The Syndrome of Irreversible Lithium Effectuated Neurotoxicity (SILENT) is a severe form of lithium toxicity.
Neurological findings:
(1) cerebellar dysfunction
(2) extrapyramidal symptoms
(3) brainstem dysfunction
(4) dementia
(5) nystagmus
(6) dysarthria
(7) choreoathetoid movements
Other findings:
(1) psychiatric symptoms
(2) myopathy
(3) elevated lithium concentration
Clinical findings often persist after removal of the drug. Symptoms may persist for months or years.
Risk factors:
(1) age > 50 years
(2) chronic lithium therapy
(3) nephrogenic diabetes insipidus (caused by lithium toxicity)
(4) hyperthyroidism
(5) impaired renal function (which results in lithium accumulation)
