According to Myers (1994),
impairments of perception and attention
are
the underlying causes of the extra-linguistic, linguistic
and nonlinguistic deficits manifested by patients with RHD.
According to Love and Webb (2001), neglect, inattention and
denial are three major characteristics of right hemisphere
syndrome. They are also characteristics of executive
function difficulty. Marshall et al., 1998.
Linguistic
Deficits
As stated above,
right hemisphere patients typically do not have the kinds of
language problems seen in aphasia. However, as some do have
specific linguistic problems, RHD patients should be given
an aphasia battery like the Boston. RHD patients might
display deficits on the following Boston subtests: Responsive naming-patients give one word answers to spoken questions. Difficulty with auditory comprehension may effect results. It is important that naming is tested using several modalities. The following sub-tests may be useful also:
Visual confrontation
naming is used on the Boston naming test. e.g. patients are asked to name pictures.
Body Part
Naming
Auditory Comprehension of Complex Material
Word Fluency
Writing (RHD patients may substitute or omit graphemes)
Auditory comprehension of difficult material
Oral sentence reading
(Myers and Mackisack, 1990, in LaPointe, 1990)
Extralinguistic
Deficits
Again, RHD
patients are unlikely to display the kinds of phonological,
syntactic or semantic problems associated with aphasia.
However, although they do not typically have many specific
language problems, they definitely have difficulty
communicating. This impairment seems to follow from an
inability to integrate information; RHD patients apparently
do not make adequate use of context in their interpretations
of linguistic or nonlinguistic messages. They have
difficulty distinguishing significant from unimportant
information. For example a patient of mine when asked to
describe the "Cookie Theft" picture card from the Boston
focused on irrelevant features without describing the
overall picture. Some aphasics with typical left hemisphere
lesions present with executive function disturbance similar
to right hemisphere syndrome.
Literal
Interpretations
RHD
patients may be able to comprehend only the literal meaning
of language. Thus, they will often fail to understand many
jokes, metaphors, irony, sarcasm, and common sayings that
include figurative language. For example, if an RHD patient
hears someone say that they are about to "hit the ceiling,"
he might assume that the person is really about to begin
striking the ceiling. Such a patient may also have trouble
understanding indirect requests. For example, if he is asked
if he "could open the window," he may fail to identify this
as a polite request and simply answer "yes" rather than
opening the window.
These problems
with figurative language may be viewed as one manifestation
of the inability to base interpretations on context.
Difficulty identifying
relevant information
When
listening to a conversation or reading, an RHD patient may
fail to abstract the main point contained in the information
being shared. This happens in spite of the fact that, unlike
an aphasic, the patient can understand all the individual
words and grammatical structures used. For RHD patients, it
appears that their comprehension of everyday language is
impaired by a failure to distinguish important information
from irrelevant detail and also by an inability to
integrate According to Blake 2007, RH patients have difficulty comprehending non-literal language, humor, and multiple interpretations Furthermore, Blake says that their difficulty with language production includes: impulsivity, inefficiency, and egocentricity. She also says that the same problems are seen in traumatic brain injury.
Inability to interpret body
language and facial expressions
In a
conversation, RHD may miss out on important cues that should
tell them about the emotional state and true intention of
the person with whom they are interacting. This inability to
interpret body language and facial expression may be related
to an overall failure to use context in the interpretation
of individual pieces of information. Problems with the
interpretation of facial expression may also be due to the
fact that RHD patients often fail to maintain eye contact
with their conversation partners.
Flat affect
RHD
patients may fail to display a wide range of facial
expressions themselves. Also their speech is frequently
aprosodic, or lacking variations in pitch and stress. Some
patients will sound "robot-like," and thus be unable to
express emotion or changes in meaning via changes in
intonation. These patients will no longer be able to vary
pitch to signal the difference between a question and a
statement or use word stress changes within a sentence to
signal a difference in meaning.
Problems with
Conversational Rules
RHD
patients may fail to follow conversational rules, including
those governing turn-taking, the initiation and closure of a
conversation. RHD patients may tend to dominate
conversations, as they are frequently verbose. They may also
fail to properly estimate levels of shared knowledge,
failing to give the listener enough background information
to understand their statements. According to Myers and
Mackisack (1990), RHD patients appear to not care about the
needs of the listener. They, like children in an early
developmental phase, may assume too much knowledge on the
part of the listener; or not enough. They appear to answer
without adequate search for the right answer. They also may
fail to pick up on non verbal cues that signal listener's
reactions.
Impulsivity
RHD
patients may exhibit poor judgment and problem solving
abilities. They may require constant supervision due to a
tendency to attempt tasks of which they are no longer
physically capable. This may be related to anosognosia. They
may also exhibit impulsivity in the sense of failing to
censor the statements they make to other people.
Confabulation
RHD
patients may make untrue statements. These do not usually
seem to be deliberate lies. According to Brownwell et al.
(1995), this may be the patient's way of responding to his
own confusion rather than attempts to mislead the
listener
RHD patients may
occasionally have hallucinations.
Nonlinguistic
Deficits
Disorientation to Time and
Direction
RHD
patients may exhibit disorientation to time and and
direction. They are usually oriented to person
and to place, however. Many hospital patients are somewhat
disoriented to time. They may be unable to give the date,
time of day, or day of the week accurately. Note that it is
important to be reasonable when assessing orientation. It is
perfectly normal to miss the day of the week or date by one
day and such errors should not be taken as an indication
that the patient is disoriented. Sometimes when I am on
vacation I may not know the day or the date. We shouldn't
expect more of our patients.
RHD patients may
also have difficulty following directions or finding their
way around a building. They will know where they are in a
general sense (e.g., in the hospital), but have trouble
finding their way to specific locations (e.g., the dining
room).
This deficit,
known as topological
disorientation, is a product of their general
inability to process spatial information. Some patients with
left hemisphere parietal lobe lesions have similar
problems
Left side
neglect
Neglect is a syndrome in which the
patient fails to recognize one side of the body and the
environmental space surrounding this side of the body in the
absence of paralysis and visual problems. Neglect is
considered a deficit in directed
attention. This means that patients
demonstrate an inability to be aware of stimuli,
attend to stimuli or recognize the
significance of stimuli. Neglect may also be
described as the inability to orient to stimuli with the
purpose of acting upon them. According to Myers (1994, in
Chapey,1994), although neglect may occur with left
hemisphere damage (LHD) it is more severe, longer lasting
and common with RHD. It can occur with
frontal,
temporal, and parietal
lobe
lesions as well as with some sub-cortical lesions ( Myers,
1994).
Patients with
neglect may fail to eat food on the left side of their
plates, begin reading in the middle of sentences and in
other ways seem to completely ignore the neglected side.
Some may even cease to identify their left side as part of
their own bodies. RHD patients have been known to give their
paralyzed left arms names like "the baby" or "the dead one."
They might also request that someone remove the other person
from their bed, referring to their left side. RHD patients
with left neglect may also have difficulty with left side
detail in visuo-constructional
tasks. For example, if drawing a picture
or building a model, they might leave out details on the
left side. The severity of neglect is usually an indication
of the size of lesion and the overall severity of the
patient's condition.
Note that RHD patients may have visual deficits including
left hemianopsia. This may occur along with neglect or might
exist alone and be mistaken for neglect. Scanning behavior
may be used to differentiate between left neglect and left
hemianopsia. A patient who has hemianopsia without neglect
will have difficulty seeing things in his left visual field,
but will not ignore his left side. For this reason, such a
patient may be observed turning his head to scan the left
visual field. On the other hand, a patient who does have
neglect will generally make few or no spontaneous efforts to
look at things in the left area of his visual field.
According to Myers (1994), most theories of neglect consider
it a deficit in attention.
At this time, the site of lesion that causes neglect is not
known. However, the syndrome is frequently associated with
parietal lobe lesions.
As mentioned above, right side
neglect does sometimes occur in patients
with left hemisphere damage. However, it is fairly uncommon.
(Right side neglect occurs in approximately twenty percent
of patients with left hemisphere damage.) It is also less
severe and usually of shorter duration than left side
neglect.
Anosognosia
This
term first used by Babinski is the failure to recognize the
symptoms of one's own illness. RHD patients may deny that
they have had a stroke. They may appear to be unaware of
their hemiplegia or their cognitive
deficits (Love and Webb, 2001). It is not uncommon for right
hemisphere patients to state that they are perfectly capable
of walking, driving and returning to work immediately
despite all evidence to the contrary. Anosognosia may be
described as severe denial. The source of this denial
appears to be cognitive rather than emotional; it seems as
though patients are unable rather than unwilling to
recognize their deficits.
Because RHD patients do not fully comprehend the extent of
their impairment, they are frequently less depressed than
those with left hemisphere damage. This type of executive
function difficulty can also appear in aphasic patients with
left hemisphere lesions.
Visuospatial Deficits
RHD
patients have difficulty processing many types of visual
stimuli. These problems are apparently due to an inability
to integrate information. RHD patients have trouble with
figure-ground
problems, recall of visual
forms
and mental rotation, or the ability to imagine
how a figure would look if its orientation in space were
changed. Constructional apraxia can also be present in
patients with RHD. Their drawings tend to be scattered,
fragmented, and spatially disorganized (Myers, 1994, in
Chapey, 1994). According to Swindell (1988, in Myers, 1994),
the drawings of RHD patients may not benefit from a model or
from cueing and are not likely to improve over time.
Prosopagnosia, or the inability to
recognize familiar faces, is one of the most striking
visuospatial processing deficits manifested by RHD patients.
This does not represent a difficulty with vision itself. A
patient with prosopagnosia is able to describe the features
of familiar faces, including eye and hair color, type of
nose, etc. An artistic patient will even be able to draw the
faces of family members and friends accurately yet be unable
to recognize them. Rather, the problem seems to be related
to the integration of visual perceptions and their
association with information stored in memory. According to
Love and Webb (2001), patients with this disorder usually
have lesions in the right occipital-temporal lobe region.
Color agnosia is often seen with prosopagnosia.