Posterior reversible encephalopathy syndrome
Encyclopedia
Posterior reversible encephalopathy syndrome (PRES), also known as reversible posterior leukoencephalopathy syndrome (RPLS), is a syndrome characterised by headache
, confusion
, seizure
s and visual loss. It may occur due to a number of causes, predominantly malignant hypertension
, eclampsia
and some medical treatments. On magnetic resonance imaging
(MRI) of the brain, areas of edema
(swelling) are seen. The symptoms tend to resolve after a period of time, although visual changes sometimes remain. It was first described in 1996.
and cyclosporine, hence it may occur in people who have undergone an organ transplant
, in which these drugs may be used to suppress transplant rejection
. It also occurs due to eclampsia
, severe high blood pressure
and hypercalcemia. Low magnesium levels can augment PRES.
of the brain; this may show hyperintensities on T2-weighed imaging
. Cerebral angiography
may provide a more definite diagnosis.
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, confusion
ConFusion
ConFusion is an annual science fiction convention organized by the Stilyagi Air Corps and its parent organization, the Ann Arbor Science Fiction Association. Commonly, it is held the third weekend of January. It is the oldest science fiction convention in Michigan, a regional, general SF con...
, seizure
Seizure
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". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
s and visual loss. It may occur due to a number of causes, predominantly malignant hypertension
Malignant hypertension
Malignant hypertension or hypertensive emergency is severe hypertension with acute impairment of an organ system and the possibility of irreversible organ-damage...
, eclampsia
Eclampsia
Eclampsia , an acute and life-threatening complication of pregnancy, is characterized by the appearance of tonic-clonic seizures, usually in a patient who had developed pre-eclampsia...
and some medical treatments. On magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(MRI) of the brain, areas of edema
Cerebral edema
Cerebral edema or cerebral œdema is an excess accumulation of water in the intracellular or extracellular spaces of the brain.-Vasogenic:Due to a breakdown of tight endothelial junctions which make up the blood-brain barrier...
(swelling) are seen. The symptoms tend to resolve after a period of time, although visual changes sometimes remain. It was first described in 1996.
Causes
PRES occurs due to the use of drugs like tacrolimusTacrolimus
Tacrolimus is an immunosuppressive drug that is mainly used after allogeneic organ transplant to reduce the activity of the patient's immune system and so lower the risk of organ rejection...
and cyclosporine, hence it may occur in people who have undergone an organ transplant
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
, in which these drugs may be used to suppress transplant rejection
Transplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after...
. It also occurs due to eclampsia
Eclampsia
Eclampsia , an acute and life-threatening complication of pregnancy, is characterized by the appearance of tonic-clonic seizures, usually in a patient who had developed pre-eclampsia...
, severe high blood pressure
Hypertensive emergency
Malignant hypertension or hypertensive emergency is severe hypertension with acute impairment of an organ system and the possibility of irreversible organ-damage...
and hypercalcemia. Low magnesium levels can augment PRES.
Diagnosis
The diagnosis is typically made on magnetic resonance imagingMagnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
of the brain; this may show hyperintensities on T2-weighed imaging
Spin-spin relaxation time
thumb|right|T2 relaxation curveSpin–spin relaxation is the mechanism by which Mxy, the transverse component of the magnetization vector, exponentially decays towards its equilibrium value of zero, in nuclear magnetic resonance and magnetic resonance imaging...
. Cerebral angiography
Cerebral angiography
Cerebral angiography is a form of angiography which provides images of blood vessels in and around the brain, thereby allowing detection of abnormalities such as arteriovenous malformations and aneurysms....
may provide a more definite diagnosis.