A brainstem variant of reversible posterior leukoencephalopathy syndrome

A Case of Posterior Reversible Encephalopathy Syndrome Mimicking Stroke

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered sensorium, visual disturbances, and diagnosed by magnetic resonance imaging (MRI). Here we report a case of cisplatin-induced PRES which was mimicking stroke and diagnosed by serial MRI and recovered completely on treatment, emphasizing fact that early diagnosis, removal of cause, and treatment can prevent the complication.

How to cite this article: Admane SS, Yelne TS, Giri PJ. A Case of Posterior Reversible Encephalopathy Syndrome Mimicking Stroke. Indian J Crit Care Med 2020;24(9):877–878.

Isolated pons involvement in Posterior Reversible Encephalopathy Syndrome: Case report and review of the literature

Background

Posterior Reversible Encephalopathy Syndrome (PRES) is a clinical-radiological syndrome, usually reversible and with a favorable prognosis, which recognizes a variety of etiologies and clinical patterns and is likely due to an impairment in cerebral blood flow autoregulation. It is typically characterized by subcortical, predominantly parieto-occipital, vasogenic brain oedema in patients with acute-subacute neurological symptoms. Infratentorial oedema on neuroimaging has been mostly described in association with the typical supratentorial pattern and seldom as isolated.

Case report

We report a case of PRES with isolated pons involvement on MRI. A woman affected by Turner syndrome, epilepsy, slight mental deficiency, obesity and hypothyroidism, experienced a progressive gait and standing impairment, worsening in the last 2 weeks. At admission blood pressure was 220/110 mmHg. Brain MRI showed a wide FLAIR signal hyperintensity on T2-weighted sequences affecting the entire pons, without contrast enhancement. Clonidine, doxazosine, furosemide and telmisartan were effective in restoring normal blood pressure. Pons hyperintensity completely resolved on MRI 3 weeks later, together with return to normal neurological examination.

Conclusions

Though isolated infratentorial involvement in PRES recognizes several causes, hypertension, which is a common feature in Turner syndrome, would have played a key role in our case with solely pons MRI T2-hyperintensity.

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Clinical and radiological findings of PRES are heterogeneous with possible atypical presentations: in this regard an accurate differential diagnosis is mandatory in order to provide prompt intervention.

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Isolated pons involvement has been rarely described. A key feature may be poor clinical presentation in spite of a radiological pattern of severity.

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Severe hypertension acts as the more frequently reported predisposing factor for isolated pontine PRES

Posterior reversible encephalopathy syndrome in malignant hypertension secondary to focal segmental glomerulosclerosis

Posterior reversible encephalopathy syndrome (PRES) is a neurological condition that occurs secondary to a variety of causes like autoimmune diseases, uncontrolled hypertension and immunosuppressive agents. We report an unusual association of PRES and malignant hypertension secondary to focal segmental glomerulosclerosis in a young woman, presenting with sudden loss of vision and seizures. She had uncontrolled hypertension and a Glasgow Coma Scale of 6/15. Brain MRI revealed high signals in cortical and subcortical white matter and some involvement of the periventricular areas. She improved dramatically with antihypertensive and antiepileptic medications and was discharged home in a stable condition. It is important to have a high clinical suspicion for this uncommon condition in an appropriate clinical setting, because a timely intervention can prevent long-term complications.

[Posterior reversible encephalopathy syndrome of the midbrain and hypothalamus - a case report of uremic encephalopathy presenting with hypersomnia]

We report the case of a 73-year-old woman presenting with hypersomnia and loss of appetite. She suffered from diabetic nephropathy without receiving dialysis, in addition to hypertension, which was well controlled without marked fluctuation. There were no objective neurological findings. Her laboratory findings showed renal failure with 3.7 mg/dl of serum creatinine and decreased serum sodium and potassium. Brain magnetic resonance imaging (MRI) showed posterior reversible encephalopathy syndrome (PRES) with vasogenic edema, which was distributed in the dorsal midbrain, medial thalamus, and hypothalamus. After we addressed the electrolyte imbalance and dehydration, her symptoms and MRI findings gradually improved, but faint high signals on MRI were still present 3 months later. Orexin in the cerebrospinal fluid was decreased on admission, but improved 6 months later. We diagnosed uremic encephalopathy with atypical form PRES showing functional disturbance of the hypothalamus.

Brainstem variant of posterior reversible encephalopathy syndrome: A case report

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition, generally observed in conjunction with severe and acute hypertension, that involves mainly the posterior head areas (occipital and temporal lobes) and anterior "watershed" areas. In this syndrome it is rare to observe a predominant involvement of the brainstem. We describe the clinical and radiological findings in a patient with brainstem involvement, discussing its pathophysiological features and possible differential diagnosis.

Isolated cerebellar involvement in posterior reversible encephalopathy syndrome

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a serious and increasingly recognized disorder in humans. However, isolated cerebellar involvement in PRES is extremely uncommon. In this study, we sought to investigate its clinical and radiological features by describing a cohort of cases with PRES and isolated cerebellar involvement.

METHODS

We report 2 patients with PRES with only cerebellar involvement and identified additional 9 cases using the PubMed database with the MeSH terms "posterior reversible encephalopathy syndrome", "hypertensive encephalopathy", "hypertension", "cerebellum", "encephalopathy", and "magnetic resonance imaging". We then collectively analyzed the clinical and imaging characteristics of these 11 cases.

RESULTS

The average age was 28years, with 8 male and 3 female patients. All cases had severe acute hypertension and T2 hyperintensity on MRI exclusively centered within the cerebellum. Of 11 patients, 7 had hypertensive retinopathy, a favorable clinical course with only antihypertensive treatment, and resolution of the cerebellar lesions on follow-up imaging. A total of 5 of the 11 patients received external ventricular drainage due to obstructive hydrocephalus and only 2 of the 11 had a seizure.

CONCLUSIONS

Isolated cerebellar involvement in PRES may be a unique variant that affects younger, male cases with severe acute hypertension and hypertensive retinopathy, but not necessarily seizure. Most patients have full recovery after fast control of blood pressure. Awareness of atypical neuroimaging features in PRES is critical for appropriate treatment.

Isolated posterior fossa involvement in posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible vasogenic edema affecting the subcortical white matter of bilateral occipital and parietal lobes. We describe a case of isolated posterior fossa involvement of PRES which occurred during remission induction chemotherapy for T-cell acute lymphoblastic leukemia. Both the brainstem and cerebellum were extensively involved, but the supratentorial structures were completely spared. The follow-up magnetic resonance images revealed reversibility of most lesions. The knowledge of atypical radiological features of PRES is essential for prompt diagnosis.

Clinical and radiological spectrum of posterior reversible encephalopathy syndrome

OBJECTIVE

Symptoms of posterior reversible encephalopathy syndrome (PRES) include headache, altered mental status, visual disturbances, and seizures. Typical radiological features include edema of the parieto-occipital lobes. The purpose of this study is to review the clinical and radiological findings in patients diagnosed with PRES.

METHODS

All patients diagnosed with PRES between January 2006 and December 2012 were retrospectively included in this study. We reviewed demographic and clinical characteristics, and radiological findings.

RESULTS

We identified 16 patients with PRES. The most common clinical presentation was seizure (n = 12, 75%). Clinical recovery occurred in all patients within days (mean, 5.7 ± 4.6 days). Comorbid conditions included hypertension (n = 4, 25%), cytotoxic medications (n = 3, 18.8%), sepsis (n = 4, 25%), malignancy (n = 4, 25%), subarachnoid hemorrhage (n = 1, 6.3%), autoimmune disorders (n = 1, 6.3%) and eclampsia (n = 1, 6.3%). The most commonly involved location was the parieto-occipital lobe (n = 13, 81.3%). Atypical radiological findings included significant basal ganglia involvement in 4 episodes; brainstem in 3, cerebellum in 2, and thalamus in 3. Eleven patients (68.8%) underwent diffusion-weighted imaging and apparent diffusion coefficient mapping. Of those, 9 patients (81.8%) had hypo- or isointensity on diffusion-weighted imaging. On the apparent diffusion coefficient map, 10 patients (90.9%) had hyperintensity, and the other had normal values.

CONCLUSION

We suggest that PRES may occur in patients with complex systemic conditions. The prognosis of PRES is usually benign. Physicians should be aware of certain atypical radiological findings to avoid a delayed diagnosis of PRES, as delayed diagnosis and treatment can result in permanent neurological sequlae.

Isolated brainstem involvement in a patient with hypertensive encephalopathy

Hypertensive encephalopathy typically presents with headache, confusion, and bilateral parietooccipital vasogenic edema. Brainstem edema in hypertensive encephalopathy usually occurs in association with typical supratentorial parieto-occipital changes and is usually asymptomatic. We report here a patient with hypertensive encephalopathy, with isolated brain stem involvement on magnetic resonance imaging (MRI). Rapid treatment of hypertension resulted in clinical and radiological improvement. Prompt recognition of the condition and aggressive treatment of hypertension in such patients is crucial to relieve edema and prevent life-threatening progression.

Reversible obstructive hydrocephalus from hypertensive encephalopathy

BACKGROUND

Diffuse edema involving the posterior fossa may be seen with hypertensive encephalopathy and has rarely been reported to cause hydrocephalus. We present three such cases and review the literature to better delineate this uniquely reversible syndrome.

METHODS

Case reports and review of literature.

RESULTS

Three patients with hypertensive encephalopathy presented to our institutions with clinical and radiographic features of obstructive hydrocephalus associated with brainstem and cerebellar edema. This required transient external drainage of cerebrospinal fluid (CSF) in two of the three patients. However, with recognition of this unusual syndrome and aggressive management of elevated blood pressure, both edema and hydrocephalus resolved. All patients made complete recoveries and did not require permanent CSF shunting. A review of the literature yielded 15 additional case reports describing reversible obstructive hydrocephalus related to hypertensive encephalopathy. All had mean arterial pressures above 130 mmHg and presented primarily with altered mental status. While half required ventriculostomy, only one required shunting. Excluding a patient who died from sepsis, all recovered neurologically once blood pressure was controlled.

CONCLUSION

It is imperative to recognize such cases where hypertension causes edema within the posterior fossa resulting in secondary hydrocephalus. Focusing management on lowering blood pressure avoids unnecessary or prolonged CSF diversion.

Anesthesia and Intensive Care Management in a Pregnant Woman with PRES: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a temporary condition that is diagnosed clinically, neurologically, and radiologically. Its symptoms vary, and nonspecific headaches, confusion, impairment of consciousness, nausea, vomiting, and visual impairment may occur. Acute hypertension often accompanies these symptoms. Patients can also suffer from convulsions, cortical visual impairment, and coma. Diagnosis can be difficult due to focal neurologic signs. Nevertheless, knowing the clinical risk factors can lead to the right diagnosis. It has been reported that this condition may also occur during organ transplantation, immunosuppressive treatment, and autoimmune diseases and chemotherapy, and also patients with eclampsia. In this paper, a 21-year-old, 31-week pregnant woman, who had been diagnosed with PRES and thanks to early diagnosis and treatment had fully recovered and discharged from the intensive care unit, is presented, and the relevant literature is discussed.

Malignant hypertension with reversible brainstem hypertensive encephalopathy and thrombotic microangiopathy

A 42-year-old woman presented with headache and nausea. Severe hypertension, renal dysfunction, thrombocytopenia, and anemia were present. A magnetic resonance imaging (MRI) scan of her head revealed widespread hyperintense lesions located in the brainstem and cerebellum on T2-weighted and fluid-attenuated inversion recovery imaging. Hypertensive encephalopathy was suspected, and antihypertensive therapy was started. A second MRI of the patient's head on day 12 of hospitalization revealed that the hyperintensities in the brainstem and cerebellum had almost disappeared, and that thrombocytopenia, anemia, and renal dysfunction had also gradually improved. Test results led to a diagnosis of malignant hypertension. This patient was regarded as suffering from malignant hypertension with reversible brainstem hypertensive encephalopathy (RBHE) and thrombotic microangiopathy (TMA). RBHE and TMA are known to occur as complications of malignant hypertension, but there has been no previous report of them occurring simultaneously. RBHE and TMA related to malignant hypertension are both conditions that can be improved by the rapid institution of antihypertensive therapy, and as such, early diagnosis and treatment are important. When treating patients with malignant hypertension, the possibility that it may be complicated by both RBHE and TMA must be kept in mind.

A 3-year old girl with seizures, hypokalemia and metabolic alkalosis

A 3-year-old girl presented to the emergency department with seizures, low-grade fever and vomiting. She had tachycardia and a slow capillary refill. Blood pressure could not be measured. Because of suspected sepsis and/or meningo-encephalitis, broad spectrum antibiotics and antiviral medication were given together, along with volume expansion and anticonvulsive therapy. A few hours later, after a second seizure, the blood pressure was extremely high (156/116 mm Hg). The girl was treated with anticonvulsants and intravenous antihypertensive agents. MRI of the brain showed signs of posterior reversible encephalopathy syndrome. Cultures of blood and cerebrospinal fluid remained sterile. Further investigation into the cause of the malignant hypertension revealed hypokalemia, metabolic alkalosis and extremely high plasma renin activity, caused by a rare renal abnormality: bilateral renal segmental hypoplasia or Ask-Upmark kidneys.

Posterior Reversible Encephalopathy Syndrome Secondary to Essential Hypertension

We present the case of a young man who was previously well, but became unconscious while watching a football match. He was initially found to be hypertensive, with clinical and echocardiographic evidence of cardiac failure. He also had a fixed and dilated pupil. CT brain scanning was normal and it was only after a MR brain scan was performed that the diagnosis of posterior reversible encephalopathy syndrome was raised. Despite the name of the condition implying that neurological deficits are reversible, this patient had a prolonged period of disability requiring long-term rehabilitation.

CT diagnosis of hypertensive brainstem encephalopathy (HBE): A diagnostic challenge in the emergency department

Hypertensive encephalopathy usually involves the posterior supratentorium, with uncommon involvement of the brainstem. We present a case of acute hypertensive encephalopathy of the brainstem diagnosed by means of CT. The brainstem was markedly hypodense, with no evidence of typical concomitant parieto-occipital involvement. The patient’s symptoms and imaging findings improved after hypertension had been controlled.

Hemorrhage in posterior reversible encephalopathy syndrome: imaging and clinical features

BACKGROUND AND PURPOSE

Hemorrhage is known to occur in posterior reversible encephalopathy syndrome (PRES), but the characteristics have not been analyzed in detail. The purpose of this study was to evaluate the imaging and clinical features of hemorrhage in PRES.

MATERIALS AND METHODS

Retrospective assessment of 151 patients with PRES was performed, and 23 patients were identified who had intracranial hemorrhage at toxicity. Hemorrhage types were identified and tabulated, including minute focal hemorrhages (<5 mm), sulcal subarachnoid hemorrhage, and focal hematoma. Clinical features of hemorrhage and nonhemorrhage PRES groups were evaluated, including toxicity blood pressure, coagulation profile/platelet counts, coagulation-altering medication, and clinical conditions associated with PRES. Toxicity mean arterial pressure (MAP) groups were defined as normal (<106 mm Hg), mildly hypertensive (106-116 mm Hg), or severely hypertensive (>116 mm Hg).

RESULTS

The overall incidence of hemorrhage was 15.2%, with borderline statistical significance noted between the observed clinical associations (P = .07). Hemorrhage was significantly more common (P = .02) after allogeneic bone marrow transplantation (allo-BMT) than after solid-organ transplantation. The 3 hemorrhage types were noted with equal frequency. A single hemorrhage type was found in 16 patients, with multiple types noted in 7. Patients undergoing therapeutic anticoagulation were statistically more likely to develop hemorrhage (P = .04). No difference in hemorrhage incidence was found among the 3 blood pressure subgroups (range, 14.9%-15.9%).

CONCLUSIONS

Three distinct types of hemorrhage (minute hemorrhage, sulcal subarachnoid hemorrhage, hematoma) were identified in PRES with equal frequency. The greatest hemorrhage frequency was seen after allo-BMT and in patients undergoing therapeutic anticoagulation. Hemorrhage rate was independent of the toxicity blood pressure.

Posterior reversible encephalopathy syndrome associated with hemorrhage

BACKGROUND

Posterior Reversible Encephalopathy Syndrome (PRES) is a clinico-radiological entity characterized by headache, encephalopathy, visual disturbances, and seizures in association with reversible vasogenic edema on neuroimaging. Intracerebral hemorrhage associated with PRES (PRES-ICH) is generally considered an atypical finding.

METHODS

Retrospective case series.

RESULTS

Seven patients were identified with PRES-ICH, four males and three females. The presenting clinical symptoms included headache (2), encephalopathy (5), vision changes (2), seizures (2), and hemiparesis (1). The co-morbid conditions included acute renal dysfunction (3), solid organ transplantation (3), bone marrow transplant (1), use of calcineurin inhibitor agents (4), and pre-eclampsia (1). Neuroimaging revealed intraparenchymal hemorrhage in six patients and subarachnoid hemorrhage in one patient. Six of the seven patients with PRES-related ICH had underlying bleeding diathesis, including one patient who was anti-coagulated with a heparin drip. The mean platelet count was 82.1 x 10(3)/microl (range, 4-232 x 10(3)/microl), and the mean INR value was 2.18 (range, 0.9-6.7). Two patients died during the acute hospitalization. Among the five survivors, only two patients had good functional outcome (pre-defined as mRS < or = 1).

CONCLUSION

In our series, the majority of patients with PRES-ICH (85%) had an underlying bleeding diathesis or coagulopathy. Although PRES is typically considered to have a favorable prognosis, the clinical outcome of PRES with associated ICH can be more variable.

A case of hypertensive encephalopathy with prominent brainstem presentation

A 39-year-old woman developed severe arterial hypertension associated with brainstem hyperintensity in T2-weighted images and hyperintense lesion in the left basal ganglia. Clinical findings were a sudden loss of consciousness, confusion, nausea, vomiting and headache. Rapid treatment of hypertension resulted in clinical and radiological improvement. Rapid identification and appropriate diagnostics are essential, as prompt treatment usually results in reversal of symptoms; permanent neurologic injury or death can occur with treatment delay.

[Brainstem variant of reversible posterior leukoencephalopathy syndrome with a prolonged clinical course: a case report]

A 38-year-old man gradually developed gait instability, dysarthria, and dysphagia over two months associated with an elevated blood pressure after starting hemodialysis therapy for diabetic nephropathy. Brain MRI studies indicated vasogenic edema in the brainstem, extending from the lower midbrain to the upper medulla oblongata. The patient's high blood pressure was refractory to treatment, and his neurological disabilities and MRI abnormalities progressed. FDG-PET, MR spectroscopy, and cerebrospinal fluid studies did not suggest neoplastic pathologies. The patient was diagnosed with a brainstem variant of reversible posterior leukoencephalopathy syndrome, and received three courses of steroid pulse therapy. After the pulse therapy, the clinical manifestations and MR findings improved. By maintaining strict management of blood pressure and body water balance during hemodialysis, he did not experience any further clinical exacerbation, and the lesion on MR images continued to regress. Ten months after the pulse therapy, T1-weighted images showed slightly hyperintense signal. This case suggests that reversible posterior leukoencephalopathy syndrome (RPLS) may take a chronic clinical course without acute onset.

Eclampsia: a neurological perspective

Eclampsia is a poorly understood disorder characterized by seizures or unexplained coma in setting of gestational hypertension. Its neurological manifestations are varied and are an important cause of the morbidity and mortality associated. We present a comprehensive prospective study of forty women recruited over four years describing neurological symptoms and signs, neuroimaging and laboratory studies as well as prognosis including 3-6 months follow-up. The seizures occurred in the postpartum period in majority of women (55%), while 45% had seizures before labor, and the rest (5%) during labor. Interestingly, one third of the women suffered their first seizures more than 48 h postpartum (late postpartum eclampsia). A sizable minority suffered more than one seizure and some had documented partial seizures. Headache preceded seizures by more than a day and was described as throbbing or pounding pain by most. The visual symptoms in decreasing frequency were blurring, blindness, scotoma and visual processing deficits. The most common finding during the neurological exam was memory deficits, followed by increased deep tendon reflexes (asymmetric in some), visual perception deficits, visual information processing deficits, altered mental status and cranial nerve deficits. Intracranial or intraspinal pressure when examined was elevated. Among neuroimaging studies, MRI was more sensitive compared to CT scan. The MRI abnormalities included both white as well as gray matter and the most common location of abnormalities was high frontal/parietal lobe. The laboratory studies revealed proteinuria in majority, but not in all. The liver function tests were abnormal in many, while few patients had HELLP syndrome. The neurological deficits resolved by the time of discharge in all. At follow-up, some patients developed new neurological problems such as recurrent headaches or seizures.

Neurologic complications of inferior petrosal sinus sampling

BACKGROUND AND PURPOSE

Inferior petrosal sinus sampling (IPSS) is a useful diagnostic technique in adrenocorticotropic hormone (ACTH)-dependent hypercortisolism with normal or equivocal MR imaging. The procedure is believed to be safe, with mostly minor complications. However, there are rare, but severe, neurologic complications that need to be considered.

MATERIALS AND METHODS

We performed an institutional review board-approved retrospective review of our institutional IPSS experience from July 2001 to January 2007. IPSS was performed for the evaluation of Cushing disease. The end points of particular interest were the indications for IPSS and the incidence of associated complications.

RESULTS

During the study period of 5(1/2) years, 44 patients underwent IPSS for evaluation of Cushing disease. There were 33 women and 11 men with a mean age of 43.1 years. Because of equivocal imaging and endocrine testing, 36 of 44 patients underwent IPSS, and 8 of 44 underwent IPSS after failed transsphenoidal exploration. The only complication was injury to the brain stem that occurred after an unremarkable procedure in a 42-year-old woman. She developed clinical evidence of pontomedullary dysfunction with MR imaging consistent with brain stem infarction. The cause of this injury is unclear, but a venous variant leading to transient venous hypertension or thrombosis is suspected.

CONCLUSION

Neurologic injury is a rare but serious complication associated with IPSS. Despite this, if performed under a strict paradigm, IPSS is both accurate and safe and can be very useful in the management of Cushing disease.

Hypertensive encephalopathy presenting with isolated brain stem and cerebellar edema

Hypertensive encephalopathy typically presents with headache and confusion and bilateral parietooccipital vasogenic edema. Brain stem and cerebellar edema in hypertensive encephalopathy usually occurs in association with these typical supratentorial changes and is usually asymptomatic. We report here an uncommon hypertensive patient with isolated, severe, and symptomatic brain stem and cerebellar edema with fourth ventricular obstruction and mild hydrocephalus. Rapid treatment of hypertension resulted in clinical and radiological improvement. Prompt recognition of the cause and aggressive treatment of hypertension in such patients are crucial to relieve edema and prevent life-threatening progression.

Central pontine lesions observed with MRI in four diabetic patients

We report four diabetic patients with a central pontine lesion on magnetic resonance imaging (MRI). All patients also had hypertension, diabetic neuropathy and nephropathy, and three had chronic hepatitis C. Their neurological symptoms were disproportionately mild compared with the MRI features, which were of high intensity on T2-weighted images, but were less prominent on T1- and diffusion-weighted images. A subclinical pontine lesion was found in two patients who had undergone MRI previously. We consider that diabetes mellitus is an important factor for developing a pontine lesion with or without symptoms, probably in association with hepato-renal problems and hypertension.

Reversible posterior leukoencephalopathy syndrome in a patient with multiple system atrophy: A possible association with oral midodrine treatment

We describe a 51-year-old man with a 3-year history of multiple system atrophy, who developed a reversible posterior leukoencephalopathy syndrome (RPLS) after receiving prescription midodrine for therapeutic treatment of orthostatic hypotension. Typical reversible magnetic resonance imaging findings, following treatment with midodrine, suggested a possible relationship between midodrine treatment, supine hypertension, and RPLS, although a cause-and-effect relationship cannot be confirmed.

Clinicoradiological factors influencing the reversibility of posterior reversible encephalopathy syndrome: a multicenter study

PURPOSE

The aim of this retrospective study was to clarify the relation between the reversibility of posterior reversible encephalopathy syndrome (PRES) with three factors: the anatomical region of the brain involved, the background clinical cause, and the diffusion weighted image (DWI) intensity of PRES lesions.

MATERIAL AND METHODS

This multicenter study, conducted by the PRES Study Group of the Neuroradiology Workshop, involved 52 cases from 28 institutions. Initial and follow-up magnetic resonance imaging were compared regarding the reversibility of PRES lesions according to anatomical location and clinical background. Initial DWI and apparent diffusion coefficient (ADC) maps were reviewed in 20 cases.

RESULTS

Reversibility was significantly lower (P < 0.01) in the brain stem (44%) and deep white matter (47%) compared to the other cortical and subcortical areas (76%-91%). The reversibility was greater in the eclampsia subgroup followed by the hypertension and chemotherapy subgroups. DWI, even with ADC maps, had limitations in predicting the outcome of PRES lesions.

CONCLUSION

The typical cortical and subcortical PRES lesions showed reversibility, whereas the brain stem and deep white matter lesions showed less reversibility. PRES due to eclampsia showed maximum reversibility compared to hypertension- and drug-related PRES. DWI, even with ADC maps, had limitations in predicting the course of PRES.

Tumor lysis syndrome as a contributory factor to the development of reversible posterior leukoencephalopathy

INTRODUCTION

Reversible posterior leukoencephalopathy syndrome (RPLS) is a recently described clinical and radiological entity comprising headache, seizures, altered level of consciousness and visual disturbances in association with transient posterior cerebral white-matter abnormalities.

METHOD

We report a young woman with Burkitt's lymphoma who developed RPLS after combined chemotherapy administered during the tumor lysis syndrome.

RESULTS

The symptoms in this patient fitted well with those of RPLS; they included abrupt alterations in mental status, seizures, headache, visual changes and characteristic neuroradiological findings. She was given further combination chemotherapy without any neurological complications, at which time she had already recovered from both RPLS and tumor lysis syndrome.

CONCLUSION

Although many etiological factors have been reported in the development of RPLS, the underlying mechanism is not yet well understood. With prompt and appropriate management, RPLS is usually reversible, and chemotherapy can be continued after complete recovery from RPLS. We suggest that tumor lysis syndrome should be considered as a contributory factor to the development of RPLS in patients for whom treatment with combined chemotherapy for hematological malignancies is planned.