The Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT): one-year follow-up of a single case

Lithium poisoning and renal replacement therapy: pathophysiology and current clinical recommendations

Lithium intoxication is still an undefined and underestimated disease, especially those cases requiring extracorporeal treatment. Lithium is a monovalent cation with small molecular mass of 7 Da that has been regularly and successfully used since 1950 in the treatment of mania and bipolar disorders. However, its careless assumption can lead to a wide spectrum of cardiovascular, central nervous system and kidney diseases in case of acute, acute on chronic and chronic intoxications. In fact, lithium serum range is strict between 0.6 and 1.3 mmol/L, with a mild lithium toxicity observed at the steady-state of 1.5-2.5 mEq/L, moderate toxicity when lithium reaches 2.5-3.5 mEq/L, and severe intoxication with observed serum levels > 3.5 mEq/L. Its favorable biochemical profile allows the complete filtration and partial reabsorption in the kidney due to the similarity to sodium and also the complete removal by renal replacement therapy, that should be considered in specific poisoning conditions. In this narrative and updated review we discussed a clinical case of lithium intoxication, the different pattern of diseases attributable to excessive lithium load and the current indications for extracorporeal treatment.

"SILENT": A case report of a rare syndromal presentation of chronic lithium toxicity

This text discusses a case report of an affected person with bipolar ailment who developed the syndrome of irreversible lithium effectuated neurotoxicity (SILENT). In this case of a 62-year-old man with bipolar affective disorder, we found how continual lithium therapy can position a patient requiring chronic mood stabilizer treatment vulnerable to developing the silent syndrome. The case presentation covered a set of symptoms inclusive of encephalopathy, cerebellar dysfunction, stress, and limb tremors at the time of admission. A serial neurological examination and mental status examination for ascertaining the diagnosis of the silent syndrome were carried out, and the affected person was advised to discontinue lithium and was handled symptomatically for other symptoms. We ought to identify and manage the hazard elements contributing to the development of this syndrome.

A Unique Case of the Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT) Presenting With Multiple Neurological Sequelae

Lithium can have toxic effects on the central nervous system (CNS) that can be both acute and chronic. The syndrome of irreversible lithium-effectuated neurotoxicity (SILENT) was suggested in the 1980s to describe lithium intoxication-induced persistent neurological sequelae. In this article, we report a 61-year-old patient with bipolar disorder who had developed expressive aphasia, ataxia, cogwheel rigidity, and fine tremors after acute on chronic lithium toxicity. These neurological symptoms remained for four months after discontinuation of lithium, confirming the persistence of CNS signs and symptoms, which makes this case meets the SILENT syndrome criteria. Although rare, our report - which shows a severe and disabling form of SILENT syndrome - highlights the need for additional caution when treating patients with lithium and the need to perform strict control of the putative risk factors argued to be associated with the development of this syndrome.

A reappraisal of the role of fever in the occurrence of neurological sequelae following lithium intoxication: a systematic review

INTRODUCTION

We aimed to review cases of Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT) characterized by neurological sequelae following acute lithium toxicity and to explore whether cerebellar sequelae are more frequent in cases presenting with fever and/or infection.

AREAS COVERED

Case reports were identified from: (i) 6 reviews published up to 2005; (ii) MEDLINE, Web of Sciences, Cochrane Library and PsycINFO search.

EXPERT OPINION

We identified 123 SILENT cases published from 1965 to 2019, in which cerebellar sequelae were observed in an overwhelming proportion (79%). SILENT may occur at any time during lithium treatment. This complication is most frequently observed during routine lithium treatment, with fewer than 10% of cases occurring after accidental or intentional overdoses. SILENT may occur even when lithium plasma levels are within the therapeutic range: 63% of cases had lithium plasma level <2.5 mEq/l (low/mild toxicity). Fever and/or infection were reported in nearly half of the patients (48%). The likelihood of presenting with cerebellar vs. other neurological sequelae was independently increased by elevated plasma lithium level (≥ 2.5 mEq/l) and by a history of fever and/or infection. Lithium users should be warned of the need to consult in case of fever to adjust their lithium dosage.

Polypharmacy-induced cognitive dysfunction and discontinuation of psychotropic medication: a neuropsychological case report

Polypharmacy is common in patients with a diagnosis of bipolar disorder. Although polypharmacy is known to increase the risk of iatrogenic neurological conditions, the recovery of cognitive function after drug withdrawal has been rarely documented in psychiatric patients using standardized neuropsychological methods. We present a neuropsychological case report of patient SN, a 41-year-old woman who developed a socially and occupationally detrimental condition of cognitive dysfunction likely induced by long-term exposure to lithium and other psychiatric medications. To shed light on SN's cognitive deficits and their recovery after drug withdrawal, neuropsychological assessments were conducted before, and approximately 2 years after, lithium and other psychiatric drugs were discontinued. Selective cognitive impairments were observed before drug discontinuation in visuomotor speed, visuoperceptual reasoning and delayed visual memory. Partial, but not complete, recovery of function was observed 2 years after drug withdrawal.

Hypertensive bipolar: chronic lithium toxicity in patients taking ACE inhibitor

A patient with bipolar I disorder has been treated with lithium and haloperidol for the last 20 years and received an ACE inhibitor for his hypertension since 9 years ago. Despite regular clinic follow-ups and blood monitoring, he recently developed tremors and delirium. On hospital admission, serum level of lithium was far above toxic level. Mental state examination revealed an anxious and disorientated man with irrelevant speech. Immediate discontinuation of lithium resulted in slow reduction of serum lithium levels and gradual resolution of tremor but his delirium persisted for 2 weeks. His condition took a turn for the worse when he developed acute renal failure and arm abscess. We discussed about lithium toxicity and the vulnerability factors which have induced delirium and renal failure in this patient.

Persistent cerebellar dysfunction following acute lithium toxicity: A report of two cases

Neurological disturbances caused by lithium range from simple side effects such as benign tremor to acute reversible neurotoxicity. Rarely, lithium is reported to cause irreversible, permanent neurological sequelae most commonly manifested as cerebellar dysfunction, although other presentations have also been described. We report two cases of persistent cerebellar syndrome following acute lithium toxicity and discuss them in the light of existing literature on the subject.

Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup

The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxicokinetic data were extracted and summarized following a predetermined format. The entire workgroup voted through a two-round modified Delphi method to reach a consensus on voting statements. A RAND/UCLA Appropriateness Method was used to quantify disagreement, and anonymous votes were compiled and discussed in person. A second vote was conducted to determine the final workgroup recommendations. In total, 166 articles met inclusion criteria, which were mostly case reports, yielding a very low quality of evidence for all recommendations. A total of 418 patients were reviewed, 228 of which allowed extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li(+)] is >4.0 mEq/L, or in the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of the [Li(+)] (1D). Extracorporeal treatment is suggested if the [Li(+)] is >5.0 mEq/L, significant confusion is present, or the expected time to reduce the [Li(+)] to <1.0 mEq/L is >36 hours (2D). Extracorporeal treatment should be continued until clinical improvement is apparent or [Li(+)] is <1.0 mEq/L (1D). Extracorporeal treatments should be continued for a minimum of 6 hours if the [Li(+)] is not readily measurable (1D). Hemodialysis is the preferred extracorporeal treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity, patient's clinical status, and availability of extracorporeal treatments.