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Pathology - Alcohol Withdrawal Seizures
Pathophysiology
These seizures usually happen six to forty-eight hours after abruptly stopping alcohol use following heavy and sustained consumption. Downregulation of gamma-aminobutyric acid A (GABAA) receptors and overexpression of N-methyl-D-aspartate (NMDA) receptors in the central nervous system cause seizures. Patients typically arrive with widespread tonic-clonic seizures. Additions to the symptoms of alcohol withdrawal syndrome include anxiety, agitation, delirium tremens, and hallucinations.
A patient who presents with delirium or seizures two days after being admitted to the hospital is not uncommon. Benzodiazepines (BZDs) are used to treat seizures and stop them from happening again. GABA is potentiated by BZDs by increasing the frequency of chloride ion channel opening.
Barbiturates function similarly, but they vary in that they prolong the opening of chloride ion channels; yet, the use of barbiturates has been limited due to the substantial danger of fatal respiratory depression.
Pathophysiology
These seizures usually happen six to forty-eight hours after abruptly stopping alcohol use following heavy and sustained consumption. Downregulation of gamma-aminobutyric acid A (GABAA) receptors and overexpression of N-methyl-D-aspartate (NMDA) receptors in the central nervous system cause seizures. Patients typically arrive with widespread tonic-clonic seizures. Additions to the symptoms of alcohol withdrawal syndrome include anxiety, agitation, delirium tremens, and hallucinations.
A patient who presents with delirium or seizures two days after being admitted to the hospital is not uncommon. Benzodiazepines (BZDs) are used to treat seizures and stop them from happening again. GABA is potentiated by BZDs by increasing the frequency of chloride ion channel opening.
Barbiturates function similarly, but they vary in that they prolong the opening of chloride ion channels; yet, the use of barbiturates has been limited due to the substantial danger of fatal respiratory depression.
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Pathology - Open Angle Glaucoma
Pathogenesis
The trabecular meshwork, which typically serves to drain intraocular fluid from the anterior chamber, is obstructed in this kind of glaucoma. The aqueous humor produced by the ciliary body persists and builds up in the anterior chamber, raising intraocular pressure. This is not painful, unlike acute angle-closure glaucoma, as it happens gradually. Damage to the optic nerve as a result increases the disc to cup ratio and impairs vision from the peripheral to the central nervous system. Venous vessel engorgement manifests as vessels with notches on the outside edge of the optic disc. Topical beta-blockers and oral carbonic anhydrase inhibitors can be used to reduce the generation of aqueous humor, whereas topical prostaglandins can be used in treatment to enhance outflow via the trabecular meshwork.
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Pathology - Closed Angle Glaucoma
Pathophysiology
When the iris dilates in patients with narrow angles, or in dimly lit environments, the iris and lens come into touch. The ciliary body continues to produce aqueous humor, but it cannot move from the posterior chamber into the anterior. A rapid increase in intraocular pressure results in conjunctival erythema, lacrimation, and discomfort. Patients may feel queasy, throw up, or have headaches. Halos around lights and diminished visual acuity are examples of visual abnormalities that could quickly lead to total blindness. In narrow-angle glaucoma, intraocular pressures usually surpass 40 mm Hg, although normal intraocular pressures are usually less than 20 mm Hg. This condition is an ophthalmological emergency that needs to be treated right away with acetazolamide, topical beta-blockers, steroids, and reduction of intraocular pressure in order to control inflammation.
Pathophysiology
When the iris dilates in patients with narrow angles, or in dimly lit environments, the iris and lens come into touch. The ciliary body continues to produce aqueous humor, but it cannot move from the posterior chamber into the anterior. A rapid increase in intraocular pressure results in conjunctival erythema, lacrimation, and discomfort. Patients may feel queasy, throw up, or have headaches. Halos around lights and diminished visual acuity are examples of visual abnormalities that could quickly lead to total blindness. In narrow-angle glaucoma, intraocular pressures usually surpass 40 mm Hg, although normal intraocular pressures are usually less than 20 mm Hg. This condition is an ophthalmological emergency that needs to be treated right away with acetazolamide, topical beta-blockers, steroids, and reduction of intraocular pressure in order to control inflammation.
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Pathology - Parkinson's disease
Pathophysiology
The hallmark of this disease is a reduction in dopaminergic activity, which results from a decrease in the activity of the substantia nigra, a region of the midbrain that secretes dopamine.
There is a clear correlation between dopamine levels and motor function, as dopamine reduces inhibition of motor performance. This is consistent with the clinical observations of bradykinesia and cogwheel rigidity, which is jerky resistance to passive range of motion. Furthermore, a decrease in dopamine suppresses emotions via acting on the prefrontal brain, which is exacerbated by facial paralysis (mask-like facies). Parkinson's patients' neurons frequently include Lewy bodies, which are inclusion bodies containing the protein alphasynuclein. Nevertheless, Parkinson's disease is not the only condition that can cause these aggregation of proteins.
Dopamine agonists and carbidopa/levodopa can be used to treat symptoms. In order to avoid undesirable side effects, carbidogopa blocks the peripheral conversion of levodopa to dopamine. Anticholinergic drugs aid in the management of tremor.
Pathophysiology
The hallmark of this disease is a reduction in dopaminergic activity, which results from a decrease in the activity of the substantia nigra, a region of the midbrain that secretes dopamine.
There is a clear correlation between dopamine levels and motor function, as dopamine reduces inhibition of motor performance. This is consistent with the clinical observations of bradykinesia and cogwheel rigidity, which is jerky resistance to passive range of motion. Furthermore, a decrease in dopamine suppresses emotions via acting on the prefrontal brain, which is exacerbated by facial paralysis (mask-like facies). Parkinson's patients' neurons frequently include Lewy bodies, which are inclusion bodies containing the protein alphasynuclein. Nevertheless, Parkinson's disease is not the only condition that can cause these aggregation of proteins.
Dopamine agonists and carbidopa/levodopa can be used to treat symptoms. In order to avoid undesirable side effects, carbidogopa blocks the peripheral conversion of levodopa to dopamine. Anticholinergic drugs aid in the management of tremor.
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Pathology - Achalasia and Dysphagia
Pathophysiology
Dysphagia may arise from an esophageal motility disease or from issues during the oropharyngeal phase of swallowing. Even though the patient can swallow and produce a bolus, the food stops in the esophagus. The most prevalent causes of motility issues in the esophagus are innervation abnormalities or blockages like cancer. Interaction between inhibitory enteric neurons, which emit vasoactive intestinal polypeptide (VIP) and nitric oxide, and excitatory vagal and enteric neurons, which release acetylcholine and substance P as neurotransmitters, is necessary for coordinated peristalsis. Loss of inhibitory neurons is assumed to be the etiology of achalasia, leading to dysregulation of peristalsis and improper relaxation of the lower esophageal sphincter. The majority of cases are idiopathic, however infrequently occurring identified causative factors include cancer and Trypanosoma cruzi, the organism that causes Chagas disease
Pathophysiology
Dysphagia may arise from an esophageal motility disease or from issues during the oropharyngeal phase of swallowing. Even though the patient can swallow and produce a bolus, the food stops in the esophagus. The most prevalent causes of motility issues in the esophagus are innervation abnormalities or blockages like cancer. Interaction between inhibitory enteric neurons, which emit vasoactive intestinal polypeptide (VIP) and nitric oxide, and excitatory vagal and enteric neurons, which release acetylcholine and substance P as neurotransmitters, is necessary for coordinated peristalsis. Loss of inhibitory neurons is assumed to be the etiology of achalasia, leading to dysregulation of peristalsis and improper relaxation of the lower esophageal sphincter. The majority of cases are idiopathic, however infrequently occurring identified causative factors include cancer and Trypanosoma cruzi, the organism that causes Chagas disease
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Pathology - GERD, or gastroesophageal reflux disease
Pathophysiology
Acid reflux disease (GERD) is a prevalent illness affecting adults that causes stomach acid to reflux into the esophagus. The degree of discomfort and the degree of damage to the esophagus mucosa vary greatly in severity. The lower esophageal sphincter's smooth muscle malfunction is the pathophysiologic mechanism of gastroesophageal reflux disease (GERD). The majority of the time, incorrect, momentary relaxations happen, but persistently low sphincter pressure (<15 mm Hg) is linked to severe GERD. Sphincter relaxation is made worse by some foods, including as chocolate, alcohol, caffeine, and peppermint. Large meals, acidic drinks, and lying down just after eating all contribute to the occurrence, which is also higher in smokers and people who are overweight.
PPIs are nearly usually effective in treating uncomplicated GERD, as this patient's did.
Constant acid reflux raises the risk of esophageal ulcers, strictures, and cancer in addition to causing esophagitis. Chronic GERD leads to Barrett's esophagus, which is characterized by a metaplastic alteration of the normal stratified squamous epithelial lining of the esophagus, the development of a columnar epithelium, and an elevated risk of future cancer.
Pathophysiology
Acid reflux disease (GERD) is a prevalent illness affecting adults that causes stomach acid to reflux into the esophagus. The degree of discomfort and the degree of damage to the esophagus mucosa vary greatly in severity. The lower esophageal sphincter's smooth muscle malfunction is the pathophysiologic mechanism of gastroesophageal reflux disease (GERD). The majority of the time, incorrect, momentary relaxations happen, but persistently low sphincter pressure (<15 mm Hg) is linked to severe GERD. Sphincter relaxation is made worse by some foods, including as chocolate, alcohol, caffeine, and peppermint. Large meals, acidic drinks, and lying down just after eating all contribute to the occurrence, which is also higher in smokers and people who are overweight.
PPIs are nearly usually effective in treating uncomplicated GERD, as this patient's did.
Constant acid reflux raises the risk of esophageal ulcers, strictures, and cancer in addition to causing esophagitis. Chronic GERD leads to Barrett's esophagus, which is characterized by a metaplastic alteration of the normal stratified squamous epithelial lining of the esophagus, the development of a columnar epithelium, and an elevated risk of future cancer.
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Pathology - Gastroparesis
Pathophysiology
Although it can also be idiopathic, diabetes and surgery are the most prevalent causes of gastroparesis. Normal stomach motility requires the sympathetic and parasympathetic (vagal) neural systems to work in concert with the enteric nervous system. Neuronal or GI smooth muscle loss of function is possible. Although the exact process relating to diabetes is unknown, it is consistent with other signs of advanced diabetic disease, such as nephropathy (see the patient's elevated serum creatinine level) and neuropathy (notice the patient's sensory loss). In this instance, nutritional anemia, brittle hair and skin, and fat loss are signs of malnutrition brought on by gastroparesis. There is dehydration, as evidenced by tachycardia and low blood pressure. Hypokalemia and metabolic alkalosis have been caused by prolonged vomiting. The use of a feeding tube or prokinetic medication may be part of the therapy. Based on the broad intestinal gas shown on the radiograph, this patient may also have weak intestinal motility.
Pathophysiology
Although it can also be idiopathic, diabetes and surgery are the most prevalent causes of gastroparesis. Normal stomach motility requires the sympathetic and parasympathetic (vagal) neural systems to work in concert with the enteric nervous system. Neuronal or GI smooth muscle loss of function is possible. Although the exact process relating to diabetes is unknown, it is consistent with other signs of advanced diabetic disease, such as nephropathy (see the patient's elevated serum creatinine level) and neuropathy (notice the patient's sensory loss). In this instance, nutritional anemia, brittle hair and skin, and fat loss are signs of malnutrition brought on by gastroparesis. There is dehydration, as evidenced by tachycardia and low blood pressure. Hypokalemia and metabolic alkalosis have been caused by prolonged vomiting. The use of a feeding tube or prokinetic medication may be part of the therapy. Based on the broad intestinal gas shown on the radiograph, this patient may also have weak intestinal motility.
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Pathology - Duodenal Ulcer
Pathophysiology
An imbalance between protective and aggressive elements might lead to mucosal abnormalities in the small intestine or stomach. The surface mucous barrier, surface cell bicarbonate secretion, and increased mucosal blood flow are significant protective benefits that are bolstered by local prostaglandin synthesis. The most frequent aggressive variables are NSAID use and H. pylori infection.
Another risk factor is smoking. Life-threatening GI bleeding, such as bleeding from a posterior ulceration into the gastroduodenal artery or peritonitis from a GI wall perforation, are examples of complications. This patient most likely has a duodenal ulcer, which, unlike gastric ulcers, is more common in younger people and is frequently eased by eating. Due to its ability to cause chronic mucosal inflammation, H. pylori infection is a major pathogenic factor in up to 90% of duodenal ulcers. Microcytic erythrocytes and blood in the stool are signs of chronic gastrointestinal bleeding in this patient, who also has iron-deficiency anemia. The goal of treatment is to get rid of aggravating factors (such H. pylori and stop taking NSAIDs) and utilize PPIs or H2 blockers to lessen acidity. The best way to diagnose and assess the severity of an ulcer, as well as to treat severe ulcers and perforations with sclerotherapy, is by endoscopy. Unlike stomach ulcers, which have a 5% to 10% chance of being malignant, duodenal ulcers never need to be biopsyed.
Pathophysiology
An imbalance between protective and aggressive elements might lead to mucosal abnormalities in the small intestine or stomach. The surface mucous barrier, surface cell bicarbonate secretion, and increased mucosal blood flow are significant protective benefits that are bolstered by local prostaglandin synthesis. The most frequent aggressive variables are NSAID use and H. pylori infection.
Another risk factor is smoking. Life-threatening GI bleeding, such as bleeding from a posterior ulceration into the gastroduodenal artery or peritonitis from a GI wall perforation, are examples of complications. This patient most likely has a duodenal ulcer, which, unlike gastric ulcers, is more common in younger people and is frequently eased by eating. Due to its ability to cause chronic mucosal inflammation, H. pylori infection is a major pathogenic factor in up to 90% of duodenal ulcers. Microcytic erythrocytes and blood in the stool are signs of chronic gastrointestinal bleeding in this patient, who also has iron-deficiency anemia. The goal of treatment is to get rid of aggravating factors (such H. pylori and stop taking NSAIDs) and utilize PPIs or H2 blockers to lessen acidity. The best way to diagnose and assess the severity of an ulcer, as well as to treat severe ulcers and perforations with sclerotherapy, is by endoscopy. Unlike stomach ulcers, which have a 5% to 10% chance of being malignant, duodenal ulcers never need to be biopsyed.
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Pathology - Zollinger-Ellison Syndrome
Pathophysiology
Acid secretion is stimulated and gastric parietal cells proliferate due to hypersecretion of the peptide hormone gastrin from a non-B-cell islet cell endocrine tumor. Gastrin mainly causes the enterochromaffin (ECL) cells of the stomach mucosa to release histamine, which in turn encourages the parietal cells to secrete acid. When the stomach pH falls below 3.0, it is generally released by enteroendocrine (G-) cells in the stomach antrum. Uncontrolled secretion of gastrin occurs when a gastrinoma other than the stomach is present, usually in the pancreas. In the small intestine, excessive acidity deactivates pancreatic enzymes and results in maldigestion, which in this instance leads to malnutrition, diarrhea, and steatorrhea. Tachycardia and low blood pressure are indicative of severe gastrointestinal bleeding. A tumor may be detected by MRI, although nuclear scintigraphy is frequently necessary.
If discrete tumors are discovered, surgical resection is the best course of action. Although ZES is an uncommon cause of peptic ulcer disease, half of cases have malignant metastases to the liver and lymph nodes. ZES sufferers that also have multiple endocrine neoplasia syndrome type 1 (MEN 1) account for thirty percent of cases.
Pathophysiology
Acid secretion is stimulated and gastric parietal cells proliferate due to hypersecretion of the peptide hormone gastrin from a non-B-cell islet cell endocrine tumor. Gastrin mainly causes the enterochromaffin (ECL) cells of the stomach mucosa to release histamine, which in turn encourages the parietal cells to secrete acid. When the stomach pH falls below 3.0, it is generally released by enteroendocrine (G-) cells in the stomach antrum. Uncontrolled secretion of gastrin occurs when a gastrinoma other than the stomach is present, usually in the pancreas. In the small intestine, excessive acidity deactivates pancreatic enzymes and results in maldigestion, which in this instance leads to malnutrition, diarrhea, and steatorrhea. Tachycardia and low blood pressure are indicative of severe gastrointestinal bleeding. A tumor may be detected by MRI, although nuclear scintigraphy is frequently necessary.
If discrete tumors are discovered, surgical resection is the best course of action. Although ZES is an uncommon cause of peptic ulcer disease, half of cases have malignant metastases to the liver and lymph nodes. ZES sufferers that also have multiple endocrine neoplasia syndrome type 1 (MEN 1) account for thirty percent of cases.
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Pathology - Small Bowel Obstruction (SBO)
Pathophysiology
In 75% of cases, the cause is either hernias or, in this instance, adhesions from prior abdominal surgery.
Because the obstruction opposes peristaltic waves, obstruction-related pain is frequently paroxysmal. Peristalstic waves have the potential to cause loud bowel sounds, or borerygmi, which will occur simultaneously with the pain. Edema of the intestinal wall and gas and fluid buildup in the gut close to the obstruction are the causes of distention of the abdomen. In an upright abdominal film, air-fluid levels can be detected proximal to the blockage as progressive black-white horizontal interfaces within the intestine; the absence of colonic gas is pathognomonic of SBO and suggests a total obstruction.
Following many hours of blockage, fluid moves into the intestinal lumen, resulting in hypovolemia, which is shown as tachycardia and low blood pressure.
Vomiting due to visceral discomfort occurs in hypovolemia and hypokalemia. In the intestine, high intraluminal pressure reduces blood flow, which results in ischemia and damage to the intestinal wall. In this instance, a fever and leukocytosis indicate a possible breach of the intestinal barrier and peritonitis.
Pathophysiology
In 75% of cases, the cause is either hernias or, in this instance, adhesions from prior abdominal surgery.
Because the obstruction opposes peristaltic waves, obstruction-related pain is frequently paroxysmal. Peristalstic waves have the potential to cause loud bowel sounds, or borerygmi, which will occur simultaneously with the pain. Edema of the intestinal wall and gas and fluid buildup in the gut close to the obstruction are the causes of distention of the abdomen. In an upright abdominal film, air-fluid levels can be detected proximal to the blockage as progressive black-white horizontal interfaces within the intestine; the absence of colonic gas is pathognomonic of SBO and suggests a total obstruction.
Following many hours of blockage, fluid moves into the intestinal lumen, resulting in hypovolemia, which is shown as tachycardia and low blood pressure.
Vomiting due to visceral discomfort occurs in hypovolemia and hypokalemia. In the intestine, high intraluminal pressure reduces blood flow, which results in ischemia and damage to the intestinal wall. In this instance, a fever and leukocytosis indicate a possible breach of the intestinal barrier and peritonitis.
