Neuroleptic malignant syndrome in a case of extra-pontine myelinolysis: On the horns of dilemma.

Osmotic demyelination syndrome (ODS) and neuroleptic malignant syndrome (NMS) lead to severe neurological sequalae. Though currently thought to be different syndromes, literature suggests a relation between the two. We present the case of a 45-year-old male who was found to have chronic severe hyponatremia and underwent rapid correction of sodium and developed parkinsonism features. Magnetic resonance imaging (MRI) confirmed extrapontine myelinolysis (a type of ODS). The patient received haloperidol for agitated behavior and developed new features of rigidity, fever, tachycardia and elevated creatine phosphokinase (CPK) levels and thus neuroleptic malignant syndrome was suspected to overlap with ODS. We report this case highlighting the difficulty in differentiating the between ODS and NMS and their relationship.

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.

Colchicine poisoning complicated by medulla oblongata myelinolysis: a case report.

Medulla oblongata myelinolysis is an extremely rare manifestation of extrapontine myelinolysis (EPM). Herein, we report a case of a 34-year-old man with a history of gout who presented repeated vomiting and diarrhea after ingesting 15 colchicine pills. A hyponatremia diagnosis was given and after an intensive treatment, his serum sodium level increased from 118 to 129 mmol/L within 24 hours. Brain magnetic resonance imaging (MRI) revealed a lesion in the medulla oblongata that appeared as a hypointense area in T1-weighted images and a hyperintense area in T2-weighted images. A diagnosis of medulla oblongata myelinolysis and colchicine poisoning was then given, and methylprednisolone therapy was initiated. Seventeen days later, the patient achieved a good outcome with methylprednisolone therapy. However, his medulla oblongata lesion remained detectable with MRI. Medulla oblongata myelinolysis is an extremely rare manifestation of EPM, and unique for being colchicine-induced. This case shows that colchicine poisoning can lead to hyponatremia, which in turn can induce myelinolysis if not treated correctly. As exemplified by our patient's case, desirable treatment outcomes are possible in such cases, although these outcomes may not be associated with a visible reduction of the brain lesions in MRI scans.

Lack of astrocytes hinders parenchymal oligodendrocyte precursor cells from reaching a myelinating state in osmolyte-induced demyelination.

Demyelinated lesions in human pons observed after osmotic shifts in serum have been referred to as central pontine myelinolysis (CPM). Astrocytic damage, which is prominent in neuroinflammatory diseases like neuromyelitis optica (NMO) and multiple sclerosis (MS), is considered the primary event during formation of CPM lesions. Although more data on the effects of astrocyte-derived factors on oligodendrocyte precursor cells (OPCs) and remyelination are emerging, still little is known about remyelination of lesions with primary astrocytic loss. In autopsy tissue from patients with CPM as well as in an experimental model, we were able to characterize OPC activation and differentiation. Injections of the thymidine-analogue BrdU traced the maturation of OPCs activated in early astrocyte-depleted lesions. We observed rapid activation of the parenchymal NG2+ OPC reservoir in experimental astrocyte-depleted demyelinated lesions, leading to extensive OPC proliferation. One week after lesion initiation, most parenchyma-derived OPCs expressed breast carcinoma amplified sequence-1 (BCAS1), indicating the transition into a pre-myelinating state. Cells derived from this early parenchymal response often presented a dysfunctional morphology with condensed cytoplasm and few extending processes, and were only sparsely detected among myelin-producing or mature oligodendrocytes. Correspondingly, early stages of human CPM lesions also showed reduced astrocyte numbers and non-myelinating BCAS1+ oligodendrocytes with dysfunctional morphology. In the rat model, neural stem cells (NSCs) located in the subventricular zone (SVZ) were activated while the lesion was already partially repopulated with OPCs, giving rise to nestin+ progenitors that generated oligodendroglial lineage cells in the lesion, which was successively repopulated with astrocytes and remyelinated. These nestin+ stem cell-derived progenitors were absent in human CPM cases, which may have contributed to the inefficient lesion repair. The present study points to the importance of astrocyte-oligodendrocyte interactions for remyelination, highlighting the necessity to further determine the impact of astrocyte dysfunction on remyelination inefficiency in demyelinating disorders including MS.

Short-course metronidazole-induced reversible acute neurotoxicity in a renal transplant recipient.

Neurotoxic manifestations due to chronic metronidazole intake are well known, but neurotoxicity due to short-term use of metronidazole is very rare. We present a case of acute neurotoxicity due to short course of injectable metronidazole given in usual doses to a renal allograft recipient for persistent diarrhea. It responded to withdrawal of the offending drug. Tacrolimus trough concentration did not increase during neurotoxicity, thereby ruling out any metronidazole-tacrolimus interaction. Magnetic resonance imaging of the brain showed widespread osmotic demyelination and its recovery after drug withdrawal. This is the first reported case of a renal transplant recipient developing acute neurotoxicity due to short-term use of metronidazole, without any increase in tacrolimus trough concentrations.

[Is physiological saline really physiological? Hyponatreamia treatment--small deviations from the rules of appropriate therapy create serious complications and side effects]. / Czy sól fizjologiczna jest fizjologiczna? Leczenie hiponatremii--male odstepstwa od regul prawidlowego leczenia powoduja powazne powiklania i objawy uboczne.

Physiological saline can hardly be treated as physiological as it contains qualitatively and quantitatively different amounts of electrolytes. In particular, it contains 50% more chlorine ions than serum. Physiological saline can cause metabolic acidosis and in diabetic patients hyperchloremic acidosis. In comparison with Ringer solution and plasma-lyte, physiological saline is causing higher number of untoward effects and mortality associated with surgery. Ringer solution should be used in the situations requiring expansion of extracellular fluid. Physiological saline is a solution of choice in hypochloremic alkalosis in the case of brain injuries quite unfavourable is unnecessary rapid correction with physiological saline which can lead to serious sequelae in form of brain oedema and central extrapontine myelinolysis (osmotic demyelinisation) and permanent brain lesions. The hyponatremia's treatment depends on severity of symptoms, neurological deficit motivates immediate 4-6 mmol/l infusion, but further correction should be prolonged to 24-hrs; cautious correction corresponds to 8-mmol/l for 24 hrs. The modern treatment encompasses the introduction of vasopressin receptors antagonist--vaptans.

Extrapontine myelinolysis associated with pituitrin: case report and literature review.

BACKGROUND: Hyponatremia is the most common electrolyte abnormality encountered in hospitalized patients, resulting from a varied spectrum of conditions. Both the primary disturbance and its correction can result in life-threatening neurological consequences. Extrapontine myelinolysis is one such complication that is associated with the rapid correction of hyponatremia. Here we describe a patient who developed extrapontine myelinolysis unexpectedly after the correction of hyponatremia, which involved the drug pituitrin. CASE PRESENTATION: A 24-year-old Chinese woman was transferred to our neurology department with the symptoms of dysarthria and quadriparesis developing one day after the correction of hyponatremia (from 118 mmol/L to 140 mmol/L), which followed with a continuous intravenous drip of pituitrin used to control hemoptysis in the emergency room. During the course, she developed involuntary movement. Magnetic resonance imaging changes were consistent with extrapontine myelinolysis. CONCLUSION: This present case describes the mechanism of profound hyponatremia involving pituitrin, and the subsequent development of extrapontine myelinolysis. Physicians may approach effective clinical management of patients through awareness of the adverse effect of pituitrin on serum sodium levels, and avoid rapid correction of hyponatremia in clinical practice.

[A case of central pontine and extrapontine myelinolysis, without hyponatremia, during alcohol withdrawal with favorable outcome]. / Un cas clinique de myélinolyse centropontine et extrapontine, sans hyponatrémie, au décours d'un sevrage alcoolique et d'évolution favorable.

Central pontine and extra-pontine myelinolysis (CPM/EPM) is a rare neurological disorder, well documented for more than 50 years but whose pathogenesis remains obscure. The existence of predisposing factors occurs in the most cases; chronic alcohol abuse is one of the most commonly encountered, among many others. Alcohol withdrawal represents an additional vulnerability factor, being responsible for electrolyte imbalances which are not always demonstrable but are certainly involved in the development of CPM and/or EPM. CPM/EPM may be responsible for severe morbidity and is potentially life-threatening. The diagnosis of CPM/ EPM remains mostly clinical and is confirmed by magnetic resonance imaging of the brain. It should be considered in the setting of any unexplained neurological symptoms during the course of alcohol withdrawal or for any patient with chronic alcohol abuse, as promptly as possible, given the potentially fatal outcome.

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.

Massive ethylene glycol poisoning triggers osmotic demyelination syndrome.

BACKGROUND: Ethylene glycol is a toxic organic solvent implicated in thousands of accidental and intentional poisonings each year. Osmotic demyelination syndrome (ODS) is traditionally known as a complication of the rapid correction of hyponatremia. OBJECTIVE: Our aim was to describe how patients with ethylene glycol toxicity may be at risk for developing ODS in the absence of hyponatremia. CASE REPORT: A 64-year old female patient was comatose upon presentation and laboratory results revealed an anion gap of 39, a plasma sodium of 150 mEq/L, a plasma potassium of 3.5 mEq/L, an osmolal gap of 218, an arterial blood gas pH of 7.02, whole blood lactate of 32 mEq/L, no measurable blood ethanol, and a plasma ethylene glycol concentration of 1055.5 mg/dL. The patient was treated for ethylene glycol poisoning with fomepizole and hemodialysis. Despite having elevated serum sodium levels, the patient's hospital course was complicated by ODS. CONCLUSIONS: Rapid changes in serum osmolality from ethylene glycol toxicity or its subsequent treatment can cause ODS independent of serum sodium levels.

Central pontine myelinolysis (CPM) associated with tacrolimus (FK506) after liver transplantation.

BACKGROUND: Central pontine myelinolysis (CPM) is the most detrimental neurologic complication after liver transplantation. The incidence of CPM after liver transplantation ascends to 17%. Although the precise etiology and pathogenesis of CPM is largely unknown, a growing literature implicates a possible role of immunosuppressive agents, such as Cyclosporine (incidence 30%) on its development. Other immunosuppressive agents also can cause CPM but the frequency of these cases is less compared to Cyclosporine. There is only one case report for Tacrolimus (FK506)-associated speech disorder, which might be an atypical presentation of CPM, and no case reports for Rapamycin. We present a case of Tacrolimus induced CPM. CASE REPORT: A 62-year-old woman who underwent liver transplantation developed clinical symptoms with radiologic evidence consistent with CPM 7 days after liver transplant. Since the electrolytes in this patient remained normal from her admission, the hypothesis of inmunossupressor neurotoxicity was established and the therapy was switched, resulting in an evident clinical and radiological improvement of her condition in the following days. Five months later, the patient's only neurological deficit was slight dysarthria and a follow-up MRI showed no abnormalities. CONCLUSIONS: This case provides evidence of Tacrolimus-associated CPM after transplantation, which presented with a classic "lock-in syndrome" with radiographic confirmation.

Ocular motor and imaging abnormalities of midbrain dysfunction in osmotic demyelination syndrome.

After rapid correction of severe hyponatremia, a 36-year-old man developed osmotic demyelination syndrome (ODS), manifested neurologically by impaired cognition, extremity weakness, bilateral third cranial nerve palsies, and gaze-evoked upbeat and rotary nystagmus. Brain MRI showed restricted diffusion in the rostral midbrain and temporal and parietal lobes but not in the pons. Over several weeks, all neurologic and imaging deficits resolved. This is the first report to document ocular motor abnormalities associated with midbrain dysfunction in ODS.

[Intoxication with lithium]. / Akzidentelle Lithiumintoxikation.

We report a case of a 75-year-old male patient who presented to the emergency room with arterial hypotension and impaired vigilance. The patient was on lithium therapy due to mood disorder. One month earlier medication with a betablocker, a loop-diuretic and an ACE-inhibitor had been started due to heart failure. Findings at admission included renal insufficiency, pneumonia and a slightly increased serum level of lithium. Three days later his Glasgow Coma Scale Score was 7, he showed gaze deviation, increased muscle tonus and cloni. The patient fully recovered after volume substitution and normalization of his renal function. Diagnosis of chronic intoxication with lithium was made due to the clinical picture and after exclusion of neurological pathologies. The pharmacokinetic characteristics of lithium is described and the risk factors leading to lithium intoxication and treatment of intoxication are discussed.