One of the most significant and common consequences of stroke is memory loss. Often, only certain memories are impaired or injured.
Recent Memory Loss
For instance, most individuals who suffer a stroke continue to recall events and information from a long time ago. This is called remote memory. However, they may have trouble remembering things that happened shortly before the stroke or since the stroke. Specifically, they may no longer be able to benefit from new memory (also called recent memory) so they may have difficulty learning and retaining new information. Thus, even though the stroke patient is told something, perhaps repeatedly, and can repeat it back initially, the patient may still be unable to remember this information a few minutes later. A patient with this problem may be unable to remember and use the new information he or she is learning in rehabilitative therapies. This same person may be able to remember the name of a second grade teacher or the details of a honeymoon, even though he or she forgets to pay the phone bill. Although this seeming inconsistency is often confusing to observers, it is a common occurrence.
Verbal or Visual Memory Loss
Depending on the location of the stroke in the brain, the patient may lose only a specific memory type (or modality). Patients who suffer strokes on the left side of the brain are more likely to have difficulty learning and remembering verbal material (e.g., names, stories, and grocery lists). Patients with strokes on the right side of the brain may be able to remember this verbal information reasonably well but have more trouble retaining information they learned visually (e.g., they may get lost because they cannot correctly identify their surroundings). A person who has experienced a stroke may have impaired verbal memory, visual memory, both, or neither, depending on the location and severity of the stroke.
Temporary Confusion or Disorientation
Sometimes memory impairment will be temporary and take the form of confusion or disorientation. For a short time after the stroke (usually days or weeks), patients may be confused even in familiar surroundings. They may be unsure of where they are, what they are doing there, and who the people around them are. Generally, patients in this condition are unaware of the stroke and the effects the stroke has had. Frequently, this severe disorientation will resolve within a few weeks. However, some degree of confusion may remain if the patient continues to have difficulty remembering new information.