Also known as a transient ischemic attack (TIA), a micro stroke occurs when the blood flow to a part of the brain is interrupted for a short period of time due to a blood clot, haemorrhage or other vessel blockage. TIAs are short, usually only lasting a few minutes -- hence the nickname "micro" or "mini" stroke. The symptoms of a TIA are exactly the same as the symptoms of a stroke; the only difference is that the duration of TIA symptoms is much shorter, since a TIA's blockage is temporary, or transient. Symptoms occur suddenly but generally disappear within an hour; the specific symptoms depend largely on what part of the brain experienced the TIA.
Balance and Coordination Issues
An abnormal sensation of movement (vertigo) and dizziness is a common symptom of a TIA, caused by the sudden lack of blood in the brain. An abrupt loss of coordination and balance can occur, as well as difficulties with walking, reading or writing and swallowing.
Numbness and Weakness
A TIA may cause numbness and tingling. Sudden muscle weakness or paralysis of the arm, leg or face is also common. Any numbness, tingling or weakness usually occurs on only one side of the body. If the TIA occurs in the left hemisphere of the brain, the right side of the body will be affected; a TIA in the right hemisphere will cause symptoms on the left side of the body.
Speech and Vision Problems
Garbled or slurred speech is a TIA symptom that is seen especially if the muscle weakness affects the right side of the body, since the speech centre is located in the left hemisphere of the brain. Difficulty comprehending the speech of others can also occur. If the TIA affects the blood supply to the eyes, double vision or sudden blindness in either or both eyes may take place.
It's possible for a TIA to cause a wide variety of other symptoms, including confusion, memory loss, personality changes and emotional or mood changes. Variations in alertness, such as being unusually sleepy, unconscious or comatose are possible. Other physical symptoms range from changes in sensation -- involving taste, smell, hearing, touch and temperature -- to lack of bladder or bowel control. A drop attack, where the victim suddenly falls without warning, can result from a TIA at the base of the brain.
The American Stroke Association calls a TIA a "warning stroke" since about one-third of people who experience a TIA have a stroke within a year. People affected by a TIA have the opportunity to act and prevent a permanent stroke from occurring. By recognising TIA symptoms and going to the hospital, people can get help in identifying the causes of the TIA and receive treatment, through surgery or medication, to avoid a stroke in the future.