I got to thinking about this and it would be kind of obvious to me that as someone who takes the sinemet (carbidopa/levodopa) in order to move otherwise I get rigid. So I would reason that no it would not be effective in reducing tremors since it enables movement, as opposed to slowing it. The DBS interrupts the signals that are too excited and cause the tremor. Just my thoughts. I would not think that the carbidopa is very effective, any input? Maybe someone who has a tremor AND rigidity?