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

Posterior reversible encephalopathy syndrome in a child, following splenectomy under combined general and spinal anaesthesia

Posterior reversible encephalopathy syndrome is a rare and serious condition that presents with acute neurological symptoms with characteristic changes on imaging. It can lead to substantial morbidity and mortality, but can be reversible if recognised and treated. Here, we report a case of posterior reversible encephalopathy syndrome in a child post-splenectomy under general anaesthesia with spinal anaesthesia. As far as we are aware, this condition has not previously been described in relation to spinal anaesthesia in the paediatric population. This case demonstrates the importance of recognising blood pressure changes in children, which can be challenging due to age-, sex- and height-related centiles for blood pressure measurements. Posterior reversible encephalopathy syndrome should be considered as a differential diagnosis for headache in a patient that has had a spinal anaesthesia.

Posterior Reversible Encephalopathy Syndrome and Pre-eclampsia/Eclampsia: Anesthetic Implications and Management

Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic disorder that has recently become more frequently diagnosed. While the exact etiology of PRES remains unclear, multiple diseases are associated with PRES. Moreover, there is increasing recognition of the association of PRES in pre-eclampsia/eclampsia with advancements in imaging techniques and increased awareness of the disorder. While pre-eclampsia/eclampsia alone presents unique perioperative challenges, PRES further complicates anesthetic management. Unfortunately, the anesthetic management for these critically ill and complex patients is not well elucidated and it is unclear whether the anesthetic choice may actually worsen neurologic symptoms. We describe two different presentations of PRES with pre-eclampsia/eclampsia, their anesthetic implications, and management.

Brain cell-derived exosomes in plasma serve as neurodegeneration biomarkers in male cynomolgus monkeys self-administrating oxycodone

Background

The United States is currently facing an opioid crisis. Novel tools to better comprehend dynamic molecular changes in the brain associated with the opioid abuse are limited. Recent studies have suggested the usefulness of plasma exosomes in better understanding CNS disorders. However, no study has ever characterized exosomes (small extracellular vesicles of endocytic origin) secreted by brain cells to understand the potential neurodegenerative effects of long-term oxycodone self-administration (SA).

Methods

MRI of Cynomolgus monkeys (Macaca fascicularis) was performed to assess alterations in gray matter volumes with oxycodone SA. We isolated total exosomes (TE) from the plasma of these monkeys; from TE, we pulled-out neuron-derived exosomes (NDE), astrocytes-derived exosomes (ADE), and microglia-derived exosomes (MDE) using surface biomarkers L1CAM (L1 cell adhesion molecule), GLAST (Glutamate aspartate transporter) and TMEM119 (transmembrane protein119), respectively.

Findings

We observed a significantly lower gray matter volume of specific lobes of the brain (frontal and parietal lobes, and right putamen) in monkeys with ∼3 years of oxycodone SA compared to controls. Higher expression of neurodegenerative biomarkers (NFL and α-synuclein) correlates well with the change in brain lobe volumes in control and oxycodone SA monkeys. We also identified a strong effect of oxycodone SA on the loading of specific miRNAs and proteins associated with neuro-cognitive disorders. Finally, exosomes subpopulation from oxycodone SA group activated NF-κB activity in THP1- cells.

Interpretation

These results provide evidence for the utility of brain cells-derived exosomes from plasma in better understanding and predicting the pro-inflammatory and neurodegenerative consequence of oxycodone SA.

Funding

NIH

Opioid and neuroHIV Comorbidity - Current and Future Perspectives

With the current national opioid crisis, it is critical to examine the mechanisms underlying pathophysiologic interactions between human immunodeficiency virus (HIV) and opioids in the central nervous system (CNS). Recent advances in experimental models, methodology, and our understanding of disease processes at the molecular and cellular levels reveal opioid-HIV interactions with increasing clarity. However, despite the substantial new insight, the unique impact of opioids on the severity, progression, and prognosis of neuroHIV and HIV-associated neurocognitive disorders (HAND) are not fully understood. In this review, we explore, in detail, what is currently known about mechanisms underlying opioid interactions with HIV, with emphasis on individual HIV-1-expressed gene products at the molecular, cellular and systems levels. Furthermore, we review preclinical and clinical studies with a focus on key considerations when addressing questions of whether opioid-HIV interactive pathogenesis results in unique structural or functional deficits not seen with either disease alone. These considerations include, understanding the combined consequences of HIV-1 genetic variants, host variants, and μ-opioid receptor (MOR) and HIV chemokine co-receptor interactions on the comorbidity. Lastly, we present topics that need to be considered in the future to better understand the unique contributions of opioids to the pathophysiology of neuroHIV.

Graphical Abstract

Cerebrospinal Fluid Hypovolemia and Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome (PRES) is a reversible neuroradiological syndrome characterized by reversible vasogenic edema. The pathophysiological mechanism is still unclear, but PRES may be triggered by various etiologies. To date, only a few PRES cases linked to cerebrospinal fluid (CSF) hypovolemia were reported. The association between PRES and CSF hypovolemia needs to be explored. We presented a case of PRES with CSF hypovolemia as a result of an inadvertent dural puncture and reviewed the literature to identify the clinical characterization and pathophysiological mechanism of PRES following CSF hypovolemia. A total of 31 cases of PRES-CSF hypovolemia was included for analysis. The median age was 33 years, with a notable female predominance (87.1%). Fifteen patients (48.4%) didn't have either a history of hypertension nor an episode of hypertension. The most common cause of CSF hypovolemia was epidural or lumbar puncture (n = 21), followed by CSF shunt (n = 6). The median interval between the procedure leading to CSF hypovolemia and PRES was 4 days. Seizure, altered mental state, and headache were the most frequent presenting symptom. The parietooccipital pattern was most frequent (71.0%). Conservative management remains the mainstay of treatment with excellent outcomes. Three patients had a second episode of PRES. CSF hypovolemia is a plausible cause of PRES via a unique pathophysiologic mechanism including arterial hyperperfusion and venous dysfunction. Patients with CSF hypovolemia is more susceptible to PRES, which is potentially life-threatening. Given that CSF hypovolemia is a common complication of anesthetic, neurological, and neurosurgical procedures, PRES should be early considered for prompt diagnosis and appropriate management.

Methadone-induced encephalopathy: a case series and literature review

BACKGROUND

Accidental ingestion or consumption of supra-therapeutic doses of methadone can result in neurological sequelae in humans. We aimed to determine the neurological deficits of methadone-poisoned patients admitted to a referral poisoning hospital using brain magnetic resonance (MR) and diffusion weighted (DW) imaging.

METHODS

In this retrospective study, brain MRIs of the patients admitted to our referral center due to methadone intoxication were reviewed. Methadone intoxication was confirmed based on history, congruent clinical presentation, and confirmatory urine analysis. Each patient had an MRI with Echo planar T1, T2, FLAIR, and DWI and apparent deficient coefficient (ADC) sequences without contrast media. Abnormalities were recorded and categorized based on their anatomic location and sequence.

RESULTS

Ten patients with abnormal MRI findings were identified. Eight had acute- and two had delayed-onset encephalopathy. Imaging findings included bilateral confluent or patchy T2 and FLAIR high signal intensity in cerebral white matter, cerebellar involvement, and bilateral occipito-parietal cortex diffusion restriction in DWI. Internal capsule involvement was identified in two patients while abnormality in globus pallidus and head of caudate nuclei were reported in another. Bilateral cerebral symmetrical confluent white matter signal abnormality with sparing of subcortical U-fibers on T2 and FLAIR sequences were observed in both patients with delayed-onset encephalopathy.

CONCLUSIONS

Acute- and delayed-onset encephalopathies are two rare adverse events detected in methadone-intoxicated patients. Brain MRI findings can be helpful in detection of methadone-induced encephalopathy.

Chronic oxycodone induces axonal degeneration in rat brain

BACKGROUND

Chronic opioid therapy for non-malignant pain conditions has significantly increased over the last 15 years. Recently, the correlation between opioid analgesics and alternations in brain structure, such as leukoencephalopathy, axon demyelination, and white matter lesions, has been demonstrated in patients with a history of long-term use of prescription opioids. The exact mechanisms underlying the neurotoxic effect of opioids on the central nervous system are still not fully understood. We investigated the effect of chronic opioids using an animal model in which female rats were orally gavaged with 15 mg/kg of oxycodone every 24 h for 30 days. In addition we tested oxycodone, morphine and DAMGO in breast adenocarcinoma MCF7 cells, which are known to express the μ-opioid receptor.

RESULTS

We observed several changes in the white matter of animals treated with oxycodone: deformation of axonal tracks, reduction in size of axonal fascicles, loss of myelin basic protein and accumulation of amyloid precursor protein beta (β-APP), suggesting axonal damages by chronic oxycodone. Moreover, we demonstrated activation of pro-apoptotic machinery amid suppression of anti-apoptotic signaling in axonal tracks that correlated with activation of biomarkers of the integrated stress response (ISR) in these structures after oxycodone exposure. Using MCF7 cells, we observed induction of the ISR and pro-apoptotic signaling after opioid treatment. We showed that the ISR inhibitor, ISRIB, suppresses opioid-induced Bax and CHOP expression in MCF7 cells.

CONCLUSIONS

Altogether, our data suggest that chronic opioid administration may cause neuronal degeneration by activation of the integrated stress response leading to induction of apoptotic signaling in neurons and also by promoting demyelination in CNS.

Posterior reversible leukoencephalopathy syndrome after kratom ingestion

Posterior reversible encephalopathy syndrome has been associated with hypertension, preeclampsia, cancer chemotherapy, and drugs of abuse, such as amphetamine and methamphetamine. We report a young man who suddenly developed severe headache, disorientation, and aphasia following ingestion of kratom and Adderall. Computed tomography and magnetic resonance imaging of his head revealed foci of vasogenic edema in the posterior occipital lobes, frontal lobes, and brainstem. In addition, he had a small area of hemorrhage in the left posterior occipital lobe. Lumbar puncture revealed an increased number of red blood cells but no other abnormalities. His initial blood pressure was elevated but returned to normal during hospitalization. This case suggests that kratom can cause posterior reversible encephalopathy syndrome and needs to be considered when patients present to emergency centers with headaches, confusion, and visual disturbances.

Rapid intracranial pressure drop as a cause for posterior reversible encephalopathy syndrome: Two case reports

Background:

Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible edematous lesions on radiological examinations as well as symptoms of altered consciousness and seizures. To date, the underlying mechanism remains largely unknown.

Case Descriptions:

Case 1 is a 72-year-old man with a history of hypertension presented with a subarachnoid hemorrhage. Fourteen days after the successful clipping of a ruptured aneurysm; he experienced inadvertent overdrainage via the intraventricular drain. Nine hours later, he started to have seizures followed by disturbances in consciousness. An emergency magnetic resonance imaging showed multiple high-intensity lesions in the frontal, temporal, parietal, and occipital lobes, basal ganglia, brainstem, and cerebellar hemispheres bilaterally, which are compatible with typical magnetic resonance findings in PRES patients. He was treated conservatively and recovered well. Case 2 is a 68-year-old woman with a mild history of hypertension and a ventriculo-peritoneal shunt for obstructive hydrocephalus, who underwent a cysto-peritoneal shunt placement because of an enlarging symptomatic arachnoid cyst. Immediately following surgery, she experienced disturbances in consciousness and developed status epilepticus. Radiological examinations revealed remarkable shrinkage of the arachnoid cyst and multiple edematous lesions, which led us to strongly suspect PRES. With conservative treatment, her symptoms and the radiological abnormalities disappeared.

Conclusion:

Based on the previous literature and our cases, we believe that the association between rapid reduction of intracranial pressure (ICP) and the development of PRES should be recognized because most neurosurgical procedures such as craniotomy or cerebrospinal fluid diversion present a potential risk of rapid reduction of ICP.

Study of Posterior Reversible Encephalopathy Syndrome in Children With Acute Lymphoblastic Leukemia After Induction Chemotherapy

Increasing occurrence of posterior reversible encephalopathy syndrome has been reported in children with acute lymphoblastic leukemia. However, the etiology of posterior reversible encephalopathy syndrome is not clear. To study the possible pathogenetic mechanisms and treatment of this complication, we reported 11 cases of pediatric acute lymphoblastic leukemia who developed posterior reversible encephalopathy syndrome after induction chemotherapy. After appropriate treatment, the clinical symptoms of posterior reversible encephalopathy syndrome in most cases disappeared even though induction chemotherapy continued. During the 1-year follow-up, no recurrence of posterior reversible encephalopathy syndrome was observed. Although the clinical and imaging features of posterior reversible encephalopathy syndrome may be diverse, posterior reversible encephalopathy syndrome should be recognized as a possible important complication of acute lymphoblastic leukemia when neurologic symptoms appear. In line with previous reports, our study also indicated that posterior reversible encephalopathy syndrome was reversible when diagnosed and treated at an early stage. Thus, the occurrence of posterior reversible encephalopathy syndrome should be considered and investigated to optimize the early induction scheme of acute lymphoblastic leukemia treatment.

Perioperative posterior reversible encephalopathy syndrome in a patient with no history of hypertension: a case report

Background

Posterior reversible encephalopathy syndrome is characterized by reversible neurological symptoms with leukoencephalopathy detectable by computed tomography (CT) and magnetic resonance (MR) imaging.

Case presentation

We here present a patient with no history of hypertension who, after being transferred back to the ward after undergoing total hysterectomy under general anesthesia, had several seizures and lost consciousness. Posterior reversible encephalopathy syndrome was suspected on the basis of brain CT images and clinical findings. She was treated with respiratory support, sedative drugs, and anticonvulsants, and MR imaging confirmed a diagnosis of posterior reversible encephalopathy syndrome. She regained consciousness and responsiveness the following day.

Conclusions

Clinically, posterior reversible encephalopathy syndrome resembles cerebral infarction or intracranial hemorrhage; MR imaging is useful for differentiating it from these conditions. Including this condition in the differential diagnosis and instituting appropriate treatment is important in minimizing the risk of development of irreversible neurological damage during the perioperative period.

Perioperative visual loss after spine surgery

Perioperative visual loss (POVL) is an uncommon, but devastating complication that remains primarily associated with spine and cardiac surgery. The incidence and mechanisms of visual loss after surgery remain difficult to determine. According to the American Society of Anesthesiologists Postoperative Visual Loss Registry, the most common causes of POVL in spine procedures are the two different forms of ischemic optic neuropathy: anterior ischemic optic neuropathy and posterior ischemic optic neuropathy, accounting for 89% of the cases. Retinal ischemia, cortical blindness, and posterior reversible encephalopathy are also observed, but in a small minority of cases. A recent multicenter case control study has identified risk factors associated with ischemic optic neuropathy for patients undergoing prone spinal fusion surgery. These include obesity, male sex, Wilson frame use, longer anesthetic duration, greater estimated blood loss, and decreased percent colloid administration. These risk factors are thought to contribute to the elevation of venous pressure and interstitial edema, resulting in damage to the optic nerve by compression of the vessels that feed the optic nerve, venous infarction or direct mechanical compression. This review will expand on these findings as well as the recently updated American Society of Anesthesiologists practice advisory on POVL. There are no effective treatment options for POVL and the diagnosis is often irreversible, so efforts must focus on prevention and risk factor modification. The role of crystalloids versus colloids and the use of α-2 agonists to decrease intraocular pressure during prone spine surgery will also be discussed as a potential preventative strategy.

Posterior reversible encephalopathy syndrome following an inadvertent dural puncture during an emergency laparotomy for ischemic colitis - a case report

Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological syndrome characterized by various symptoms of neurological disease. It has commonly been reported in association with acute hypertension, pre-eclampsia, eclampsia, sepsis, and exposure to immunosuppressants. Here, we report on a normotensive woman who developed a severe frontal headache, visual disturbances, and hypertension 3 days after undergoing an emergency laparotomy for ischemic colitis during which she suffered an inadvertent dural puncture. Neuro-imaging revealed features consistent with PRES. The patient went on to make a good recovery, being discharged 21 days postoperatively, with only minor visual disturbances and memory problems. This case highlights the importance of awareness of PRES to all specialties. On reviewing the literature, we feel that PRES may be a potential differential diagnosis to post-procedural neurological symptoms in those patients undergoing routine procedures such as spinal anesthetics or lumbar punctures.

Perioperative visual loss and anesthetic management

PURPOSE OF REVIEW

Perioperative visual loss (POVL) is an uncommon complication primarily associated with cardiac, spine, and head and neck surgery that can have a potentially severe impact on quality of life. The largest multicenter case control study to date on POVL recently identified risk factors associated with ischemic optic neuropathy and prone spinal fusion surgery. This review will summarize these findings and the updated American Society of Anesthesiologists practice advisory on POVL to provide guidance on identification and management of high-risk patients undergoing prone spine surgery. Epidemiology data on POVL from national databases, POVL in robotic surgery, and posterior reversible encephalopathy syndrome as a newer cause of POVL will also be discussed.

RECENT FINDINGS

Risk factors associated with prone spinal fusion surgery and ischemic optic neuropathy identified in a large multicenter case-control study include male sex, obesity, use of the Wilson spinal frame, longer anesthetic duration, greater blood loss, and a lower percentage of colloid in the nonblood fluid administration.

SUMMARY

Strategies aimed at modifying risk factors for ischemic optic neuropathy associated with prone spinal fusion surgery that are extrinsic to the patient may decrease its incidence. Further research is needed to validate this concept.

Ciprofloxacin-associated posterior reversible encephalopathy

Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological syndrome characterised by numerous symptoms and of no specific aetiology. Headache, confusion, seizures, cortical visual disturbances or blindness are the key symptoms. As this syndrome is reversible and readily treated by interrupting or discontinuing the aetiology, it should sharply be acknowledged. Ciprofloxacin was associated with PRES in an adolescent male treated from chest infection. It was managed in a hospital intensive care unit and was observed until disappearance.

[Postoperative cortical blindness after right upper lung lobectomy]

Changes in vision after non-ophthalmic surgery are a serious complication that can have devastating consequences due to its potential irreversibility. This not only leads to medical problems, but also legal ones. Many causes that affect sight during the peri-operative period have been identified, whether due to optic nerve damage or of extra-ocular origin (in the neuro-optic pathways and/or cerebral cortex). AU these may have a multifactorial origin, and there is still controversy as regards it pathogenesis and treatment. We present the case of a thoracic surgery patient who had a bilateral amaurosis in the post-operative period, which had a favourable outcome.

A rare case of antepartum posterior reversible encephalopathy syndrome

Pre-eclampsia and eclampsia are well-known causative factors of posterior reversible encephalopathy syndrome (PRES). There are only a few reported cases of antepartum PRES. We report a 25-year-old primigravid woman who presented with eight months of amenorrhoea and an abrupt onset of eclampsia associated with a history of a fall. A computed tomography scan ruled out intracranial haemorrhage and PRES was diagnosed. She responded well to supportive care, labour was induced and maternal and neonatal outcomes were good. Antepartum PRES poses different challenges to those of PRES in non-obstetric or postpartum patients, because of the additional management aspects required to ensure foetal wellbeing. We were posed with a difficult decision about the disadvantages of caesarean section versus those of vaginal delivery in our patient.

Reversible posterior leukoencephalopathy syndrome after lateral skull base surgery

OBJECTIVE

To describe the clinical course, diagnostic features and management of a case of reversible posterior leukoencephalopathy syndrome after a lateral cranial base removal.

PATIENT

A 58-year-old male patient with an inconspicuous clinical history presented with a lethargic state without localized neurologic deficit in the postoperative period of a subtotal petrosectomy for an adenoid cystic carcinoma of the temporal bone.

INTERVENTIONS

Cranial T2-weighted magnetic resonance imaging showed increased signal intensity in the occipital and cerebellar regions, centered at the cortical and subcortical white matter. Antihypertensive drugs, anticonvulsants, and antibiotics were administered. A complete resolution of the symptoms and radiologic findings were achieved within 1 to 2 weeks.

RESULTS

The clinical presentation, radiologic findings, and resolution of the clinical setting are consistent with a diagnosis of reversible posterior leukoencephalopathy syndrome.

CONCLUSION

To our knowledge, this is the first report of reversible posterior leukoencephalopathy syndrome after a lateral cranial base surgery.