Hypophosphatemic encephalopathy in a CAPD patient

Phosphate in the Context of Cognitive Impairment and Other Neurological Disorders Occurrence in Chronic Kidney Disease

The nervous system and the kidneys are linked under physiological states to maintain normal body homeostasis. In chronic kidney disease (CKD), damaged kidneys can impair the central nervous system, including cerebrovascular disease and cognitive impairment (CI). Recently, kidney disease has been proposed as a new modifiable risk factor for dementia. It is reported that uremic toxins may have direct neurotoxic (astrocyte activation and neuronal death) and/or indirect action through vascular effects (cerebral endothelial dysfunction, calcification, and inflammation). This review summarizes the evidence from research investigating the pathophysiological effects of phosphate toxicity in the nervous system, raising the question of whether the control of hyperphosphatemia in CKD would lower patients’ risk of developing cognitive impairment and dementia.

Food Coma: Hyperammonemic Encephalopathy From Refeeding Syndrome

Hyperammonemic encephalopathy (HAE) from extrahepatic causes is increasingly being recognized. Refeeding syndrome is characterized by severe fluid and electrolyte shifts following the reintroduction of nutrition. We describe the case of a 67-year-old man with bilateral maxillary sinus squamous cell carcinoma on nivolumab who became comatose after initiation of enteral feeding. Initial workup was notable for severe hypophosphatemia (<1 mg/dL) and markedly elevated ammonia (226 µmol/L). Neuroimaging was unrevealing. Correction of hypophosphatemia did not improve mental status. Ammonia levels briefly decreased while holding enteral feeding but worsened again on resumption. High-volume continuous renal replacement therapy was recommended but deferred in accordance with family wishes. We hypothesize that HAE may have been precipitated by a combination of refeeding-induced high nitrogen burden and limited detoxification via the urea cycle and extrahepatic pathways in the setting of severe protein-energy malnutrition and underlying malignancy. Nivolumab could have contributed as well.

Uremic encephalopathy in patients undergoing assisted peritoneal dialysis: a case series and literature review

We sometimes hesitate to switch renal replacement therapy from peritoneal dialysis (PD) particularly in elderly patients due to their physical tolerance levels and lifestyles. Here, we describe the cases of three patients treated with PD alone despite an anuric status who subsequently developed uremic encephalopathy, which was successfully treated with hemodialysis (HD). The first patient was a 75-year-old woman who developed uremic encephalopathy with an anuric status and inadequate PD after 7 months of treatment. HD immediately improved her condition; encephalopathy did not recur with combined therapy of PD and HD. The second patient was a 69-year-old woman who developed anuria and was treated with combined therapy. Her arteriovenous fistula was obstructed; therefore, she was treated with PD alone. Total weekly Kt/V was sufficiently high at 1.95; however, she developed uremic encephalopathy the following month, which was successfully treated with HD. The third patient was an 84-year-old woman who developed anuria, but was treated with PD alone with adequate total weekly Kt/V of 2.2. PD could not be performed for 2 days because of myocardial infarction intervention; subsequently, she developed uremic encephalopathy, which was successfully treated with HD. These cases are the first of their kinds, wherein patients undergoing PD, developed uremic encephalopathy without any obvious triggers, including drugs, and illustrate the necessity of initiating combined therapy for such patients considering the risk of developing severe uremia leading to uremic encephalopathy, in spite of it being less preferable for elderly patients due to their physical conditions and lifestyles.

Refeeding encephalopathy in a patient with severe hypophosphataemia and hyperammonaemia

The refeeding syndrome is a potentially fatal condition that affects multiple organ systems. It is the consequence of fluid and electrolyte shifts that may occur in a malnourished patient following the introduction of nutrition therapy. The most prominent characteristic is hypophosphataemia. Although hyperammonaemia is usually seen in decompensated liver cirrhosis or acute liver failure, it may occur in other settings. We report a clinical case of prolonged and severe encephalopathy accompanied by hypophosphataemia and hyperammonaemia in a 59-year-old woman with no preexisting liver disease, urea cycle defects or portosystemic shunting. We suggest that these biochemical abnormalities were caused by uncontrolled refeeding and that the clinical picture was consistent with refeeding encephalopathy.

Multiple etiologies of axonal sensory motor polyneuropathy in a renal transplant recipient: a case report

INTRODUCTION

Neurological complications leading to morbidity and mortality are not frequent in renal transplant recipients. Here, we report a renal transplant recipient who presented with diminished strength in his limbs probably due to multiple etiologies of axonal sensorimotor polyneuropathy, which resolved with intravenous immunoglobulin.

CASE PRESENTATION

A 49-year-old Iranian male renal transplant recipient with previous history of autosomal dominant polycystic kidney disease presented with diminished strength in his limbs one month after surgery. Our patient was on cyclosporine A, mycophenolate mofetil and prednisone. Although a detected hypophosphatemia was corrected with supplemental phosphate, the loss of strength was still slowly progressive and diffuse muscular atrophy was remarkable in his trunk, upper limb and pelvic girdle. Meanwhile, his cranial nerves were intact. Post-transplant diabetes mellitus was diagnosed and insulin therapy was initiated. In addition, as a high serum cyclosporine level was detected, the dose of cyclosporine was reduced. Our patient was also put on intravenous ganciclovir due to positive serum cytomegalovirus immunoglobulin M antibody. Despite the reduction of oral cyclosporine dose along with medical therapy for the cytomegalovirus infection and diabetes mellitus, his muscular weakness and atrophy did not improve. One week after administration of intravenous immunoglobulin, a significant improvement was noted in his muscular weakness.

CONCLUSION

A remarkable response to intravenous immunoglobulin is compatible with an immunological basis for the present condition (post-transplant polyneuropathy). In cases of post-transplant polyneuropathy with a high clinical suspicion of immunological origin, administration of intravenous immunoglobulin may be recommended.