Abstract
Transient neurological symptoms often present a difficult diagnostic dilemma. It is often difficult to tell if the transient symptoms were due to ischemia or due to something else (see Chapter 1). Usually, by the time the physician sees the patient, the neurological exam has returned to normal. On the other hand, it is critically important not to miss the diagnosis of transient ischemic attack (TIA). TIAs may provide an opportunity for physicians to intervene and prevent an ischemic stroke and subsequent disability, and must be taken seriously. The search for an etiology must be done expeditiously. Just as angina may serve as a warning for future myocardial infarction, a TIA is often a warning sign of an impending stroke.
Transient neurological symptoms often present a difficult diagnostic dilemma. It is often difficult to tell if the transient symptoms were due to ischemia or due to something else (see Chapter 1). Usually, by the time the physician sees the patient, the neurological exam has returned to normal. On the other hand, it is critically important not to miss the diagnosis of transient ischemic attack (TIA). TIAs may provide an opportunity for physicians to intervene and prevent an ischemic stroke and subsequent disability, and must be taken seriously. The search for an etiology must be done expeditiously. Just as angina may serve as a warning for future myocardial infarction, a TIA is often a warning sign of an impending stroke.
Definition
A transient ischemic attack (TIA) is a brief episode of neurological dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than 1 hour, and without evidence of acute infarction on brain imaging.1
Etiology
The causes are the same as for ischemic stroke. Determining the etiology of the TIA expeditiously and providing the appropriate treatment is very important, as it may prevent a future stroke. Examples include atrial fibrillation and symptomatic carotid stenosis.
Presentation
TIAs present the same way as an acute ischemic stroke. The only difference is that the symptoms and signs rapidly and completely resolve, usually within minutes. There is not a typical presentation – it depends on the vascular territory affected.
Differential Diagnosis
Syncope – look for pre-syncopal symptoms.
Seizure – ask about prior history of seizure, or if any of the following occurred with the event: shaking, clouding of consciousness, tongue-biting, incontinence.
Migraine – be careful about attributing a TIA or stroke to migraine unless there is a clear history of previous migraine with focal features similar to this event.
Vestibular dysfunction, vertigo.
Anxiety, panic attack.
Hypoglycemia.
Drug intoxication.
Mass such as tumor or subdural hematoma.
Metabolic encephalopathy.
Stroke recrudescence – reappearance or worsening of pre-existing stroke deficit usually due to toxic or metabolic factors (infection, sedative drugs, etc.).
Clinical Approach to a Patient With Suspected TIA
Evaluation of TIA is the same as for ischemic stroke, since the pathophysiology of TIA and ischemic stroke is the same. TIA should be thought of as a briefer, smaller ischemic stroke, but with the same implications for recurrence.
History and Physical Exam
Make sure that the neurological symptoms have resolved!
▪ If you document a normal neurological exam and later the patient develops recurrent neurological deficits, they can still be treated with tPA because the clock starts over from the time of new symptoms, as long as the patient was completely back to normal in between.
Since you are likely to be seeing the patient after, and not during, the TIA, get an objective description as much as possible, perhaps from a witness:
▪ “Were you able to move your arm?”
▪ “Was his speech slurred?”
▪ “Was she able to walk normally?”
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