Two cases of malignant hypertension with reversible diffuse leukoencephalopathy exhibiting a reversible nocturnal blood pressure "riser" pattern

Etiologies, Cerebral Vasomotion, and Endothelial Dysfunction in the Pathophysiology of Posterior Reversible Encephalopathy Syndrome in Pediatric Patients

The posterior reversible encephalopathy syndrome was characterized by Hinchey and colleagues in the 1990s. The condition frequently afflicts patients suffering from hematologic and solid organ malignancy and individuals undergoing transplantation. Cases are more frequently described in the adult population compared with children. In the pediatric population, malignancy, transplantation, renal disease, and hypertension represent the most common etiologies. Theories on pathogenesis have centered upon cerebrovascular dysautoregulation with increases in blood–brain barrier permeability. This generates vasogenic edema of the cerebral parenchyma and consequent neurologic deficits. The parietal and occipital lobes are affected with greatest prevalence, though frontal and temporal lobe involvement is frequent, and that of the contents of the infratentorial posterior cranial fossa are occasionally described. The clinical presentation involves a characteristic constellation of neurologic signs and symptoms, most typically inclusive of headache, visual-field disturbances, abnormalities of visual acuity, and seizures. Supportive care, withdrawal of the offending agent, antihypertensive therapy, and prophylactic anticonvulsants affect convalescence in majority of cases. The principal challenge lies in identifying the responsible agent precipitating the condition in patients with malignancy and those having undergone transplantation and thus deciding which medication among a multidrug treatment regimen to withhold, the duration of drug cessation required to effect clinical resolution, and the safety of resuming treatment with the compound. We accordingly reviewed and evaluated the literature discussing the posterior reversible encephalopathy syndrome in children.

Posterior reversible encephalopathy syndrome in pediatric patients: pathophysiology, diagnosis, and management

Posterior reversible encephalopathy syndrome (PRES) is well-described in adults, but has been reported with relative rarity in children, usually occurring in the context of chemotherapy for acute leukemia. Pathogenesis involves perturbed cerebral autoregulation leading to vasogenic edema predominantly affecting the parieto-occipital white matter, though involvement of the frontal and temporal lobes, as well as posterior fossa, is also described. We review the literature on the pathophysiology, diagnosis, and management of PRES in pediatric patients.

Posterior reversible encephalopathy syndrome in pediatric patients undergoing treatment for hemophagocytic lymphohistiocytosis: clinical outcomes and putative risk factors

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare multiorgan disease of toxic immune activation caused by the interaction of cytotoxic T cells and innate immune cells and frequently involves the central nervous system (CNS). Posterior reversible encephalopathy syndrome (PRES) might develop during treatment with the HLH-2004 protocol from the Histiocyte Society. The aims of this study were to evaluate clinical outcomes and putative risk factors for prediction of PRES related to HLH.

Methods

We reviewed the medical records of 28 patients with HLH who were treated between April 2005 and April 2012. We compared various clinical and laboratory parameters in patients without or with PRES to evaluate putative risk factors related to development of PRES.

Results

Six (21.4%) of the patients experienced PRES during treatment with the HLH-2004 protocol. Clinical and laboratory manifestations were not different compared with other conditions causing PRES. The main mechanism of PRES may be related to the HLH-2004 protocol and a high pro-inflammatory state. Most patients recovered quickly from neurologic manifestations without significant long-term sequelae. Preceding hypertension, an increase in ferritin level >50% compared with 1 week before development of PRES and hyponatremia were statistically significant factors.

Conclusion

PRES is clinically reversible and has a favorable outcome in patients with HLH. Awareness of PRES and a differential diagnosis of other causes of neurologic complications, including CNS involvement of HLH, can help avoid unnecessary treatment or delayed management. Patients with preceding hypertension, hyponatremia, and rising ferritin levels during HLH treatment should be closely monitored for PRES.

Posterior reversible encephalopathy associated with nocturnal blood pressure non-dipping pattern

We report the case of a 70-year-old man who presented with a recent history of headache, altered mental status and sleepiness. He was known to have type II diabetes mellitus, and a mild, treated and apparently well controlled hypertension. Brain magnetic resonance imaging demonstrated extensive abnormalities in the parieto-occipital white matter, suggestive of posterior reversible encephalopathy syndrome (PRES). An extensive diagnostic evaluation did not allow the detection of any known cause of the syndrome. Twenty-four-hour non-invasive ambulatory blood pressure monitoring showed a mild to moderate hypertension, with non-dipping pattern. This case suggests that, in the context of an overnight blunted blood pressure profile, even a mild or moderate hypertension can result in cerebral vasogenic oedema, underlining the diagnostic importance of 24-h blood pressure monitoring in patients with PRES without severe hypertension or other commonly recognized causes of posterior reversible encephalopathy.

Predisposing factors of posterior reversible encephalopathy syndrome in acute childhood leukemia

A retrospective chart review was performed on 19 patients aged <18 years who developed posterior reversible encephalopathy syndrome as a complication during treatment of acute childhood leukemia. Posterior reversible encephalopathy syndrome was most often observed during acute lymphoblastic leukemia induction chemotherapy (n = 9, 47.4%) and after hematopoietic stem cell transplantation (n = 8, 42.1%). Among eight patients with the complication of posterior reversible encephalopathy syndrome after hematopoietic stem cell transplantation, five (62.5%) had a history of hypertension. In contrast, among 11 patients with the complication of posterior reversible encephalopathy syndrome without hematopoietic stem cell transplantation, only one (9.1%) had a history of hypertension. Moreover, unlike other leukemia induction chemotherapy, posterior reversible encephalopathy syndrome developed only in patients who received acute lymphoblastic leukemia induction chemotherapy. Posterior reversible encephalopathy syndrome patients required long-term anticonvulsant therapy (n = 9, 50.0%) and manifested intractable seizures (n = 3, 16.7%). Sequelae were evident in long-term follow-up magnetic resonance images (n = 5, 26.3%). Acute lymphoblastic leukemia chemotherapy regimens apparently comprised the main predisposing factors for posterior reversible encephalopathy syndrome complicated during induction chemotherapy, compared with hypertension and immunosuppressive agents after hematopoietic stem cell transplantation.

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.

Clinical features of encephalopathy in children with cancer requiring cranial magnetic resonance imaging

We analyzed acute neurotoxic problems attributable to chemotherapy or immunosuppression in the context of childhood neoplastic diseases, based on clinical and neuroradiologic findings. This retrospective single-center study reviewed the acute neurologic complications of 62 children receiving conventional chemotherapy or hematopoietic stem cell transplantation from July 2005-July 2008. We excluded patients with central nervous system metastasis and various neurotoxic manifestations not usually requiring cranial magnetic resonance imaging. Of 62 patients, 12 (19.3%) developed acute neurologic complications. The most common complications included posterior reversible encephalopathy syndrome in six of 12 (50%) patients, and Wernicke's encephalopathy in three of 12 (25%) patients. Other complications included chemical arachnoiditis, grey matter injury induced by postchemotherapeutic angiopathy, and leukoencephalopathy. Posterior reversible encephalopathy syndrome was accompanied by hypertensive episodes in most patients (5/6), and Wernicke's encephalopathy was evident with altered mental status in malnourished children. These data indicate that posterior reversible encephalopathy syndrome and Wernicke's encephalopathy are the predominant complications in children undergoing chemotherapy or hematopoietic stem cell transplantation. Early radiologic and clinical evaluation and prompt treatment for these complications are necessary to prevent their progression to irreversible brain damage.

Reversible multifocal leukoencephalopathy associated with a nocturnal blood pressure non-dipper pattern

The majority of cases of leukoencephalopathy related to hypertensive crisis show brain lesions predominantly in the posterior lobe. Such cases are usually classified as reversible posterior leukoencephalopathy syndrome (RPLS). A multifocal distribution pattern is also possible, but occurs seldom. Here we report two patients with extensive white matter lesions that affect the entire brain, related to hypertensive crisis associated with a non-dipper pattern of blood pressure during the night as well as renal dysfunction. This nocturnal blood pressure abnormality may be relevant for the distribution pattern of cerebral white matter lesions and underlines the concept that in these cases a 24-h ambulatory blood pressure monitoring is needed.

[Reversible posterior leukoencephalopathy: report of two cases after vincristine treatment]

Reversible posterior leukoencephalopathy syndrome is a clinical-radiological phenomenon associated with headache, vomiting, lethargy, visual disturbances and seizures, concomitant with radiological abnormalities predominantly within posterior cerebral white matter due to cerebral edema. There are multiple triggers as acute hypertension, cancer, hematological disease, renal pathology, red cells transfusions and different drugs. We present two patients with reversible posterior leukoencephalopathy under treatment for acute lymphoblastic leukemia because of the probable association with vinca alkaloids.

Renal Sodium Handling and Nighttime Blood Pressure

Blood pressure follows a circadian rhythm with a physiologic 10% to 20% decrease during the night. There is now increasing evidence that a blunted decrease or an increase in nighttime blood pressure is associated with a greater prevalence of target organ damage and a faster disease progression in patients with chronic kidney diseases. Several factors contribute to the changes in nighttime blood pressure including changes in hormonal profiles such as variations in the activity of the renin-angiotensin and the sympathetic nervous systems. Recently, it was hypothesized that the absence of a blood pressure decrease during the nighttime (nondipping) is in fact a pressure-natriuresis mechanism enabling subjects with an impaired capacity to excrete sodium to remain in sodium balance. In this article, we review the clinical and epidemiologic data that tend to support this hypothesis. Moreover, we show that most, if not all, clinical conditions associated with an impaired dipping profile are diseases associated either with a low glomerular filtration rate and/or an impaired ability to excrete sodium. These observations would suggest that renal function, and most importantly the ability to eliminate sodium during the day, is indeed a key determinant of the circadian rhythm of blood pressure.

Posterior reversible encephalopathy syndrome in children with cancer

PURPOSE

To identify predisposing factors, radiologic features, and clinical outcome of posterior reversible leucoencephalopathy (PRES) in children receiving cancer treatment.

METHODS

We identified 11 patients (7 female) who had radiological and clinical features consistent with PRES and were treated for cancer at St. Jude Children's Research Hospital between January 1995 and January 2005. Clinical and radiographic data were abstracted from their records.

RESULTS

The average age at the time of PRES onset was 10.4 years. Primary diagnoses were acute leukemia (n = 8), non-Hodgkin lymphoma (n = 2), and Ewing sarcoma (n = 1). PRES occurred in 8 patients during the induction phase of treatment, and all 11 patients had hypertension (5 chronically). Seizure activity was proximate to cytarabine and tacrolimus administration in three patients and further seizures occurred with re-administration of these medications in two patients. Coagulation and chemistry studies were normal. Concurrent brain magnetic resonance imaging (MRI) demonstrated T2 signal abnormalities in all 11 patients, restricted diffusion in 4, and hemorrhage in 3. Follow-up MRI showed chronic changes consistent with a previous hemorrhage in three and evidence of prior parenchymal ischemia in one. Three patients developed epilepsy and remain on chronic anticonvulsant therapy.

CONCLUSIONS

PRES is an increasingly recognized complication of pediatric cancer treatment. Risk factors for PRES in pediatric cancer patients include hypertension (not necessarily acute), remission induction chemotherapy, and administration of tacrolimus. MR images often show atypical findings, some of which are irreversible. A significant number of patients develop epilepsy despite clinical and radiographic evidence of recovery.

A case of reversible posterior leukoencephalopathy syndrome caused by transient hypercoagulable state induced by infection

We report a normotensive case of reversible posterior leukoencephalopathy syndrome caused by transient hypercoagulable state. Hypertension is the main risk factor for reversible posterior leukoencephalopathy syndrome, which is believed to occur as a result of high blood pressure-related dysfunction of cerebrovascular endothelial cells, because it commonly appears in hypertensive emergency. However, in this completely normotensive case, the typical clinical findings of reversible posterior leukoencephalopathy syndrome were triggered by transient hypercoagulable state without any blood pressure variation. The case was successfully treated with anticoagulation therapy using heparin. Thus, this case indicates that reversible posterior leukoencephalopathy syndrome is induced by cerebrovascular endothelial dysfunction, which is induced not only by high blood pressure but also hemostatic dysfunction.

Reversible Leukoencephalopathy Syndrome Associated to Leukopenia in a Chronic Hemodialysis Patient

Reversible leukoencephalopathy syndrome (RLS) is a rare brain disorder, characterized by diffuse attenuation of cerebral white matter, which has been most commonly observed in transplant patients receiving calcineurin inhibitors or in patients with severe hypertension. We report an episode of RLS in a 22-year-old male patient on chronic hemodialysis with well-controlled moderate hypertension who presented with de novo headache and generalized seizures. Cranial magnetic resonance image (MRI) revealed multiple areas of increased signal intensity in the white matter on T2-weighed images which resolved spontaneously at subsequent MRIs. White blood cell count showed leucopenia with normal CD4 count at flow cytometry. A viral etiology could not be demonstrated. Reversible leukoencephaolopathy syndrome symptoms remitted within 72 h but leukopenia persisted over 10 months. The patient received a kidney transplant 15 months after RLS onset and has received cyclosporine since the second post-transplant day. No recurrence of RLS symptoms has been observed. The etiology of the MRI changes in the present case seemed not to be either vasogenic or cytotoxic.

Event-Related Brain Potentials in Elderly Dippers and Nondippers with Recently Diagnosed Hypertension

Several studies have shown a relationship between blood pressure (BP) and cognitive function. Yet very few studies have addressed circadian BP patterns in this context, perhaps due to poor availability of suitable methods to detect slight changes in the cognitive state. Today, brain event-related potentials (ERPs) allow us to detect subclinical changes in cognitive function. We enrolled 30 elderly patients with recently diagnosed hypertension (<2 years) that had never been treated: 18 dippers and 12 nondippers. Patients underwent 24-h ambulatory blood pressure monitoring (ABPM). Careful assessment of their cognitive state was carried out using the mini mental state examination (MMSE), and the recording of P300 and N2 ERPs. No significant differences between the two groups were found. MMSE scores in dippers and nondippers were similar (29.5+/-0.71 vs. 29.3+/-1.07, respectively; p =0.611), as were P300 latency values (377.78+/-33.28 vs. 364.67+/-35.12 in the central (Cz) position, p =0.310; 379.22+/-32.94 vs. 365.25+/-35.07 in the occipital (Pz) position, p =0.277) and N2 wave latency values (253.83+/-24.9 vs. 249.17+/-24.47 in the Cz position, p =0.617; 251.56+/-25.86 vs. 246.58+/-25.46 in the Pz position, p =0.608). These data show no association between the nondipping pattern and lower cognitive function in elderly subjects with recent hypertension.

Management of hypertension emergencies

Although they have become less common, hypertensive emergencies occur with an incidence of approximately 1 to 2/100,000 people per year. Our knowledge about this problem, its pathophysiology, risk factors, and appropriate treatment options has expanded during the past decade. A hypertensive emergency can be declared when an elevated blood pressure is associated with acute target-organ damage. Rapid evaluation and treatment (typically with an intravenously administered agent) should be instituted, usually in an intensive care unit setting, and the patient should be observed carefully during acute blood-pressure lowering. When properly treated, the prognosis for these patients is not nearly as dismal as it was more than 60 years ago, and the initial level of function of target organs (brain, heart, kidneys) is more indicative of an emergency than the actual level of blood pressure. Therapeutic options include the time-tested sodium nitroprusside (which has toxic metabolic products and is contraindicated in pregnancy, tobacco amblyopia, and Leber's optic atrophy); fenoldopam mesylate; and nicardipine. When properly treated, "malignant hypertension" need be considered malignant no longer.