Right Hemisphere Disorder

(History of RHD) Left hemisphere:

• Broca & Wernicke discovery in 1800s led to a century of exploration of left hemisphere abilities

(History of RHD) Right hemisphere:

• Considered “subordinate, minor, unconscious”

• Largely ignored until advent of corpus commisurotomy in 1960s

  • Allowed the study of each cerebral hemisphere’s indepedent functions

  • Sperry won the Nobel prize in 1981 for his work on brain lateralization in split brain patients

What is RHD?

• group of deficits or changes that may occur following insult to a person’s right cerebral hemisphere

• communicative defects of RHD have been collectively called “Pragmatic aphasia,” “Cognitive-Communicative Disorder”

Are communication problems in RHD patients language based?

• NO, rather a result of impaired cognition

• if you pull out WAB & other language assessments, all those language processes would likely be intact

What is the etiology of RHDs?

• any etiology that damages right hemisphere:

  • Stroke

  • Disease

  • Trauma

  • Seizure disorders

  • Infection

  • Toxicity

• Level of deficit or disorder depends on the location & extent of damage (e.g., a small focal stroke may produce isolated deficits while a large stroke may produce deficits across all areas of cognition)

What are the Cognitive Behaviors present in RHD?

1. Hemi spatial Neglect (Left Neglect)

2. Agnosia types

3. Topographical disability

4. Constructional impairments

5. Emotions

6. Fundamental cognitive processes

1. Hemi spatial Neglect or Left Neglect or Unilateral Neglect:

• Fail to report, respond to, or orient towards stimuli contralateral to their brain lesions

• Can follow LHD, but occurs more frequently, lasts longer, & is generally more severe after RHD

• Visual neglect has been documented most & studied most extensively

What are the 3 types of Unilateral Neglect?

• Personal space

• Peri-personal space

• Extra-personal space

Personal space:

• one’s own body

  • somatophrenia is inability to perceive their own body parts as being part of themselves

  • Neglect to shave, comb, dress on left side of body

  • might accompany neglect piece, but not always. Person may be so unaware of left arm, that they might bump into things. Reveals that they may have difficulty perceiving their own body

Peri-personal space:

• within reaching distance

  • Neglect of items in drawing/copying/reading tasks

  • Neglect of items on left-side of table/tray

Extra-personal space:

• beyond arm’s reach

• Neglect of people standing on left side

• Neglect of items (TV, window) on left side of room

Peri-personal Neglect Types:

• Viewer-centered (Egocentric)

• Object-centered (Allocentric)

• Combination Viewer- & Object-centered

Left Neglect:

• Impairment in attention

• Able to see but not notice (can see when pointed to)

• Unaware of problem

• Can learn to compensate

Left hemianopia:

• Sensory impairment affecting the ability to see the left visual fields

• Aware of the problem

• Compensate w/ eye or head movement

(Neglect & Language) Neglect dyslexia:

• Can affect reading & writing

  • Omit, substitute letters on left side of words/sentences

(Neglect & Language) Neglect dysgraphia:

• Begin writing in middle or on right side of page

• Letter & line perseverations

• May not write left to right, may start from the middle instead

(2. Agnosias) What is Anosognosia?

• denies having impairment!

• Lack of knowledge of a disease or imperception of disease

• May deny the need for treatment, or “disown” his own affected side

• _____ & neglect often co-occur

• _____ affects awareness of neglect, physical communication, & cognitive deficits

• Impacts Rehab & post-rehab: Poorer compliance & participation, poorer outcome

(2. Agnosias) What is Prosopagnosia?

• Ability to recognize faces is important in discriminating familiar/non-familiar faces

  • Visual agnosia is the inability to perceive visual stimuli due to damage to the CNS NOT damage to the optic nerve or eyes

  • Prosopagnosia is the inability to recognize faces in the absence of other visual agnosia

  • Damage to visual association areas in occipital lobe that are used to process/interpret visual info from the eyes

• Individuals w/ prosopagnosia may not recognize others visually by their face, but they may recognize them by voice, smell, clothing, or other distinctive features

Prosopagnosia - Comprehending & Producing Facial Expressions:

• Right hemisphere allows us to evaluate facial expressions

  • Problems interpreting facial expressions & emotions conveyed on faces (challenging for them to associate meanings w/ expressions)

• Inability to process emotions expressed by facial expressions lead to more literal interpretation (patient would not get sarcasm, embedded meanings that involve facial expressions)

• Damage to right hemisphere limits expressivity on the left side of the face, the most expressive portion of the face

• Due to this, they display a flat affect & reduced facial expression

(2. Agnosias) (2. Agnosias) Amusia or Music Agnosia:

• Impairment in the recognition, production, & reproduction of melodies

• Pitch & Melody:

  • RHD: Pitch perception impaired; Speech perception intact

  • LHD: Pitch perception intact; Speech perception impaired

• Recognizing music w/o lyrics → difficult in RHD!

3. Topographical disorientation:

• Confusion about a location in space

• Difficulty describing how to travel from one place to another or getting los

• Disorientation to immediate environment

4. Constructional impairments:

• Difficulty in assembling components to form an object or a drawing

• Also called visuo-constructional deficits

• Constructional deficits in RHD & LHD:

  • RHD: Disturbances of spatial relationships, whole picture is distorted (e.g., fragmented or rotated drawing)

  • LHD: Produce generally simpler drawings w/ fewer lines & fewer details

5. Emotions:

• Difficulty reccognizing & using facial expressions

• Poor emotional language

  • “I passed the test!” vs. “He passed away”

• Hypo-affectivity: reduced ability to experience or express emotions, may appear flat, blunted, less animations in facial expressions

• Hyper-affectivity: excessive emotional responses, including emotional outbursts & excessive animations in facial expressions

• These presentations* may be similar to depression, PTSD, etc.

  • RHD: Laugh excessively

  • LHD: Mostly depressive

6. Fundamental Cognitive Processes

• Orientation

• Attention

• Memory

• Executive functions

  • Organization

  • Problem solving

  • Reasoning

(6. Fundamental Cognitive Processes) Orientation & Arousal:

• Hypoaroused or less attentive to external stimuli

• Disorientation to date, time, &/or place

• Disorientation to self

  • Cannot recall personal info, such as birth date, age, or family members’ names - A&O(x3)

• Arousal: when someone is interacting with patient, are they responding appropriately? Typically, they're not responding as well as they should 

(6. Fundamental Cognitive Processes) Attention:

• Sustained, selective, and divided attention

• May cause individuals w/ RHD to miss relevant info, be distracted by irrelevant stimuli, & further lose track of what is being spoken of

(6. Fundamental Cognitive Processes) Memory:

• Working memory

• Long term memory

  • Problems recalling street names or important dates or faces (Prosopagnosia), & learning new info

  • ST & LT recall for verbal & non-verbal material is affected (Auditory WM task)

(6. Fundamental Cognitive Processes - Executive Functions) Problem solving:

• • Difficulty responding appropriately to common events, such as car breakdown or overflowing sink

    • • may need to provide cues for patient to discuss process of solving an issue, e.g., car breaking down, fire. Patient may provide bizarre answers that are not the main picture or solves problem as it typically should 

  • Unable to initiate, or may act too quickly (impulsive) w/o first organizing info & identifying the best solutions

    • important for SLPs to train patient on inhibition

  • Cause injury to self, or others

(6. Fundamental Cognitive Processes - Executive Functions) Organization:

• Trouble telling a story in order, giving directions, or planning an event

  • patient may be missing appointments & actually experiencing problems, but to everyday people it comes off as disorganized & messy. 

(6. Fundamental Cognitive Processes - Executive Functions) Reasoning:

• Difficulty in thinking rationally or finding logical answers

  • “Why cant you touch fire?”

What are the Communicative Behaviors present in RHD?

1. Aprosodia

2. Pragmatics

   • Non-literal interpretation (Humor, sarcasm, etc.)

3. Discourse

4. Conversation

Aprosodia:

• Reduced use of pitch, duration, loudness & pause time to convery (production) or interpret (comprehension) meaning

• Expressive: RHDs speak w/ a flat contour or monotone

• Receptive: Poor identification of emotions in sentences

• RHD: Affective prosody

  • Attitudes of speaker (e.g., politeness, rudeness)

  • Emotional sentences (e.g., happy, sad)

  • Facial expressions

• LHD: Linguistic prosody

  • sentences w/ declarative/interrogrative contours

Pragmatics:

• Non-literal interpretation

• RHD - “extreme literalness”

  • Difficulty understanding idioms

  • Metaphors

  • Sarcasm

  • Indirect requests

  • Ironies

• Focus on unimportant details & miss the main point

• anything they have to interpret beyond what is being said w/ words

• Ask "Can you please shut the door?" patient would say "Yes I can" & not shut door, despite implication. You deal w/ pragmatics everyday, social media, music, media 

Inferences:

• Difficulty making inferences (e.g., About characters’ attitudes/motives)

• John-“I am searching for a new place to live”

  Greg-“Oh, I don’t have a roommate!”

  What is Greg implying?

Discourse comprehension:

• Poor coherence (cannot apply/connect meanings from one paragraph to another)

• Macrostructure deficits: Overall theme, central message of narratives, pictured scenes or discourse.

Discourse production:

• Verbose, literal, focused on detail and empty

  • Cookie theft picture- “Well, its on a 8x11 inch paper covered with plastic, done with drawing pens..on a white paper…”

• Disorganized, tangential, overly-personalized discourse production

• Reduced eye contact, turn-taking

• Reduced use of emotionally-laden words

• Lack of sensitivity to shared knowledge

• Difficulty extracting story morals or giving titles to story contents

Conversation:

• Deficient Theory of Mind (ToM)

  • Ability to infer another person’s mental states

• Difficulty interpreting jokes, sarcasm (require understanding another’s perspective or intent)

• Poor coherence (don’t clarify pronouns or provide explicit references to avoid confusion)

• Difficulty in lengthy conversations

• Poor topic maintenance

  • Abrupt termination of conversation topics

  • Introducing unrelated tangential topics

• Conversation breakdowns occur frequently

• Repair strategies typically used by partners