Lithium Toxicity

My brother was diagnosed with bi-polar many years ago. He was prescribed lithium. He went through a period of time when he would take himself off of the lithium. This always resulted in him being admitted into mental hospitals, even in straight jackets) but, finally, he surrendered to the importance of taking the lithium and maintained that until this past year. He had been in a serious accident on his job the year before resulting in many doctors having access to him and all sorts of medical decisions had to be made. During that time the lithium was questioned and a chain of events began that ended up in a horrific event a full year later. My brother had developed a life that basically included work, home and work. Extremely ordered. We did not know him that well because he had this life and it worked for him. He loves us but he had found a path he could walk and manage his life in an acceptable manner. We had no idea how critically important that was to his life with bi-polar but we certainly did not rock that boat. We love our brother very much. He has had struggles with himself since he was young but aspects of our family life did not make room for identifying or addressing those aspects. I am coming to a point, really, long story and I think background will help all of you help me to think through what is currently going on. Due to the accident my brother could no longer work and was involved with workman's comp. My sister became his power of attorney and worked closely with the workman's comp rep and doctors, hospitalizations, etc. We were in close contact and talked everything out thoroughly. My brother also is served by the Veteran's Administration doctors. This is a blessing and a curse when trying to work things out between civilian doctors and VA doctors. There came a point when Workman's Comp felt my brother had recovered enough to let him go. We did not think that he was ready because, of course, we were close to my brother and saw all the remaining challenges for him but hiring a lawyer to represent him was out of the question given his mental health and mania. This past year we received a call from his step-daughter that something was wrong with Leo. I drove right away and called my sister to come. My brother was so close to death. He had confused his medications which we did not understand fully at the time. He had been given seroquel in addition to his lithium but the dosages had been changed. We kept my brother in a motel before our efforts to get the attention of the emergency room in his area finally worked. During that time it was a nightmare of watching him hallucinate, confuse rooms and using the bathroom in weird places. Not knowing what to do we decided to lower his Seroquel slowly assuming it was the problem and having no medical guidance. Our good intentions probably nearly killed him. When he was finally admitted to the hospital he was severely dehydrated and he was lithium toxic to the extreme. We realized later that the level had been identified at the VA but not followed up on. The hospital took him off of all lithium and placed him on depakote which is what he is taking today. All that to ask this question. My brother is maintaining on the depakote but the bi-polar is bleeding over into some significant areas. He talks about it which is good. He becomes paranoid making it difficult for him to be in groups. His mania is clearly challenging him. But, he is trying very hard to manage this in his decision making for his day. We are gravely considered for his future with bi-polar as he does not represent himself clearly to doctors and believes the VA is the gospel. I did some reading on lithium toxicity and believe they are saying that after a period of time, and with the appropriate testing in place, patients may be able to resume lithium. Do any of you know anything about this or had experience with depakote. It may be that an increased dosage would help. Discussing this with my brother causes him to experience anxiety. He is 70 and has led his life his way for a long time. He appreciates our concerns for him but does not handle much discussion about his bi-polar. We will not impose anything on him but information that could return him to the use of lithium would be a wonderful piece of information.