Authors: Lewis, Steven L.
Title: Field Guide to the Neurologic Examination, 1st Edition
Copyright ©2004 Lippincott Williams & Wilkins
> Table of Contents > Section 2 – Neurologic Examination > Mental Status Examination > Chapter 6 – Language Testing
Chapter 6
Language Testing
PURPOSE
The purpose of language testing is to look for evidence
of dysfunction of the hemispheric cortical regions that are involved in
the production or comprehension of spoken or written language.
of dysfunction of the hemispheric cortical regions that are involved in
the production or comprehension of spoken or written language.
WHEN TO TEST LANGUAGE
The ability of your patient to understand and produce
spoken language should be evident by informal observation during the
history and throughout your interaction with the patient. More formal
evaluation of language function should be performed when there is a
complaint of difficulty with language or speech, or when you suspect a
disorder of language from your conversation with the patient during the
history. In addition, language function should be tested in any patient
with a right hemiparesis to look for evidence of localization of the
neurologic process to the cortex.
spoken language should be evident by informal observation during the
history and throughout your interaction with the patient. More formal
evaluation of language function should be performed when there is a
complaint of difficulty with language or speech, or when you suspect a
disorder of language from your conversation with the patient during the
history. In addition, language function should be tested in any patient
with a right hemiparesis to look for evidence of localization of the
neurologic process to the cortex.
NEUROANATOMY OF LANGUAGE
Language function resides in the left hemispheric cortex
in essentially all right-handed patients and at least one-half of
left-handed patients. The side of the brain where a patient’s language
is located is called the dominant hemisphere.
in essentially all right-handed patients and at least one-half of
left-handed patients. The side of the brain where a patient’s language
is located is called the dominant hemisphere.
There are two main areas of the dominant hemisphere that
are important for language function: Broca’s area and Wernicke’s area.
Broca’s area is located in the inferior frontal lobe, just anterior to
the motor cortex, and is involved in the production of language.
Wernicke’s area is located in the posterior-superior temporal lobe,
near the auditory cortex, and is involved in the comprehension of
language.
are important for language function: Broca’s area and Wernicke’s area.
Broca’s area is located in the inferior frontal lobe, just anterior to
the motor cortex, and is involved in the production of language.
Wernicke’s area is located in the posterior-superior temporal lobe,
near the auditory cortex, and is involved in the comprehension of
language.
EQUIPMENT NEEDED TO TEST LANGUAGE
None.
HOW TO EXAMINE LANGUAGE
-
Listen to the patient’s spontaneous
speech (this can be done while you are taking the history). Assess
whether the speech is fluent and meaningful, if there are any errors in
producing individual words, and if there are any unusual or nonexistent
words. Also note if there is any problem with articulation (i.e.,
slurring) of speech.If more formal language evaluation is necessary (see When to Test Language), proceed further: -
Ask the patient to name one or a few
commonly available objects, such as a pen, a watch, or a tie. Hold the
object in front of the patient and ask, “What is this called?” After
the patient has named the object, ask the patient to name one or two
smaller parts of the object, such as the cap of the pen, the stem (or
winder) or the wristband of the watch, or the knot of the tie. Having
the patient name smaller parts of the objects is a more difficult task
than simply naming only the object itself and may uncover aphasic
errors that would not otherwise be evident. -
Ask the patient to repeat a sentence
after you have said it, such as “I am in the hospital” or any sentence
of your choice. It is also helpful to ask the patient to repeat the
phrase “no ifs, ands, or buts,” because this kind of phrase is
particularly difficult for aphasic patients to say. -
Give the patient a sheet of paper and a pen or pencil and ask the patient to write any sentence of his or her choice.
-
Hand the patient a magazine or brochure
(or other nontechnical material available nearby) and ask the patient
to read a few sentences to you.
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NORMAL FINDINGS
Normally, patients should be able to speak fluently,
appropriately, and clearly, to comprehend spoken and written language
well, and to name and repeat.
appropriately, and clearly, to comprehend spoken and written language
well, and to name and repeat.
ABNORMAL FINDINGS
Two kinds of abnormalities may be found when assessing
speech: aphasia or dysarthria. Patients who are aphasic have a problem
with the production or comprehension of spoken or written language due
to dysfunction of brain regions important for language. Patients who
are dysarthric do not have language dysfunction, but they have speech
that is slurred and inarticulate; this is due simply to a problem with
control of the structures that move the mouth or tongue.
speech: aphasia or dysarthria. Patients who are aphasic have a problem
with the production or comprehension of spoken or written language due
to dysfunction of brain regions important for language. Patients who
are dysarthric do not have language dysfunction, but they have speech
that is slurred and inarticulate; this is due simply to a problem with
control of the structures that move the mouth or tongue.
Aphasias
Broca’s Aphasia (Also Called Motor or Expressive Aphasia)
-
The speech of patients with Broca’s
aphasia is nonfluent, with obvious hesitancy and pauses between words
and grammatic errors. The words that are produced, although hesitant
and produced with difficulty, are generally correct, but there may be
paraphasic errors. Paraphasic errors are words that are produced with
inappropriate substitutions of parts of the words, such as saying
“lencil” for “pencil.” -
Patients with Broca’s aphasia generally
have intact ability to comprehend written and spoken language and to
follow commands, but they do have difficulty repeating phrases. -
Patients with Broca’s aphasia often say
something like (although hesitantly and nonfluently) “I know what I
want to say but I can’t get the words out,” and they usually appear
frustrated because of their awareness of their difficulty communicating. -
Broca’s aphasia occurs because of a
lesion at or near Broca’s area in the dominant frontal lobe. There is
often an accompanying hemiparesis because of the proximity of Broca’s
area to the motor strip.
Wernicke’s Aphasia (Also Called Sensory or Receptive Aphasia)
-
The speech of patients with Wernicke’s
aphasia is fluent but makes little if any sense. Their speech is filled
with nonsensical words and neologisms (“new words” that do not really
exist in the patient’s language), unusual combinations of words, and
paraphasic errors. -
Patients with Wernicke’s aphasia have
poor comprehension but have little awareness of this; therefore, they
produce strings of fluent, unusual sentences without the frustration
seen in patients with Broca’s aphasia. Like patients with Broca’s
aphasia, patients with Wernicke’s aphasia also have difficulty with
repetition. -
Wernicke’s aphasia occurs because of a
lesion at or near Wernicke’s area in the dominant temporal lobe.
Because of the distance of Wernicke’s
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area
from the motor strip, patients with Wernicke’s aphasia often do not
have an associated hemiparesis. The only additional finding that may be
found (although not always easily detected) in patients with Wernicke’s
aphasia is a right upper quadrant visual field deficit, due to the
passage of these visual pathway fibers through the temporal lobe (see Chapter 13, Visual Field Examination).
Dysarthria
-
Patients who are dysarthric have slurring
of their speech but have no problem with language function. They can
name, read, comprehend, and repeat but simply have poorly articulated
speech that, depending on the severity of the dysarthria, can be
difficult to understand. -
Dysarthria can occur due to dysfunction
anywhere in the brain, brainstem, or cerebellum; therefore, the finding
of dysarthria may not be helpful in specific neurologic localization.
Dysarthria can also occur due to nonneurologic processes, such as any
local cause of dysfunction of the mouth or tongue. -
Severe dysarthria particularly occurs in the setting of a pseudobulbar palsy.
In addition to a marked “explosive” spastic dysarthria, patients with
this syndrome usually have dysphagia and emotional lability.
Pseudobulbar palsies occur due to bilateral lesions (e.g., due to
multiple sclerosis or strokes) of the cerebral hemispheres, internal
capsule, or upper brainstem affecting the corticobulbar tracts.
ADDITIONAL POINTS
-
Because patients with Wernicke’s aphasia
often don’t have other obvious findings on examination, and because the
fluent speech disorder of Wernicke’s aphasia is so unusual, patients
with Wernicke’s aphasia are often misdiagnosed as having a psychiatric
disorder. Think about the possibility of Wernicke’s aphasia in any
patient who presents with an acute onset of a “confusional” state;
listen carefully for the presence of paraphasic errors and neologisms
that may help you determine that the “confused” patient is actually
aphasic. -
Transcortical aphasias are additional
types of aphasia that occur due to lesions near but not in Broca’s area
(transcortical motor aphasia) or Wernicke’s area (transcortical sensory
aphasia). The transcortical aphasias resemble Broca’s or Wernicke’s
aphasias, but the ability to repeat is intact. These types of aphasia
are not discussed further in this text because, for the purposes of
gross neuroanatomic localization, it generally suffices to simply
recognize that the patient has a motor or sensory aphasia and,
therefore, likely has a problem in the dominant hemisphere that is most
likely in or near the frontal lobe (motor aphasia) or the temporal lobe
(sensory aphasia).