Posterior reversible encephalopathy syndrome (PRES): electroencephalographic findings and seizure patterns

Posterior reversible encephalopathy syndrome associated with antibiotic therapy: a case report and systematic review

Posterior reversible encephalopathy syndrome (PRES) is an acute neurological condition associated with different etiologies, including antibiotic therapy. To date, most data regarding antibiotic-related PRES are limited to case reports and small case series. Here, we report a novel case description and provide a systematic review of the clinico-radiological characteristics and prognosis of available cases of PRES associated with antibiotic therapy. We performed a systematic literature search in PubMed and Scopus from inception to 10 January 2024, following PRISMA guidelines and a predefined protocol. The database search yielded 12 subjects (including our case). We described the case of a 55-year-old female patient with PRES occurring one day after administration of metronidazole and showing elevated serum neurofilament light chain protein levels and favorable outcome. In our systematic review, antibiotic-associated PRES was more frequent in female patients (83.3%). Metronidazole and fluoroquinolones were the most reported antibiotics (33.3% each). Clinical and radiological features were comparable to those of PRES due to other causes. Regarding the prognosis, about one third of the cases were admitted to the intensive care unit, but almost all subjects (90.0%) had a complete or almost complete clinical and radiological recovery after prompt cessation of the causative drug. Antibiotic-associated PRES appears to share most of the characteristics of classic PRES. Given the overall good prognosis of the disease, it is important to promptly diagnose antibiotic-associated PRES and discontinue the causative drug.

Water exchange across the blood-brain barrier and epilepsy: Review on pathophysiology and neuroimaging

The blood-brain barrier (BBB) is a barrier protecting the brain and a milieu of continuous exchanges between blood and brain. There is emerging evidence that the BBB plays a major role in epileptogenesis and drug-resistant epilepsy, through several mechanisms, such as water homeostasis dysregulation, overexpression of drug transporters, and inflammation. Studies have shown abnormal water homeostasis in epileptic tissue and altered aquaporin-4 water channel expression in animal epilepsy models. This review focuses on abnormal water exchange in epilepsy and describes recent non-invasive MRI methods of quantifying water exchange. PLAIN LANGUAGE SUMMARY: Abnormal exchange between blood and brain contribute to seizures and epilepsy. The authors describe why correct water balance is necessary for healthy brain functioning and how it is impacted in epilepsy. This review also presents recent MRI methods to measure water exchange in human brain. These measures would improve our understanding of factors leading to seizures.

Posterior reversible encephalopathy syndrome in postpartum patients with gestational hypertension: A case report emphasizing early recognition and management

Posterior reversible encephalopathy syndrome (PRES) is a rare neuroradiological condition causing headaches, altered mental status, seizures, visual disturbances, and focal deficits. It is often associated with preeclampsia and eclampsia in pregnancy, but can also occur in patients with other medical conditions, such as hypertension, autoimmune diseases, renal dysfunction etc. This case report highlights the importance of recognizing PRES in postpartum patients with hypertension and the need for prompt diagnosis and management to prevent potential complications. A 30-year-old woman with gestational hypertension underwent scheduled induction of labor. After a successful delivery, she experienced a sudden headache but no other neurological symptoms. Imaging showed bilateral frontoparietal white matter edema, consistent with PRES. She was closely monitored, treated with analgesics, and improved within a week. The case highlights the rarity of PRES in postpartum patients without preeclampsia or eclampsia. It underscores the importance of considering PRES as a possible diagnosis in postpartum patients with hypertension, even in the absence of typical risk factors. Prompt control of blood pressure and careful monitoring are essential to ensure a positive outcome, as PRES can lead to life-threatening complications if not managed appropriately. The study highlights the importance of heightened awareness of PRES in postpartum patients with gestational hypertension. Early detection and timely management can improve prognosis, even in atypical cases. Healthcare professionals should be vigilant in assessing hypertension patients to diagnose and manage PRES, preventing neurological sequelae. Further research is needed to better understand PRES pathophysiology and risk factors in postpartum patients.

Convexity subarachnoid haemorrhage: a practical guide

Atraumatic convexity subarachnoid haemorrhage describes spontaneous bleeding into the convexities of the brain sulci without parenchymal involvement. Its many causes include reversible cerebral vasoconstriction syndrome, cerebral sinus venous thrombosis, posterior reversible encephalopathy syndrome and (in older people) cerebral amyloid angiopathy. We describe the clinical and radiological features of non-traumatic convexity subarachnoid haemorrhage with its various presentations, causes, treatments and prognoses, and use clinical vignettes to highlight important clinical points and pitfalls.

Can Post-Operative Posterior Reversible Encephalopathy Syndrome (PRES) Be Considered an Insidious Rare Surgical Complication?

Introduction: Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by neurological symptoms and distinctive neuroimaging findings. There are a few cases reported in the literature in which PRES can occur after surgery, and there is no clear direct relationship between a procedure and its debut. Methods: We performed a review of the literature by analyzing all reported cases of PRES syndrome which debuted after a surgical procedure with the aim of identifying the clinical features, the timing of the symptoms' onset and the therapy of patients suffering from this unusual surgical complication. Results: The total number of patients collected was 47, with a mean age of 40.9 years. Postoperative PRES can occur in either pediatric or adult patients (ages 4-82 years). The most frequent form of comorbidity reported was cardiovascular disease (fourteen patients, 29.78%). Sixteen patients (36%) had no relevant risk factors or comorbidities at the time of the surgical procedure. The types of surgery most correlated were cranial neuro and maxillofacial surgery (twenty-one patients, 44.68%) followed by transplant surgery (eight patients, 17%). The time of onset of PRES after surgery occurred within the first 3 weeks (mean time of onset 4.7 days), and when rapidly treated with antihypertensive and antiepileptic drugs appeared to have a reversible and benign course. Conclusion: PRES syndrome can be considered a rare complication of procedures and can occur following a wide range of surgeries, especially cranial and transplant surgery. Being able to recognize it in time and treat it ensures a full reversibility of symptoms in most cases.

Long-term risk of seizure after posterior reversible encephalopathy syndrome

OBJECTIVE

Patients with posterior reversible encephalopathy syndrome (PRES) can develop seizures during the acute phase. We sought to determine the long-term risk of seizure after PRES.

METHODS

We performed a retrospective cohort study using statewide all-payer claims data from 2016-2018 from nonfederal hospitals in 11 US states. Adults admitted with PRES were compared to adults admitted with stroke, an acute cerebrovascular disorder associated with long-term risk of seizure. The primary outcome was seizure diagnosed during an emergency room visit or hospital admission after the index hospitalization. The secondary outcome was status epilepticus. Diagnoses were determined using previously validated ICD-10-CM codes. Patients with seizure diagnoses before or during the index admission were excluded. We used Cox regression to evaluate the association of PRES with seizure, adjusting for demographics and potential confounders.

RESULTS

We identified 2095 patients hospitalized with PRES and 341,809 with stroke. Median follow-up was 0.9 years (IQR, 0.3-1.7) in the PRES group and 1.0 years (IQR, 0.4-1.8) in the stroke group. Crude seizure incidence per 100 person-years was 9.5 after PRES and 2.5 after stroke. After adjustment for demographics and comorbidities, patients with PRES had a higher risk of seizure than patients with stroke (HR, 2.9; 95% CI, 2.6-3.4). Results were unchanged in a sensitivity analysis that applied a two-week washout period to mitigate detection bias. A similar relationship was observed for the secondary outcome of status epilepticus.

INTERPRETATION

PRES was associated with an increased long-term risk of subsequent acute care utilization for seizure compared to stroke.

Increased volume of cerebral oedema is associated with risk of acute seizure activity and adverse neurological outcomes in encephalitis - regional and volumetric analysis in a multi-centre cohort

BACKGROUND

Seizures can occur unpredictably in patients with acute encephalitis syndrome (AES), and many suffer from poor long-term neurological sequelae. Establishing factors associated with acute seizures risk and poor outcomes could support clinical care. We aimed to conduct regional and volumetric analysis of cerebral oedema on magnetic resonance imaging (MRI) in patients with AES. We assessed the relationship of brain oedema with acute seizure activity and long-term neurological outcome.

METHODS

In a multi-centre cohort study, adults and children presenting with an AES were recruited in the UK. The clinical and brain MRI data were retrospectively reviewed. The outcomes variables were inpatient acute seizure activity and neurological disability at six-months post-discharge. A poor outcome was defined as a Glasgow outcome score (GOS) of 1-3. We quantified regional brain oedema on MRI through stereological examination of T2-weighted images using established methodology by independent and blinded assessors. Clinical and neuroimaging variables were analysed by multivariate logistic regression to assess for correlation with acute seizure activity and outcome.

RESULTS

The study cohort comprised 69 patients (mean age 31.8 years; 53.6% female), of whom 41 (59.4%) had acute seizures as inpatients. A higher Glasgow coma scale (GCS) score on admission was a negative predictor of seizures (OR 0.61 [0.46-0.83], p = 0.001). Even correcting for GCS on admission, the presence of cortical oedema was a significant risk factor for acute seizure activity (OR 5.48 [1.62-18.51], p = 0.006) and greater volume of cerebral oedema in these cortical structures increased the risk of acute seizures (OR 1.90 [1.12-3.21], p = 0.017). At six-month post-discharge, 21 (30.4%) had a poor neurological outcome. Herpes simplex virus encephalitis was associated with higher risk of poor outcomes in univariate analysis (OR 3.92 [1.08-14.20], p = 0.038). When controlling for aetiology, increased volume of cerebral oedema was an independent risk factor for adverse neurological outcome at 6 months (OR 1.73 [1.06-2.83], p = 0.027).

CONCLUSIONS

Both the presence and degree of cerebral oedema on MRIs of patients with AES may help identify patients at risk of acute seizure activity and subsequent long-term morbidity.

A Near-Global Slowing of Background Activity and Epileptic Discharges in Children With Mild to Moderately Symptomatic COVID-19 Infection: An Electro-Neurophysiological Study

Background. To assess the functional involvement of the central nervous system (CNS) via quantitative electroencephalography (EEG) analysis in children with mild to moderate COVID-19 infection who were otherwise previously healthy children. Methods. This prospective, case-control study was conducted between June and September 2020. Sleep EEG records of at least 40 min were planned for children who tested positive for COVID-19 using real-time PCR analysis and within 4-6 months post-recovery. All of the EEG analyses in this study were performed on an Ubuntu 20.04.2 LTS Operating System with the developed software using Python 3.7.6. The quantitative analysis of the epileptic discharges within the EEG records was performed using random forest after elimination of the artifacts with a model training accuracy of 98% for each sample data point. The frequency analysis was performed using the Welch method. Results. Among the age and sex-matched groups, the global mean frequency was significantly lower among the COVID-19 patients, with a P-value of 0.004. The spike slow-wave and sharp slow-wave indices were significantly higher in the patients when compared to the controls. The mean frequency values were significantly lower in almost all of the electrodes recording the frontal, central, and occipital areas. For the temporal and parietal areas, those significantly low mean frequencies were limited to the right hemisphere. Conclusion. A near-global involvement of background activity with decreased frequency, in addition to epileptic discharges, was recorded in mild to moderately COVID-19 infected children post-infection.

Factors associated with acute symptomatic seizure occurrence among patients with posterior reversible encephalopathy syndrome

OBJECTIVES

We aimed to define the factors associated with acute symptomatic seizure occurrence in posterior reversible encephalopathy syndrome (PRES) in the Thai-Asian population.

MATERIALS AND METHODS

We conducted a retrospective cohort study enrolling patients with PRES admitted to the hospital between 2006 and 2019. In addition to seizure characteristics, baseline characteristics, clinical presentations, precipitating factors, neuroimaging characteristics, hospital complications, and hospital outcomes were compared between the seizure and non-seizure groups. Factors with p-value <0.05 in the univariate analysis were entered into the first model of multivariate logistic regression analysis to determine the factors associated with seizure occurrence if the p-value <0.05. The interaction of associated factors was also analyzed in the final multiple logistic regression analysis model.

RESULTS

Acute symptomatic seizure, which is mainly based on the clinical documentation without electroencephalography, occurred in 50.0% of 136 patients with PRES. Of these, early seizures within 14 days of PRES occurred in 98.5% which mostly developed at presentation (82.4%) with a single seizure attack (55.9%). Convulsive seizures (77.9%) were the most common seizure semiology. The seizure group was significantly younger (median [interquartile range: IQR] 36.00 years old (21.75-48.50) vs 46.50 years old (31.25-61.00), p = 0.003). In univariate analysis, the seizure group had a higher prevalence of consciousness impairment (61.76% vs 26.47%, p < 0.001), Glasgow coma scale (GCS) score of 0-13 (42.46% vs 13.23%, p < 0.001), preeclampsia (20.58% vs 4.41%, p = 0.004), autoimmune disease (17.65% vs 5.88%, p = 0.033), and frontal lesions (25.00% vs 11.76%, p = 0.046) than those in the non-seizure group. In contrast, the seizure group had a lower prevalence of headache (27.94% vs 61.76%, p < 0.001). In the final multivariate logistic regression analysis which included the interaction terms, the acute symptomatic seizure occurrence directly associated with preeclampsia (adjusted odds ratio (aOR) 6.426, 95% confidence interval (CI) 1.450-27.031, p = 0.016) and autoimmune disease (aOR 4.962, 95% CI 1.283-18.642, p = 0.025), while headache showed a reverse association (aOR 0.310, 95% CI = 0.158-0.721, p = 0.008).

CONCLUSIONS

Acute symptomatic seizure occurred in a half of patients with PRES in this cohort. Preeclampsia and autoimmune disease were directly associated with seizure occurrence, while headache showed a reverse association.

Posterior Reversible Encephalopathy in Sepsis-Associated Encephalopathy: Experience from a Single Center

BACKGROUND

Sepsis-associated encephalopathy (SAE) is frequently encountered in sepsis and is often accompanied by neuroimaging findings indicating ischemia, hemorrhage, and edema. Posterior reversible encephalopathy syndrome (PRES) has been vastly underrecognized in previously reported cohorts of patients with sepsis and SAE. Our aim was to determine the prevalence and distinguishing clinical, neuroimaging, and electroencephalography features of PRES in SAE.

METHODS

In this prospective observational study, patients with radiologically identified PRES were selected from a consecutively enrolled cohort of 156 patients with SAE and assessed for neurological outcome using the extended Glasgow Outcome Scale for 12 months. Patients with SAE and PRES and other types of brain lesions were compared in terms of clinical and diagnostic workup features.

RESULTS

Fourteen of 156 patients (8.9%) were determined to be radiologically compatible with PRES, whereas 48 patients displayed other types of acute brain lesions. Patients with PRES often showed lesions in atypical regions, including frontal lobes, the corpus callosum, and the basal ganglia. Source of infection was mostly gram-negative bacteria originating from pneumonia or intraabdominal infections. Patients with PRES were not different from other patients with SAE with brain lesions in terms of features of sepsis and neurological outcome. However, patients with PRES showed increased prevalence of seizures and intraabdominal source of infection.

CONCLUSIONS

PRES is highly prevalent in SAE, often encompasses unusual brain regions, and usually presents with generalized seizures. Patients with SAE and PRES do not appear to have distinguishing clinical and diagnostic workup features. However, generalized seizures may serve as warning signs for presence of PRES in patients with SAE.

Posterior reversible encephalopathy syndrome (PRES): diagnosis and management

Posterior reversible encephalopathy syndrome (PRES) may present with diverse clinical symptoms including visual disturbance, headache, seizures and impaired consciousness. MRI shows oedema, usually involving the posterior subcortical regions. Triggering factors include hypertension, pre-eclampsia/eclampsia, renal failure, cytotoxic agents and autoimmune conditions. The mechanism underlying PRES is not certain, but endothelial dysfunction is implicated. Treatment is supportive and involves correcting the underlying cause and managing associated complications, such as seizures. Although most patients recover, PRES is not always reversible and may be associated with considerable morbidity and even mortality.

The association of posterior reversible encephalopathy syndrome with COVID-19: A systematic review

The rise in Coronavirus disease 2019 (COVID-19) cases is revealing its unique neurological manifestations. In light of the emerging evidence, a possible association with Posterior Reversible Encephalopathy Syndrome (PRES) is being consistently reported. We conducted a systematic literature search on four databases namely Pubmed/MEDLINE, Cochrane, Google Scholar, and Science Direct. After rigorous screening as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a total of 34 articles describing 56 cases were selected as a part of this review. The mean age of the patients was 56.6 ± 15.3 years. The most common clinical presentation of PRES was altered mental status (58.9%) followed by seizures (46.4%) and visual disturbances (23.2%) while hypertension and diabetes mellitus were the most commonly reported comorbidities. 91.1% of the cases reported Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) findings suggestive of PRES in the brain. Symptomatic management was employed in most of the cases to control seizures and blood pressure, and 44 patients (78.5%) fully or partially recovered. The most likely underlying mechanism involves COVID-19 mediated cytokine storm syndrome that leads to endothelial damage and increased permeability of the cerebral vessels, thus causing the characteristic edema of PRES. High neuronal and glial cell expression of Angiotensin Converting Enzyme-2 (ACE-2) receptors also suggests the possibility of direct viral damage. Since timely diagnosis and treatment reports a good prognosis, it is vital for physicians and neurologists to be well-versed with this association.

Posterior Reversible Encephalopathy Syndrome

Purpose of Review

This review provides an updated discussion on the clinical presentation, diagnosis and radiographic features, mechanisms, associations and epidemiology, treatment, and prognosis of posterior reversible encephalopathy syndrome (PRES). Headache is common in PRES, though headache associated with PRES was not identified as a separate entity in the 2018 International Classification of Headache Disorders. Here, we review the relevant literature and suggest criteria for consideration of its inclusion.

Recent Findings

COVID-19 has been identified as a potential risk factor for PRES, with a prevalence of 1–4% in patients with SARS-CoV-2 infection undergoing neuroimaging, thus making a discussion of its identification and treatment particularly timely given the ongoing global pandemic at the time of this writing.

Summary

PRES is a neuro-clinical syndrome with specific imaging findings. The clinical manifestations of PRES include headache, seizures, encephalopathy, visual disturbances, and focal neurologic deficits. Associations with PRES include renal failure, preeclampsia and eclampsia, autoimmune conditions, and immunosuppression. PRES is theorized to be a syndrome of disordered autoregulation and endothelial dysfunction resulting in preferential hyperperfusion of the posterior circulation. Treatment typically focuses on treating the underlying cause and removal of the offending agents.

Characteristics and Outcomes of Critically Ill Pediatric Patients with Posterior Reversible Encephalopathy Syndrome

BACKGROUND/OBJECTIVE

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiologic entity, typically manifesting as reversible neurological symptoms and signs of white matter edema on magnetic resonance imaging. PRES has been widely described in adults. Studies of PRES in children are mostly limited to case series and case controls.

METHODS

Retrospective chart review of patients under 21 years with PRES admitted at a tertiary children's hospital from 2011 to 2016. They were compared to controls matched for age and mortality risk using the Pediatric Index of Mortality-2 score.
 RESULTS: Sixteen cases of PRES were identified in 13 patients (ages 5-17 years, 46% male). PRES presented with altered mental status (75%), seizures (77%), headache (31%), and vision changes (23%). In patients who recovered (n = 11), median days to symptom resolution was three (range 1-8). PRES patients had a higher mortality rate (15% vs. 5%, p < 0.05) and higher mean length of stay (13.1 vs. 4.6 days) and were more likely to have autoimmune disease (p < 0.05), immunosuppression (p < 0.05), and anemia (p < 0.05). No PRES patients were diagnosed with epilepsy by last known follow-up, and all of whom had been started on an antiepileptic drug were discontinued within 13 months. Sepsis was suspected in 53% of PRES patients and 59% of controls (p = 1.00). All PRES patients had stage II hypertension, versus 41% of controls (p < 0.05). Average creatinine in PRES was 2.35 mg/dL compared to 0.90 mg/dL in controls (p < 0.05). PRES patients had lower serum calcium (p < 0.05). After correcting for albumin, no association between PRES and hypocalcemia remained. PRES patients had a higher length of stay (13.1 vs. 4.6 days, p < 0.05) and mortality rate (15% vs. 3%, p < 0.05).

CONCLUSIONS

Immunosuppression, autoimmune disease, renal insufficiency, anemia, and hypertension are associated with PRES after controlling for mortality risk in critically ill children. There was no association between corrected serum calcium and sepsis with PRES.

Chemotherapy and Immunosuppressant Therapy-Induced Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome (PRES) is an entity which is characterized by acute to subacute onset of neurological symptoms like altered mental status, seizures, headaches and other focal neurological deficits. It is diagnosed with the help of MRI findings which typically involve the subcortical white matter of parieto-occipital lobes. In this review, we will discuss the various etiologies and risk factors including some of the most common chemotherapeutic agents and immunosuppressant agents associated with this disorder. We will discuss the mechanism of actions and side effect profiles of a few drugs and their role in causation of PRES. This review article discusses if there is any difference in presentation and imaging findings of PRES caused by cytotoxic agents versus caused by other etiologies. It also highlights the difficulty in management of PRES caused by cytotoxic agents as the discontinuation of these drugs could be life-threatening due to graft rejections or graft versus host disease.

Atypical Posterior Reversible Encephalopathy Syndrome due to Oral Tyrosine Kinase Inhibitor Cabozantinib: First Case Report

We report here a rare case of atypical posterior reversible encephalopathy syndrome (PRES) due to oral tyrosine kinase inhibitor cabozantinib. No case reports of such have been found in our literature search. The patient, a 70-year-old female with metastatic renal cell cancer on oral tyrosine kinase inhibitor cabozantinib, was brought into the emergency room because of confusion and seizures, found to have elevated blood pressure and atypical MRI findings consistent with PRES due to cabozantinib.

[Posterior reversible encephalopathy syndrome and arterial hypertension]

OBJECTIVE

To identify a correlation between systolicdiastolic blood pressure (BP) and severity of clinical/radiological presentations in patients with posterior reversible encephalopathy syndrome (PRES).

MATERIAL AND METHODS

Clinical and paraclinic data of patients with PRES hospitalized in the Republican Clinical Hospital, Kazan in 2010-2018 were analyzed. Nineteen patients were found, all of them were women, aged 18-67 years, mean age 33.50±15.03 years. Clinical and paraclinic data included anamnesis, neurological examination, neuroimaging, first measurements of systolic and diastolic BP after symptoms'onset.

RESULTS AND CONCLUSION

Diastolic BP values can be associated with the incidence of depression of consciousness, systolic BP values - with the number of damaged structures. In total, BP is the significant factor implemented in the presence of endothelial dysfunction that defines the severity of encephalopathy.

Electroencephalogram (EEG) in COVID-19: A systematic retrospective study

OBJECTIVES

Although rare, neurological manifestations in SARS-CoV-2 infection are increasingly being reported. We conducted a retrospective systematic study to describe the electroencephalography (EEG) characteristics in this disease, looking for specific patterns.

METHODS

EEGs performed in patients with positive PCR for SARS-CoV-2 between 25/03/2020 and 06/05/2020 in the University Hospital of Bicêtre were independently reviewed by two experienced neurologists. We used the American Clinical Neurophysiology Society's terminology for the description of abnormal patterns. EEGs were classified into five categories, from normal to critically altered. Interobserver reliability was calculated using Cohen's kappa coefficient. Medical records were reviewed to extract demographics, clinical, imaging and biological data.

RESULTS

Forty EEGs were reviewed in 36 COVID-19 patients, 18 in intensive care units (ICU) and 22 in medicine units. The main indications were confusion or fluctuating alertness for 23 (57.5%) and delayed awakening after stopping sedation in ICU in six (15%). EEGs were normal to mildly altered in 23 (57.5%) contrary to the 42.5% where EEG alterations were moderate in four (10%), severe in eight (20%) and critical in five (12.5%). Generalized periodic discharges (GPDs), multifocal periodic discharges (MPDs) or rhythmic delta activity (RDA) were found in 13 recordings (32.5%). EEG alterations were not stereotyped or specific. They could be related to an underlying morbid status, except for three ICU patients with unexplained encephalopathic features.

CONCLUSION

In this first systematic analysis of COVID-19 patients who underwent EEG, over half of them presented a normal recording pattern. EEG alterations were not different from those encountered in other pathological conditions.

Cerebellar Parieto-occipital Posterior Reversible Encephalopathy Syndrome and Cerebral Metamorphopsia Associated with Asymptomatic Atrial Septum Vegetation and Renal Disease: Case Report

Patient: Female, 25-year-old

Final Diagnosis: Posterior reversible encephalopathy syndrome

Symptoms: Visual disturbances

Medication: —

Clinical Procedure: —

Specialty: Neurology

Severe pre-eclamptic women with headache: is posterior reversible encephalopathy syndrome an associated concurrent finding?

BACKGROUND

A high incidence of posterior reversible encephalopathy syndrome (PRES) has been observed in women with eclampsia on imaging. However this association was documented mostly after convulsions occurred. This study aimed to detect the development of PRES using magnetic resonance imaging (MRI) in women with severe preeclampsia and headache, and evaluate the clinical and radiological findings in obstetric outcomes.

METHODS

A prospective single-center cohort study comprising 20 pregnant women with severe pre-eclampsia related headache was conducted using Numeric Rating Scale (NRS) score of ≧4. Additionally, non-contrast brain MRI was used to detect PRES and related radiological central nervous system (CNS) abnormalities.

RESULTS

Patients were enrolled at a mean gestational age of 32 weeks (range 29-38 weeks). Two women were unable to complete the scanning. Of the 18 MRI scans, 15 (83%) revealed abnormal findings. One patient developed an altered mental state and diffuse PRES, with the occipital, temporal, thalamus, and basal ganglia, the brain stem, and the cerebellum being affected. Two patients had abnormal susceptibility-weighted imaging (SWI) findings, indicating micro-hemorrhages. The majority (12 cases, 66%) of the patients had abnormal cortical hyperintensities in the occipital and temporal lobes. Only three patients had normal MRI pictures. None of the women had eclampsia occurred during the peripartum period, and only one unrelated neonatal death due to congenital anomalies.

CONCLUSION

A high incidence of abnormal cortical hyperintensity changes at locations typical for PRES on MRI was noted in women with severe pre-eclampsia and headache. These early hypertensive neurological signs allowed prompt and efficient obstetrical management, to prevent the development of eclampsia and PRES.

Posterior reversible encephalopathy syndrome, a clinically diverse and challenging disorder

The characterizing features of Posterior reversible encephalopathy syndrome (PRES) are broad and diverse, making early recognition and diagnosis challenging tasks. To illustrate the heterogeneous nature of PRES, we present three cases and discuss their clinical and radiological presentation.

Posterior Reversible Encephalopathy Syndrome: Clinical Features and Outcome

Background: Posterior reversible encephalopathy syndrome (PRES) is an acute neurotoxic syndrome that is characterized by a spectrum neurological and radiological feature from various risk factors. Common neurological symptoms includes headache, impairment in level of consciousness, seizures, visual disturbances, and focal neurological deficits. Common triggering factors include blood pressure fluctuations, renal failure, eclampsia, exposure to immunosuppressive or cytotoxic agents and autoimmune disorders. The classic radiographic findings include bilateral subcortical vasogenic edema predominantly affecting the parieto-occipital regions but atypical features include involvement of other regions, cortical involvement, restricted diffusion, hemorrhage, contrast enhancement. This review is aimed to summarize the updated knowledge on the typical and atypical clinical and imaging features, prognostic markers and identify gaps in literature for future research.

Methods: Systematic literature review using PUBMED search from 1990 to 2019 was performed using terms PRES was performed.

Results: While clinical and radiographic reversibility is common, long-standing morbidity and mortality can occur in severe forms. In patients with malignant forms of PRES, aggressive care has markedly reduced mortality and improved functional outcomes. Although seizures were common, epilepsy is rare. Various factors that have been associated with poor outcome include altered sensorium, hypertensive etiology, hyperglycemia, longer time to control the causative factor, elevated C reactive protein, coagulopathy, extensive cerebral edema, and hemorrhage on imaging.

Conclusion: Large prospective studies that accurately predict factors that are associated with poor outcomes, determine the pathophysiology, and targeted therapy are required.

Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome: Clinical and Radiological Considerations

Posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) are relatively uncommon neurological disorders, but their detection has been increasing mainly due to clinical awareness and spreading of magnetic resonance imaging (MRI). Because these syndromes share some common clinical and radiologic features and occasionally occur in the same patient, misdiagnosis may occur. PRES is characterized by varied neurological symptoms including headache, impaired visual acuity or visual field deficit, confusion, disorders of consciousness, seizures, and motor deficits often associated to peculiar neuroradiological pattern even if uncommon localization and ischemic or hemorrhagic lesions were described. RCVS is a group of diseases typically associated with severe headaches and reversible segmental vasoconstriction of cerebral arteries, often complicated by ischemic or hemorrhagic stroke. Pathophysiological basis of PRES and RCVS are still debated but, because they share some risk factors and clinical features, a possible common origin has been supposed. Clinical course is usually self-limiting, but prognosis may fluctuate from complete recovery to death due to complications of ischemic stroke or intracranial hemorrhage. Neuroradiological techniques such as digital angiography and MRI are helpful in the diagnostic pathway and a possible prognostic role of MRI has been suggested. This review will serve to summarize clinical, neuroradiological features and controversies underlying both syndromes that may mislead the diagnostic pathway and their possible relationship with pathophysiology, clinical course, and prognosis.

Neurotoxicity including posterior reversible encephalopathy syndrome after initiation of calcineurin inhibitors in transplanted methylmalonic acidemia patients: Two case reports and review of the literature

Introduction

New neurological symptoms in methylmalonic acidemia (MMA) patients after liver and/or kidney transplantation (LKT) are often described as metabolic stroke‐like‐events. Since calcineurin inhibitors (CNIs) are a well‐known cause of new neurological symptoms in non‐MMA transplanted patients, we investigated the incidence of CNI‐induced neurotoxicity including posterior reversible encephalopathy syndrome (PRES) in post‐transplanted MMA patients.

Methods

We report the two MMA patients treated with LKT in our center. Additionally, we performed a systematic review of case reports/series of post‐transplanted MMA patients and determined if CNI‐induced neurotoxicity/PRES was a likely cause of new neurological symptoms. Definite CNI‐induced neurotoxicity was defined as new neurological symptoms during CNI treatment with symptom improvement after CNI dose reduction/discontinuation. PRES was defined as CNI‐induced neurotoxicity with signs of vasogenic edema on brain magnetic resonance imaging (MRI)‐scan post‐transplantation.

Results

Our two MMA patients both developed CNI‐induced neurotoxicity, one had PRES. In literature, 230 transplanted MMA patients were identified. Neurological follow‐up was reported in 54 of them, of which 24 were excluded from analysis since no anti‐rejection medication was reported. Thirty patients, all using CNI, were included. Sixteen patients (53%) had no new neurological symptoms post‐transplantation and five patients (17%) had definite CNI neurotoxicity of whom two had PRES. Including our cases this results in a pooled incidence of 22% (7/32) definite CNI neurotoxicity and 9% PRES (3/32) in post‐transplanted MMA patients on CNI.

Conclusion

In MMA post‐transplanted patients with new neurological symptoms CNI‐induced neurotoxicity/PRES should be considered. Early recognition of CNI‐induced neurotoxicity is essential to initiate dose reduction/discontinuation of CNI to minimize persistent neurologic damage and improve outcome.

Concise one sentence take home message

In all post‐transplanted MMA patients with new neurological symptoms CNI‐induced neurotoxicity/PRES should be considered, and directly reducing the dose/discontinuation of CNI is essential.

Clinical Correlates of Periodic Discharges and Nonconvulsive Seizures in Posterior Reversible Encephalopathy Syndrome (PRES)

IMPORTANCE

The pathophysiological mechanisms of Posterior Reversible Encephalopathy Syndrome (PRES) and related seizures remain poorly understood. The prevalence and clinical significance of nonconvulsive seizures (NCSz) and related epileptiform patterns during continuous electroencephalography monitoring (CEEG) in PRES have not been well described.

OBJECTIVE

To report the prevalence, characteristics and risk factors for NCSz and related highly epileptiform patterns in patients with PRES, and to determine their relation to imaging abnormalities and outcome.

DESIGN, SETTING AND PARTICIPANTS

From a prospective CEEG database, we retrospectively identified patients with PRES and reviewed their medical charts. Based on CEEG findings, we designed a retrospective cohort study comparing two groups defined based on the presence or the absence of NCSz and/or periodic discharges (PDs).

MAIN OUTCOMES AND MEASURES

The prevalence and risk factors for PDs and NCSz, description of EEG and magnetic resonance imaging (MRI) abnormalities and functional outcome as measured by the Glasgow Outcome Scale (GOS) at hospital discharge.

RESULTS

Among 37 eligible patients, 23 (62%) had PDs or NCSz. The presence of NCSz was associated with the presence of PDs (15/22 vs. 1/15; p = 0.0002). NCSz and PDs were usually either lateralized or bilateral independent and predominated in the posterior regions. No clinical features were associated with the occurrence of PDs or NCSz. Cortical restricted diffusion on MRI was more frequent in the PDs/NCSz group (17/23 vs. 1/14; p < 0.001). PDs/NCSz were associated with worse outcome, with 3 deaths vs. 0 in the no PDs/NCSz group and fewer cases with low disability (4 vs. 9 cases with GOS = 5, p < 0.04).

CONCLUSIONS AND RELEVANCE

Our results reveal a high prevalence of NCSz and PDs in critically ill patients with PRES and an association with restricted diffusion and worse outcome, whether treating or preventing these EEG findings can improve outcome requires further research.

EEG Findings in Posterior Reversible Encephalopathy Syndrome

Introduction. Posterior reversible encephalopathy syndrome (PRES) is a relatively common cause of encephalopathy in the hospital setting, and the EEG findings have not been well described. The purpose of this study was to review the EEG findings in a series of patients with PRES. Methods. We retrospectively reviewed our electronic medical record database to identify patients who received a diagnosis of PRES at Tampa General Hospital from January 2016 to October 2017. The diagnosis of PRES was suspected on clinical presentation and confirmed by magnetic resonance imaging. We selected patients with PRES who had received at least 1 EEG. EEGs were interpreted by 2 board-certified electroencephalographers. Results. From January 2016 to October 2017, 19 patients were diagnosed with PRES at Tampa General Hospital. Of those, 10 received at least 1 EEG. Four patients were male, 6 were female. The ages ranged from 21 to 87 (mean was 47). The patients had the following clinical presentations: 5 with encephalopathy, 8 with seizures, 2 with vision changes, and 3 with headache (some patients had more than 1 symptom). EEGs findings were as follows: 3 were normal; 3 showed intermittent generalized slowing; 2 showed continuous generalized slowing; 3 showed background slowing; 1 showed background suppression; 1 showed generalized rhythmic delta activity (GRDA); 1 showed GRDA, plus spike/sharp-wave discharges; 1 showed generalized periodic discharges. The etiologies were as follows: 9 from hypertension, 1 secondary to eclampsia, 3 due to posttransplant immunosuppression, and 1 patient was undergoing chemotherapy (some were multifactorial). Conclusion. EEG findings in PRES are diverse, with no specific or even predominant pattern, based on this small sample size.

Posterior reversible encephalopathy syndrome as a complication of pre-eclampsia in the early postpartum period

We present the case of a 30-year-old woman with posterior reversible encephalopathy syndrome (PRES) as a complication of pre-eclampsia in the early postpartum period. PRES is a rare neurological disorder which causes non-specific neurological symptoms such as headache, seizures and visual disturbances. It generally has a good prognosis, but severe complications can arise. Therefore, early recognition and treatment are paramount. Pre-eclampsia is a multiorgan disease and is associated with both maternal and foetal morbidity and mortality. Neurological symptoms occurring in the postpartum period indicate pre-eclampsia until proven otherwise. This case report was written to stress the attention on this rare complication of pre-eclampsia. When a patient in the postpartum period presents with a combination of seizures, disturbed vision and headache, PRES should always be kept in mind.

Influence of Tacrolimus on Depressive-Like Behavior in Diabetic Rats Through Brain-Derived Neurotrophic Factor Regulation in the Hippocampus

The neurotoxicity of immunosuppressive agents and diabetes mellitus are known risk factors of neurological complications in kidney transplant recipients. The aim of the present study was to investigate the influence of tacrolimus on brain-derived neurotrophic factor (BDNF), the critical protein for maintenance of neuronal functions, in the hippocampus in a diabetic condition. A diabetic rat model was established by a single streptozotocin injection (60 mg/kg). Control and diabetic rats then received daily tacrolimus (1.5 mg/kg per day) injections for 6 weeks. BDNF expression in the hippocampus was examined in the dentate gyrus (DG) and CA3 region using immunohistochemistry. There was a significant decrease of BDNF expression in the DG and CA3 region in tacrolimus-treated and diabetic rats compared with that of the control group injected with vehicle only. However, there was no difference in BDNF expression between the two experimental groups. Tacrolimus treatment in diabetic rats further decreased the BDNF expression level in the DG and CA3 region. Interestingly, mossy fiber sprouting, demonstrated by prominent punctate immunolabeling of BDNF with synaptoporin, was observed in the diabetic group treated with tacrolimus, which localized at the stratum oriens of the CA3 region. These data suggest that tacrolimus treatment or a diabetic condition decreases BDNF expression in the hippocampus, and that tacrolimus treatment in the diabetic condition further injures the CA3 region of the hippocampus. In addition to BDNF expression, decreased locomotor activity and evident depressive behavior were observed in tacrolimus-treated diabetic rats. Moreover, there were significant decreases of the mRNA levels of γ-aminobutyric acid and serotonin receptors in the diabetic hippocampus with tacrolimus treatment. This finding suggests that tacrolimus treatment may cause further psychiatric and neurological complications for patients with diabetes, and should thus be used with caution.

Hypertension, seizures, and epilepsy: a review on pathophysiology and management

BACKGROUND

Epilepsy and hypertension are common chronic conditions, both showing high prevalence in older age groups. This review outlines current experimental and clinical evidence on both direct and indirect role of hypertension in epileptogenesis and discusses the principles of drug treatment in patients with hypertension and epilepsy.

METHODS

We selected English-written articles on epilepsy, hypertension, stroke, and cerebrovascular disease until December, 2018.

RESULTS

Renin-angiotensin system might play a central role in the direct interaction between hypertension and epilepsy, but other mechanisms may be contemplated. Large-artery stroke, small vessel disease and posterior reversible leukoencephalopathy syndrome are hypertension-related brain lesions able to determine epilepsy by indirect mechanisms. The role of hypertension as an independent risk factor for post-stroke epilepsy has not been demonstrated. The role of hypertension-related small vessel disease in adult-onset epilepsy has been demonstrated. Posterior reversible encephalopathy syndrome is an acute condition, often caused by a hypertensive crisis, associated with the occurrence of acute symptomatic seizures. Chronic antiepileptic treatment should consider the risk of drug-drug interactions with antihypertensives.

CONCLUSIONS

Current evidence from preclinical and clinical studies supports the vision that hypertension may be a cause of seizures and epilepsy through direct or indirect mechanisms. In both post-stroke epilepsy and small vessel disease-associated epilepsy, chronic antiepileptic treatment is recommended. In posterior reversible encephalopathy syndrome blood pressure must be rapidly lowered and prompt antiepileptic treatment should be initiated.

Posterior reversible encephalopathy syndrome in children with acute lymphoblastic leukemia: Clinical characteristics, risk factors, course, and outcome of disease

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a distinct entity with incompletely known predisposing factors. The aim of this study is to describe the incidence, risk factors, clinical course, and outcome of PRES in childhood acute lymphoblastic leukemia (ALL).

PROCEDURE

Patients aged 1.0 to 17.9 years diagnosed with ALL from July 2008 to December 2015 and treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol were included. Patients with PRES were identified in the prospective NOPHO leukemia toxicity registry, and clinical data were collected from the medical records.

RESULTS

The study group included 1378 patients, of whom 52 met the criteria for PRES. The cumulative incidence of PRES at one month was 1.7% (95% CI, 1.1-2.5) and at one year 3.7% (95% CI, 2.9-4.9). Older age (hazard ratios [HR] for each one-year increase in age 1.1; 95% CI, 1.0-1.2, P = 0.001) and T-cell immunophenotype (HR, 2.9; 95% CI, 1.6-5.3, P = 0.0005) were associated with PRES. Central nervous system (CNS) involvement (odds ratios [OR] = 2.8; 95% CI, 1.2-6.5, P = 0.015) was associated with early PRES and high-risk block treatment (HR = 2.63; 95% CI, 1.1-6.4, P = 0.033) with late PRES. At follow-up of the PRES patients, seven patients had epilepsy and seven had neurocognitive difficulties.

CONCLUSION

PRES is a neurotoxicity in the treatment of childhood ALL with both acute and long-term morbidity. Older age, T-cell leukemia, CNS involvement and high-risk block treatment are risk factors for PRES.

Isolated pontine involvement in posterior reversible encephalopathy syndrome with coincidental acute ischaemic stroke

Posterior reversible encephalopathy syndrome (PRES) is a cliniconeuroradiological syndrome characterised by a unique reversible pattern on imaging and total regression of clinical symptoms and signs. We describe an unusual case of PRES with isolated pontine involvement with coincidental acute ischaemic stroke in a 60-year-old man who presented with headache, unsteadiness of gait, blurred vision and elevated blood pressure. MRI scan revealed an expanded pons with diffuse T2 and Fluid attenuated Inversion Recovery (FLAIR) hyperintensities and an acute infarct in the right temporal lobe. A diagnosis of PRES was considered most likely after exclusion of other differentials and the patient was started on antihypertensive treatment as for hypertensive encephalopathy. He became asymptomatic after controlling blood pressure and the follow-up MRI scan at 3 weeks showed complete resolution of the pontine high signals which confirmed the diagnosis of PRES.

Postpartum Posterior Reversible Encephalopathy Syndrome (PRES): Three Case Reports and Literature Review

Posterior reversible encephalopathy syndrome is a rare complication generally associated with headache and acute changes in blood pressure. Delay in the diagnosis and treatment may result in death or in irreversible neurological sequelae. We present three cases of PRES occurring in young women during puerperium. We report a literature review ranged from January 1990 to June 2015 describing clinical features, diagnostic and medical approach, and maternal outcome.

Establishment and utility assessment of posterior reversible encephalopathy syndrome early warning scoring (PEWS) scale establishment and utility assessment of PEWS scale

Background

Posterior reversible encephalopathy syndrome (PRES) is a complication that occurs during various diseases’ treatment. Imaging examination is the gold standard for diagnosis. PRES frequently occurrence in patients with hematological malignancies results in poorer prognosis and higher mortality. We aim to establish a practical and operable scale for early prediction, assessment of the severity of the Posterior Reversible Encephalopathy Syndrome, and timely intervention for better prognosis.

Methods

The scale designed by reviewing the literature and by referring to clinical practice. We assessed the reliability and validity of the scale. Scale-based assessment of children undergoing chemotherapy for acute lymphoblastic leukemia conducted as early warning and intervention for those who may have PRES.

Results

Establishment of Posterior Reversible Encephalopathy Syndrome early warning scoring (PEWS) scale included three parts, as follows: (1) risk factors, including underlying disease, hypertension, Infection, and drug toxicity; (2) clinical features, including high cranial pressure, visual symptoms, seizure, and disturbance of consciousness; and (3) EEG features, including slow wave and epileptiform discharges. Utility assessment of PEWS scale showed that in 57 patients with acute lymphoblastic leukemia, 54 scored less than 10 and none of them detected as PRES. The other two had scores of 12 and 13 both diagnosed with PRES by brain MRI scan.

Conclusions

PEWS scale can predict PRES early. PRES was highly suspected when the score was 10 points and more. Thus, prophylactic intervention can give to improve the prognosis of PRES.

Neuroimaging Correlates of Periodic Discharges

Despite being first described over 50 years ago, periodic discharges continue to generate controversy as to whether they are always, sometimes, or never "ictal." Investigators and clinicians have proposed adjunctive markers to help clarify this distinction-in particular measures of perfusion and metabolism. Here, we review the growing number of neuroimaging studies using Fluorodeoxyglucose-PET, MRI diffusion, Magnetic resonance perfusion, Single Photon Emission Computed Tomography, and Magnetoencepgalography to gain further insight into the physiology and clinical significance of periodic discharges. To date, however, no definitive consensus exists regarding the features of periodic discharges that warrant treatment intensification. However, an emerging consilience among neuroimaging modalities suggests that periodic discharges can induce a hyperexcitatory state with associated hypermetabolism and hyperperfusion, which may result in local metabolic failure.

Posterior reversible encephalopathy syndrome (PRES) after bevacizumab therapy for metastatic colorectal cancer

Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognizable neuro-clinical syndrome. Clinical and neurological manifestations of PRES include hypertension, headache, encephalopathy, seizures, and symmetrical white matter changes on brain MRI. Most common precipitants of PRES are acute medical illness, hypertensive crisis, eclampsia, immunosuppressive therapy, and chemotherapy. Bevacizumab is a monoclonal antibody that halts angiogenesis by inhibiting vascular endothelial growth factor. It has gained widespread popularity in oncology world especially for metastatic and recurrent cancers due to its inherent ability to stop angiogenesis; a vital step for tumor growth. Bevacizumab has also been implicated as the cause of PRES due to dysregulation of the blood-brain barrier. We are reporting a case of PRES induced by Bevacizumab in a patient of colorectal cancer.

Seizure prophylaxis in the neuroscience intensive care unit

Background

Seizures are a considerable complication in critically ill patients. Their incidence is significantly high in neurosciences intensive care unit patients. Seizure prophylaxis with anti-epileptic drugs is a common practice in neurosciences intensive care unit. However, its utility in patients without clinical seizure, with an underlying neurological injury, is somewhat controversial.

Body

In this article, we have reviewed the evidence for seizure prophylaxis in commonly encountered neurological conditions in neurosciences intensive care unit and discussed the possible prognostic role of continuous electroencephalography monitoring in detecting early seizures in critically ill patients.

Conclusion

Based on the current evidence and guidelines, we have proposed a presumptive protocol for seizure prophylaxis in neurosciences intensive care unit. Patients with severe traumatic brain injury and possible subarachnoid hemorrhage seem to benefit with a short course of anti-epileptic drug. In patients with other neurological illnesses, the use of continuous electroencephalography would make sense rather than indiscriminately administering anti-epileptic drug.

Posterior reversible encephalopathy syndrome

The posterior reversible encephalopathy syndrome (PRES) is a neurological disorder of (sub)acute onset characterized by varied neurological symptoms, which may include headache, impaired visual acuity or visual field deficits, disorders of consciousness, confusion, seizures, and focal neurological deficits. In a majority of patients the clinical presentation includes elevated arterial blood pressure up to hypertensive emergencies. Neuroimaging, in particular magnetic resonance imaging, frequently shows a distinctive parieto-occipital pattern with a symmetric distribution of changes reflecting vasogenic edema. PRES frequently develops in the context of cytotoxic medication, (pre)eclampsia, sepsis, renal disease or autoimmune disorders. The treatment is symptomatic and is determined by the underlying condition. The overall prognosis is favorable, since clinical symptoms as well as imaging lesions are reversible in most patients. However, neurological sequelae including long-term epilepsy may persist in individual cases.

Evaluation of the first seizure patient: Key points in the history and physical examination

PURPOSE

This review will present the history and physical examination as the launching point of the first seizure evaluation, from the initial characterization of the event, to the exclusion of alternative diagnoses, and then to the determination of specific acute or remote causes. Clinical features that may distinguish seizures from alternative diagnoses are discussed in detail, followed by a discussion of acute and remote first seizure etiologies.

METHODS

This review article is based on a discretionary selection of English language articles retrieved by a literature search in the PubMed database, and the authors' clinical experience.

RESULTS

The first seizure is a dramatic event with often profound implications for patients and family members. The initial clinical evaluation focuses on an accurate description of the spell to confirm the diagnosis, along with careful scrutiny for previously unrecognized seizures that would change the diagnosis more definitively to one of epilepsy. The first seizure evaluation rests primarily on the clinical history, and to a lesser extent, the physical examination.

CONCLUSIONS

Even in the era of digital EEG recording and neuroimaging, the initial clinical evaluation remains essential for the diagnosis, treatment, and prognostication of the first seizure.

Posterior Reversible Encephalopathy Syndrome with Bilateral Independent Epileptic Foci Precipitated By Guillain-Barrè Syndrome

We report the case of a 56-year-old woman who developed status epilepticus (SE) related to independent occipital foci as clinical manifestation of posterior reversible encephalopathy syndrome (PRES) in the background of Guillain-Barrè syndrome (GBS). SE resulted from a series of focal seizures clinically characterized by left- and rightward deviations of the head and consequent oculoclonic movements. Electroencephalography recorded independent seizure activity in both occipital regions with alternate involvement of the two cerebral hemispheres. The epileptic foci corresponded topographically to parenchymal abnormalities of PRES in the occipital lobes. The manifestation of bilateral, independent occipital seizures with alternate deviations of the head and oculoclonic movements, previously not reported in patients with PRES, highlights the acute epileptogenicity of the cerebral lesions in this syndrome. Despite the variable clinical expression of seizures due to occipital damage in PRES, the development of independent seizure activity in both occipital lobes might represent a distinctive epileptic phenomenon of this encephalopathy.

Development of epilepsy after posterior reversible encephalopathy syndrome

PURPOSE

This study was intended to describe the risk of epilepsy subsequent to posterior reversible encephalopathy syndrome (PRES) and the clinical features of post-PRES epilepsy.

METHOD

We retrospectively identified all patients with PRES who were admitted to Severance Hospital and consulted with the Department of Neurology between 2001 and 2013 and the subgroup of these patients who subsequently developed epilepsy. We also describe clinical features of patients who were not treated with PRES as inpatients at our center but who presented later with post-PRES epilepsy during the study period. We studied clinical characteristics during the acute symptomatic phase of PRES and after the development of epilepsy.

RESULTS

During the study period 102 patients were treated at our center during the acute phase of PRES. Four of these patients (3.9%) subsequently developed epilepsy. Two additional patients with a history of PRES presented to our hospital after the acute phase of their illness with post-PRES epilepsy. During the acute phase, five of six patients had acute symptomatic seizures and four had convulsive or nonconvulsive status epilepticus (SE). Acute phase MRI showed cytotoxic edema in five patients, and follow-up MRI showed focal atrophic changes including hippocampal sclerosis in four. Presumptive epileptogenic foci were located in the left-side temporal, parietal and occipital lobes, corresponding to the regions that showed cytotoxic edema or severe vasogenic edema as well as with the location or lateralization of EEG abnormalities during the acute phase.

CONCLUSION

Our findings indicate a small but not insignificant risk for the development of epilepsy after PRES. The presence of cytotoxic edema and severe, acute symptomatic seizures, such as SE suggests irreversible brain damage and may predict the development of epilepsy.

Neurological Complications after Renal Transplantation: A Retrospective Clinical Study

INTRODUCTION

The aim of this study was to evaluate the incidence and types of neurological complications (NCs) and associated factors in renal transplantation (RT) patients.

METHODS

Three hundred and forty-four patients who had RT performed at our institution between January 2005 and July 2014 were retrospectively evaluated.

RESULTS

File records of the patients revealed 19 who experienced a total of 22 episodes of NCs, of whom three had more than one episode. The mean age of 19 patients included in the study, of whom eight were female, was 37.52±13.08 (range, 18-65) years. NCs were classified into central or peripheral depending on the location of involvement of the central nervous system (CNS). CNS involvement was found in 16 (84.2%) of the 19 patients. Tremor (36.8%) was the most common CNS complication in these patients. Encephalopathy, generalized tonic-clonic seizures, and status epilepticus were observed in two patients (10.5%). Delirium and dementia were observed in one patient (5.2%). Headache was experienced by one patient, and agitated depression was observed in one patient. Six patients (26.3%) had the peripheral nervous system involvement. One patient had the numbness of hands with normal electromyography findings, and four patients had polyneuropathy. In one patient, lumbar plexopathy was observed. Seventeen of the 22 NCs were considered to be caused by immunosuppressive agents. Each incidence of amyloidosis, infection, septic emboli, and hypoglycemia caused a neurological episode. The etiology of one episode was unknown.

CONCLUSION

Different neurological disorders can be seen after RT, and most of them are caused by immunosuppressive drugs. NCs seen after RT can be treated by decreasing the dose or changing the immunosuppressive drug.

Clinical and neuroimaging findings in children with posterior reversible encephalopathy syndrome

OBJECTIVE

To clarify the clinical and radiological spectrum of posterior reversible encephalopathy syndrome (PRES) in children, and to identify the prognostic factors.

METHODS

The records of 40 children with PRES were reviewed. Acute clinical symptoms, MRI including apparent diffusion coefficient (ADC) maps in the acute and follow-up periods and neurological sequelae, including epilepsy, were noted.

RESULTS

Age at onset ranged from 2 to 16 years. Underlying disorders were hematological or neoplastic disorders (n = 20), renal diseases (n = 14) and others (n = 6). In the acute period, 31 patients had seizures, 25 had altered consciousness, 11 had visual disturbances and 10 had headache. Of 29 patients who had ADC maps in the acute period, 13 had reduced diffusivity as shown by ADC within PRES lesions. Of 26 patients with follow-up MRI, 13 had focal gliosis or cortical atrophy. No patients had motor impairment, and four patients had focal epilepsy. No clinical variables were associated with focal gliosis or cortical atrophy on follow-up MRI, but lesional ADC reduction in the acute period was prognostic for focal gliosis or cortical atrophy on follow-up MRI (p = 0.005).

CONCLUSIONS

To the best of our knowledge, this is the largest cohort study to date involving PRES in children. Acute symptoms in pediatric patients are similar to those reported in adults, but altered consciousness was more frequent in children. Lesional ADC reduction in the acute period was common and was a good predictor of later, irreversible MRI lesions.