Right Hemisphere Dysfunction Flashcards
Hemispheric Asymmetry
- the right and left hemispheres of the brain are anatomically and functionally asymmetrical
- differences are greatest in certain areas surrounding the sylvian fissure
- sylvian fissure is slightly longer in the left hemisphere than on the right
- planum temporale is a part of the superior surface of the superior temporal gyrus; this area is larger on the left than the right for most people
- left temporal opercular region is larger and more infolded on the left than on the right; region is aka Broca’s area
Hemisphere connections
- the two hemispheres are well connected via the corpus callosum
- contains more than 300 million axons aka commissural fibers
Right Brain
- uses feeling
- “big picture” oriented
- imagination rules
- symbols and images
- present and future
- philosophy and religion
- can “get it” (meaning)
- believes/appreciates
- spatial perception
- knows objects function
- fantasy based
- present possibilities
- impetuous and risk takers
Left Brain
- uses logic
- detail oriented
- facts rule
- words and language
- present and past
- math and science
- can comprehend
- knowing/acknowledges
- order/pattern perception
- knows object name
- reality based
- forms strategies
- practical and safe
Left Hemisphere:
1. Language (6)
- Constructions
- Speaking Aloud
Auditory Comprehension
Naming
Reading Comprehension
Reading Aloud
Writing
- Internal detail
Left Hemisphere:
1. Calculation
- Memory
- Miscellaneous
- Arithmetic processing
- Verbal
- Praxis
Right Hemisphere:
1. Language
- Constructions
- Auditory Comprehension
Reading Comprehension
Prosodic Expression
Prosodic Comprehension
- External configurations
Right hemisphere:
1. Calculation
- Memory
- Miscellaneous
- Spatial arrangement
- Visuospatial
- Facial recognition
Right hemisphere functions
- the right brain is seemingly responsible for:
— arousal, orientation and attention
— visual perception
— emotional experience and expressions
- Arousal
- Orientation
- Vigilance
- Arousal- general readiness to respond to external stimuli (alert, ready to react)
- Orientation- directing one’s attention to a specific stimulus, event, or location
- Vigilance- sustained attention used to detect changes in a stimulus
- Selective attention
2. Sustained attention
- ignoring a distracting stimuli while paying attention to the relevant stimuli
- prolonged attention to a task (sustain your focus)
Visual Perception:
The right hemisphere appears to process:
- holistic, gestalt-like stimuli
- geometric and spatial information
- facial recognition
- body image
- holistic, gestalt-like stimuli
- geometric and spatial information
- facial recognition
- body image
- Holistic, gestalt-like stimuli- looking at the big picture- grasping the meaning of the total picture
- Geometric and spatial information- understanding, recognizing spatially organized shapes or figures
- Facial recognition- responsible for recognizing familiar faces. Your four to ten month old infants will show an interest in their mother’s face
- Body image- Helps you maintain a proper body image. Feelings of an acceptable body image, what you feel is acceptable socially
The right hemisphere is dominant for:
1. emotions
- perceptions of temporal order
- perception of musical harmony
- certain aspects of communication
- emotions: expression of being angry, happy, sad, etc. and understanding how those emotions effect you based on the stimuli you are getting from the environment
- perceptions of temporal order: dominate for perceiving the temporal order or sequence of events
- perception of musical harmony: music and processing of acoustic signals
- certain aspects of communication: pragmatics, prosody, semantics, and discourse
Communicative Functions 1
- possible interplay b/w the right and left hemispheres with regards to discourse comprehension and production
- right hemisphere may be less efficient in understanding verbs than nouns
- right hemisphere may help make inferences implied in verbal exchanges
- communicative efficiency and specificity may be centered in the right hemisphere
- understanding alternative and ambiguous meanings
- understanding or expressing emotional tone of verbal expression
Communicative Functions 2
- understanding or expressing prosodic aspects of speech
- understanding contextual information of verbal expression
- managing pragmatic communication skills
– turn-taking
– topic maintenance
– social appropriateness of communication
– eye contact
Neuropathologies of Right Hemisphere Dysfunction
- etiologies: CVA, tumors, head trauma and various neurological disease processes
- individuals who sustain RHD secondary to posterior lesions do not have motor disabilities; those with frontal lobe damages will have motor disturbances
Functional Involvement
common grouping of deficits
- varied symptoms Pts w/RHD might exhibit may be grouped according to:
- perceptual and attention deficits
- affective deficits
- communication deficits
Perceptual and attention deficits
- left-neglect- - reduced sensitivity or absence of responses on their left side or left visual field
- visuospatial impairments
- forms of disorientation
Left Neglect
- reduced sensitivity to stimuli, reduced awareness of space or absence of previously learned responses from stimuli in certain visual fields
– neglect can result from damage to any lobe
– neglect can be right or left dominant
– right parietal lobe damage produces left-neglect in most pts
*** Goal draw focus to the left side, do all therapy on the left side.
Left Neglect Characteristics (6)
- Right Focus
- difficulty shifting attention from right-to-left
- failure to perceive left-sided tactile or perceptual stimuli
- failure to copy the left side of a picture or a geometric design
- disownership of left body parts or belongings
- denying illness (anosagnosia)
- right focus
- Difficulty shifting attention from right to left
- Failure to perceive left sided tactile or perceptual stimuli
- stimuli on the right side seems to capture and hold the patients attention
- Can only focus on the right side
- cannot feel a pinprick on the left side
- Failure to copy the left side of a picture or a geometric design
- auditory neglect
- Prosopagnosia
- will left the left side of an image off, or left neglect when reading
- ignores sounds from the left side of the room but reflexes are intact, motor is okay.
- Inability to recognize familiar faces, hard for families to deal with.
FACIAL RECOGNITION DEFICITS
- prosopagnosia
- seen in Pts with posterior right hemisphere damage
- difficulty recognizing familiar faces
- difficulty choosing pictures of faces just shown
- problems naming the pictures of faces of famous persons
Constructural Impairments
- problems constructing block designs
- difficulty reproducing two-dimensional stick figures
- errors in drawing or copying geometric designs
- often seen in Pts with all kinds of brain damage
- with left hemisphere involvement: Pt will draw w/difficulty but make fewer mistakes; drawings are better w/models than without
- with right hemisphere involvement: Pt will draw hastily, make many mistakes, add unnecessary lines to correct mistakes, do not show improvements w/models
Attention deficits
- reduced state of arousal: Pt’s w/RHD are described as hypoaroused
- difficulty in sustaining attention: Pt’s attention wanders from task to task or from stimuli to stimuli
- difficulty paying selective attention: Pt may find it difficult to focus on a particular stimuli in the presence of multiple stimuli
Disorientation (3)
- topographic disorientation: inability to orient in the surrounding
- geographic disorientation: inability to orient to city/state/country
- reduplication paramnesia: is the delusional belief that a place or location has been duplicated, existing in two or more places simultaneously, or that it has been ‘relocated’ to another site
Visual Perceptual Deficits
- difficulty recognizing line-drawn pictures or incomplete drawings
- drawings that distort the representation by showing unusual size, dimension or orientation
- drawings that are superimposed on other drawings
Affective Deficits
- pts with RHD tend to be emotionally indifferent
- difficulty understanding emotions
- difficulty stating the emotions depicted in pictures
- problem recognizing emotions expressed in isolated spoken sentences
- difficulty understanding emotional tone of voice
- difficulty expressing their own emotions correctly
Memory Deficits
- nonverbal amnesia
— references impaired recall of nonverbal visual material
— ex: impairment in the retention of complex visual patterns and faces
Neuropsychiatric Disorders
1. Visual Hallucinations
- Mania
- visual hallucinations
— claims to see something that the observer cannot see
— may occur as part of a seizure or may be associated w/visual field deficits
— most common form of hallucination in persons w/dementia
- mania
— elated and/or irritable mood lasting at least one week and combined with any of the following:
— hyperactivity; flight of ideas; grandiosity; diminished sleep; distractibility; lack of judgment; rapid speech
Communication Deficits
- communication problems are found in about 50% of individuals who have RHD
— difficulties are unlike those associated w/left-hemisphere damage
— RHD: no word-retrieval issues
— RHD: no significant circumlocutions or paraphasias
— RHD: speak in grammatically accurate sentences
— RHD: have good comprehension
— pts w/RHD do exhibit: prosodic deficits; impaired discourse; semantic problems; pragmatic deficits
Prosodic Deficits
- prosody references: stress patterns, intonation, rhythm, melodious qualities of speech that convey meaning
- output may be:
— monotone
— impaired in stress patterns; may change intensity levels
— reduced rate of speech
— devoid of emotion
— impaired in prosodic comprehension; difficulty understanding the emotional tone heard
Impaired discourse
- discourse is a set of social communication skills; may involve narration, procedures, expository discourse
- pts with RHD exhibit:
— difficulty distinguishing significant from irrelevant information
— difficulty understanding implied meanings, abstract words, metaphors, irony and humor
— premature and incorrect inferences
— confabulation and excessive speech
Semantics
- left hemisphere: active in promptly and quickly understanding concrete meanings of words
- right hemisphere: involved in understanding or producing words w/complex, abstract, metaphoric, and multiple meanings
Semantic Difficulties
- pts w/RHD exhibit:
— difficulty understanding implied, alternative or abstract meanings
— failure to grasp the overall meaning of situations, events, stories or pictures (miss the central message)
— difficulty understanding idioms, proverbs and metaphors
— difficulty naming abstract categories in contrast to the names of individual items in a category
— difficulty w/irony, humor, and sarcasm
— problems in understanding logical errors in sentences
Pragmatic Difficulties
- pragmatic language problems could include:
— difficulty in conversational turn-taking
— difficulty with topic maintenance
— difficulty in maintaining eye contact
— insensitivity to communicative contexts: assume too much about what their listeners know about the topic of conversation
Associated Language Difficulties (3)
- right hemisphere’s receptive language capabilities
1. disturbance in comprehension of logical syllogisms
— all trees have root systems
— all root systems need nitrogen
— therefore, all trees need nitrogen
- pictorial interpretations of metaphors
— it’s raining cats and dogs
- concrete interpretation of proverbs/idioms
— abstract verbal tasks pose problems
— the greatest talkers are the least doers
— a heavy heart-
