Acute headache as a presenting symptom of tacrolimus encephalopathy

Thirty Years of Tacrolimus in Clinical Practice

Tacrolimus was discovered in 1984 and entered clinical use shortly thereafter, contributing to successful solid organ transplantation across the globe. In this review, we cover development of tacrolimus, its evolving clinical utility, and issues affecting its current usage. Since earliest use of this class of immunosuppressant, concerns for calcineurin-inhibitor toxicity have led to efforts to minimize or eliminate these agents in clinical regimens but with limited success. Current understanding of the role of tacrolimus focuses more on its efficacy in preventing graft rejection and graft loss. As we enter the fourth decade of tacrolimus use, newer studies utilizing novel combinations (as with the mammalian target of rapamycin inhibitor, everolimus, and T-cell costimulation blockade with belatacept) offer potential for enhanced benefits.

Impact of calcineurin inhibitors on rat glioma cells viability

Background

Although kidney transplantation outcomes have improved dramatically after using calcineurin inhibitors (CNIs), CNI toxicity continues to be reported and the mechanism remains uncertain. Here, we investigated the neurotoxicity of CNIs by focusing on the viability of glioma cells.

Methods

Glioma cells were treated with several concentrations of CNIs for 24 hours at 37℃ and their cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Results

Exposure to 0, 0.25, 0.5, 2.5, 5.0, and 10.0 mM concentrations respectively showed 100%, 64.3%, 61.3%, 68.1%, 62.4%, and 68.6% cell viability for cyclosporine and 100%, 38.6%, 40.8%, 43.7%, 37.8%, and 43.0% for tacrolimus. The direct toxic effect of tacrolimus on glioma cell viability was stronger than that of cyclosporine at the same concentration.

Conclusion

CNIs can cause neurological side effects by directly exerting cytotoxic effects on brain cells. Therefore, we should carefully monitor the neurologic symptoms and level of CNIs in kidney transplant patients.

Recent Topics on The Mechanisms of Immunosuppressive Therapy-Related Neurotoxicities

Although transplantation procedures have been developed for patients with end-stage hepatic insufficiency or other diseases, allograft rejection still threatens patient health and lifespan. Over the last few decades, the emergence of immunosuppressive agents such as calcineurin inhibitors (CNIs) and mammalian target of rapamycin (mTOR) inhibitors have strikingly increased graft survival. Unfortunately, immunosuppressive agent-related neurotoxicity commonly occurs in clinical practice, with the majority of neurotoxicity cases caused by CNIs. The possible mechanisms through which CNIs cause neurotoxicity include increasing the permeability or injury of the blood–brain barrier, alterations of mitochondrial function, and alterations in the electrophysiological state. Other immunosuppressants can also induce neuropsychiatric complications. For example, mTOR inhibitors induce seizures, mycophenolate mofetil induces depression and headaches, methotrexate affects the central nervous system, the mouse monoclonal immunoglobulin G2 antibody (used against the cluster of differentiation 3) also induces headaches, and patients using corticosteroids usually experience cognitive alteration. Therapeutic drug monitoring, individual therapy based on pharmacogenetics, and early recognition of symptoms help reduce neurotoxic events considerably. Once neurotoxicity occurs, a reduction in the drug dosage, switching to other immunosuppressants, combination therapy with drugs used to treat the neuropsychiatric manifestation, or blood purification therapy have proven to be effective against neurotoxicity. In this review, we summarize recent topics on the mechanisms of immunosuppressive drug-related neurotoxicity. In addition, information about the neuroprotective effects of several immunosuppressants is also discussed.

Posterior Reversible Encephalopathy Syndrome in a Bone Marrow Transplant Patient: A Complication of Immunosuppressive Drugs?

Posterior reversible encephalopathy is a complex but well-recognized clinical and radiological entity associated with a variety of benign and malignant conditions including hypertensive encephalopathy, eclampsia, renal failure and immunosuppressive drugs. The pathogenesis is incompletely understood, although it seems to be related to the breakthrough of auto-regulation and endothelial dysfunction. The clinical syndromes typically involve headache, altered mental status, seizures, visual disturbance and other focal neurological signs and radiographically reversible vasogenic subcortical edema without infarction. Here, we report a case of posterior reversible encephalopathy syndrome in a patient with chronic myeloid leukemia who received allogenic bone marrow transplantation (allo-BMT) and immunosuppressive drugs.

A systematic review of causes of sudden and severe headache (Thunderclap Headache): should lists be evidence based?

Background

There are many potential causes of sudden and severe headache (thunderclap headache), the most important of which is aneurysmal subarachnoid haemorrhage. Published academic reviews report a wide range of causes. We sought to create a definitive list of causes, other than aneurysmal subarachnoid haemorrhage, using a systematic review.

Methods

Systematic Review of EMBASE and MEDLINE databases using pre-defined search criteria up to September 2009. We extracted data from any original research paper or case report describing a case of someone presenting with a sudden and severe headache, and summarized the published causes.

Results

Our search identified over 21,000 titles, of which 1224 articles were scrutinized in full. 213 articles described 2345 people with sudden and severe headache, and we identified 6 English language academic review articles. A total of 119 causes were identified, of which 46 (38%) were not mentioned in published academic review articles. Using capture-recapture analysis, we estimate that our search was 98% complete. There is only one population-based estimate of the incidence of sudden and severe headache at 43 cases per 100,000. In cohort studies, the most common causes identified were primary headaches or headaches of uncertain cause. Vasoconstriction syndromes are commonly mentioned in case reports or case series. The most common cause not mentioned in academic reviews was pneumocephalus. 70 non-English language articles were identified but these did not contain additional causes.

Conclusions

There are over 100 different published causes of sudden and severe headache, other than aneurysmal subarachnoid haemorrhage. We have now made a definitive list of causes for future reference which we intend to maintain. There is a need for an up to date population based description of cause of sudden and severe headache as the modern epidemiology of thunderclap headache may require updating in the light of research on cerebral vasoconstriction syndromes.

Neurologic aspects of multiple organ transplantation

Complex multiorgan failure may require simultaneous transplantation of several organs, including heart-lung, kidney-pancreas, or multivisceral transplantation. Solid organ transplantation can also be combined with hematopoietic stem cell transplantation to modulate immunologic response to a solid organ allograft. Combined multiorgan transplantation may offer a lower rate of allograft rejection and lower immunosuppression needs. In recent years, intestinal and multivisceral transplantations became viable as a rescue treatment for patients with irreversible intestinal failure who can no longer tolerate total parenteral nutrition with 70% survival after 5 years which is comparable to other types of solid organ allografts. Post-transplant neurologic complications were reported in up to 86% of allograft recipients and greatly overlap in intestinal and multivisceral allograft recipients, without a significant effect on the outcome of transplantation. Other common organ combinations in multiorgan transplantation include kidney-pancreas, which is mostly used for patients with renal failure and uncontrolled diabetes, and heart-lung for patients with congenital heart disease and idiopathic pulmonary arterial hypertension. Kidney-pancreas transplantation frequently results in an improvement of diabetic complications, including diabetic neuropathy. Heart-lung allograft recipients have very similar clinical course and spectrum of neurologic complications to lung transplant recipients. At this time there are no reports of an increased risk of graft-versus-host disease with combined transplantation of solid organ allograft and hematopoietic stem cells. Chronic immunosuppression and complex toxic-metabolic disturbances after multiorgan transplantation create a permissive environment for development of a wide spectrum of neurologic complications which largely resemble complications after transplantations of individual components of complex multiorgan allografts.

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.

Influence of CYP3A5 and ABCB1 gene polymorphisms on calcineurin inhibitor-related neurotoxicity after hematopoietic stem cell transplantation

BACKGROUND

One severe side effect of calcineurin inhibitors (CNIs: such as cyclosporine [CsA] and tacrolimus [FK506]) is neurotoxicity. CNIs are substrates for CYP3A5 and P-glycoprotein (P-gp), encoded by ABCB1 gene. In the present study, we hypothesized that genetic variability in CYP3A5 and ABCB1 genes may be associated with CNI-related neurotoxicity.

METHODS

The effects of the polymorphisms, such as CYP3A5 A6986G, ABCB1 C1236T, G2677T/A, and C3435T, associated with CNI-related neurotoxicity were evaluated in 63 patients with hematopoietic stem cell transplantation.

RESULTS

  Of the 63 cases, 15 cases developed CNI-related neurotoxicity. In the CsA patient group (n = 30), age (p = 0.008), hypertension (p = 0.017), renal dysfunction (p < 0.001), ABCB1 C1236T (p < 0.001), and G2677T/A (p = 0.014) were associated with neurotoxicities. The CC genotype at ABCB1 C1236T was associated with it, but not significantly so (p = 0.07), adjusted for age, hypertension, and renal dysfunction. In the FK506 patient group (n = 33), CYP3A5 A6986G (p < 0.001), and ABCB1 C1236T (p = 0.002) were associated with neurotoxicity. At least one A allele at CYP3A5 A6986G (expressor genotype) was strongly associated with it according to logistic regression analysis (p = 0.01; OR, 8.5; 95% CI, 1.4-51.4).

CONCLUSION

  The polymorphisms in CYP3A5 and ABCB1 genes were associated with CNI-related neurotoxicity. This outcome is probably because of CYP3A5 or P-gp functions or metabolites of CNIs.

Neurologic complications of cardiac surgery and interventional cardiac procedures

Neurologic complications of cardiac surgery and interventional cardiac procedures may affect the central nervous system or the peripheral nervous system. The most common central nervous system complications are strokes and seizures. This article provides a succinct neuroanatomic and pathophysiologic approach to a wide array of neurologic complications associated with cardiac procedures.

Reversible posterior leukoencephalopathy syndrome

Reversible posterior leukoencephalopathy syndrome (RPLS) is characterized by subacute onset of headache, decreased alertness, vomiting, seizures, visuoperceptual disturbances, together with bilateral white matter lesions in posterior brain regions on brain imaging. The most frequently associated conditions related to RPLS are arterial hypertension and the use of immunosuppressive or cytotoxic treatment. T2-, Fluid Attenuation Inversion Recovery (FLAIR), and Apparent Diffusion Coefficient (ADC)-weighted magnetic resonance imaging (MRI) reveal hyperintensities in parietooccipital white matter but grey matter and other regions including frontal and temporal lobes, brainstem, cerebellum, basal ganglia, or even spinal cord may also be involved. According to ADC findings, the underlying pathophysiologic mechanism is probably one of vasogenic (rather than cytotoxic) oedema. These MRI findings help in differentiating RPLS from ischaemic events and other diseases resembling RPLS. Failure of cerebral autoregulation, endothelial dysfunction, disrupted blood-brain barrier, vasospasm, and direct toxic drug effects may all play a role in the pathophysiology of RPLS. Treatment consists of discontinuation of the causal drug, treatment of high blood pressure, and antiepileptic therapy. Clinical recovery and regression of radiological abnormalities are typically seen after early treatment. However, delay in diagnosis and treatment can result in irreversible brain damage, often in association with complicating cerebral infarction or haemorrhage.

The production of reactive oxygen species in tacrolimus-treated glial cells

OBJECTIVE

After organ transplantation, some patients suffer from mild neurological symptoms, such as tremor, to severe complications, including seizures and encephalopathy. These neurological side effects can be caused by immunosuppressants such as tacrolimus. However, the mechanism of encephalopathy by tacrolimus is not fully understood.

METHODS

We measured the production of reactive oxygen species (ROS) in glioma cells after tacrolimus treatment. Tacrolimus added to glioma cells was incubated for 60 minutes at 37 degrees C. The production of ROS was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2',7'-dichlorofluorescin using VICTOR3TM multilabel counter.

RESULTS

Tacrolimus resulted in the production of the ROS in glioma cells. The production of the ROS was increased in time-dependent fashion.

CONCLUSIONS

These findings indicated that the tacrolimus may contribute the neurological side effects by ROS production.

Entzündliche Erkrankungen des ZNS sowie immunmodulatorische Therapie und ihr Einfluss auf primäre Kopfschmerzen

Headaches are a well known symptom in systemic or local inflammatory diseases such as pneumonia or meningitis. These headaches may mimic primary headaches and are thought to be generated by inflammatory mediators acting directly on nociceptors or indirectly - via facilitation of neurons. Apart from prostaglandin and nitric oxide also cytokines (TNF-alpha or interleukin-6) may play a role. In primary headaches such as migraine inflammatory mechanisms also have been acclaimed to contribute to pain generation. The recently observed increase of migraine attacks under immunmodulatory therapy in multiple sclerosis has focussed attention on primary headaches in states of altered immunity, for instance in autoimmune disorders like lupus erythematosus, rheumatoid arthritis, or in patients treated with immunosuppressants. This article describes the standard of knowledge and tries to shed light on possible mechanisms of pain generation in the respective conditions.

Bombesin can rescue the enteric ganglia from FK506 neurotoxicity on small bowel transplantation

BACKGROUND/PURPOSE

FK506 has been reported to have neurotoxic effects. The aim of this study was to investigate whether FK506 causes neurotoxic effects on the transplanted graft enteric ganglia (TGEG) and whether bombesin (BBS) can prevent such atrophy.

METHODS

Thirty rats heterotopically underwent small bowel transplantation and were divided into 5 groups as follows: group A, syngraft (SYN) alone; group B, SYN with FK506; group C, SYN with FK506 and BBS; group D allograft with FK506; group E, allograft with FK506 and BBS. From postoperative days 14 to 28, either BBS or normal saline was administered continuously. All recipients except for group A received FK506 daily. The ganglionic count was obtained by counting the number of protein gene product 9.5 immunohistochemically stained ganglia in the cross sections of each graft.

RESULTS

The number of TGEG in groups A, B, and C was 69.7 +/- 6.0, 51.5 +/- 7.7, and 84.8 +/- 10.2 ganglia per cross section, respectively. There was a significant difference between each group (P < .001). The number of TGEG in groups D and E was 44.6 +/- 7.5 and 65.1 +/- 9.5 ganglia per cross section, respectively. There was a significant difference between the 2 groups (P < .001).

CONCLUSIONS

FK506 causes severe neurotoxicity in transplanted grafts, and BBS protects graft enteric ganglia against the neurotoxic effects of FK506.

Transient Ischemic Attack After Rizatriptan Administration in a Liver Transplant Recipient: A Case Report

We report the case of a male liver transplant recipient who developed de novo migraine while on tacrolimus therapy. Considering the inadequate control of pain using nonsteroidal antiinflammatory drugs, rizatriptan benzoate (10 mg orally) was administered (double administration). After both administrations a clinically transient ischemic attack (TIA) occurred. Rizatriptan was discontinued, the patient recovered without sequelae from both episodes of TIA. Remission of migraine occurred after discontinuation of tacrolimus and substitution with cyclosporine. We suggest that the association of rizatriptan and tacrolimus could potentially lead to an excessive risk of cerebral vasospasm and should be used with caution. A change in immunosuppressive therapy (from tacrolimus to cyclosporine or sirolimus) may improve migraine and should be the first choice. Further prospective comparative randomized trials are needed to establish the best therapeutic option in this particular subset of patients.

Brain MR imaging abnormalities in kidney transplant recipients

BACKGROUND AND PURPOSE

On the basis of limited available data, brain MR imaging abnormalities in kidney transplant recipients (KTRs) have been predominantly attributed to calcineurin inhibitors (CIs), characteristically presenting as posterior reversible encephalopathy syndrome (PRES). The goal of this study was to evaluate whether CIs play an important role in the incidence, nature, and location of MR imaging brain lesions in adult KTRs by comparing them with dialysis-dependent patients.

METHODS

We retrospectively analyzed 98 brain MR imaging examinations in 77 consecutive KTRs presenting with neurologic symptoms from 1990 to 2003. The data were separated into 3 groups according to duration after transplantation of MR imaging: group 1, 0-3 months; group 2, 3-12 months; and group 3, >12 months. Twenty-six MR imaging examinations from 24 additional dialysis-dependent adults were used as controls and comprised group 0.

RESULTS

Acute changes (infarcts, infections, PRES) comprised 24% and 19% of lesions in KTRs and group 0 patients, respectively, with infarcts being the most common in all groups. Chronic lesions were responsible for 76% of changes in KTR and 81% in group 0 and were predominantly vascular in etiology. No statistically significant differences in incidence of PRES or other acute changes were found between dialysis-dependent patients and either individual KTR groups or all KTR patients combined. The deep gray matter lesions were more common in KTR, whereas frontal white matter was more frequently affected in patients on dialysis.

CONCLUSION

Our study does not support suggestion that MR imaging brain abnormalities in KTR are predominantly due to direct CI toxicity.

The use of cyclosporine in a boy with a prior episode of posterior encephalopathy

We report the case of a 12- year-old Japanese boy who was receiving cyclosporine (Cs A) for steroid-dependent nephrotic syndrome despite a prior episode of Cs A-associated posterior encephalopathy. At the third relapsing of nephrotic syndrome, Cs A was initiated. Eight days after the Cs A therapy, the boy was admitted to the University Hospital of Tsukuba because of generalized convulsion. Magnetic resonance imaging (MRI) showed hyperintense lesions involving the bilateral parieto-occipital region. Cs A was discontinued, and cyclophosphamide was started. The boy had a 6-month drug-free period after the cyclophosphamide treatment and then relapsed three more times in the following 5 months. As the prednisolone dosage could not be decreased to less than 2 mg/kg/48 h, the patient was re-challenged with Cs A 1 1/2 years later. Blood pressure and serum Cs A levels were measured frequently, an anti-hypertensive drug was given, and MRI was done four times to detect hyperintense lesions. He has been receiving Cs A for 9 months, and MRI has revealed no abnormalities. At the latest follow-up, dated 12 April 2004, he was in a remissive state of nephrotic syndrome. This is the first report of giving Cs A to a nephrotic child who had a previous history of Cs A-associated posterior encephalopathy.

Recurrence of Migraine With Aura Due to Tacrolimus Therapy in a Liver Transplant Recipient Successfully Treated With Sirolimus Substitution

We report the case of a female liver transplant recipient who developed a recurrence of severe migraine with aura while on tacrolimus therapy with subsequent remission of headache following discontinuation of tacrolimus and substitution with sirolimus therapy. Headaches in transplant-recipient patients have become a new area of interest for headache specialists. In particular, immunosuppressant medications such as cyclosporine, tacrolimus, sirolimus, and OKT3 have been associated with development of headache syndromes in the transplant patient, exacerbation of previous headaches syndromes, and development of encephalopathies including headache as a clinical feature.