Hypertensive encephalopathy

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Hypertensive encephalopathy
Specialty Emergency medicine, Cardiology, Neurology
Symptoms Headache, vomiting, trouble with balance, confusion [1]
Complications Seizures, bleeding in the back of the eye [1]
Usual onsetSudden [1]
Causes Kidney failure, rapidly stopping blood pressure medication, pheochromocytoma, taking monoamine oxidase inhibitor with foods containing tyramine, eclampsia [2]
Diagnostic method Blood pressure > 200/130 mmHg and general brain dysfunction [1]
Differential diagnosis Uremic encephalopathy, stroke (ischemic or bleeding), hydrocephalus, cocaine toxicity [1] [2]
Medication Labetalol, sodium nitroprusside [2]
FrequencyUncommon [2]

Hypertensive encephalopathy (HE) is general brain dysfunction due to significantly high blood pressure. [3] Symptoms may include headache, vomiting, trouble with balance, and confusion. [1] Onset is generally sudden. [1] Complications can include seizures, posterior reversible encephalopathy syndrome, and bleeding in the back of the eye. [1] [3]

Contents

In hypertensive encephalopathy, generally the blood pressure is greater than 200/130 mmHg. [1] Occasionally it can occur at a BP as low as 160/100 mmHg. [4] This can occur in kidney failure, those who rapidly stop blood pressure medication, pheochromocytoma, and people on a monoamine oxidase inhibitor (MAOI) who eat foods with tyramine. [2] When it occurs in pregnancy it is known as eclampsia. [2] The diagnosis requires ruling out other possible causes. [1]

The condition is generally treated with medications to relatively rapidly lower the blood pressure. [2] [3] This may be done with labetalol or sodium nitroprusside given by injection into a vein. [2] In those who are pregnant, magnesium sulfate may be used. [2] Other treatments may include anti-seizure medications. [2]

Hypertensive encephalopathy is uncommon. [2] It is believed to occur more often in those without easy access to health care. [2] The term was first used by Oppenheimer and Fishberg in 1928. [5] [6] It is classified as a type of hypertensive emergency. [4]

Signs and symptoms

Hypertensive encephalopathy is most commonly encountered in young and middle-aged people who have hypertension. [7] [8] [9] Overall, the condition is rare even among people with hypertension. Studies report that from 0.5 to 15% of people with malignant hypertension develop hypertensive encephalopathy. [10] [11] [12] [13] With the development of methods for detection and treatment of hypertension, hypertensive encephalopathy has been becoming more rare.[ citation needed ]

Symptoms of hypertensive encephalopathy typically start to occur 12–48 hours after a sudden and sustained increase in blood pressure. The first manifestation of these symptoms is a severe headache. Headache occurs in greater than 75% of patients. [10] The patient becomes restless. Alterations in consciousness may follow several hours later, which include impaired judgement and memory, confusion, somnolence and stupor. If the condition is not treated, these neurological symptoms may worsen and ultimately turn into a coma. Other symptoms may include increased irritability, vomiting, diplopia, seizures, twitching and myoclonus of the limbs. Alterations in vision (vision blurring, hemivisual field defects, color blindness, cortical blindness) are common. They occur in 4 out of 11 cases (Jellinek et al. 1964). Hemiparesis, intracerebral hemorrhage, aphasia may also occur, but they are less common.[ citation needed ]

Pathogenesis

Hypertensive encephalopathy is caused by an increase in blood pressure. Several conditions may evoke blood pressure elevation: acute nephritis, eclampsia, crises in chronic essential hypertension, sudden withdrawal of antihypertensive treatment. Additionally, hypertensive encephalopathy may occur in pheochromocytoma, Cushing's syndrome, renal artery thrombosis.[ citation needed ]

The impairment of cerebral blood flow that underlies hypertensive encephalopathy is still controversial. Normally, cerebral blood flow is maintained by an autoregulation mechanism that dilates arterioles in response to blood pressure decreases and constricts arterioles in response to blood pressure increases. This autoregulation falters when hypertension becomes excessive. According to the over-regulation conception, brain vessels spasm in response to acute hypertension, which results in cerebral ischemia and cytotoxic edema. [14] [15] According to the autoregulation breakthrough conception, cerebral arterioles are forced to dilate, leading to vasogenic edema. [12]

Cerebral edema can be generalized or focal. Brain ventricles are compressed, cortical gyri flattened.[ citation needed ]

Diagnosis

Diagnostic methods for hypertensive encephalopathy include physical examination, blood pressure measurement, blood sampling, ECG, EEG, chest X-ray, urinalysis, arterial blood gas analysis, and imaging of the head (CAT scan and/or MRI). Since decreasing blood pressure is essential, anti-hypertensive medication is administered without awaiting the results of the laboratory tests. Electroencephalographic examination detects the absence of alpha waves, signifying impaired consciousness. In people with visual disturbances, slow waves are detected in the occipital areas.[ citation needed ]

Treatment

The initial aim of treatment in hypertensive crises is to rapidly lower the diastolic pressure to about 100 to 105 mmHg; this goal should be achieved within two to six hours, with the maximum initial fall in BP not exceeding 25 percent of the presenting value. [16] [17] This level of BP control will allow gradual healing of the necrotizing vascular lesions. More aggressive hypotensive therapy is both unnecessary and may reduce the blood pressure below the autoregulatory range, possibly leading to ischemic events (such as stroke or coronary disease). [18] [19]

Once the BP is controlled, the person should be switched to medication by mouth, with the diastolic pressure being gradually reduced to 85 to 90 mmHg over two to three months. The initial reduction to a diastolic pressure of approximately 100 mmHg is often associated with a modest worsening of renal function; this change, however, is typically transient as the vascular disease tends to resolve and renal perfusion improves over one to three months. [20] Antihypertensive therapy should not be withheld in this setting unless there has been an excessive reduction in BP. A change in medication, however, is indicated if the decline in renal function is temporally related to therapy with an angiotensin (ACE) converting enzyme inhibitor or angiotensin II receptor blocker, which can interfere with renal autoregulation and produce acute kidney failure in patients with bilateral renal artery stenosis. (See "Renal effects of ACE inhibitors in hypertension".)[ citation needed ]ref

Several parenteral antihypertensive agents are most often used in the initial treatment of malignant hypertension. [16] [17]

The major risk with oral agents is ischemic symptoms (e.g., angina pectoris, myocardial infarction, or stroke) due to an excessive and uncontrolled hypotensive response. [23] Thus, their use should generally be avoided in the treatment of hypertensive crises if more controllable drugs are available.[ citation needed ]

Prognosis

Patients with hypertensive encephalopathy who are promptly treated usually recover without deficit. However, if treatment is not administered, the condition can lead to death. [6]

History

The first descriptions of the condition date back to the early 1900s. In 1914, Volhard and Fahr distinguished a neurological disorder caused by acute hypertension from a uremic state. [24] He described this condition a "pseudouremia". The term "hypertensive encephalopathy" was introduced by Oppenheimer and Fishberg in 1928 to describe the case of a patient with acute nephritis, severe hypertension, and cerebral symptoms. [6]

In the past, the term "hypertensive encephalopathy" has been applied to a range of neurological problems occurring in hypertensive patients, such as headache, dizziness cerebral hemorrhage and transient ischemic attacks. However, currently this term is narrowed down to a clinical condition produced by elevated blood pressure and which can be reversed by blood pressure reduction. [25] [26] [7]

Related Research Articles

<span class="mw-page-title-main">Hypertension</span> Long-term high blood pressure in the arteries

Hypertension, also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high blood pressure, however, is a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide.

A hypertensive urgency is a clinical situation in which blood pressure is very high with minimal or no symptoms, and no signs or symptoms indicating acute organ damage. This contrasts with a hypertensive emergency where severe blood pressure is accompanied by evidence of progressive organ or system damage.

<span class="mw-page-title-main">Hypertensive retinopathy</span> Medical condition

Hypertensive retinopathy is damage to the retina and retinal circulation due to high blood pressure.

<span class="mw-page-title-main">Eclampsia</span> Pre-eclampsia characterized by the presence of seizures

Eclampsia is the onset of seizures (convulsions) in a woman with pre-eclampsia. Pre-eclampsia is a hypertensive disorder of pregnancy that presents with three main features: new onset of high blood pressure, large amounts of protein in the urine or other organ dysfunction, and edema. If left untreated, pre-eclampsia can result in long-term consequences for the mother, namely increased risk of cardiovascular diseases and associated complications. In more severe cases, it may be fatal for both the mother and the fetus. The diagnostic criteria for pre-eclampsia is high blood pressure occurring after 20 weeks gestation or during the second half of pregnancy. Most often it occurs during the 3rd trimester of pregnancy and may occur before, during, or after delivery. The seizures are of the tonic–clonic type and typically last about a minute. Following the seizure, there is either a period of confusion or coma. Other complications include aspiration pneumonia, cerebral hemorrhage, kidney failure, pulmonary edema, HELLP syndrome, coagulopathy, placental abruption and cardiac arrest.

<span class="mw-page-title-main">Cerebral edema</span> Excess accumulation of fluid (edema) in the intracellular or extracellular spaces of the brain

Cerebral edema is excess accumulation of fluid (edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compression of brain tissue and blood vessels. Symptoms vary based on the location and extent of edema and generally include headaches, nausea, vomiting, seizures, drowsiness, visual disturbances, dizziness, and in severe cases, coma and death.

Antihypertensives are a class of drugs that are used to treat hypertension. Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, hearth failure, kidney failure and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers.

<span class="mw-page-title-main">Nifedipine</span> Calcium channel blocker medication

Nifedipine, sold under the brand name Adalat and Procardia, among others, is a calcium channel blocker medication used to manage angina, high blood pressure, Raynaud's phenomenon, and premature labor. It is one of the treatments of choice for Prinzmetal angina. It may be used to treat severe high blood pressure in pregnancy. Its use in preterm labor may allow more time for steroids to improve the baby's lung function and provide time for transfer of the mother to a well qualified medical facility before delivery. It is a calcium channel blocker of the dihydropyridine type. Nifedipine is taken by mouth and comes in fast- and slow-release formulations.

<span class="mw-page-title-main">Hypertensive kidney disease</span> Medical condition

Hypertensive kidney disease is a medical condition referring to damage to the kidney due to chronic high blood pressure. It manifests as hypertensive nephrosclerosis. It should be distinguished from renovascular hypertension, which is a form of secondary hypertension, and thus has opposite direction of causation.

<span class="mw-page-title-main">Hypertensive emergency</span> Profoundly elevated blood pressure resulting in symptomatic end-organ injury

A hypertensive emergency is very high blood pressure with potentially life-threatening symptoms and signs of acute damage to one or more organ systems. It is different from a hypertensive urgency by this additional evidence for impending irreversible hypertension-mediated organ damage (HMOD). Blood pressure is often above 200/120 mmHg, however there are no universally accepted cutoff values. Signs of organ damage are discussed below.

Severely elevated blood pressure is referred to as a hypertensive crisis, as blood pressure at this level confers a high risk of complications. People with blood pressures in this range may have no symptoms, but are more likely to report headaches and dizziness than the general population. Other symptoms accompanying a hypertensive crisis may include visual deterioration due to retinopathy, breathlessness due to heart failure, or a general feeling of malaise due to kidney failure. Most people with a hypertensive crisis are known to have elevated blood pressure, but additional triggers may have led to a sudden rise.

<span class="mw-page-title-main">Fenoldopam</span> Antihypertensive agent, also used in hypertensive crisis

Fenoldopam mesylate (Corlopam) is a drug and synthetic benzazepine derivative which acts as a selective D1 receptor partial agonist. Fenoldopam is used as an antihypertensive agent. It was approved by the Food and Drug Administration (FDA) in September 1997.

Autonomic dysreflexia (AD) is a potentially fatal medical emergency classically characterized by uncontrolled hypertension and bradycardia, although tachycardia is known to commonly occur. AD occurs most often in individuals with spinal cord injuries with lesions at or above the T6 spinal cord level, although it has been reported in patients with lesions as low as T10. Guillain–Barré syndrome may also cause autonomic dysreflexia.

<span class="mw-page-title-main">Treprostinil</span> Chemical compound

Treprostinil, sold under the brand names Remodulin for infusion, Orenitram for oral, and Tyvaso for inhalation, is a vasodilator that is used for the treatment of pulmonary arterial hypertension. Treprostinil is a synthetic analog of prostacyclin (PGI2).

<span class="mw-page-title-main">Posterior reversible encephalopathy syndrome</span> Medical condition

Posterior reversible encephalopathy syndrome (PRES), also known as reversible posterior leukoencephalopathy syndrome (RPLS), is a rare condition in which parts of the brain are affected by swelling, usually as a result of an underlying cause. Someone with PRES may experience headache, changes in vision, and seizures, with some developing other neurological symptoms such as confusion or weakness of one or more limbs. The name of the condition includes the word "posterior" because it predominantly though not exclusively affects the back of the brain. Common underlying causes are severely elevated blood pressure, kidney failure, severe infections, certain medications, some autoimmune diseases, and pre-eclampsia. The diagnosis is usually made by brain scan (MRI) on which areas of swelling can be identified.

<span class="mw-page-title-main">Clevidipine</span> Chemical compound

Clevidipine is a dihydropyridine calcium channel blocker indicated for the reduction of blood pressure when oral therapy is not feasible or not desirable. Clevidipine is used IV only and practitioners titrate this drug to lower blood pressure. It has a half-life of approximately one minute. It is rapidly inactivated by esterases.

<span class="mw-page-title-main">Nitrovasodilator</span> Drug that causes vasodilation by releasing nitric oxide

A nitrovasodilator is a pharmaceutical agent that causes vasodilation by donation of nitric oxide (NO), and is mostly used for the treatment and prevention of angina pectoris.

<span class="mw-page-title-main">Complications of hypertension</span>

Complications of hypertension are clinical outcomes that result from persistent elevation of blood pressure. Hypertension is a risk factor for all clinical manifestations of atherosclerosis since it is a risk factor for atherosclerosis itself. It is an independent predisposing factor for heart failure, coronary artery disease, stroke, kidney disease, and peripheral arterial disease. It is the most important risk factor for cardiovascular morbidity and mortality, in industrialized countries.

Orthostatic hypertension is a medical condition consisting of a sudden and abrupt increase in blood pressure (BP) when a person stands up. Orthostatic hypertension is diagnosed by a rise in systolic BP of 20 mmHg or more when standing. Orthostatic diastolic hypertension is a condition in which the diastolic BP raises to 98 mmHg or over in response to standing, but this definition currently lacks clear medical consensus, so is subject to change. Orthostatic hypertension involving the systolic BP is known as systolic orthostatic hypertension.

<span class="mw-page-title-main">Sodium nitroprusside</span> Medication for lowering blood pressure

Sodium nitroprusside (SNP), sold under the brand name Nitropress among others, is a medication used to lower blood pressure. This may be done if the blood pressure is very high and resulting in symptoms, in certain types of heart failure, and during surgery to decrease bleeding. It is used by continuous injection into a vein. Onset is nearly immediate and effects last for up to ten minutes.

<span class="mw-page-title-main">Hypertension and the brain</span>

Hypertension is a condition characterized by an elevated blood pressure in which the long term consequences include cardiovascular disease, kidney disease, adrenal gland tumors, vision impairment, memory loss, metabolic syndrome, stroke and dementia. It affects nearly 1 in 2 Americans and remains as a contributing cause of death in the United States. There are many genetic and environmental factors involved with the development of hypertension including genetics, diet, and stress.

References

  1. 1 2 3 4 5 6 7 8 9 10 Goldman L, Schafer AI (2011). Goldman's Cecil Medicine E-Book. Elsevier Health Sciences. p. 2326. ISBN   978-1437736083. Archived from the original on 2017-10-22.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 Lynn DJ, Newton HB, Rae-Grant A (2004). The 5-minute Neurology Consult. Lippincott Williams & Wilkins. p. 174. ISBN   9780683307238. Archived from the original on 2017-10-22.
  3. 1 2 3 Price RS, Kasner SE (2014). "Hypertension and hypertensive encephalopathy". Handbook of Clinical Neurology. 119: 161–7. doi:10.1016/B978-0-7020-4086-3.00012-6. ISBN   9780702040863. PMID   24365295.
  4. 1 2 Cameron P, Jelinek G, Kelly A, Brown AF, Little M (2014). Textbook of Adult Emergency Medicine E-Book. Elsevier Health Sciences. p. 274. ISBN   9780702054389. Archived from the original on 2017-10-22.
  5. ↑ Johnson RJ, Feehally J, Floege J (2014). Comprehensive Clinical Nephrology E-Book. Elsevier Health Sciences. p. 439. ISBN   9780323242875. Archived from the original on 2017-10-22.
  6. 1 2 3 Oppenheimer, B. S. (December 1979). "Hypertensive encephalopathy". Archives of Internal Medicine. 2 (6202): 1387–8. doi:10.1001/archinte.1928.00130140126010. PMC   1597139 . PMID   519473.
  7. 1 2 Dinsdale HB (1983). "Hypertensive encephalopathy". Neurologic Clinics. 1 (1): 3–16. doi:10.1016/s0733-8619(18)31167-8. PMID   6687306.
  8. ↑ Moyer JH, Miller SI, Tashner AB, Snyder H, Bowman RO (1953). "Malignant hypertension and hypertensive encephalopathy". The American Journal of Medicine. 14 (2): 175–183. doi:10.1016/0002-9343(53)90017-5. PMID   13016599.
  9. ↑ Chester EM, Agamanolis DP, Banker BQ, Victor M (September 1978). "Hypertensive encephalopathy: a clinicopathologic study of 20 cases". Neurology. 28 (9 Pt 1): 928–39. doi:10.1212/wnl.28.9.928. PMID   567764. S2CID   23916848.
  10. 1 2 Clarke E, Murphy EA (December 1956). "Neurological manifestations of malignant hypertension". BMJ. 2 (5005): 1319–26. doi:10.1136/bmj.2.5005.1319. PMC   2036170 . PMID   13374330.
  11. ↑ Hauser, Robert A.; Lacey, D. M.; Knight, M. R. (1988). "Hypertensive Encephalopathy". Archives of Neurology. 45 (10): 1078–1083. doi:10.1001/archneur.1988.00520340032007. PMID   3178528.
  12. 1 2 Healton EB, Brust JC, Feinfeld DA, Thomson GE (February 1982). "Hypertensive encephalopathy and the neurologic manifestations of malignant hypertension". Neurology. 32 (2): 127–32. doi:10.1212/wnl.32.2.127. PMID   7198739. S2CID   44662827.
  13. ↑ Perera GA (1955). "Hypertensive vascular disease; description and natural history". Journal of Chronic Diseases. 1 (1): 33–42. doi:10.1016/0021-9681(55)90019-9. PMID   13233309.
  14. ↑ Strandgaard S, Paulson OB (June 1989). "Cerebral blood flow and its pathophysiology in hypertension". American Journal of Hypertension. 2 (6 Pt 1): 486–92. doi:10.1093/ajh/2.6.486. PMID   2757806.
  15. ↑ Tamaki, K.; Sadoshima, S.; Baumbach, G. L.; Iadecola, C.; Reis, D. J.; Heistad, D. D. (1984). "Evidence that disruption of the blood-brain barrier precedes reduction in cerebral blood flow in hypertensive encephalopathy". Hypertension. 6 (2_pt_2): I75-81. doi:10.1161/01.hyp.6.2_pt_2.i75. PMID   6724673.
  16. 1 2 3 4 5 6 Kaplan, NM. Hypertensive crises. In: Kaplan's Clinical Hypertension, 9th ed, Neal, W (Ed), Lippincott, Williams and Wilkins, Baltimore 2006. p.311.
  17. 1 2 3 4 5 6 Vaughan CJ, Delanty N (2000). "Hypertensive emergencies". Lancet. 356 (9227): 411–7. doi:10.1016/s0140-6736(00)02539-3. PMID   10972386. S2CID   17373676.
  18. ↑ Ledingham JG, Rajagopalan B (1979). "Cerebral complications in the treatment of accelerated hypertension". Q J Med. 48 (189): 25–41. PMID   482589.
  19. ↑ Haas DC, Streeten DH, Kim RC, et al. (1983). "Death from cerebral hypoperfusion during nitroprusside treatment of acute angiotensin-dependent hypertension". Am J Med. 75 (6): 1071–6. doi:10.1016/0002-9343(83)90891-4. PMID   6650540.
  20. ↑ Woods JW, Blythe WB (July 1967). "Management of malignant hypertension complicated by renal insufficiency". The New England Journal of Medicine. 277 (2): 57–61. doi:10.1056/nejm196707132770201. PMID   6027134.
  21. ↑ Neutel JM, Smith DH, Wallin D, Cook E, Ram CV, Fletcher E, et al. (July 1994). "A comparison of intravenous nicardipine and sodium nitroprusside in the immediate treatment of severe hypertension". American Journal of Hypertension. 7 (7 Pt 1): 623–8. doi:10.1093/ajh/7.7.623. PMID   7946164.
  22. ↑ Angeli P, Chiesa M, Caregaro L, et al. (1991). "Comparison of sublingual captopril and nifedipine in the immediate treatment of hypertensive emergencies. A randomized, single-blind clinical trial". Arch Intern Med. 151 (4): 678–682. doi:10.1001/archinte.1991.00400040032008. PMID   2012448.
  23. ↑ Grossman E, Messerli FH, Grodzicki T, Kowey P (1996). "Should a moratorium be placed on sublingual nifedipine capsules given for hypertensive emergencies and pseudoemergencies?". JAMA. 276 (16): 1328–1331. doi:10.1001/jama.1996.03540160050032. PMID   8861992.
  24. ↑ Volhard F, Fahr T (1914) Die Brittische Nierenkrankheit, Vol. 2 (German). Berlin, Springer 232-265.
  25. ↑ Finnerty FA Jr (1972). "Hypertensive encephalopathy". The American Journal of Medicine. 52 (5): 672–678. doi:10.1016/0002-9343(72)90057-5. PMID   5063657.
  26. ↑ Ram CV (1978). "Hypertensive encephalopathy: recognition and management". Archives of Internal Medicine. 138 (12): 1851–1853. doi:10.1001/archinte.138.12.1851. PMID   718353.
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