Posterior reversible encephalopathy syndrome after solid organ transplantation

Posterior reversible encephalopathy syndrome in a renal allograft recipient: A complication of immunosuppression?

Posterior reversible encephalopathy syndrome (PRES) is an uncommon post-renal transplant complication. We report a 16-year-old boy who had an acute cellular rejection immediate post-transplant and was given intravenous methylprednisolone along with an increase in tacrolimus dose. He was diagnosed to have PRES based on clinical and radiological features within 6 h of intensified immunosuppression. This is an unusual case report of successfully managing PRES with continuation of the intensified immunosuppression as warranted by the clinical situation, along with aggressive blood pressure control. After 6 weeks, magnetic resonance imaging showed complete resolution of lesions. He has good graft function and no residual neurological deficits while on small doses of three antihypertensives, 12 months after transplantation.

Posterior reversible encephalopathy syndrome independently associated with tacrolimus and sirolimus after multivisceral transplantation

Posterior reversible encephalopathy syndrome (PRES) is a small vessel microangiopathy of the cerebral vasculature that occurs in 0.5-5% of solid organ transplant recipients, most commonly associated with tacrolimus (Tac). Clinical manifestations include hypertension and neurologic symptoms. We report an adult multivisceral transplant recipient who experienced recurrent PRES initially associated with Tac and subsequently with sirolimus. A 49-year-old woman with short bowel syndrome underwent multivisceral transplantation due to total parenteral nutrition-related liver disease. She was initially maintained on Tac, mycophenalate mofetil (MMF) and prednisone. Three months after transplantation, she developed renal dysfunction, leading to a reduction in Tac and the addition of sirolimus. Eight months after transplantation, she developed PRES. Tac was discontinued and PRES resolved. Sirolimus was increased to maintain trough levels of 12-15 ng/mL. Fourteen months after transplant, she experienced recurrent PRES which resolved after discontinuing sirolimus. Currently 3 years posttransplant, she is maintained on cyclosporine, MMF and prednisone with no PRES recurrence. In addition to calcineurin inhibitors, sirolimus may also be associated with PRES after solid organ transplantation. Ours is the first report of sirolimus-associated PRES in the setting of multivisceral transplantation. Identifying a safe alternative immunosuppression regimen was challenging but ultimately successful.

Lung transplantation and posterior reversible encephalopathy syndrome: a case series

Posterior reversible encephalopathy syndrome is a neurological problem characterized by headache, altered mental status, focal neurological deficits, visual disorders, and seizures. The disorder is related to a number of diseases including calcineurin inhibitor therapy in solid organ transplantation. The incidence of posterior reversible encephalopathy syndrome in lung transplantation patients is unclear; probably the majority of the cases are unreported. The authors have described a case series constituted of four patients presenting posterior reversible encephalopathy syndrome after bilateral lung transplantation. The cases had in common complicated surgery and a posttransplant course characterized by hypertension, hypomagnesemia and acidosis. Invasive mechanical ventilation, calcineurin inhibitor discontinuation, aggressive antihypertensive therapy, and electrolyte regulation led to near complete recovery of symptoms.

Fatal atypical reversible posterior leukoencephalopathy syndrome: a case report

INTRODUCTION

Reversible posterior leukoencephalopathy syndrome - a reversible subacute global encephalopathy clinically presenting with headache, altered mental status, visual symptoms such as hemianopsia or cortical blindness, motor symptoms, and focal or generalized seizures - is characterized by a subcortical vasogenic edema symmetrically affecting posterior brain regions. Complete reversibility of both clinical signs and magnetic resonance imaging lesions is regarded as a defining feature of reversible posterior leukoencephalopathy syndrome. Reversible posterior leukoencephalopathy syndrome is almost exclusively seen in the setting of a predisposing clinical condition, such as pre-eclampsia, systemic infections, sepsis and shock, certain autoimmune diseases, various malignancies and cytotoxic chemotherapy, transplantation and concomitant immunosuppression (especially with calcineurin inhibitors) as well as episodes of abrupt hypertension. We describe for the first time clinical, radiological and histological findings in a case of reversible posterior leukoencephalopathy syndrome with an irreversible and fatal outcome occurring in the absence of any of the known predisposing clinical conditions except for a hypertensive episode.

CASE PRESENTATION

A 58-year-old Caucasian woman presented with a two-week history of subacute and progressive occipital headache, blurred vision and imbalance of gait and with no evidence for raised arterial blood pressure during the two weeks previous to admission. Her past medical history was unremarkable except for controlled arterial hypertension. Cerebral magnetic resonance imaging demonstrated cortical and subcortical lesions with combined vasogenic and cytotoxic edema atypical for both venous congestion and arterial infarction. Routine laboratory and cerebrospinal fluid parameters were normal. The diagnosis of reversible posterior leukoencephalopathy syndrome was established.Within hours after admission the patient showed a rapidly decreasing level of consciousness, extension and flexion synergisms, bilaterally extensor plantar responses and rapid cardiopulmonary decompensation requiring ventilatory and cardiocirculatory support. Follow-up cerebral imaging demonstrated widespread and confluent cytotoxic edematous lesions in different arterial territories, global cerebral swelling, and subsequent upper and lower brainstem herniation. Four days after admission, the patient was declared dead because of brain death.

CONCLUSION

This case demonstrates that fulminant and fatal reversible posterior leukoencephalopathy syndrome may occur spontaneously, that is, in the absence of any of the known predisposing systemic conditions.

Neurologic Implications of Critical Illness and Organ Dysfunction

Critical illness has consequences for the nervous system. Patients experiencing critical illness are at risk for common global neurologic disturbances, such as delirium, long-term cognitive dysfunction, ICU-acquired weakness, sleep disturbances, recurrent seizures, and coma. In addition, complications related to specific organ dysfunction may be anticipated. Cardiovascular disease presents the possibility for CNS injury after cardiac arrest, sequelae of endocarditis, aberrancies of blood flow autoregulation, and malperfusion. Respiratory disease is known to cause short-term effects of hypoxia and long-term effects after ARDS. Sepsis encephalopathy and sickness behavior syndrome are early signs of infection in patients. In addition, commonly encountered organ dysfunction including uremia, hepatic failure, endocrine, and metabolic disturbances present with neurologic findings which may manifest in the critically ill patient as well.

Reversible cerebral vasoconstriction syndrome

Recurrent thunderclap headaches, seizures, strokes, and non-aneurysmal subarachnoid haemorrhage can all reveal reversible cerebral vasoconstriction syndrome. This increasingly recognised syndrome is characterised by severe headaches, with or without other symptoms, and segmental constriction of cerebral arteries that resolves within 3 months. Reversible cerebral vasoconstriction syndrome is supposedly due to a transient disturbance in the control of cerebrovascular tone. More than half the cases occur post partum or after exposure to adrenergic or serotonergic drugs. Manifestations have a uniphasic course, and vary from pure cephalalgic forms to rare catastrophic forms associated with several haemorrhagic and ischaemic strokes, brain oedema, and death. Diagnosis can be hampered by the dynamic nature of clinicoradiological features. Stroke can occur a few days after initial normal imaging, and cerebral vasoconstriction is at a maximum on angiograms 2-3 weeks after clinical onset. The calcium channel blocker nimodipine seems to reduce thunderclap headaches within 48 h of administration, but has no proven effect on haemorrhagic and ischaemic complications.

Seizure treatment in transplant patients

OPINION STATEMENT

Solid organ transplantation is frequently complicated by a spectrum of seizure types, including single partial-onset or generalized tonic-clonic seizures, acute repetitive seizures or status epilepticus, and sometimes the evolution of symptomatic epilepsy. There is currently no specific evidence involving the transplant patient population to guide the selection, administration, or duration of antiepileptic drug (AED) therapy, so familiarity with clinical AED pharmacology and application of sound judgment are necessary for successful patient outcomes. An initial detailed search for symptomatic seizure etiologies, including metabolic, infectious, cerebrovascular, and calcineurin inhibitor treatment-related neurotoxic complications such as posterior reversible encephalopathy syndrome (PRES), is imperative, as underlying central nervous system disorders may impose additional serious risks to cerebral or general health if not promptly detected and appropriately treated. The mainstay for post-transplant seizure management is AED therapy directed toward the suspected seizure type. Unfavorable drug interactions could place the transplanted organ at risk, so choosing an AED with limited interaction potential is also crucial. When the transplanted organ is dysfunctional or vulnerable to rejection, AEDs without substantial hepatic metabolism are favored in post-liver transplant patients, whereas after renal transplantation, AEDs with predominantly renal elimination may require dosage adjustment to prevent adverse effects. Levetiracetam, gabapentin, pregabalin, and lacosamide are drugs of choice for treatment of partial-onset seizures in post-transplant patients given their efficacy spectrum, generally excellent tolerability, and lack of drug interaction potential. Levetiracetam is the drug of choice for primary generalized seizures in post-transplant patients. When intravenous drugs are necessary for acute seizure management, benzodiazepines and fosphenytoin are the traditional and best evidence-based options, although intravenous levetiracetam, valproate, and lacosamide are emerging options. Availability of several newer AEDs has greatly expanded the therapeutic armamentarium for safe and efficacious treatment of post-transplant seizures, but future prospective clinical trials and pharmacokinetic studies within this specific patient population are needed.

Posterior reversible encephalopathy syndrome: the importance of early diagnosis

A 14-year-old boy was submitted to cardiac transplant due to a dilated cardiomyopathy. On the fourth day of immunosuppression (corticosteroids, mycophenolate mofetil and tacrolimus), he developed right focal seizures and drowsiness. Blood pressure was in the normal range and laboratory findings in cerebral spinal fluid and blood were unremarkable, with drugs in non-toxic levels. The EEG showed a slow background rhythm more pronounced on the right and a seizure onset in the right occipital region. MRI revealed a diffuse hyperintense subcortical white-matter lesion on fluid attenuated inversion recovery, with lesser involvement of left temporal-occipital region. There was no enhancement with gadolinium and MRI diffusion-weighted imaging was consistent with vasogenic oedema. Tacrolimus was stopped with regression of MRI abnormalities and clinical recovery. Posterior reversible encephalopathy associated with tacrolimus is a rare but potentially serious complication of solid organ transplants. A prompt diagnosis and correct treatment is essential to avoid irreversible brain damage.

Posterior reversible encephalopathy syndrome in liver transplant patients: clinical presentation, risk factors and initial management

Posterior reversible encephalopathy syndrome (PRES) is an uncommon but well-known complication after transplantation diagnosed by characteristic radiological features. As limited data on this complex syndrome exist we sought to better define the incidence, clinical presentation and risk factors for PRES in liver transplant (LTx) patients. We conducted a retrospective analysis of 1923 adult LTx recipients transplanted between 2000 and 2010. PRES was diagnosed radiologically in 19 patients (1%), with 84% of cases occurring within 3 months post-LTX. We compared this cohort of PRES patients to 316 other LTx recipients also requiring radiographic imaging within 3 months after LTx for neurological symptoms. Seizure was the most common clinical manifestation in the PRES group (88% vs. 16%, p< 0.001) and 31% had an intracranial hemorrhage. Those with hemorrhage on imaging were more likely to be coagulopathic. PRES patients were significantly more likely to have had alcoholic liver disease and infection/sepsis. These factors may be related to a common pathway of vascular dysregulation/damage that appears to characterize this complex syndrome. Intracranial bleeding and seizures may be the end result of these phenomena. The relationship of these associated factors to the hypothesized pathophysiology of PRES is discussed.

[Posterior reversible encephalopathy syndrome]

Posterior reversible encephalopathy syndrome (PRES) is a clinically and radiologically defined syndrome characterized by seizures, headaches, visual disturbances, and altered mental status or focal neurological deficits. Imaging frequently shows abnormalities in the posterior brain regions, especially the occipital and the parietal lobes. PRES has been described in association with a wide spectrum of underlying causes. The most common conditions include hypertension, renal disease, preeclampsia/eclampsia, or status post transplantation. The pathophysiology of PRES has not been sufficiently elucidated as yet; however, endothelial damage caused by different mechanisms possibly plays a central role. The prognosis of PRES is usually benign when intensive care and withdrawal of the causative agent is instituted early. Delay in diagnosis and treatment may lead to complications and permanent neurological deficits. The clinical and radiological landmarks of this syndrome as well as causes, pathophysiological hypotheses, and the basic therapeutic principles of PRES are the subject of the present review.

Nonsurgical care of intestinal and multivisceral transplant recipients: a review for the intensivist

Intestinal and multivisceral transplantation has evolved from an experimental procedure to the treatment of choice for patients with irreversible intestinal failure and serious complications related to long-term parenteral nutrition. Increased numbers of transplant recipients and improved survival rates have led to an increased prevalence of this patient population in intensive care units. Management of intestinal and multivisceral transplant recipients is uniquely challenging because of complications arising from the high incidence of transplant rejection and its treatment. Long-term comorbidities, such as diabetes, hypertension, chronic kidney failure, and neurological sequelae, also develop in this patient population as survival improves. This article is intended for intensivists who provide care to critically ill recipients of intestinal and multivisceral transplants. As perioperative care of intestinal/multivisceral transplant recipients has been described elsewhere, this review focuses on common nonsurgical complications with which one should be familiar in order to provide optimal care. The article is both a review of the current literature on multivisceral and isolated intestinal transplantation as well as a reflection of our own experience at the University of Miami.

Reversible posterior leukoencephalopathy syndrome: diagnosis and management in the setting of lung transplantation

Reversible posterior leukoencephalopathy syndrome (RPLS) is a potentially devastating early complication of calcineurin inhibitor (CNI) therapy in solid organ transplantation. Management centres on cessation of CNI therapy; however, this strategy is complicated in lung transplantation because of the threat of allograft rejection, or, if CNI is replaced with mammalian target of rapamycin-based immunosuppression, poor wound healing and bronchial dehiscence. We describe four cases of RPLS after lung transplantation, emphasizing the diagnostic and management approach required to maintain a healthy allograft and ensure that RPLS is, as the name suggests, reversible.

Analytic Review: Neurological Complications of Transplantation

Recipients of solid organ or hematopoietic cell transplants are at risk of life-threatening neurological disorders including encephalopathy, seizures, infections and tumors of the central nervous system, stroke, central pontine myelinolysis, and neuromuscular disorders—often requiring admission to, or occurring in, the intensive care unit (ICU). Many of these complications are linked directly or indirectly to immunosuppressive therapy. However, neurological disorders may also result from graft versus host disease, or be an expression of the underlying disease which prompted transplantation, as well as injury induced during radiation, chemotherapy, surgery, and ICU stay. In rare cases, neuroinfectious pathogens may be transmitted with the transplanted tissue or organ. Diagnosis may be a challenge because clinical symptoms and findings on neuroimaging lack specificity, and a biological specimen or tissue diagnosis is often needed for definitive diagnosis. Management is centered on preventing further neurological injury, etiology-targeted therapy, and balancing the benefits and toxicities of specific immunosuppressive agents.

Posterior reversible encephalopathy syndrome after liver transplantation in children: a rare complication related to calcineurin inhibitor effects

PRES is a neuroclinical and radiological syndrome that results from treatment with calcineurin inhibitor immunosuppressives. Severe hypertension is commonly present, but some patients may be normotensive. We report herein two children who received liver transplants, as treatment for biliary atresia in the first case and for Alagille's syndrome in the second one. In the early postoperative, both patients presented hypertension and seizures. In both cases, the image findings suggested the diagnosis of PRES. The CT scan showed alterations in the posterior area of the brain, and brain MRI demonstrated parietal and occipital areas of high signal intensity. Both children were treated by switching the immunosuppressive regimen and controlling arterial blood pressure. They displayed full recuperation without any neurologic sequelae. Probably, the pathophysiology of PRES results from sparse sympathetic innervation of the vertebrobasilar circulation, which is responsible for supplying blood to the posterior areas of the brain. In conclusion, all liver-transplanted children who present with neurological symptoms PRES should be considered in the differential diagnosis, although this is a rare complication. As treatment, we recommend rigorous control of arterial blood pressure and switching the immunosuppressive regimen.

Visuospatial impairment in children and adolescents after liver transplantation

A minority of children with liver transplants exhibit significant delay in global intelligence; others have specific learning disabilities. More specific data on neurocognitive strengths and weaknesses are lacking. Eighteen children aged 7-16 yr, who had undergone LTx in Finland participated in the study. They were assessed on an average 7.6 (s.d. 4.5, range 1.0-15.0) years post-operatively at a mean age of 11.8 (s.d. 3.1, range 7.2-16.1). A standardized test of intelligence (WISC-III), a neuropsychological test battery (NEPSY-II), and a parental questionnaire on the child's development (FTF) were administered. The neuropsychological test profile of the LTx group was compared with that of a matched control group of healthy children. The LTx children achieved on an average normal FSIQ 94.0 and VIQ 99.6. Their Performance Intelligence Quotient (PIQ 88.9, p=0.043) was, however, significantly lower than the population mean. On neuropsychological assessment, the LTx children scored generally lower than the control group (p=0.004), a difference significant in sub-tests assessing visuospatial and visuoconstructive functions and social perception. No differences emerged in sub-tests of attention and executive functions, memory and learning, or language functions. LTx children are at increased risk for impairment in the visuospatial domain.

Gemcitabine monotherapy associated with posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome is a clinicoradiologic entity that may present with headaches, altered mental status, seizures and visual loss as well as specific neuroimaging findings. We report a case of a 74-year-old woman receiving adjuvant gemcitabine chemotherapy as monotherapy for a stage IIa pancreatic adenocarcinoma, who developed posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual disturbances, and seizures. Radiological features typically include edema of the posterior cerebral regions, especially of the parietooccipital lobes. Atypical imaging features, such as involvement of anterior cerebral regions, deep white matter, and the brain stem are also frequently seen. Vasoconstriction is common in vascular imaging. Different conditions have been associated with PRES, but toxemia of pregnancy, solid organ or bone marrow transplantation, immunosuppressive treatment, cancer chemotherapy, autoimmune diseases, and hypertension are most commonly described. The pathophysiology of PRES is unclear and different hypotheses are being discussed. Posterior reversible encephalopathy syndrome is best managed by monitoring and treatment in the setting of a neurointensive care unit. The prognosis is usually benign with complete reversal of clinical symptoms within several days, when adequate treatment is immediately initiated. Treatment of severe hypertension, seizures, and withdrawal of causative agents represent the hallmarks of specific therapy in PRES. Delay in diagnosis and treatment may lead to permanent neurological sequelae. Therefore, awareness of PRES is of crucial importance for the intensivist.

Tacrolimus-induced polyneuropathy after heart transplantation

Tacrolimus has been often described to induce neuropathy in liver-, pancreas-, and renal-transplanted patients. Here, we report the first case of a 56-year-old woman who developed a progressive symmetric demyelinating sensorimotor polyneuropathy in the distal muscles of the lower limbs after therapy with tacrolimus because of heart transplantation. This condition suddenly reverted after the tacrolimus was stopped.

Epilepsy after neuroimaging normalization in a woman with tacrolimus-related posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is known to occur after solid organ transplantation, and is caused by immunosuppressive agents such as tacrolimus. PRES onset usually occurs within the first 2months after liver transplantation. Clinical findings include seizures, headache, focal neurological deficits, visual disturbances, and altered mental status. These are associated with characteristic imaging features of subcortical white matter lesions on brain MRI. Atypical localizations of this posterior leukoencephalopathy have been reported. Expeditious recognition of the syndrome may lead to a complete recovery. Abnormalities of EEG during follow-up might be associated with unfavorable seizure outcome, even when neuroimaging changes resolve. We report a case of late-onset PRES with atypical localization following liver transplantation. The patient developed epilepsy despite resolution of MRI lesions at 8 months of follow-up. EEG was a prognostic factor of seizure persistence, suggesting an incomplete recovery of brain lesions in contrast to neuroimaging findings.

Nonimmune complications after transplantation

As posttransplant longevity has increased, nonimmune complications related to the transplant and posttransplant course have emerged as important factors in defining long-term outcomes. The incidence of, and risk factors for these complications may vary by transplanted organ based on immunosuppressive protocols and preexisting risk factors. This article discusses the relevant nonimmune complications associated with posttransplant care, with a focus on risk factors and management strategies.

Psychiatric issues in solid organ transplantation

The identification and treatment of psychiatric comorbidity in patients undergoing solid organ transplantation present a unique opportunity for psychiatric involvement in the care of medically complex patients. The burden of psychiatric illness in patients awaiting transplant and following transplant is significant and associated with potential morbidity and mortality. Possibilities for psychiatric liaison with our colleagues in transplant medicine and surgery start with the comprehensive psychiatric evaluation that is often performed with potential organ recipients and donors. The vital role of the psychiatrist continues following transplantation, as adjustment is often a stressful experience with associated psychiatric comorbidity. The treatment of psychiatric illness in patients following transplantation requires an understanding of the immunosuppressant medications that patients may be taking, coupled with an awareness of the associated risks of adverse effects and drug-drug interactions.

Neurocognitive-neurological complications of liver transplantation: a review

Neurological complications are common after liver transplantation (LT) and they are associated with a significant morbidity. Long-term effects of LT on cognitive and psychological outcomes are not clear. The objective of this study was to summarize the present knowledge on the neurological and cognitive complications of LT, resulting from a systematic review of the literature in the last 10 years. Several studies have investigated the incidence and the pathophysiology of neurological complications; in contrast, the knowledge of cognitive and psychological status after LT is poor. Currently, the effect of LT on mental performance is debated. Some studies have shown an improvement of cognitive function after OLTX and, at the same time, a persistence of different cognitive deficits. In addition, the quality of life (QoL) and the psychological status after LT seem to improve but LT recipients have significant deficiencies in most QoL domains. Consequently, future studies are necessary in order to investigate cognitive alterations and QoL in LT recipients.

[Medical complications of lung transplantation]

In 2010, lung transplantation is a valuable therapeutic option for a number of patients suffering from of end-stage non-neoplastic pulmonary diseases. The patients frequently regain a very good quality of life, however, long-term survival is often hampered by the development of complications such as the bronchiolitis obliterans syndrome, metabolic and infectious complications. As the bronchiolitis obliterans syndrome is the first cause of death in the medium and long term, an intense immunosuppressive treatment is maintained for life in order to prevent or stabilize this complication. The immunosuppression on the other hand induces a number of potentially severe complications including metabolic complications, infections and malignancies. The most frequent metabolic complications are arterial hypertension, chronic renal insufficiency, diabetes, hyperlipidemia and osteoporosis. Bacterial, viral and fungal infections are the second cause of mortality. They are to be considered as medical emergencies and require urgent assessment and targeted therapy after microbiologic specimens have been obtained. They should not, under any circumstances, be treated empirically and it has also to be kept in mind that the lung transplant recipient may present several concomitant infections. The most frequent malignancies are skin cancers, the post-transplant lymphoproliferative disorders, Kaposi's sarcoma and some types of bronchogenic carcinomas, head/neck and digestive cancers. Lung transplantation is no longer an exceptional procedure; thus, the pulmonologist will be confronted with such patients and should be able to recognize the symptoms and signs of the principal non-surgical complications. The goal of this review is to give a general overview of the most frequently encountered complications. Their assessment and treatment, though, will most often require the input of other specialists and a multidisciplinary and transversal approach.

Posterior reversible encephalopathy syndrome and cerebral vasculopathy associated with influenza A infection: report of a case and review of the literature

BACKGROUND AND PURPOSE

Influenza A infection can precipitate encephalopathy, encephalitis, or Reye syndrome with the development of cerebral edema in children and is associated with an increased incidence of stroke in adults. The mechanism of these events is poorly understood. Posterior reversible encephalopathy syndrome (PRES) is seen in association with infection/sepsis, and cerebral vasculopathy has been demonstrated in PRES. We describe a case of PRES that develops in association with influenza A.

SUMMARY OF CASE

A normotensive 65-year-old woman presented with altered mentation and nausea in the setting of a viral prodromal illness ultimately confirmed as influenza A. Posterior reversible encephalopathy syndrome developed on the second day after admission. Catheter cerebral angiogram documented vasculopathy in PRES-involved regions with areas of focal vessel dilatation and string-of-bead appearance.

CONCLUSIONS

The association between influenza A and PRES with documentation of cerebral vasculopathy suggests a common systemic vascular mechanism behind PRES and influenza-related encephalopathic edema and stroke.

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.

Severe neurologic side effects in patients being treated for hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic Lymphohistiocytosis (HLH) is characterized by uncontrolled inflammation that is generally fatal without immune modulating chemotherapy. At Texas Children's Hospital, we have observed significant central nervous system (CNS) toxicity in several patients treated for HLH according to the Histiocyte Society protocol HLH-2004 in which cyclosporine is given early in the treatment regimen.

METHODS

Patients diagnosed with HLH at Texas Children's Hospital between April 2004 and October 2007 were identified and charts were reviewed. A reference group of patients treated between August 2001 and March 2004, prior to the introduction of HLH-2004, was also evaluated.

RESULTS

Five of 17 patients in the study group developed severe neurotoxicity. Four had new onset seizures associated with significant MRI abnormalities, while the fifth died of intracerebral hemorrhage. Timing of the development of neurologic side effects ranged from day 5 to week 6 of therapy. Cyclosporine levels were outside the therapeutic range (200-300 ng/ml) prior to the onset of symptoms in two of the five patients. Systolic blood pressures for all five patients were greater than the 95th percentile for age on at least one measurement within 24 hr of the onset of neurologic symptoms. MRI scans obtained within 24 hr of seizure activity in four patients were consistent with posterior reversible encephalopathy syndrome (PRES). By comparison only one patient in the reference group (n = 15) had neurotoxicity (PRES).

CONCLUSIONS

Patients being treated for HLH appear to be at risk for neurotoxicity, particularly PRES. Elevated blood pressure, worsening renal and liver function, increased cyclosporine levels, and CNS involvement of HLH may be triggers for the neurotoxic side effects of treatment. Patients being treated on HLH-2004 require close monitoring of their neurologic status and modifiable risk factors such as hypertension should managed aggressively. If larger studies validate our observations, it will be important to determine if up-front cyclosporine in HLH protocols confers a survival benefit that outweighs the potential risk of increased neurotoxicity.

Atypical imaging findings in a renal transplant patient with reversible posterior leukoencephalopathy syndrome: a case report

Background

Atypical clinical and imaging findings in Reversible Posterior Leukoencephalopathy Syndrome are recognized with increasing frequency.

Case report

We report a case of an adult in his 5^th decade immunosupressed with methilprednisolone, tacrolimus and micophenolate who two months after renal transplantation, multiple infections and an episode of humoral rejection became hypertensive with severe headaches, visual field abnormalities, seizures, left hemiparesis and hemineglect.

Computed Tomography scan of the brain showed a hypo dense lesion in the left occipital lobe. Ischemic stroke was diagnosed and aspirin and permissive hypertension were indicated. Twelve hours later he developed left sided motor seizures and cortical blindness. Magnetic Resonance Image showed hyper intensity in T2 and FLAIR in both occipital lobes and a small area of cortical restricted diffusion in Diffuson Weighted Images in the left occipital lobe. With a diagnosis of Reversible Posterior Leukoencephalopathy Syndrome his blood pressure was controlled with intravenous labetalol, and two days later the neurologic findings returned to baseline and most Computed tomography findings resolved.

Conclusion

This case underscores that in the appropriate setting Reversible Posterior Leukoencephalopathy Syndrome should be suspected and the clinician should not be misled by atypical clinical or imaging findings. In contrast to other pathologies that resemble Reversible Posterior Leukoencephalopathy Syndrome, with the right and timely treatment, signs, symptoms and images can be completely reversible.

Posterior reversible encephalopathy syndrome after combined general and spinal anesthesia with intrathecal morphine

We describe a patient who was in a stupor for several days after combined general-spinal anesthesia. Both clinical manifestations and magnetic resonance imaging findings were consistent with posterior reversible encephalopathy syndrome and resolved after the patient recovered spontaneously.

Posterior reversible encephalopathy syndrome

PURPOSE OF REVIEW

The ophthalmologist may be called upon to evaluate visual loss in a patient with posterior reversible encephalopathy syndrome. Familiarity with presentation and clinical management is imperative, as visual loss is often reversible with prompt treatment directed at causative factors.

RECENT FINDINGS

Since its initial description in 1996, the predisposing factors, clinical presentation and radiographic variation of posterior reversible encephalopathy syndrome continue to expand. Case reports of newly uncovered associations of the syndrome appear frequently. Originally considered a subcortical disease of the posterior cerebrum, posterior reversible encephalopathy syndrome has been shown to affect gray matter and can involve both the anterior and posterior cortex, brainstem, cerebellum or even the spinal cord. The pathophysiologic basis of cerebral edema and molecular mechanisms of edema underlying the syndrome are currently being revealed.

SUMMARY

Acute hypertension, eclampsia, immunosuppressive medication, infection or autoimmune diseases can all result in the clinical syndrome of vasogenic edema in the central nervous system leading to headache, seizure, confusion and frequent visual loss. The biologic basis for the syndrome is likely an insult to cerebral vascular autoregulation. MRI is essential in diagnosing a cerebral cause for visual loss. The ophthalmologist may have the initial opportunity to diagnose the syndrome. Treatment may reverse clinical deficits, and is based on eliminating the etiologic causation.

Posterior reversible encephalopathy syndrome, part 1: fundamental imaging and clinical features

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state coupled with a unique CT or MR imaging appearance. Recognized in the setting of a number of complex conditions (preeclampsia/eclampsia, allogeneic bone marrow transplantation, organ transplantation, autoimmune disease and high dose chemotherapy) the imaging, clinical and laboratory features of this toxic state are becoming better elucidated. This review summarizes the basic and advanced imaging features of PRES, along with pertinent features of the clinical and laboratory presentation and available histopathology. Many common imaging/clinical/laboratory observations are present among these patients, despite the perception of widely different associated clinical conditions.

Posterior reversible encephalopathy syndrome, part 2: controversies surrounding pathophysiology of vasogenic edema

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state accompanied by a unique brain imaging pattern typically associated with a number of complex clinical conditions including: preeclampsia/eclampsia, allogeneic bone marrow transplantation, solid organ transplantation, autoimmune diseases and high dose cancer chemotherapy. The mechanism behind the developing vasogenic edema and CT or MR imaging appearance of PRES is not known. Two theories have historically been proposed: 1) Severe hypertension leads to failed auto-regulation, subsequent hyperperfusion, with endothelial injury/vasogenic edema and; 2) vasoconstriction and hypoperfusion leads to brain ischemia and subsequent vasogenic edema. The strengths/weaknesses of these hypotheses are reviewed in a translational fashion including supporting evidence and current available imaging/clinical data related to the conditions that develop PRES. While the hypertension/hyperperfusion theory has been most popular, the conditions associated with PRES have a similar immune challenge present and develop a similar state of T-cell/endothelial cell activation that may be the basis of leukocyte trafficking and systemic/cerebral vasoconstriction. These systemic features along with current vascular and perfusion imaging features in PRES appear to render strong support for the older theory of vasoconstriction coupled with hypoperfusion as the mechanism.