Authors: Lewis,
Steven L.
Steven L.
Title: Field
Guide to the Neurologic Examination, 1st Edition
Guide to the Neurologic Examination, 1st Edition
Copyright ©2004 Lippincott Williams &
Wilkins
Wilkins
> Table of Contents > Section 3 –
Neurologic Examination in Common Clinical Scenarios > Chapter 48 –
Examination of the Patient With Transient Focal Neurologic Symptoms
Neurologic Examination in Common Clinical Scenarios > Chapter 48 –
Examination of the Patient With Transient Focal Neurologic Symptoms
Chapter 48
Examination of the Patient With Transient Focal Neurologic
Symptoms
Symptoms
GOAL
The goal of the history and examination of the patient with
transient focal neurologic symptoms is to determine the most likely
pathophysiology and localization of the patient’s symptoms.
transient focal neurologic symptoms is to determine the most likely
pathophysiology and localization of the patient’s symptoms.
PATHOPHYSIOLOGY OF TRANSIENT FOCAL NEUROLOGIC SYMPTOMS
Transient—lasting seconds, minutes, or hours—focal neurologic
dysfunction generally occurs as a result of one of three major mechanisms:
ischemia, seizure, or migraine.
dysfunction generally occurs as a result of one of three major mechanisms:
ischemia, seizure, or migraine.
Ischemia causes transient focal neurologic symptoms [i.e.,
transient ischemic attacks (TIAs)] due to diminished blood flow to a focal
brain region (see Chapter 52, Examination of the Patient
with a Probable Stroke). By definition, a TIA is transient ischemia; a TIA
that doesn’t resolve is called a stroke.
Partial (also called focal) seizure
disorders cause transient focal neurologic symptoms due to focal cortical
epileptic activity. Partial seizures that do not impair consciousness are
called simple partial seizures. Partial seizures
that impair consciousness (such as many temporal lobe seizures) are called
complex partial seizures. Partial seizures may
spread to involve the whole brain, causing a secondarily generalized seizure
(in contrast to a primary generalized seizure, which begins simultaneously on
both sides of the brain and does not have a focal onset or focal
symptomatology).
Migraine can cause transient focal neurologic symptoms; the
pathogenesis of migrainous neurologic symptoms is uncertain but may be due to
a slowly spreading wave of depolarization called spreading
cortical depression.
TAKING THE HISTORY OF A PATIENT WITH TRANSIENT FOCAL NEUROLOGIC
SYMPTOMS
SYMPTOMS
The major clues to the localization and mechanism of the patient’s
symptoms are likely to be found from a careful neurologic history aimed at
listening to the patient’s (and witnesses’) description of the episodes.
symptoms are likely to be found from a careful neurologic history aimed at
listening to the patient’s (and witnesses’) description of the episodes.
Ischemia
TIAs usually occur suddenly and last seconds or minutes before
resolving.
Depending on the arterial distribution, ischemia can cause any
kind of focal neurologic deficit, such as focal weakness, numbness, vision
loss or diplopia, vertigo, aphasia or dysarthria. Listen for the distribution
of the patient’s symptoms to determine the most likely involved vascular
territory (see Chapter 52, Examination of the Patient
with a Probable Stroke).
A history of recurrent, stereotyped TIAs in the same distribution
(i.e., the same deficit occurring multiple times over days, weeks, or months)
suggests the presence of a focal arterial stenosis rather than a cardioembolic
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source (see Chapter
52, Examination of the Patient with a Probable Stroke).
Ask about any transient monocular visual disturbances consistent
with amaurosis fugax that would suggest the possibility of carotid stenosis
(see Chapter 49, Examination of the Patient with Visual
Symptoms, and Chapter 52, Examination of the Patient
with a Probable Stroke).
Seizure
Take time to ask the patient to report the whole story of their
events from beginning to end. Get history from a witness for symptoms the
patient may not be aware of, such as lip smacking or automatisms (e.g.,
picking at the clothes) that may occur while consciousness is impaired during
a complex-partial seizure.
Seizure symptoms are usually stereotypical for each patient.
Depending on the location of the focus, seizures may cause motor,
somatosensory, visual, olfactory, visceral, or emotional symptoms. Seizures
usually cause “positive” symptoms, such as hallucinations or shaking, rather
than “negative” symptoms, such as weakness, as expected with
ischemia.
Always ask the patient about the presence of frequent déjà vu
phenomena (a sense of familiarity or having done something before), jamais vu
(unfamiliarity), or an olfactory aura (hallucination of a smell). These are
typical symptoms of temporal lobe seizures, but patients may not volunteer
these symptoms unless asked.
Seizures may begin with one symptom and spread quickly to involve
other symptoms and may then generalize to a tonic-clonic seizure. When
patients present because of a generalized seizure, inquire about prodromal
symptoms suggestive of a focal onset.
Ask the patient about symptoms that might suggest unrecognized
generalized seizures, such as episodes of nocturnal tongue biting or
incontinence.
Migraine
Neurologic symptoms due to migraine may occur with or without
headache (see Chapter 45, Examination of the Patient
with Headache) or scintillating visual disturbances (see Chapter 49, Examination of the Patient with Visual Symptoms).
When present, however, these are helpful clues to a migrainous cause of the
patient’s symptoms.
Focal neurologic symptoms from migraine typically march more
slowly than symptoms of a seizure; for example, migrainous sensory symptoms
may begin with tingling in the hand and slowly spread to the cheek over 15 to
30 minutes. As the symptom progresses, there may even be an associated aphasia
or weakness.
EXAMINING THE PATIENT WITH TRANSIENT FOCAL NEUROLOGIC
SYMPTOMS
SYMPTOMS
By definition, examination of the patient with transient symptoms
is likely to be normal because patients are rarely examined during the deficit.
There are a few clues that may be helpful if found, however. For example, when
TIA is a consideration, listen for a carotid bruit (see Chapter
52, Examination of the Patient with a Probable Stroke), although this is
not a sensitive sign for carotid disease. The presence of any focal findings on
examination may suggest a previous infarct in a patient with TIA or may be a
clue to an underlying gross structural brain lesion causing
seizures.
is likely to be normal because patients are rarely examined during the deficit.
There are a few clues that may be helpful if found, however. For example, when
TIA is a consideration, listen for a carotid bruit (see Chapter
52, Examination of the Patient with a Probable Stroke), although this is
not a sensitive sign for carotid disease. The presence of any focal findings on
examination may suggest a previous infarct in a patient with TIA or may be a
clue to an underlying gross structural brain lesion causing
seizures.
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ADDITIONAL COMMENTS
Multiple sclerosis attacks generally do not cause transient
symptoms in the sense described earlier; neurologic dysfunction from
exacerbations of multiple sclerosis tends to last days, weeks, or even months
before resolving. Transient symptoms can occur in multiple sclerosis due to
short circuits through demyelinated lesions, however. These symptoms are often
painful, repetitive, brief (seconds), and stereotypical for an individual
patient, and they may manifest as tingling, flexion (flexor spasms), or
extension (painful tonic spasms) of a
limb.
symptoms in the sense described earlier; neurologic dysfunction from
exacerbations of multiple sclerosis tends to last days, weeks, or even months
before resolving. Transient symptoms can occur in multiple sclerosis due to
short circuits through demyelinated lesions, however. These symptoms are often
painful, repetitive, brief (seconds), and stereotypical for an individual
patient, and they may manifest as tingling, flexion (flexor spasms), or
extension (painful tonic spasms) of a
limb.