Complex Neurological, Endocrine, Gastrointestinal, and Hepatobiliary Conditions

Comprehensive vocabulary flashcards covering etiology, clinical manifestations, diagnostics, and management of stroke, traumatic brain injuries, pituitary and thyroid disorders, adrenal imbalances, hepatic dysfunction, and pancreatic/biliary conditions.

Ischemic Stroke

A disruption of blood flow through cerebral arteries caused by an occlusion, blood clot, or calcification that blocks perfusion past a specific point and results in cellular death.

Transient Ischemic Attack (TIA)

A temporary, brief disruption in cerebral blood flow producing stroke-like symptoms that completely resolve without permanent tissue necrosis.

Hemorrhagic Stroke

Extravasation or leakage of blood outside cerebral arterial walls (e.g., from aneurysm rupture or arteriovenous malformation), leading to decreased downstream perfusion and elevated intracranial pressure from cerebral edema.

Cytotoxic Edema

Swelling that occurs when oxygen-deprived brain cells fail to regulate volume, causing water to shift intracellularly, leading to rapid cell rupture and brain tissue enlargement.

Alteplase

A fibrinolytic agent administered for acute ischemic stroke that must be initiated within a strict window of $3\text{--}4\text{ hours}$ from the patient's last known well time to avoid high risks of hemorrhagic conversion.

Carotid Endarterectomy

A surgical procedure used to clear atherosclerotic plaque blockages from the carotid artery to restore cerebral blood flow, requiring post-operative head neutrality and strict blood pressure control.

Cerebral Vasospasm

The reactive clamping down and constriction of cerebral blood vessels caused by direct contact with toxic free extravascular hemoglobin, which decreases perfusion and risks ischemic conversion.

Craniectomy

The surgical removal of a portion of the skull bone to provide space for swollen brain tissue and reduce intracranial pressure, often requiring the patient to wear a helmet post-operatively.

Nimodipine

A calcium channel blocker administered to prevent cerebral vasospasm and improve cerebral arterial dilation following subarachnoid or intracranial hemorrhage.

National Institutes of Health Stroke Scale (NIHSS)

A standardized clinical assessment tool used to evaluate neurological deficits following a stroke, where higher numerical scores indicate more severe impairment and disability.

Concussion

A mild traumatic brain injury caused by a direct impact to the head without loss of consciousness, typically presenting with headache, amnesia, and symptoms that resolve within $3\text{--}5\text{ days}$.

Diffuse Axonal Injury (DAI)

Widespread, bilateral shearing injury to axonal tracts throughout the brain resulting from severe rotational or blunt acceleration-deceleration trauma, typically causing immediate stupor or coma.

Coup-Contrecoup Injury

A dual-mechanism brain injury where the primary damage occurs directly at the point of impact (coup) and secondary damage occurs on the opposite side as the brain rebounds against the skull (contrecoup).

Basilar Skull Fracture

A fracture of the base of the skull manifested by late physical signs such as bilateral periorbital ecchymosis (raccoon eyes), mastoid ecchymosis (Battle's sign), and cerebrospinal fluid leaks from the nose or ears.

Halo Sign

A diagnostic indicator of a cerebrospinal fluid leak observed when drainage placed on sterile gauze separates into a central spot of blood surrounded by a clear or yellow ring containing protein and glucose.

Cushing's Triad

A life-threatening constellation of clinical signs indicating critically increased intracranial pressure, characterized by bradycardia, widening pulse pressure (increased systolic and stable/decreased diastolic blood pressure), and irregular respirations.

Decorticate Posturing

An abnormal motor response characterized by rigid flexion of the arms pulled tightly inward toward the core, indicating severe bilateral damage to the cerebral hemispheres.

Decerebrate Posturing

An ominous abnormal motor response marked by rigid extension and hyperpronation of the arms away from the body, indicating damage to the brainstem.

Mannitol

An osmotic diuretic administered intravenously that draws excess fluid from swollen brain tissue into the vascular space to be excreted by the kidneys, reducing intracranial pressure.

Therapeutic Hyperventilation

The mechanical reduction of arterial $P\text{CO}_2$ to $30\text{--}35\text{ mmHg}$, which induces cerebral vasoconstriction, thereby decreasing intracranial blood volume and brain edema.

Ventriculostomy

A specialized intraventricular catheter placed into the brain to continuously monitor intracranial pressure waveforms and therapeutically drain excess cerebrospinal fluid via an external system.

Diabetes Insipidus (DI)

A disorder characterized by a deficiency in or insensitivity to antidiuretic hormone (ADH), producing massive diuresis of dilute, pale urine ($>3\text{ L/day}$), low urine specific gravity, hypernatremia, and severe dehydration.

Water Deprivation Test

A diagnostic procedure involving an $8\text{-hour}$ NPO status followed by the administration of desmopressin to assess changes in urine osmolality, differentiating central from nephrogenic diabetes insipidus.

Desmopressin (DDAVP)

A synthetic exogenous antidiuretic hormone replacement administered via IV, PO, or intranasal routes to treat central diabetes insipidus by halting uninhibited diuresis.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

A syndrome caused by the overproduction of antidiuretic hormone (ADH), leading to fluid volume excess, water retention, dilutional hyponatremia, and concentrated urine with elevated specific gravity.

Hashimoto's Thyroiditis

An autoimmune disorder characterized by destructive antithyroid antibodies that progressively destroy functional glandular tissue, representing the leading cause of primary hypothyroidism.

Levothyroxine

Synthetic thyroid hormone (T4) replacement taken orally $30\text{--}60\text{ minutes}$ before breakfast on an empty stomach to treat hypothyroidism, requiring monitoring of TSH and T4 every $2\text{--}3\text{ weeks}$ during initial titration.

Myxedema Coma

A life-threatening complication of severe, untreated hypothyroidism characterized by hypothermia, profound bradycardia, hypotension, respiratory failure, hyponatremia, and comatose mental status.

Graves' Disease

An autoimmune hyperthyroid condition caused by thyroid-stimulating autoantibodies that induce hyperplasia of the thyroid gland (goiter) and accelerated synthesis of T3 and T4.

Thyroid Storm

An acute, life-threatening hypermetabolic crisis caused by surging thyroid hormones, presenting with extreme hyperpyrexia ($104\text{--}106^\text{o}\text{F}$), tachycardia ($>140\text{ bpm}$), dysrhythmias, agitation, and multisystem organ decompensation.

Addison's Disease

A primary adrenocortical insufficiency characterized by deficient secretion of both glucocorticoids (cortisol) and mineralocorticoids (aldosterone), manifesting with hyponatremia, hyperkalemia, hypoglycemia, and hypotension.

Addisonian Crisis

A severe, acute adrenal insufficiency precipitated by acute physical stress, trauma, or the abrupt cessation of systemic steroids, causing hypovolemic shock, hyperkalemia, and cardiovascular collapse.

Cushing's Syndrome

A metabolic condition resulting from chronic exposure to excessive cortisol or exogenous corticosteroids, characterized by central trunk obesity, moon facies, muscle atrophy, hyperglycemia, and osteoporosis.

Pheochromocytoma

A catecholamine-producing tumor of the adrenal medulla that hypersecretes epinephrine and norepinephrine, triggering paroxysmal hypertension crises, profound tachycardia, diaphoresis, and severe headaches.

Hepatic Encephalopathy

A reversible neuropsychiatric complication of advanced cirrhosis caused by the accumulation of unmetabolized systemic ammonia that crosses the blood-brain barrier, resulting in confusion, lethargy, and asterixis.

Lactulose

An osmotic laxative administered in cirrhosis that acidifies colon contents to convert diffusible ammonia into non-absorbable ammonium, promoting its evacuation through frequent loose stools.

Sengstaken-Blakemore Tube

A triple-lumen gastrointestinal device fitted with inflatable gastric and esophageal balloons used to apply direct mechanical tamponade to actively bleeding esophageal and gastric varices.

Cholecystitis

Inflammation of the gallbladder wall, most commonly triggered by gallstone obstruction (cholelithiasis) in the cystic duct, causing bile retention, spasms, and sharp right upper quadrant pain.

Acute Pancreatitis

An acute inflammatory disorder where premature intrapancreatic activation of digestive enzymes (amylase, lipase, and proteases) causes autodigestion of pancreatic parenchyma, severe epigastric pain, and hypocalcemia.

Pancrelipase

An exogenous pancreatic enzyme mixture containing amylase, lipase, and protease that must be administered with every meal and snack to enable nutrient absorption in patients with pancreatic insufficiency.