Incidence and risk factors for seizures after heart transplantation

Neurological Complications in Patients with Heart Transplantation

Neurological complications after heart transplantation are common and include cerebrovascular events (ischemic strokes, hemorrhagic strokes, and transient ischemic attacks), seizures, encephalopathy, central nervous system (CNS) infections, malignancies, and peripheral nervous system complications. Although most neurological complications are transient, strokes and CNS infections can result in high mortality and morbidity. Early recognition and timely management of these serious complications are crucial to improve survival and recovery. Diagnosing CNS infections can be challenging because their clinical presentation can be subtle in the setting of immunosuppression. Immunosuppressive medications themselves can cause a broad spectrum of neurological complications including seizures and posterior reversible encephalopathy syndrome. This article provides a review of the diagnosis and management of neurological complications after cardiac transplantation.

Neurologic Complications of Transplantation

Neurologic disturbances including encephalopathy, seizures, and focal deficits complicate the course 10-30% of patients undergoing organ or stem cell transplantation. While much or this morbidity is multifactorial and often associated with extra-cerebral dysfunction (e.g., graft dysfunction, metabolic derangements), immunosuppressive drugs also contribute significantly. This can either be through direct toxicity (e.g., posterior reversible encephalopathy syndrome from calcineurin inhibitors such as tacrolimus in the acute postoperative period) or by facilitating opportunistic infections in the months after transplantation. Other neurologic syndromes such as akinetic mutism and osmotic demyelination may also occur. While much of this neurologic dysfunction may be reversible if related to metabolic factors or drug toxicity (and the etiology is recognized and reversed), cases of multifocal cerebral infarction, hemorrhage, or infection may have poor outcomes. As transplant patients survive longer, delayed infections (such as progressive multifocal leukoencephalopathy) and post-transplant malignancies are increasingly reported.

Seizures after transplantation

PURPOSE

To summarize information on the history, incidence, clinical manifestation, best treatment, as well as prognosis of seizures in transplant recipients.

METHODS

In October 2017, we searched the literature on PubMed in English with the search terms: "transplantation" AND "seizure", "transplantation" AND "epilepsy", "transplantation"AND "status epilepticus", "immunosuppressant" AND "seizure", "immunosuppressant" AND "epilepsy". Publications not based on new data and original research were not included in this article.

RESULTS

Seizures including generalized seizures, focal seizures and status epilepticus are a common central nervous system complication after transplantation. The incidence of seizures varied between different kinds of transplantations. The reported incidence of seizures was 7%-27% in association with solid organ transplantations and 1.6%-15.4% with hematopoietic stem cell transplantation. Most of seizures appeared in the early post-transplantation period. Patients often had a favorable prognosis, however, in some conditions, recurrent or intractable seizures may occur.

CONCLUSIONS

The underlying pathogenesis of new-onset seizures or epilepsy in recipients of transplantation needs to be further elucidated. In addition, more information is required from prospective studies and research focusing on therapeutic strategies.

Neurologic complications of transplantation

Major neurologic morbidity, such as seizures and encephalopathy, complicates 20-30% of organ and stem cell transplantation procedures. The majority of these disorders occur in the early posttransplant period, but recipients remain at risk for opportunistic infections and other nervous system disorders for many years. These long-term risks may be increasing as acute survival increases, and a greater number of "sicker" patients are exposed to long-term immunosuppression. Drug neurotoxicity accounts for a significant proportion of complications, with posterior reversible leukoencephalopathy syndrome, primarily associated with calcineurin inhibitors (i.e., cyclosporine and tacrolimus), being prominent as a cause of seizures and neurologic deficits. A thorough evaluation of any patient who develops neurologic symptoms after transplantation is mandatory, since reversible and treatable conditions could be found, and important prognostic information can be obtained.

Calcineurin Inhibitors Associated Posterior Reversible Encephalopathy Syndrome in Solid Organ Transplantation: Report of 2 Cases and Literature Review

Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic side effect of calcineurin inhibitors (CNIs) with poorly understood clinical features.We report cases of 2 patients with PRES developing after kidney transplantation and summarize PRES clinical features through a literature review.The 1st case was a 28-year-old man who received a kidney transplant from a deceased donor. Initial immunosuppressive therapy consisted of tacrolimus/mycophenolate mofetil/prednisolone. He developed headache and blurred vision with visual field loss15 days after transplantation and generalized seizures 4 days later. The 2nd case was a 34-year-old man who received a living kidney transplant. His initial immunosuppressive therapy comprised tacrolimus/mycophenolate mofetil/prednisolone. Two months after transplantation, he developed seizures. Both patients were diagnosed with PRES based on neurological symptoms and magnetic resonance imaging (MRI) findings; they recovered after switching from tacrolimus to either a cyclosporine or a lower tacrolimus dose. CNI-associated PRES is an acute neurological syndrome with seizures, encephalopathy, visual abnormalities, headache, focal neurological deficits, and nausea/vomiting. It is always accompanied by hypertension. A fluid-attenuated inversion recovery signal MRI scan typically shows reversible subcortical white matter changes in the posterior cerebral hemisphere that usually occur within the 1st month after transplantation. CNI-associated PRES has a generally favorable prognosis with early diagnosis and prompt treatment including alternating or discontinuing CNIs and blood pressure control.CNI-associated PRES should be considered in patients exhibiting acute neurological symptoms after transplantation. Early diagnosis and immediate treatment are critical for a favorable prognosis.

Cerebral pathology post heart transplantation

Cerebral pathology is frequently encountered post heart transplantation with a cumulative incidence of about 80% after 15 years. A broad spectrum of disease entities is reported, from minor abnormalities to life-threatening diseases. Although cerebral infections and malignancies are rare in this patient population, they have a high mortality rate. Since 1991, 171 orthotopic heart transplantations were performed at the Ghent University Hospital with a 10-year survival rate of 75%. Severe cerebral complications occurred in 10 patients, with epilepsy in 2 patients, cerebrovascular accidents in 4 patients, cerebral infections in 3 patients and a cerebral malignancy in 1 patient, resulting in a fatal outcome in 7 patients. We present four of these cases.

Metabolische Störungen

Im folgenden Kapitel werden die verschiedenen metabolischen Störungen betrachtet. Zunächst wird auf die allgemeinen und spezifischen neurologischen Komplikationen bei Organtransplantation eingegangen. Dann geht es um die metabolischen Enzephalopathien: Störungen der Gehirntätigkeit bei angeborenen und erworbenen Stoffwechselerkrankungen im engeren Sinn, Elektrolytstörungen, Hypovitaminosen, zerebrale Folgen einzelner Organdysfunktionen, zerebrale Hypoxien, Endotheliopathien und Mitochondropathien. Anschließend werden das Alkoholdelir und die Wernicke-Enzephalopathie erörtert. Bei zahlreichen akuten Erkrankungen von Gehirn, Rückenmark und peripherem Nervensystem treten typische Störungen vegetativer Systeme auf, deren Erkennung und Therapie insbesondere bei Intensivpatienten eine vitale Bedeutung haben kann: die autonomen Störungen. Bei der zentralen pontinen Myelinolyse kommt es zu einer akuten, vorwiegend fokal-symmetrischen Demyelinisierung im Hirnparenchym. Auch Basalganglienerkrankungen können intensivmedizinisch relevant werden. Und schließlich wird die akute Stressreaktion betrachtet, die aufgrund der vielfältigen metabolischen und endokrinen Veränderungen bei kritischen Erkrankungen entsteht. Gerade das RCVS als neuere Krankheitsentität und wichtige Differenzialdiagnose zur Vaskulitis des ZNS verdient einen eigenen Platz, in diesem Unterkapitel werden ebenfalls verwandte Syndrome wie die hypertensive Enzephalopathie und das PRES abgehandelt.

Neurologic aspects of heart transplantation

Cardiac transplantation remains the best treatment option for patients with end-stage, NYHA class IV heart failure who have failed conventional therapy. However, transplant rates have remained static largely due to limited organ donor supplies. Therefore, appropriate allocation of this precious resource is critical to maximize benefit, both at a patient level and at a societal level. Neurologic diseases, such as cerebrovascular disease and peripheral neuropathy, are prevalent in this patient population, as the major risk factors for heart disease place patients at risk for neurologic disease as well. Examples include hypertension, smoking, hypercholesterolemia, obesity, and diabetes. Pretransplant neurologic evaluation is very important to identify conditions that may limit survival after cardiac transplantation. In general, systemic diseases exacerbated by immunosuppression, conditions limiting ability to rehabilitate, and dementias are considered contraindications. Post-transplant neurologic complications are divided into central versus peripheral, and early versus late. The most common early complication is ischemic stroke. Other serious complications include hemorrhagic stroke, encephalopathy, and critical illness neuropathy. Over the long term, post-transplant immunosuppressive regimens are considered "a double edged sword." Although immunosuppressive medications are critical to preventing rejection and allograft dysfunction, they do have significant risk of morbidity and mortality associated with them, including neurologic side-effects. These include: (1) drug toxicities, such as lowering of seizure thresholds; (2) encephalopathy, such as posterior reversible encephalopathy syndrome (PRES); (3) infections; (4) malignancies, such as post-transplant lymphoproliferative disorder (PTLD). Many of the same considerations discussed in adult heart transplant recipients apply to pediatric heart transplant recipients as well. In children, seizures are the most common neurologic complication, although other neurologic complication rates are comparable.

[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.

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.