Clinical semiology and neuroradiologic correlates of acute hypernatremic osmotic challenge in adults: a literature review

Pontine Osmotic Demyelination Syndrome in a Pregnant Woman With Sepsis and Wernicke's Encephalopathy

A pregnant woman was brought to the emergency department looking starved and neglected. She was diagnosed with sepsis and started on intravenous antibiotics. She was also disoriented and hypernatremic. When the fetal heart sounds were found to be absent, the patient was diagnosed with septic miscarriage, which was managed by misoprostol, and after the expulsion of the products of conception, she was taken for evacuation of the uterus under anesthesia. Her brain CT was normal; however, due to her disorientation and altered mental status, a brain MRI was done, which revealed findings suggestive of Wernicke's encephalopathy and pontine osmotic demyelination syndrome (ODS), for which she received intravenous fluids, high doses of vitamins B, C and D, as well as other supplements like calcium, magnesium, and zinc. She received nasogastric feeding as she had difficulty swallowing and physiotherapy for the weakness in her upper and lower limbs. The patient was stable on discharge with good oral intake and was able to mobilize with a wheelchair.

A novel association of osmotic demyelination in Sjögren's syndrome prompts revisiting role of aquaporins in CNS demyelinating diseases: A literature review

BACKGROUND

Primary Sjögren's syndrome (SS) is a chronic systemic autoimmune disease with varied neurological manifestations. SS is associated with anti-aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD), a demyelinating autoimmune disorder of the central nervous system (CNS). Intriguingly, there are reports of osmotic demyelinating syndrome (ODS), a supposedly non-inflammatory disorder, in the context of SS and renal tubular acidosis (RTA), both of which are not yet established risk factors for ODS.

METHODS

A literature search was undertaken to identify case reports of ODS in patients with SS. Details of the clinical and laboratory features of these patients were compiled. Additionally, we searched for NMOSD in patients with SS. We looked for co-existing RTA in patients with SS-ODS as well as SS-NMOSD. We also screened for reports of ODS in RTA without underlying SS.

RESULTS & DISCUSSION

We identified 15 patients (all women, median age 40 years) with ODS in SS, and all of these patients had comorbid RTA. There were only three reported cases of ODS in RTA without underlying SS. We identified a total of 67 patients with SS-NMOSD, of whom only 3 (4.5%) had RTA. Hence, unlike NMOSD, the development of ODS in SS requires a prolonged osmotic or electrolyte abnormality caused by the comorbid RTA. The 15 patients with ODS and SS -RTA, showed heterogeneous clinical manifestations and outcomes. The most common symptom was quadriparesis, seen in 14 of the 15 patients. Eleven of the 15 patients had one of the following features, either alone or in combination: worsening of the sensorium, extensor plantar response, dysphagia/dysarthria, and facial palsy. The latter four manifestations were present at the onset in 7 patients and later in the course of the illness in the remaining 4 patients. Ocular palsy was seen in only four of the 15 patients and was a late manifestation. One patient who had extensive long-segment myelitis and subsequent ODS died, but most patients recovered without significant sequelae. None had hyponatremia, while all patients had hypokalemia and/or hypernatremia. Hypokalemia causing nephrogenic diabetes insipidus (NDI) followed by rapid rise in sodium and the resultant osmotic stress could potentially explain the occurrence of ODS in SS-RTA. Aquaporin (AQP) in astrocytes is implicated in ODS, and renal AQP is downregulated in NDI. Antibodies against AQPs are present in some patients with SS. Defective AQP is therefore a common link underlying all the connected diseases, namely SS, NDI, and ODS, raising the possibility of immune-mediated AQP dysfunction in the pathogenesis.

CONCLUSION

The hitherto unreported association between SS-RTA and ODS may implicate SS and/or RTA in the development of ODS. In the setting of SS-RTA, ODS must be suspected when a patient with flaccid quadriparesis does not respond to the correction of potassium or develops additional neurological features along with a rise in sodium. Defective functions of AQPs may be a possible mechanism linking demyelinating CNS lesions, SS, and RTA. Studies evaluating AQP functions and serum antibodies against AQPs in these conditions are warranted.

Diagnosis and treatment of brain injury complicated by hypernatremia

Hypernatremia is a common electrolyte disorder in patients with brain injury. The mortality of brain injury patients with severe hypernatremia may be as high as 86.8%. The efficacy of conventional treatment for hypernatremia is limited. Continuous renal replacement therapy (CRRT) can slowly, controllably, and continuously reduce the blood sodium concentration and gradually become an important treatment for severe hypernatremia patients. This review aims to provide important information for clinicians and clinical researchers by describing the etiology, diagnosis, hazards, conventional treatment, and CRRT treatment of hypernatremia in patients with traumatic brain injury.

Postpartum Hypernatremia with Extrapontine Rhabdomyelinolysis: A Case Report

Hypernatremia (serum sodium>160 meq/L) present with diverse neurological manifestations, ranging from flaccid paralysis to impaired cognition, encephalopathy, and even deep coma. Osmotic demyelination refers to changes in brain cells because of an acute change in plasma osmolality. It is further divided into two types, i.e., central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM). Patients with EPM, besides spasticity, may also present with other movement disorders such as catatonia, parkinsonism, and dystonia. We present a case of a postpartum woman bought to the emergency department by her relatives in an unconscious state. In view of poor sensorium (Glasgow coma scale < 7), she was intubated and received mechanical ventilatory support. On admission, computed tomography ofthebrain was normal, and the patient was transferred to the intensive care unit (ICU) for further management. The preliminary work-up in the ICU showed hypernatremia (serum sodium of 182 mEq/L) with hyper-osmolality (359 mOsm/kgH₂O). She was managed as per the ICU protocol for hypernatremia. During her ICU stay, her sensorium improved, but she developed flaccid paralysis and was quadriplegic. Thus, a tracheostomy was performed, and she was weaned from the ventilator. After ventilator weaning, she was transferred to the ward for further rehabilitation. During rehabilitation, the patient was able to sit and takefoodorally.To date, only a few cases are reported in postpartum women with acute severe hypernatremia caused by high-grade fever and loss of body fluids leading to extra-pontine demyelination and flaccid paralysis. This case highlightsthat prompt recognition and appropriate intervention can improve the outcomes in these patients.

Topiramate-induced severe electrolyte abnormalities and hypernatremia leading to central pontine myelinolysis

Central pontine myelinolysis (CPM) develops due to acute hypernatremia from a normal baseline serum sodium in the setting of electrolyte abnormalities induced by topiramate use. Topiramate is a commonly used medication with several indications including migraines, myoclonic jerks and seizures. It has been reported to cause renal tubular acidosis and severe electrolyte abnormalities, which in turn predispose patients to neuropathology via renal concentration defects and osmotic shifts. Our patient is a 55-year-old woman with a history of multiple sclerosis and myoclonus on topiramate for several years who presented with weakness and was found to be profoundly hypokalemic. She went on to develop changes in mental status, motor deficits and evidence of CPM on MRI during her hospitalisation. Surprisingly, the patient never had hyponatremia; however, she had an acute rise in serum sodium from a normal baseline after fluid resuscitation with normal saline for hypotension during her admission.

Acute Acquired Metabolic Encephalopathy Based on Diffusion MRI

Metabolic encephalopathy is a critical condition that can be challenging to diagnose. Imaging provides early clues to confirm clinical suspicions and plays an important role in the diagnosis, assessment of the response to therapy, and prognosis prediction. Diffusion-weighted imaging is a sensitive technique used to evaluate metabolic encephalopathy at an early stage. Metabolic encephalopathies often involve the deep regions of the gray matter because they have high energy requirements and are susceptible to metabolic disturbances. Understanding the imaging patterns of various metabolic encephalopathies can help narrow the differential diagnosis and improve the prognosis of patients by initiating proper treatment regimen early.

Neuroimaging Spectrum of Severe Hypernatremia in Infants with Neurological Manifestations

BACKGROUND

Variable neurological manifestations and imaging findings have been described in children with severe hypernatremia. We aimed to describe the spectrum of neuroimaging changes in infants with severe hypernatremia.

METHODS

This retrospective study included infants with severe hypernatremia (serum sodium >160 mEq/L), abnormal neurological examination, and an abnormal magnetic resonance imaging (MRI) of the brain over a period of 2 years in a tertiary care hospital. Relevant clinical data, including the feeding practices, clinical features, complications, and biochemical and radiological parameters, were entered in a structured pro forma. MRI findings were classified as vascular (hemorrhages and cerebral sinus venous thrombosis), osmotic demyelination syndrome (pontine and extrapontine myelinolyses), and white matter changes.

RESULTS

The common clinical features in the neonates were poor feeding (n = 4) and decreased urine output (n = 4); the older infants presented with gastrointestinal losses (n = 5). All cases had dehydration with encephalopathy. The patterns of radiological injury were vascular (hemorrhages, n = 5 and venous thrombosis, n = 3), osmotic demyelination (n = 8), and white matter changes (n = 7). Coagulopathy was correlated with the vascular complications (r = 0.8, p < 0.0001); the degree of dehydration was correlated with the venous thrombosis (r = 0.7, p < 0.04) and acute kidney injury (r = 0.8, p < 0.001). Neurological sequelae were seen in four cases and correlated with hypernatremia (r = 0.6, p = 0.03) and hyperosmolarity (r = 0.6, p = 0.03).

CONCLUSION

Characteristic neuroimaging findings are vascular changes in the form of venous thrombosis and hemorrhages, osmotic demyelination and white matter tract injury, and/or mostly combinations of these findings. Severe hypernatremia and resulting hyperosmolarity frequently cause neurological sequelae in neonates and infants.

Pontine Myelinolysis Caused by Hypovolemic Hypernatremia

Introduction. Central pontine myelinolysis is characterized by the occurrence of acute demyelinating lesions of cells in the pons secondary to abrupt oscillations of serum osmolarity. Its exact incidence is not well defined, but studies show a prevalence of 0.25 to 0.5% in the general population, 2.5% in the intensive care unit, and up to 10% in patients with risk factors, such as chronic liver disease and hepatic transplantation, alcoholism, malnutrition, diuretic therapy, electrolyte imbalance, hypoglycemia, and hyperglycemia. Case Report. A 70-year-old white female with extranodal diffuse large B-cell non-Hodgkin's lymphoma (extensive mass on the left anterior chest wall), stage IVA, developed pontine myelinolysis secondary to hypovolemic acute hypernatremia, which occurred due to diarrhea caused by chemotherapy (rituximab, cyclophosphamide, doxorubicin, and vincristine). Discussion. Pontine myelinolysis occurs most often due to the rapid correction of chronic hyponatremia. But here, we describe a case of the disease secondary to the occurrence of hypovolemic acute hypernatremia in a patient with a hematological malignancy under treatment, who was on chronic treatment with thiazide diuretics and who presented with other electrolyte disturbances as risk factors for the development of pontine myelinolysis.

Fatal case of hospital-acquired hypernatraemia in a neonate: lessons learned from a tragic error

A 3-week-old boy with viral gastroenteritis was by error given 200 mL 1 mmol/mL hypertonic saline intravenously instead of isotonic saline. His plasma sodium concentration (PNa) increased from 136 to 206 mmol/L. Extreme brain shrinkage and universal hypoperfusion despite arterial hypertension resulted. Treatment with glucose infusion induced severe hyperglycaemia. Acute haemodialysis decreased the PNa to 160 mmol/L with an episode of hypoperfusion. The infant developed intractable seizures, severe brain injury on magnetic resonance imaging and died. The most important lesson is to avoid recurrence of this tragic error. The case is unique because a known amount of sodium was given intravenously to a well-monitored infant. Therefore the findings give us valuable data on the effect of fluid shifts on the PNa, the circulation and the brain’s response to salt intoxication and the role of dialysis in managing it. The acute salt intoxication increased PNa to a level predicted by the Edelman equation with no evidence of osmotic inactivation of sodium. Treatment with glucose in water caused severe hypervolaemia and hyperglycaemia; the resulting increase in urine volume exacerbated hypernatraemia despite the high urine sodium concentration, because electrolyte-free water clearance was positive. When applying dialysis, caution regarding circulatory instability is imperative and a treatment algorithm is proposed.

Hypernatremia-induced Neurologic Complications After Hepatic Hydatid Cyst Surgery: Pretreat to Prevent

Introduction:

Surgery is effective treatment for echinococcosis; however, there is a risk of hypertonic saline resorption and acute hypernatremia.

Aim:

We report two cases of severe hypernatremia following hydatid cyst removal.

Case reports:

A 17-year-old girl underwent surgical removal of hepatic hydatid cyst. Following the surgery, she developed seizures evolving to status epilepticus, and was sedated and mechanically ventilated. Blood chemistry showed hypernatremia. Fluid resuscitation with 5% dextrose infusions was started in combination with furosemide. Electrolytes were monitored frequently until plasma sodium levels normalized, 30 hours later. The patient was seizure free 48 hours later. The second patient is a 70-year-old man with hepatic hydatid cyst. After the surgery he became somnolent and confused due to severe hypernatremia. Intravenous administration of five percentage dextrose was initiated and high doses of furosemide. Sodium level normalized within 38 hours. The patient’s mental status improved.

Conclusion:

A hospital protocol was established aiming to prevent hypernatremia and neurological complications.

Can osmotic demyelination syndrome be a complication of liver failure?

This case demonstrates that osmotic demyelination syndrome (ODS) can occur in absence of hyponatremia in patients with fulminant liver failure and markedly high bilirubin levels. Extremely high bilirubin levels, such as >900 μmol/L in the case presented here, may lead to blood brain barrier dysfunction by disrupting blood vessel endothelial cell function as well as increase the release of inflammatory cytokines. As demonstrated in the case here, even small fluctuations in electrolytes may make the brain increasingly more vulnerable to ODS. Clinicians should keep ODS high on their differential even in eunatremic patients with liver failure who have decreased levels of consciousness or coma.

Therapeutic Effect of Steroids in Osmotic Demyelination of Infancy

An 11-month-old male presented with acute gastroenteritis, seizures, and altered mental status. Laboratory workup revealed serum sodium of 177 mmol/L. Magnetic resonance imaging of the brain showed reduced diffusion in the supratentorial white matter, T2 hyperintensities in the left central pons and midbrain, subacute stroke in the right occipital lobe, and bilateral cerebellar hemorrhagic infarcts. The child was presumed to have hypernatremia-induced central pontine and extrapontine myelinolysis. He received 5 days of high-dose methylprednisolone for persistent encephalopathy and spastic quadriparesis with rapid recovery of his cognitive function and neurological examination. The child remained seizure-free and achieved normal development at 3-month and 2-year follow-ups. Osmotic demyelination of infancy may leave children with a significant neurological deficit. For favorable neurological outcome, early steroids should be considered.

A Case of Osmotic Demyelination Presenting with Severe Hypernatremia

Osmotic demyelination syndrome is a demyelinating disorder associated with rapid correction of hyponatremia. But, it rarely occurs in acute hypernatremia, and it leads to permanent neurologic symptoms and is associated with high mortality. A 44-year-old woman treated with alternative medicine was admitted with a history of drowsy mental status. Severe hypernatremia (197mEq/L) with hyperosmolality (415mOsm/kgH2O) was evident initially and magnetic resonance imaging revealed a high signal intensity lesion in the pons, consistent with central pontine myelinolysis. She was treated with 0.45% saline and 5% dextrose water and intravenous corticosteroids. Serum sodium normalized and her clinical course gradually improved. Brain lesion of myelinolysis also improved in a follow-up imaging study. This is the first report of a successful treatment of hypernatremia caused by iatrogenic salt intake, and it confirms the importance of adequate fluid supplementation in severe hypernatremia.

Plasma exchange successfully treats central pontine myelinolysis after acute hypernatremia from intravenous sodium bicarbonate therapy

BACKGROUND

Osmotic demyelination syndrome (ODS) primarily occurs after rapid correction of severe hyponatremia. There are no proven effective therapies for ODS, but we describe the first case showing the successful treatment of central pontine myelinolysis (CPM) by plasma exchange, which occurred after rapid development of hypernatremia from intravenous sodium bicarbonate therapy.

CASE PRESENTATION

A 40-year-old woman presented with general weakness, hypokalemia, and metabolic acidosis. The patient was treated with oral and intravenous potassium chloride, along with intravenous sodium bicarbonate. Although her bicarbonate deficit was 365 mEq, we treated her with an overdose of intravenous sodium bicarbonate, 480 mEq for 24 hours, due to the severity of her acidemia and her altered mental status. The next day, she developed hypernatremia with serum sodium levels rising from 142.8 mEq/L to 172.8 mEq/L. Six days after developing hypernatremia, she exhibited tetraparesis, drooling, difficulty swallowing, and dysarthria, and a brain MRI revealed high signal intensity in the central pons with sparing of the peripheral portion, suggesting CPM. We diagnosed her with CPM associated with the rapid development of hypernatremia after intravenous sodium bicarbonate therapy and treated her with plasma exchange. After two consecutive plasma exchange sessions, her neurologic symptoms were markedly improved except for mild diplopia. After the plasma exchange sessions, we examined the patient to determine the reason for her symptoms upon presentation to the hospital. She had normal anion gap metabolic acidosis, low blood bicarbonate levels, a urine pH of 6.5, and a calyceal stone in her left kidney. We performed a sodium bicarbonate loading test and diagnosed distal renal tubular acidosis (RTA). We also found that she had Sjögren's syndrome after a positive screen for anti-Lo, anti-Ra, and after the results of Schirmer's test and a lower lip biopsy. She was discharged and treated as an outpatient with oral sodium bicarbonate and potassium chloride.

CONCLUSION

This case indicates that serum sodium concentrations should be carefully monitored in patients with distal RTA receiving intravenous sodium bicarbonate therapy. We should keep in mind that acute hypernatremia and CPM can be associated with intravenous sodium bicarbonate therapy, and that CPM due to acute hypernatremia may be effectively treated with plasma exchange.