Final answer:
For lithium intoxication with symptoms such as impaired consciousness and seizures, diazepam, an anticonvulsant, is the treatment of choice administered by healthcare professionals.
Step-by-step explanation:
The treatment of choice for a person experiencing lithium intoxication with impaired consciousness, neuromuscular irritability, and seizures is the administration of anticonvulsants, for example, diazepam. Diazepam helps to manage seizures and thus is critical in improving the long-term prognosis and reducing the risk of brain damage. It is important to note that this medication is administered by healthcare professionals and is not meant for self-administration.