Neurologic Problems After Pediatric Liver Transplantation and Combined Liver and Bowel Transplantations: A Single Tertiary Centre Experience

Factors Associated With Neurobehavioral Complications in Pediatric Abdominal Organ Transplant Recipients Identified Using Computable Composite Definitions

OBJECTIVES

Neurologic complications occur in up to 40% of adult abdominal solid organ transplant recipients and are associated with increased mortality. Comparable pediatric data are sparse. This study describes the occurrence of neurologic and behavioral complications (neurobehavioral complications) in pediatric abdominal solid organ transplant recipients. We examine the association of these complications with length of stay, mortality, and tacrolimus levels.

DESIGN

The electronic health record was interrogated for inpatient readmissions of pediatric abdominal solid organ transplant recipients from 2009 to 2017. A computable composite definition of neurobehavioral complication, defined using structured electronic data for neurologic and/or behavioral phenotypes, was created.

SETTING

Quaternary children's hospital with an active transplant program.

PATIENTS

Pediatric abdominal solid organ transplant recipients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Computable phenotypes demonstrated a specificity 98.7% and sensitivity of 63.0% for identifying neurobehavioral complications. There were 1,542 readmissions among 318 patients, with 65 (20.4%) having at least one admission with a neurobehavioral complication (total 109 admissions). Median time from transplant to admission with neurobehavioral complication was 1.2 years (interquartile range, 0.52-2.28 yr). Compared to encounters without an identified neurobehavioral complication, encounters with a neurobehavioral complication were more likely to experience ICU admission (odds ratio, 3.9; 2.41-6.64; p < 0.001), have longer ICU length of stay (median 10.3 vs 2.2 d; p < 0.001) and hospital length of stay (8.9 vs 4.3 d; p < 0.001), and demonstrate higher maximum tacrolimus level (12.3 vs 9.8 ng/mL; p = 0.001). Patients with a neurobehavioral complication admission were more likely to die (odds ratio, 5.04; 1.49-17.09; p = 0.009). In a multivariable analysis, type of transplant, ICU admission, and tacrolimus levels were independently associated with the presence of a neurobehavioral complication.

CONCLUSIONS

Common electronic health record variables can be used to accurately identify neurobehavioral complications in the pediatric abdominal solid organ transplant population. Late neurobehavioral complications are associated with increased hospital resource utilization, mortality, and tacrolimus exposure. Additional studies are required to delineate the relationship between maximum tacrolimus level and neurobehavioral complications to guide therapeutic drug monitoring and dosing.

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.

Epidemiology, Comorbidities, and Outcomes of Posterior Reversible Encephalopathy Syndrome in Children in the United States

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognized entity with certain identified predisposing factors in children. However, the actual incidence, comorbidities, outcomes, and hospitalization charges among children (aged less than 20 years) in the United States are largely unknown.

METHODS

We analyzed the Kids' Inpatient Database for incidence of PRES-related hospitalizations, associated diagnoses, in-hospital outcomes, and charges for children in the United States in 2016. We report demographics, risk factors, discharge status, mortality, length of stay, and hospitalization charges.

RESULTS

In 2016, 825 pediatric hospitalizations related to PRES were captured in the Kids' Inpatient Database. Hospital discharges including solid organ transplant, bone marrow transplant, hypertension, renal disorder, primary immunodeficiency, malignancy, sepsis, severe sepsis, systemic connective tissue disorder, blood transfusion, hypomagnesemia, and sickle cell anemia were queried for presence of PRES. The majority of patients were discharged home. We found that PRES-related hospitalizations were significantly associated with increased length of stay and hospitalization charges in 2016 (P < 0.001). A mortality rate of 3.2% was found in PRES-related hospitalizations when compared with 0.4% in non-PRES hospitalizations (P < 0.001).

CONCLUSION

PRES accounted for 0.04% of the hospitalizations in this database. Hypertension and the presence of a renal disorder are the most significant risk factors found to be associated with PRES. The presence of PRES was associated with a significant increase in hospitalization charges and increased length of stay.

Dephosphorylation by calcineurin regulates translocation of dynamin-related protein 1 to mitochondria in hepatic ischemia reperfusion induced hippocampus injury in young mice

Hepatic ischemia reperfusion (HIR) has been found to induce brain injury and cognitive dysfunction. Dynamin-related protein 1 (Drp1) mediated mitochondrial fission involves oxidative stress, apoptosis and several neurological diseases. In this study, we investigated whether Drp1 translocation to mitochondria was implicated in HIR induced hippocampus injury in young mice, and further detected the role of calcineurin in the regulation of mitochondrial dynamics. 2-week C57BL/6 mice were chosen to make HIR model. Western blot was used to detect mitochondrial dynamics regulating proteins in whole hippocampal tissues and extracted mitochondria. Transmission electron microscopy was used to observe mitochondrial morphology. TUNEL staining and ELISA (serum S100β/NSE concentrations) were used to evaluate neurons apoptosis and brain injury respectively. Drp1 inhibitor Mdivi-1 and calcineurin inhibitor FK506 were utilized to further confirm the role of Drp1 and calcineurin. Results showed that HIR affected mitochondrial dynamics in a fission-dominant manner with translocation of Drp1 to mitochondria in hippocampus of young mice. HIR induced increased expression of calcineurin and dephosphorylation of Drp1 at Ser637 in hippocampus. Treatment with Mdivi-1 and FK506 upregulated the phosphorylation of Drp1, inhibited Drp1 translocation to mitochondria, and alleviated mitochondrial fragmentation after HIR. What's more, Mdivi-1 and FK506 restrained cytochrome c release and cleaved caspase-3 expression, ameliorated hippocampal neurons apoptosis, and decreased serum S100β/NSE concentrations as well. These data suggest that calcineurin mediated Drp1 dephosphorylation and translocation to mitochondria play a crucial role in HIR induced mitochondrial fragmentation and neurons apoptosis in hippocampus.

Liver transplantation during infancy: No increased rate of neurological complications

pLT is a highly standardized therapy for children with end-stage liver disease and liver-based metabolic diseases. However, NCs after transplantation occur and especially younger children are considered as more vulnerable and susceptible to NCs. Up to now, detailed data particularly for the very young age group do not exist. We therefore retrospectively studied NCs in children after pLT under age of 24 months. Forty children aged between 19 days and 22 months were evaluated according to type of NC and potential risk factors. NCs occurred in 8/40 patients (20%). All experienced new-onset seizures and in 1/6 surviving patients, seizures evolved into epilepsy. Other NCs were intracerebral abscess (1/8 patients) and subdural hemorrhage (1/8 patients). The overall 3-year mortality rate was 10% (4/40 patients). Significant risk factors for NCs and therefore seizures were HAT (P = 0.020), total surgery time (P = 0.009), retransplantation (P < 0.001), period of catecholamine therapy (P = 0.024), period of mechanical ventilation (P = 0.014), and period of sedation (P = 0.010). Our study is the first to provide detailed information on NCs after pLT in children under 24 months of age. The incidence of NCs in this particular group of very young patients was not increased compared to previously published data of children of all ages. Main NC was new-onset seizure. In the surviving infants, prognosis of seizure was excellent and the risk of developing epilepsy was low. Even more, the occurrence of NCs did not significantly affect mortality or survival in this particular age group.

Fludarabine-Induced Posterior Reversible Encephalopathy Syndrome in a Pediatric Patient With β-Thalassemia: Case Report and Literature Review

Posterior reversible encephalopathy syndrome is a disorder of reversible subcortical vasogenic brain edema in the context of different diseases or exposure to cytotoxic drugs such as fludarabine. We present the case of a pediatric patient with β-thalassemia who develops a fludarabine-induced posterior reversible encephalopathy while he received an induction regimen to achieve an allogenic hematopoietic cell transplantation. The clinical presentation consists in altered mental state, headache, status epilepticus, visual disturbance, and hypertension. His treatment was carried out with the suspension of the medication and the control of hypertension and status epilepticus; the final outcome was positive without additional complications. There are published reports about fludarabine toxicity in the central nervous system with different doses of the drug in different clinical context. We also made a review of the literature available and conclude that fludarabine is not an extraordinary cause of posterior reversible encephalopathy syndrome.

Childhood Stroke and Vision: A Review of the Literature

OBJECTIVE

Here we review the current literature regarding visual outcome after perinatal and childhood stroke.

BACKGROUND

Visual deficits following stroke in adults are common and have been previously reviewed. Less is known about visual deficits following stroke in neonates and older children. Most of the literature regarding this subject has focused on preterm infants, or on other types of brain injury. This review summarizes the types of visual deficits seen in term infants following perinatal stroke and children following childhood stroke and predictors of outcome. This review suggests areas for future research.

METHODS

We performed Ovid MEDLINE searches regarding visual testing in children, vision after childhood stroke, neuroplasticity of vision, treatment of visual impairment after stroke, and driving safety concerns after stroke.

RESULTS

Visual field defects were the most commonly reported visual deficits after perinatal and childhood stroke. There is a significant lack of literature on this subject, and most is in the form of case reports and case series. Children can experience significant visual morbidity after stroke, and have the potential to show some recovery, but guidelines on assessment and treatment of this population are lacking.

CONCLUSIONS

There were limitations to this study, given the small amount of literature available. Although stroke in children can result in severe visual deficits, most children regain at least a portion of their vision. However, more research is needed regarding visual assessment of this population, long-term visual outcomes, specific predictors of recovery, and treatment options.

Early and late neurological complications of liver transplantation in pediatric patients

NCs occur commonly after solid organ transplantation and affect 15%-30% of liver transplant recipients. The aim of this retrospective study was to evaluate the type and incidence of neurologic events in pediatric patients following LT. Between May 2006 and June 2015, 242 patients (118 females, 124 males) requiring LT for different etiologies at the İnönü University Liver Transplantation Institute were included. The incidence, types, and risk factors of NCs that occurred following LT were evaluated retrospectively. Neurologic events occurred in 57 (23.5%) of the patients. Early NCs were encephalopathy (12.4%), seizures (11.5%), and PRES (7%). Of 57 patients, five (8.7%) experienced NCs at least 1 month after LT; these late NCs included tremor, headaches, encephalopathy, ataxia, and neuropathy. The psychiatric symptoms after LT were noted in 42 patients (17.4%). The mortality rate after LT in those with or without neurological events was not significantly different (P=.73). There was a high incidence of serious neurologic events after LT. The major neurologic manifestation in our patients was encephalopathy followed by seizures.

Neurologic Complications After Cardiac Transplant

OBJECTIVES

Cardiac transplant is the best available therapy for patients with end-stage heart failure. Neurologic complications occur at a rate of 30% to 70% in patients undergoing cardiac transplant, and they affect mortality and morbidity of these patients. Risk factors for neurologic complications include immunosuppressive medication toxicity, infections, brain lesions, and metabolic disorders. The aim of our study was to determine the incidence of neurologic complications in adult patients undergoing cardiac transplant.

MATERIALS AND METHODS

We retrospectively evaluated the medical records of 70 patients who underwent cardiac transplant between 2004 and April 2016. We recorded the demographic data, neurologic symptoms, neurologic examination findings, laboratory test results, brain imaging study results, and treatments received of the patients.

RESULTS

Of the 70 patients enrolled, 55 were male and 15 were female patients. The age range was 18 to 63 years, and the mean age was 42.4 years. Twelve patients had encephalopathy, 4 had neuropathic pain, 3 had tremor, 2 had ischemic cerebrovascular accident, 7 had posterior reversible encephalopathy syndrome, and 1 had drop foot. Encephalopathy usually developed secondary to other neurologic disorders. The incidence of neurologic complications in adult patients undergoing cardiac transplant was 30%.

CONCLUSIONS

Neurologic complications are common after cardiac transplant. We observed an incidence of 30% for neurologic complications in our clinic, with encephalopathy being the most common complication. Encephalopathy most commonly developed secondary to posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome: clinical and radiological manifestations, pathophysiology, and outstanding questions

Almost two decades have elapsed since posterior reversible encephalopathy syndrome (PRES) was described in an influential case series. This usually reversible clinical syndrome is becoming increasingly recognised, in large part because of improved and more readily available brain imaging. Although the pathophysiological changes underlying PRES are not fully understood, endothelial dysfunction is a key factor. A diagnosis of PRES should be considered in the setting of acute neurological symptoms in patients with renal failure, blood pressure fluctuations, use of cytotoxic drugs, autoimmune disorders, or eclampsia. Characteristic radiographic findings include bilateral regions of subcortical vasogenic oedema that resolve within days or weeks. The presence of haemorrhage, restricted diffusion, contrast enhancement, and vasoconstriction are all compatible with a diagnosis. In most cases, PRES resolves spontaneously and patients show both clinical and radiological improvements. The range of symptoms that can comprise the syndrome might be broader than usually thought. In its mild form, this disorder might cause only one clinical symptom (headache or seizure) and radiographically might show few areas of vasogenic oedema or even normal brain imaging in some rare cases. In severe forms, PRES might cause substantial morbidity and even mortality, most often as a result of acute haemorrhage or massive posterior fossa oedema causing obstructive hydrocephalus or brainstem compression.

PRES in Children Undergoing Hematopoietic Stem Cell or Solid Organ Transplantation

Posterior reversible encephalopathy syndrome (PRES) is a clinical neuroradiologic entity that is becoming increasingly well known and documented in pediatrics. It is characterized by a variable association of seizures, headache, vomiting, altered mental status, visual disturbances, and seizures, as well as imaging suggesting white-gray matter edema involving the posterior regions of the central nervous system in most cases. The pathophysiology of PRES remains unclear. Although PRES has been associated with a widespread range of clinical conditions, namely infections, adverse drug events, autoimmune diseases, and many others, its onset after hematopoietic stem cell and solid organ transplantation remains the most commonly reported. Historically, PRES has proved to be generally reversible and associated with good clinical outcomes; however, severe complications, sometimes life-threatening, can also occur. Most reported cases of childhood PRES after hematopoietic stem cell or solid organ transplantation have been case reports or series across a broad spectrum of different transplant settings, and no clear consensus exists regarding how best to manage the syndrome. Thus, in this article, we provide a comprehensive review of the pathophysiological, clinical, and diagnostic aspects of PRES in children, with a specific focus on the transplant scenario. Differential diagnoses with other neurologic complications after pediatric transplantation are reviewed, and crucial issues in the management of PRES and the development of future research are ultimately addressed.

Risk factors for neurological complications and their correlation with survival following pediatric liver transplantation

Despite the improved outcomes of LT, post-operative NCs remain a significant cause of morbidity and mortality. The aim of the study was to identify the incidence of and risk factors for NCs in children who underwent LT. The medical records of pediatric patients who underwent LT at Asan Medical Center Children's Hospital between January 1994 and December 2010 were retrospectively analyzed. The onset and types of NC and pretransplant variables associated with NC were evaluated. We identified 190 children (85 boys [44.7%], 105 girls [55.3%]) of mean age 4.1 ± 4.7 yr, who underwent LT. Forty-six NCs occurred in 41 (21.6%) patients after LT, the most common being seizures (n = 13, 28.3%) and encephalopathy (n = 10, 21.7%). Of the 46 NCs, 24 (52.2%) occurred within three months after LT. Multivariate analysis showed that primary liver disease, preoperative neurological problems, preoperatively higher serum creatinine concentration, and graft failure were significant risk factors for NCs. The survival rate was significantly lower for patients with NCs than for those without (p < 0.001). NCs after pediatric LTs were common and associated with a higher mortality rate in our study. Close monitoring and appropriate risk management may improve the long-term outcomes of pediatric patients who undergo LT.

Tacrolimus-related seizure after pediatric liver transplantation--a single-center experience

To identify the risk factors for new-onset seizures after pediatric LT and to assess their clinical implications and long-term prognosis. The clinical and laboratory data of 27 consecutive children who underwent LT from January 2007 to December 2010 in our center were analyzed retrospectively. Patients were divided into seizures group and a non-seizures group. Pre-operative, intra-operative, and post-operative data were collected. Seizures occurred in four children, an incidence of 14.8%. All exhibited generalized tonic-clonic seizures within the first two wk after LT. Univariate analysis showed that the risk factors associated with seizures after pediatric LT included gender, pediatric end-stage liver disease score before surgery, Child-Pugh score before surgery, serum total bilirubin after surgery, and trough TAC level. Multivariate analysis showed that trough TAC level was the only independent risk factor associated with the seizures. All children who experienced seizures survived with good graft function and remained seizure-free without anti-epileptic drugs over a mean follow-up period of 33.7 ± 14.6 months. High trough TAC level was the predominant factor that contributed to seizures in the early post-operative period after pediatric LT. High PELD and Child-Pugh scores before LT and high post-operative serum Tbil may be contributory risk factors for TAC-related seizures.

Neurologic complications of pancreas and small bowel transplantation

In the past decade, substantial improvements in patient and graft survival for pancreas and small bowel transplants have been achieved. Despite this progress, many patients still develop neurologic complications in the course of their illness. Small bowel transplants produce more neurologic complications because of the complex metabolic environment in which the procedure is performed and because of the intense immune suppression necessitated by the greater immunogenicity of the intestinal mucosa. Pancreas transplants stabilize and/or improve the signs and symptoms of diabetic neuropathy over time. Because transplantation of the pancreas is often coupled with a kidney transplant and small intestine with liver, neurologic complications in these patients sometimes reflect problems involving the organ partner or both organs. The spectrum of neurologic complications for pancreas and small bowel transplant recipients is similar to other organ transplants but their frequency varies depending on the type of transplant performed.

Posterior reversible encephalopathy syndrome: incidence and associated factors in a pediatric critical care population

BACKGROUND

Posterior reversible encephalopathy syndrome may occur frequently and be underrecognized in children and young adults admitted to a pediatric critical care unit.

METHODS

Patients <21 years of age with the diagnosis of posterior reversible encephalopathy syndrome were reviewed in this retrospective cohort study conducted over a 30-month period.

RESULTS

There were 2588 admissions to pediatric critical care unit, 226 neurology service consultations, and 10 patients diagnosed with posterior reversible encephalopathy syndrome (incidence of 1 in 259 pediatric critical care unit admissions, 0.4%). The majority of posterior reversible encephalopathy syndrome patients (9/10) presented with generalized tonic and or clonic seizures. Apart from hypertension and cytotoxic medication use, anemia, a previously unreported risk factor, was found in all 10 (100%) patients with posterior reversible encephalopathy syndrome. One-year follow up available in eight patients showed no residual neurological deficits attributable to posterior reversible encephalopathy syndrome with significant resolution of white matter signal abnormalities on neuroimaging.

CONCLUSION

Our case cohort includes an estimation of incidence of posterior reversible encephalopathy syndrome in children and young adults with 1-year follow-up and anemia as a potential previously unreported risk factor.

[Neurological complications in patients receiving solid organ transplants]

INTRODUCTION

Neurological complications (NC) are a significant cause of morbidity and mortality in paediatric patients receiving solid organ transplants. Our aim was to describe the experience of our hospital with NC in paediatric patients receiving heart, lung and liver transplants.

PATIENTS AND METHODS

A retrospective study was conducted on 140 paediatric patients who received a solid organ transplant during the period 2000-2011.

RESULTS

A total of 23 paediatric solid organ transplant recipients (16.4% of cases), with a median age of 6 years, had NC. The symptoms were, in order of frequency: acute symptomatic seizures (12 patients); acute encephalopathy (11 patients); neuromuscular weakness (4 children), tremor (4 children), headache (2 children), neuropathic pain (2 children), and visual disturbances (2 children). The aetiologies of NC were: the neurotoxicity of the immunosuppressive drugs (12 patients), post-hypoxic-ischaemic encephalopathy (6 patients), infections (2 cases), mechanical compression of peripheral nerve during surgery (2 cases), and a metabolic complication (1 case). The five patients who met the criteria of posterior reversible encephalopathy syndrome had a favourable outcome. Seven patients died, four of them due to hypoxic-ischaemic encephalopathy.

CONCLUSIONS

NC are common in paediatric patients receiving heart, liver, lung, and renal transplants, with acute symptomatic seizures and acute encephalopathy being the most common clinical signs. No differences were found in the NC with the different types of transplants. Neurotoxicity of the immunosuppressive drugs and hypoxic-ischaemic encephalopathy were the main causes of NC, having different management and outcomes. The prognosis was favourable in most of the patients, except for those who had moderate or severe post-hypoxic-ischaemic damage.

Central pontine myelinolysis: a case report and clinical-pathological review

An 11-yr-old child presented with acute mental status changes and spastic quadriplegia after orthotopic liver transplantation. Magnetic resonance (MR) imaging findings were consistent with central pontine and EPM. Initial immunosuppression included tacrolimus, mycophenolate mofetil, and corticosteroids. Given that neurotoxicity is a well-established side effect of CNI, the patient was converted to rapamycin and subsequently experienced significant neurologic recovery. The temporal resolution of the patient's symptoms suggests that prompt recognition of central pontine and EPM and conversion from tacrolimus to rapamycin during the early post-operative course may have therapeutic benefits for patients undergoing pediatric transplant with CNI-related neurotoxicity.