Symptoms of significant brain atrophy include progressive cognitive impairment involving multiple cognitive functions, otherwise known as dementia, seizures and aphasia, which is the disruption in the understanding or production of language or both.
The Senate majority leader has somewhat less official power than the Speaker of the House. This is because the vice president is technically the Senate's presiding officer, a ceremonial position that calls chiefly for casting a vote in the event of a tie.
The Senate Minority Leader is acts as the direct counterpart to the Senate Majority Leader. The Senate Minority leader is to act as the chief spokesperson for the their respective party, and are responsible for the coordination and managing for their party's agenda in the Senate. Currently, the Senate Minority Leader is Republican Mitch McConnell from Kentucky. With the current Senate composition having a Democratic Majority, McConnell acts as the main spokesman for the Republican agenda in the Senate. Senate Republicans currently hold 41 seats in the Senate, while Democrats hold the majority at 57. The practice of instituting party leaders in the Senate can be dated back to 1920, when the Democrats at the time elected their first floor party leaders. At the time, the Democratic party was in the minority. Senate Republicans would also adopt the practice, but will not do so until 1925, at which time they would hold the majority.