| Reversible posterior leukoencephalopathy syndrome (RPLS), is a newly recognized clinicoradiographic syndrome, characterized by neuroimaging findings of reversible vasogenic subcortical edema without infarction. RPLS is often associated with an abrupt and significant elevation in blood pressure, as well as the clinical presentation typically involving headache, nausea and vomiting, seizures, altered mental functioning, visual disturbances, and occasionally focal neurologic deficit. The causes of RPLS are diverse, but the common ones include hypertensive encephalopathy, pre-eclampsia/eclampsia, immunosuppressive and cytotoxic drugs. The classically neuroimaging findings of RPLS are associated with subcortical vasogenic edema, patchy symmetrical bilateral involvement with predominant involvement of the posterior head regions. CT scans and MRI imagings are the favorite techniques used for detecting the lesions. Diffuse-weighted imaging (DWI) and apparent diffusion coefficient (ADC) map images are helpful in distinguishing vasogenic edema, the predominant abnormality in RPLS, from cytotoxic edema. The majority of patients with RPLS have an excellent prognosis,and early recognition of this syndrome is of utmost importance because prompt and effective therapy will cause reversability of the syndrome, and the clinical sign and symptoms will fully disappear. Delay in the diagnosis and treatment can result in permanent damage, even death. Objective:To explore the etiologies, pathophysiology, clinical and imaging features, diagnosis and differential diagnosis, therapy and prognosis of RPLS, raise the doctor's attention to RPLS, and reduce wrong diagnosis and avoid missing dignosis.Methods:A series of 13 patients recruited from Qilu Hospital of Shandong University and the Second Affiliated Hospital of Fujian Medical University, whose clinical manifestations and neuroimagings fulfill the diagnosis criteria of RPLS, consecutively admitted between July 2007 and January 2010 were reviewed retrospectively.Results:(1)There are 13 patients in our study, whose ages ranged from 7 to 41 years (the average age was 23.5 years), and the ratio of gender was 1:3.33(3 males vs.10 females).(2)Etiology: In our study, there were 6 patients presented with eclampsia or preeclampsia of pregnancy-induced hypertension; one patient presented with pheochromocytoma; one patient presented with IgA nephropathy;one patient presented with chronic nephritis with renal insufficiency; 3 patients presented with systemic lupus erythematosus(SLE), of which 1 patient combined late pregnancy; one patient presented with taking ketamine.(3)Clinical manifestations: In this group,9 patients had acute onset; 4 patients had sub-acute onset.11 patients had an elevation of blood pressure; headache occured in 10,8 patients had seizures(mainly tonic-clonic seizures); 8 patients presented with different degrees of consciousness dysfunction, including awareness of hazy, lethargy, drowsiness, and coma; visual disturbance happened in 7, including blurred vision and cortical blindness; 7 cases presented with positive Babinski sign; limb paresis or paralysis happened in 3 cases; neck resistance, Kernig sign in 2 cases; other clinical manifestations, including psychiatric symptoms, such as irritability, reflecting the slow, nonsense, etc.; dizziness, vomiting, computing power, memory loss, pupillary changes and extraocular muscle paralysis.1 case due to hypertensive crisis, multiple organ failure discharged from hospital and died several days later.(4) Neuroimaging:5 patients had CT scan in early onset of symptoms, and the hypodensity lesions were found;MRI were performed in 12 patients and the characterized neuroimagings were found, with low signal intensity or isointense on T1-weighted images and high signal intensity on T2-weighted images and FLAIR images. DWI were performed in 9 patients, with low signal intensity or isointense in 7, and high signal intensity in 2; 5 patients had ADC map with high signal intensity.It showed symmetrical distribution of lesions to subcortical white matter dominated, but the cortical involvement was also common with 6 cases (46.2%) involved. In our group, areas of T2WI signal abnormality included parietal lobe lesions in 12 patients, occipital lobe lesions in 12 patients, frontal lobe lesions in 7 patients, and temporal lobe lesions in 5 patients. Basal ganglia involvement in RPLS occurred in 3 patients, thalamus and brainstem involvement were present in 2 and 2 patients separately. Cerebellum involvement were present in 2 patients. Splenium of corpus callosum and cingulate gyrus lesion occurred in 1 patient. MRA were taken into 3 patients,and 1 patient was normal,1 patient had narrow lumens in the terminal (C1) segment of bilateral internal carotid artery (ICA) and the base segment of bilateral anterior cerebral artery(ACA) and middle cerebral artery(MCA),the other patient had multiple local stenosis of bilateral ACA, MCA and posterior cerebral artery(PCA).Patients underwent MRV examinations showed no obvious abnormalities, thus exclude venous sinus thrombosis. Complete reversibility is generally regarded as a defining feature of RPLS. In addition to 1 death in this group, 5 cases underwent repeated angiography, 3 patients underwent CT review, 2 cases MRI review, 5 cases lesions seen in patients with radiological review significantly improved or disappeared.(5)Tightly relied on the clinical manifestations and neuroimagings was helpful for diagnosing RPLS. The differential diagnosis of RPLS included cerebral infarction (especially top of the basilar artery syndrome), demyelinating disease, encephalitis, venous sinus thrombosis.(6)13 patients had given dehydration, lowering blood pressure, treatment of seizures, termination of pregnancy, removal or significant reduction of the causative immunosuppressive/cytotoxic drugs, deprived of the drug addiction,allopathic and supportive treatments, and clinical manifestations disappeared or almost disappeared in 12 patients, and 1 died. 5 cases received repeated brain imaging,and the lesions were obviously disappeared in 3 patients,and completely reversible in 2 patients. Conclusions:1. Reversible posterior leukoencephalopathy syndrome (RPLS) is a group from a variety of causes of nervous system abnormalities as the main performance syndrome. 2. The common causes of RPLS include hypertensive encephalopathy, pre-eclampsia/eclampsia.3. With acute onset, RPLS mainly present as seizures, headache, altered mental stations, visual disturbance, and an abrupt and significant elevation in blood pressure.4. The characterized neuroimaging features of RPLS are associated with subcortical vasogenic edema, patchy symmetrical bilateral involvement with preferential involvement of the posterior head regions. The lesions show hypodensity on CT scan, usually isointense to hypointense on T1WI, hyperintense on T2WI, and hyperintense on FLAIR images. DWI and ADC map can be combined with identification of vasogenic edema and cytotoxic edema.5. The common differential diagnosis of RPLS includes cerebral infarction (especially top of the basilar artery syndrome), demyelinating disease, encephalitis, venous sinus thrombosis.6. The patients usually have a good prognosis. Control of blood pressure and termination of seizures are the key point of treatment. Early recognition of this condition is of paramount importance because prompt and effective therapy will cause reversal of the syndrome, and the clinical sign and symptoms will fully disappear.7. Because of the reversibility of RPLS, early diagnosis and early treatment is important. If treatment is not timely, it may produce a permanent or irreversible brain damage. |
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