients with no Barrett's esophagus, which justifies why close follow-up and multiple endoscopies to screen for dysplasia and adenocarcinoma are indicated once the diagnosis is made. Treatment of Barrett's esophagus and prevention of dysplasia are generally by aggressive management of GERD using acid-suppressive therapy.<br/>
'''Educational Objective:''' Barrett's esophagus is a premalignant lesion of the distal esophagus. It is a form of metaplasia, whereby normal esophageal nonkeratinized stratified squamous epithelium is replaced by glandular columnar epithelium.<br/>
'''References:''' Sharma P. Barrett's esophagus. N Engl J Med. 2009;361:2548-56.<br>
Sjogren RW, Johnson LF. Barrett's esophagus: a review. Am J of Med. 1983; 74(2):313-321.<br>
First Aid 2014 page 350 +
Multiple sclerosis (MS) is a chronic autoimmune disorder of the CNS. MS is a demyelinating inflammatory disease that usually involves the white matter of the cervical region. It features asymmetric lesions due to the autoimmune myelin and axonal destruction. Although the etiology of the disease is still unknown, it is believed that MS may be caused by environmental triggers in genetically predisposed individuals. It commonly affects women aged between 20-45 years. In the majority of cases, manifestations of MS are reversible neurological deficits in the early stages of the diseases with progression to irreversible deterioration. The disease course may be any of 4 types: relapsing remitting (most common) characterized by flare-ups followed by period of remission, secondary progressive characterized by an initial relapsing remitting course that transforms into continuous deterioration in later stages, primary progressive characterized by early continuous deterioration, and finally progressive-remitting course characterized by a continuous deterioration with intermittent flare-ups in the absence of remission periods. MS is generally suspected by history and physical examination. Classical signs and symptoms include scanning speech, loss of vision due to optic neuritis, diplopia, and bilateral trigeminal neuralgia. Other common signs and symptoms include spasticity of the extremities, paresthesias, dysesthesias, ataxia, vertigo, and urinary dysfunction. The diagnosis is often confirmed by brain MRI that shows multiple periventricular plaques at various levels, and lumbar puncture that shows evidence of inflammation and oligoclonal bands. Therapy of MS aims to decrease the intensity and the frequency of acute flare-ups and to improve patient quality of life. Pharmacological therapy of MS includes beta-interferons (naturally-occurring cytokines), glatiramer acetate (a synthesized copolymer polypeptide), mitoxantrone (a synthetic antineoplastic agent), natalizumab (a recombinant humanized immunoglobulin monoclonal antibody), and fingolimood (a sphingosine-1-phosphate receptor modulator).<br/>
'''Educational Objective:''' Multiple sclerosis is characterized by patchy asymmetric lesions of the white matter in the central nervous system.<br/>
'''References:''' Goldernberg MM. Multiple sclerosis review. P T. 37(3):175-84.<br>
First Aid 2014 page 484
Amyotrophic lateral sclerosis (ALS or Lou Gehrig disease) is a progressive neurodegenerative disorder of the central and peripheral motor systems. The hallmark of ALS is the presence of signs and symptoms that suggest the simultaneous involvement of upper motor and lower motor neuron disease. Notably, ALS does not affect the sensory, cognitive, or oculomotor nervous systems. Manifestations of ALS vary, and symptoms may suggest prognosis and progression. Presentations may have a limb-onset, bulbar-onset, or less commonly pure upper/lower motor neuron involvement. Patients may develop of limb spasticity, weakness, fasciculations, wasting, and hyperreflexia. In addition, bulbar symptoms may include spastic dysarthria that causes distorted nasal speech, flaccid dysarthria, brisk gag/jaw jerks, or dysphagia. This patient has signs and symptoms consistent with ALS. Fasciculations and muscle atrophy are signs of lower motor neuron involvement, whereas rigidity, hyperreflexia marked by a positive Babinski test, and stuttered speech are signs of upper motor neuron involvement. Weakness in his extremities may be signs of either upper or lower motor neuron involvement. The cause of ALS is unknown, but some have speculated a role of superoxide dismutase 1 defects in the pathogenesis of the disease. The majority of patients with ALS die within 30 months of onset of symptoms, and less than 20% survive beyond 5 years. The management of ALS is very limited, riluzole has demonstrated modest improvement in survival among ALS patients.<br/>
'''Educational Objective:''' ALS is a progressive neurodegenerative disorder characterized by involvement of upper and lower motor neuron systems. In the spinal cord, ALS is caused by lesions that typically involve the white and grey matters.<br/>
'''References:''' Kiernan MC, Vucic S, Cheah BC, et al. Amyotrophic lateral sclerosis. Lancet. 2011;377:942-55.<br>
First Aid 2014 page 467 +
Cerebral perfusion is highly regulated by the cerebral blood pH that is mainly driven by the CO2 partial pressure in the cerebral arteries. In fact, cerebral perfusion is closely associated with intracranial volume regulation. CO2 is a potent vasodilator that is thought to act by directly affecting extracellular hydrogen ions on vascular smooth muscles along with induction of local prostanoids and nitric oxide secretion in the cerebral circulation. As such, hyperventilation, which decreases the partial pressure of CO2, is important to decrease the intracranial pressure among patients with cerebral edema. Hypercapnia causes vasodilation of cerebral arteries and leads to increased cerebral blood flow. In contrast, hypocapnia results in vasoconstriction and decreased cerebral blood flow. During ischemia, an increase in CO2 results in an acidic pH that causes vasodilation and consequently leads to an increase in the cerebral blood perfusion. CO2 affects cerebral perfusion until the partial pressure of CO2 reaches 90 mmHg, beyond which CO2 no longer regulates cerebral perfusion. In contrast, cerebral blood flow remains constant until severe hypoxemia is present, where partial pressure of oxygen needs to fall below 50 mmHg for changes in cerebral perfusion to be present. It is thought that acute hypoxia results in a drop of ATP that leads to opening of the K-ATP channels on smooth muscles. As channels open, hyperpolarization and vasodilation ensue.<br/>
'''Educational Objective:''' Cerebral perfusion is regulated by the pH of the blood, which is mainly driven by pCO2 in the cerebral blood. pCO2 affects cerebral perfusion until pCO2 reaches 90 mmHg, beyond which CO2 no longer regulates cerebral perfusion. pO2 does not affect cerebral perfusion unless it falls below 50 mmHg.<br/>
'''References:''' Battisti-Charbonney A, Fisher J, Duffin J et al. The cerebrovascular response to carbon dioxide in humans. J Physiol. 2011;589(12):3039-48.<br>
Cipolla MJ. The Cerebral Circulation. San Rafael (CA): Morgan & Claypool Life Sciences; 2009. Chapter 5, Control of Cerebral Blood Flow.<br>
First Aid 2014 page 459
Cocaine is a powerful stimulant drug and one of the most commonly abused substances in the world. Acute cocaine toxicity usually presents with hallucinations and paranoid behavior, nausea, vomiting, chest pain, dyspnea, tremors, fever, tachycardia, mydriasis, nystagmus, and seizures. Physical exam usually reveals track marks, skin puncture wounds, and/or eroded nasal mucosa depending on the route of administration. While snorting cocaine is the most common route of administration, IV administration is used as well and is more commonly associated with overdose. Cocaine acts by inhibiting reuptake of several neurotransmitters, with the most prominent effect on dopamine and norepinephrine reuptake from the synaptic cleft. This causes an increase in neurotransmitter concentration at the synaptic cleft leading to the classic cocaine associated symptoms.<br/>
'''Educational Objective:''' Cocaine exerts its effect by inhibiting the reuptake of dopamine and norepinephrine from the synaptic cleft.<br/>
'''References:''' Gawin FH. Cocaine addiction: psychology and neurophysiology. Science. 1991;251(5001):1580-6. +
Schizoid personality disorder is characterized by voluntary social withdrawal and indifference. Patients with schizoid personality disorder express little emotion and are content with being socially isolated and not having relationships. They usually feel little if any desire for sexual relationships. Patients typically have hobbies and daily work activities that require as little social contact as possible. On the other hand, avoidant personality disorder describes a pattern of hypersensitivity and social inhibition in patients who are usually very shy. These patients desire social relationships but are very timid, often feel inadequate, and are afraid of rejection.
Five features are usually seen in schizoid personality disorder: Social withdrawal, social detachement, intimacy avoidance, restricted affectivity, and anhedonia.<br/>
'''Educational Objective:''' Schizoid personality disorder is characterized by voluntary social withdrawal with no desire for social contact or relationships.<br/>
'''References:''' American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA:American Psychiatric Publishing. +
Borderline personality disorder is characterized by a pattern of excessive instability of interpersonal relationships and self-image. Patients are usually impulsive, have a pattern of intense unstable relationships, and recurrent suicidal behavior or threats. Patients can also exhibit mood instability, self-mutilation, and chronic feelings of emptiness. A classical defense mechanism associated with borderline personality disorder is splitting. Splitting is described as intolerance to ambiguity with a belief that people are either completely good or bad at a given time. Patients have alternating extremes of idealization and devaluation towards certain individuals.
Ex: All waiters are nice and kind, while waitresses are mean and insensitive.<br/>
'''Educational Objective:''' Splitting is a defense mechanism seen in borderline personality disorder by which a patient sees people as either completely bad or good with no room for ambiguity.<br/>
'''References:''' American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA:American Psychiatric Publishing. +
The most common cause of small bowel obstruction in infants is intussusception. Intussusception is defined as the circumferential infolding of the rectal mucosa that is commonly present at the level of the ileocecal junction. It is a relatively common disease in the pediatric population that is characterized by the triad of nonbilious vomiting (that might become bilious in the case of complete obstruction), severe colicky abdominal pain, and currant jelly stools. Intussusception typically occurs following an upper respiratory tract infection, commonly an adenovirus infection (upper respiratory infection with bilateral conjunctivitis), similar to the patient's presentation. Physical examination may be remarkable for a palpable abdominal mass, commonly in the right lower abdominal quadrant side. Intussusception is considered an emergency and should be treated promptly, and air enema is considered both diagnostic and therapeutic. On the other hand, intussusception among the adult population usually prompts the investigation for a tumor that acts as a lead point for the infolding of the mucosa.<br/>
'''Educational Objective:''' Intussusception is a pediatric emergency that is characterized by the circumferential infolding of the rectal mucosa. Symptoms include the triad of vomiting, colicky abdominal pain, and currant jelly stools. Air enema is both diagnostic and therapeutic.<br/>
'''References:''' First Aid 2014 page 356 +
Eosinophilic esophagitis (EoE) is an emerging pathological entity that has first been described fairly recently. It is characterized by a chronic allergic inflammation of the esophagus. Typically, presents present with symptoms similar to symptoms of GERD, such as dysphagia and heartburn, but are often refractory to proton pump inhibitor (PPI) therapy. Although it is more common among children and young adults, EoE may manifest at any age. The exact cause of EoE remains unknown, but it is thought to be a combination of genetic and unclear environmental factors, including food allergies. It is difficult to distinguish EoE from GERD or peptic strictures by mere clinical suspicion; thus, endoscopy with biopsy is required for definitive diagnosis. Endoscopy often demonstrates nonspecific esophageal erythema and rings around the esophageal wall. Biopsy demonstrates characteristic infiltration of eosinophilic cells into the non-keratinized stratified squamous epithelium of the esophagus with formation of microabscesses and expansion of the basal layer. Treatment is by diet therapy, PPI to reduce the symptoms associated with esophageal inflammation, topical corticosteroids (e.g. swallowed fluticasone). esophagel dilatation for strictures. The efficacy of either systemic corticosteroids or anti-histamines is still unknown and is currently being evaluated.<br/>
'''Educational Objective:''' Eosinophilic esophagitis is characterized by the presence of eosinophilic infiltrates in the esophageal mucosa with thickening of the basal layer. Patients often complain of GERD-like symptoms that are refractory to PPI therapy.<br/>
'''References:''' Dellon ES, Gonsalves N, Hirano I, et al. ACG clinical guideline: Evidenced based approach to the diagnosis and management of esophageal eosinophilia and eosinophilic esophagitis (EoE). Am J Gastroenterol. 2013;108(5):679-92.<br>
Image attribution: "Eosinophilic esophagitis - very high mag.jpg" by user:Nephron under the terms of GNU Free Documentation License v1.2 under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Hepatic angiosarcoma is a rare, malignant, vascular tumor that is associated with chronic exposure to chemical carcinogens, such as polyvinvyl chloride (PVC), thorium dioxide (Thorotrast), radium, and arsenic. Hepatic angiosarcoma is very aggressive and has a very poor prognosis with a very high rate of mortality. The disease was first discovered among employees of PVC industry. Patients often present with non-specific abdominal complaints, such as dull abdominal pain in the right upper quadrant, fatigue, and unexplained weight loss. It is considered one of the most common forms of plastics. On the other hand, arsenic (a metalloid element) is usually found in water and food contaminated with pesticide.<br/>
'''Educational Objective:''' Chronic exposure to polyvinyl chloride, a material often found in plastics, is associated with development of hepatic angiosarcoma.<br/>
'''References:''' Molina E, Hernandez A. Clinical manifestations of primary hepatic angiosarcoma. Dig Dis Sci. 2003; 48(4):677-682.<br>
First Aid 2014 page 362 +
The researcher has a type II (beta) error, or false-negative error, whereby he failed to demonstrate statistical significance despite its presence in the study. The researcher most probably could not demonstrate a significant association between omeprazole and gastric acid suppression in his study because the sample size in his trial is too small (n=10). As such, the study does not have substantial power (Power = 1-beta). Based on his statistical findings, the researcher could not demonstrate a significant association between omeprazole and acid suppression. Accordingly, he cannot reject the null hypothesis and has to accept it. Had the patient had a larger sample size, the study would have been more statistically powerful, and the researcher would have been able to demonstrate significant association and to reject the null hypothesis. On the other hand, a type I (alpha) error, or false-positive error, is defined as the perception of statistical significance when in fact there isn't any.<br/>
'''Educational Objective:''' Type II error is also known as false-negative error. It is present when a researcher fails to demonstrate significance when in fact there is one.<br/>
'''References:''' First Aid 2014 page 57 +
Dementia with Lewy bodies (DLB) is a relatively common neurodegenerative disorder and a frequent cause of dementia. It is characterized by rapid progression (compared with Alzheimer's disease), visual hallucinations (compared with auditory hallucinations observed in schizophrenia), symptoms of Parkinsonism, and featurs of psychosis. Frequent falls occur early in the disease as compared with the delayed falls observed in Parkinson's disease. It is postulated that DLB is caused by the dopaminergic and acetylcholinergic pathway destruction. As a result, patients with DLB are especially susceptible to neuroleptics that often have anti-dopaminergic properties. Administration of neuroleptics often exacerbates extrapyramidal symptoms and makes the management of psychotic symptoms very difficult in patients with DLB. This phenomenon is called "neuroleptic sensitivity" and is in fact a hallmark of DLB. On histopathological examination, DLB is characterized by the presence of Lewy bodies in neurons of the cerebral cortex, which are faintly eosinophilic structures without a sharply demarcated halo around them and do not contain a radial filamentous substructure. In contrast, Parkinson's disease is also characterized by the presence of Lewy bodies; but they often have a well-demarcated halo around them and contain a radial filamentous substructure.<br/>
'''Educational Objective:''' Dementia with Lewy bodies (DLB) is a neurodegenerative disorder characterized by dementia, visual hallucinations, frequent falling, and symptoms of Parkinsonism. Neuroleptic sensitivity, defined as worsening of symptoms following neuroleptic administration, is characteristic of DLB. On histopathological examination, Lewy bodies are found and are distinguished from Lewy bodies of Parkinson's disease by their faintly eosinophilic appearance, the absence of a well-demarcated surrounding halo, and the absence of a radial filamentous substructure.<br/>
'''References:''' Mrak RE, Griffin WS. Dementia with lewy bodies: definition, diagnosis, and pathogenic relationship to Alzheimer's disease. Neuropsychiatr Dis Treat. 2007; 3(5):619-625.<br>
Baskys A. Lewy body dementia: the litmus test for neuroleptic sensitivity and extrapyramidal symptoms. J Clin Psychiatry. 2004; 65 Suppl 11:16-22.<br>
First Aid 2014 page 483
Benzodiazepines (BZDs), especially lorazepam and less commonly diazepam and midazolam, are indicated in the acute management of seizures and status epilepticus, defined as continuous seizure lasting more than 30 minutes or recurrent seizures without regaining consciousness for more than 30 minutes. While BZDs are administered to acutely manage the seizure, patients should also be administered anticonvulsants (such as phenytoin) to prevent new seizures. Benzodiazepines are generally indicated in anxiety and sleep disorders, mood disorders, restless leg syndrome, and symptomatic improvement of substance withdrawal. They are considered teratogenic and are thus contraindicated in pregnancy. They are also contraindicated in acute liver toxicity, acute angle glaucoma, and myasthenia gravis (potentiation of respiratory depression in myasthenic patients with diaphragmatic involvement).<br/>
'''Educational Objective:''' Benzodiazepines are indicated in the acute management of seizures. They are also generally indicated in the management of anxiety and sleep disorders, mood disorders, restless leg syndrome, and symptomatic improvement of substance withdrawal.<br/>
'''References:''' First Aid 2014 page 493 +
Cataracts is a frequent cause of vision loss among the elderly and a common complication of diabetes mellitus. It results from the accumulation of sorbitol, which is normally produced from glucose by the action of aldose reductase. The retina, the kidney, and schwann cells of the nervous system are especially susceptible to sorbitol accumulation because they normally lack sorbitol dehydrogenase that depletes sorbitol by an oxidation reaction via the formation of fructose. Cataract is characterized by the opacification of the lens. It is a painless condition and often occurs bilaterally. Classical symptoms are progressive visual loss, clouding of vision, and glare when looking at lights that appear abnormally bright.<br/>
'''Educational Objective:''' Cataract is caused by sorbitol accumulation in diabetic patients. The eye retina, the kidney, and schwann cells of the nervous system are especially susceptible to sorbitol accumulation because they normally lack sorbitol dehydrogenase that depletes sorbitol via the formation of fructose (an oxidation reaction).<br/>
'''References:''' Omotosho IO, Obisesan OB, Oluleye O. Sorbitol dehydrogenase activity in diabetes mellitus and cataract patients. J Applied Med Sci. 2014;3(1):61-5.<br>
Faes L, Bodmer NS, Bachmann LM, et al. Diagnostic accuracy of the Amsler grid and the preferential hyperacuity perimetry in the screening of patients with age-related macular degeneration: systematic review and meta-analysis. Eye (Lond). 2014;28(7):788-96.<br>
First Aid 2014 page 107 +