Lithium Salt Intoxication and Neurologic Sequelae

To the Editor.  —In the recent article by Donaldson and Cuningham,¹ "Persisting Neurologic Sequelae of Lithium Carbonate Therapy," all patients had maximum plasma lithium ion levels above the accepted ranges of 0.8 to 1.4 mEq/L for acute episodes and 0.6 to 1.0 mEq/L for maintenance therapy.² Consequently, a more appropriate title would have been "Persisting Neurologic Sequelae of Lithium Carbonate Intoxication." Subsequent reporting of this article by the news media led a number of patients to express concern that their carefully monitored lithium carbonate treatment was likely to result in brain damage. The authors explored a number of explanations for the persistence of symptoms without mentioning the duration of elevated serum lithium ion levels, which is well recognized as a critical variable that affects the severity of intoxication and quite probably the outcome of an episode of lithium carbonate poisoning.^3-6We agree with the authors' concluding statement about the necessity