How could a brain tumor or other lesion cause severe insomnia?

Related to location. Brain lesions effects the brain based on the function of the brain and the area it is located. If you have a tumor that is located in the area of the brain effects you consciousness then it will effect you consciousness.
Comments. Brain tumors and the needed treatments such as chemotherapy and/ or surgery, can all change the neurochemical balance of the brain. Sleep disorders are not uncommon in these situations.