C53-33 The SILENT Killer

Abstract Lithium has a narrow therapeutic window. Frequent monitoring of both serum levels and clinical signs of toxicity is warranted because toxicity may be present even when concentrations are within the therapeutic range. (1)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. (2) Patient is a 70-year-old female who presented to the ED for evaluation of worsening altered mental status for the past 2 to 3 days with left-sided facial drooping. Patient was admitted for AKI and acute encephalopathy. Multiple EEGs were performed without showing epileptic activity but did demonstrate mildly abnormal intermixed theta activity.Her home meds are Lithium, depakote sprinkles, zyprexa, Latuda, ropinirole and amantadine. Lithium level came back elevated at 1.8.Patient opened eyes to vocal stimulus, appeared to grimace in response to noxious stimuli. Pupils bilaterally were fixed, sluggishly responsive to light. Positive neck rigidity and spastic arms bilaterally. Patient’s hospital stay was complicated by acute hypoxic respiratory failure requiring intubation twice with a result of tracheostomy and PEG tube placement. Patient was discharged to LTAC for continuing care. The syndrome of irreversible lithium-effectuated neurotoxicity (SILENT) is defined by persistent lithium-induced neurological symptoms. Presentation of AMS in this patient in the context of lithium use, raised concerns for drug toxicity and ultimately suspicion of SILENT. (3)SILENT syndrome is defined as prolonged neurological complications of lithium toxicity despite removal of the medication and normalization of serum lithium levels. Lithium is known to have slow absorption into the central nervous system making serum concentrations unreliable when correlating clinically. (4)In our case, the patient had Lithium toxicity and manifestations lasted for an extended period of time (Around 3 weeks in the hospital before discharge to LTAC).Conclusion As clinicians, we must remain vigilant and bring awareness regarding the recognition and management of SILENT and other medication-induced neurological complications.Lithium toxicity may persist for a prolonged period of time including:Coarse tremor,hyperreflexia, nystagmus, and ataxia References: (1) Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT):A ReviewC Fernandes Santos, R Gomes2022 Sep 1;65(Suppl 1):S717 (2) A Unique Case of the Syndrome of Irreversible Lithium-Effectuated Neurotoxicity(SILENT) Presenting With Multiple Neurological (3) Complexity of diagnosis and management of silent syndrome (4) But the lithium level is normal!”SILENT Syndrome:A rare diagnosis ofirreversible lithium toxicity to consider in cases of irreversible neurotoxicitySarab Sodhi, Samantha Lee, Antoinette SpevetzDOI:10.15761/TEC.1000111 This abstract is funded by: None