Objective: To share an exciting case of effective treatment of Syndrome of Irreversible Lithium Effectuated Neurotoxicity (SILENT) after an inadvertent lithium overdose using Deep Brain Stimulation (DBS).

Background: SILENT syndrome is a rare consequence of lithium toxicity, characterized by persistent neurological symptoms for at least 2 months post-lithium cessation with the absence of pre-existing neurological disorders[1]. Typical clinical presentation consists of cerebellar dysfunction, brainstem dysfunction, and extrapyramidal symptoms [2].This condition is more commonly seen among chronic lithium users [3]. SILENT poses a management challenge [4]. The efficacy of DBS in managing drug-induced tremors was prescribed, however literature on DBS application in SILENT syndrome is limited [5]. We present a case of effective treatment of SILENT syndrome using DBS [4].

Method: A 64-year-old Lady with a history of bipolar disorder presented with debilitating involuntary movements affecting all extremities and trunk of 2-years duration. Movements started after 10-day coma following accidental lithium overdose and have persisted despite attempts with various medications(Carbidopa-Levodopa, propranolol,and primidone).Patient felt symptoms were worsening, with more difficulty with daily activities and increased falls. Clinical examination revealed kinetic tremors in all limbs(< 4.5 Hz)and torso, bradykinesia and rigidity predominantly on the right side, positive cerebellar signs and shuffling gait.

Results: The patient was diagnosed with SILENT syndrome due to acute Lithium toxicity. After inadequate response to medical therapy, the patient opted for Left Ventral Intermediate (Vim) DBS. After two months, a partial improvement in the right arm noticed, progressing to complete resolution of rest tremor at 5-month follow-up and sustained at 4-year follow-up. Patient declined right Vim DBS due to anxiety associated with awake surgery.

Conclusion: DBS has been utilized in a variety of movement disorders including those induced by medications, however there are few reports of the application of DBS in patients with ataxia and medications-induced tremor. This case highlights the application of DBS to achieve a favorable outcome observed in managing SILENT syndrome. This suggests that further consideration should be given to DBS in cases of SILENT symptom refractory to medical management.

Figure 1. After DBS

References: [1] Señga MM, Sarapuddin G, Saniel E. A Case Report on an Atypical Presentation of the Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT) in a War Veteran with Bipolar Disorder and PTSD. Case Rep Psychiatry. 2020 Jun 4;2020:5369297.
[2] Lithium toxicity: The SILENT threat – PubMed [Internet]. [cited 2024 Feb 6]. Available from: https://pubmed-ncbi-nlm-nih-gov.ezp.slu.edu/34802989/
[3] Lithium intoxication: Incidence, clinical course and renal function – a population-based retrospective cohort study – PubMed [Internet]. [cited 2024 Feb 3]. Available from: https://pubmed-ncbi-nlm-nih-gov.ezp.slu.edu/27307388/
[4] Santos CF, Gomes R. Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT): A Review. European Psychiatry. 2022 Jun;65(S1):S717–S717.
[5] Amerika WE, van der Gaag S, Mosch A, van der Gaag NA, Hoffmann CFE, Zutt R, et al. Medical and Surgical Treatment for Medication‐Induced Tremor: Case Report and Systematic Review. Mov Disord Clin Pract. 2022 May 24;9(5):676–87.

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/reversing-the-irreversible-the-application-of-deep-brain-stimulation-in-the-syndrome-of-irreversible-lithium-effectuated-neurotoxicity/