America witnessed a dramatic ezample of speech arrest or expressive aphasia when Serena Branson began speaking incoherently when reporting on the Grammies while on- air. According to news reports, her symptoms resolved within a few minutes at the most and she refused further medical assistance after the paramedics found her vital signs to be stable. There is great interest in knowing what could have caused a dramatic and sudden but thankfully brief loss of speech.
There are numerous possible causes of sudden aphasia that fully resolves. These include transient ischemic attacks, seizures, brain hemorrhages, low blood pressure, low blood sugar, multiple sclerosis and inflammatory conditions of the brain and blood vessels.
What comes to mind first is a transient ischemic attack (TIA). This is due to a brief reduction of blood flow to a portion of the brain but with resumption of adequate blood flow before damage to that area occurs. The reduction in blood flow can be due to a piece of "debris" breaking off a plaque in a narrowed, diseased artery in the neck or when there is such a high degree of narrowing of an artery in the neck or brain that briefly the blood flow through that artery is profoundly reduced. These events usually occur in individuals over the age of sixty. Another cause of TIA can be due to an abnormality in the heart such as an infection in the heart or an abnormal heart rhythm. In these instances a small piece of "debris" can be released from the heart into the blood stream and then into the brain. A TIA can also be caused by birth control pills, blood disorders and drugs such a cocaine. Inflammation of arteries, refered to as arteritis is another cause of TIAs.
TIAs are highly significant because they are often precurors of major strokes leading to permanent neurologic dysfunction. Therefore, it is important to diagnose the cause of a TIA and treat it appropriately and rapidly.
A focal seizure can present as a brief loss of neurologic dysfunction including a brief episode of aphasia as Serena Branson experienced. Again, there are numerous possible causes for the new onset of a seizure. A brain tumor, drug reaction, brain hemorrhage or low blood sugar are all possible causes of a focal seizure.
Even when someone recovers fully and feels well after an brief episode of aphasia, as apparently was the case with Serena Branson, the individual needs a full and careful medical evaluation. Not only do they need an MRI of the brain, which may, in fact, be normal but the arteries in the neck and the heart need to be fully evaluated. Additionally blood tests need to be performed. Without appropriate diagnosis and treatment, a permanent stroke could ensue or a minor hemorrhage in the brain could lead to a major hemorrhage. If a seizure has occured, a subsequent seizure might be more profound. The early stage of an infection such as encephalitis could become a life-threatening infection of the brain.
Certainly Ms. Branson will have a thorough medical evaluation and hopefully the cause of her episode of aphasia will be found to be readily treatable and she will not suffer future neurologic dysfunction.