Right Hemisphere Disorders (RHD)

In 1974, William O. Douglas, Associate

Supreme Court Justice suffered a stroke

In 1974, William O. Douglas, Associate

Supreme Court Justice suffered a stroke

He recovered quickly, checked himself out of rehab.In court he dozed and asked irrelevant questions and

rambled on. He was asked to resign------ “he came back to his office, buzzed for his clerks and asked to participate in, draft, and even publish his own opinions separately; and he requested that a tenth seat be placed at the Justices’ bench.” (Gardner, 1982)

Ok, the historyOk, the history

Historically, non-dominant hemisphere strokes were not referred to slp clinics

Mainly because the primary disorders are related to nonverbal cognitive systems

Don’t display word-finding and grammatical deficits associated with aphasia

Zoom to today, (history lesson

is done!!)

Zoom to today, (history lesson

is done!!)Non dominant strokes now referred usually for:

Pt has a swallowing problem or motor speech deficitPt has an old RHD recently suffered a left

hemisphere strokePt has communicative difficulties caused by right

hemisphere stroke---as with Justice Douglas

Language EvaluationsLanguage Evaluations

We might typically begin with an aphasia assessment tool, but:

RHD pts are most often not aphasic in that they can normally process most words and sentence in isolation

Language ComprehensionLanguage Comprehension

Sometimes perform as poorly as aphasic subjects

Can display good word comprehension, with mild deficit when presented with up to 4 semantically similar picture options

Not usually deficient short term memory spanCan follow directions (Token Test)

Difficulty arranging words into a grammatical sentence

Problems with sentence comprehension with thematic roles in passive sentences

Subtle!

RHD: Language Production

RHD: Language Production

Tend to name common objects effectivelyWord finding problems occur on divergent

thinking (expansion) tasksTend to generate fewer words (fluency) More problems with lexical semantics than with

phonology and syntaxErrors increase with processes that are “less

automatic”

RHD: language productionRHD: language production

May score similarly on clinical tests but for different reasons!

Because RHD pts have impaired attention, perception and organizational skills

So let’s look at the primary cognitive impairments caused by right hemispheric stroke

RHD: awareness of deficits

RHD: awareness of deficits

Anosognosia: lack of awareness or recognition of disease or disability

“lack of insight” or “imperception of disease”Essentially, pts are unable to become aware of the

neurological dysfunctionBut, denial of impairment is a psychological defense

mechanism---a pt who is strictly in denial is considered to be capable of awareness of deficit

Anosognosia is usually observed as lack of awareness of paralysis

Self awareness of deficits was not correlated with actual task performance (Pendley and Ramsberger, 19960

Visuospatial FunctionsVisuospatial Functions

WAIS scores show a pattern that is reversed relative to aphasia

RHD pts are likely to have a discrepancy score in which the Performance IQ (requires visuospatial recognition and reasoning skills) is lowered relative to the Verbal IQ

Left neglect is more common that right neglect---pts with posterior RHD bump into things on their left, leave food on the left side of a plate, dress only the right side, draw on the right side of an object

Wheel chair accidents!Crossing Out Test, Line cancellation Test, etc.

Auditory-Vocal ModalitiesAuditory-Vocal Modalities

Auditory agnosia: impaired ability to recognize sounds despite adequate hearing

May refer to deficient recognition of nonverbal or environmental sounds (auditory sound agnosia)

EmotionEmotion

Complex relationship between the limbic and the autonomic nervous systems---a message recognized in the cognitive cortex

Although both hemispheres are involved, the RH is dominant for emotion

RHD pts may display flat affect or indifference that accompanies left neglect

Hypoarousal to emotional pictures

Attention and ReadingAttention and Reading

RHD: tend to misread the beginning of words, Some omit or misread words on the left side of

the pageSome have both of these problemsMisreading the left side of words or left side of a

page indicates neglect dyslexia

Emotion and ProsodyEmotion and Prosody

Aprosodia: Flat contour or monotoneFailure to identify emotional tone in mundane

sentencesUnable to detect happy, sad or angry faces

Interpreting SituationsInterpreting Situations

RHD: difficulty recognizing emotion or humor in pictured scenes; unlike aphasics!

RHD: difficulties with sorting implicit themes like “love” from explicit themes like getting a hug

Suggests that RHDs have a problem with inferring the nature of situations when it is not concrete or obvious

Metaphor comprehensionMetaphor comprehension

“Metaphor is a pragmatic convention used for studying comprehensions of speaker-meaning that differs from literal content” (Marquart, 2000)

Inference is presumed to be a necessityInterpreting idioms like “bury the hatchet” or

“shoot the bull”

DiscourseDiscourse

RHDs recall main ideas better than details and explicit information

Tend to “miss the point”