frontal lobe - Callie Chatterton

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Transcript frontal lobe - Callie Chatterton

Callie Chatterton
Facts
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Located directly behind the forehead
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Most frequently injured
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Largest portion of the brain
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1/3 of cortical area of cerebral hemisphere
Connected to many other portions of the
brain
Frontal Lobe
Functions
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Frontal lobe is critical in executive roles
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Goal-setting
Completion of purposeful activities
Planning
Also plays important role in social behavior
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Inhibition
Judgment/insight
Attention
Phineas Gage
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Foreman of a track construction gang
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Responsible and well-liked by his crew
Building a railroad through Vermont’s Green Mts.
Frontal lobe damage
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13.25 lb, 3.5 ft. tamping iron penetrates brain
Passes from behind the left eye through the top of the
head carrying away a substantial part of the frontal
lobe
Phineas Gage
Phineas Gage
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No immediate problems after incident
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Phineas Gage supposedly never lost consciousness and
was up and discussing the accident soon after it happened
Did eventually develop a wound infection but recovered
quickly and was soon deemed physically able to return to
work
“Gage is no longer Gage”
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Before the accident he was responsible, caring, and wellbehaved in a social setting.
After the accident he became erratic, profane, and
impatient
Causes of Injury
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Trauma
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Blows from the front, back, or side of the head can
result in frontal lobe injury
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Even injuries not involving the head can cause bruising of
the brain (whiplash)
Diseases
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Strokes, lesions, meningitis, tumors
Causes of Injury
Consequences of Injury
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Three Frontal Lobe syndromes
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Orbitofrontal syndrome (lacks inhibition)
Frontal Convexity syndrome (apathetic)
Medial Frontal syndrome (akinetic)
Answer lab assessments correctly but make
poor choices in real situations
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Tests of perception, construction, language, and
spatial attention are unharmed
Three Syndromes
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Orbitalfrontal syndrome
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Commonly caused by closed-head injury
Characterized by disinhibited, impulsive behavior,
difficulty in controlling their emotions, lacking in
judgment and are easily distracted
Many patients are incorrectly diagnosed with a
personality disorder
Possible link between violent offenders and traumatic
brain injury
Three syndromes
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Frontal Convexity syndrome
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Characterized by disinterest, slowing of the motor
functions and apathy
Inability to regulate behavior according to personal
goals
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Inability to plan ahead, lack of motivation and concern
Generally not caring about the world around them
Three Syndromes
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Medial Frontal syndrome
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Characterized by occasional mutism, inability to
control sexual appetite and akinesia
Loss of sensation in lower extremities as well as
weakness also occur
Many patients experience symptoms from
each syndrome
Detection
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Unless noticeable damage occurs (car
accident trauma, etc.) tests are not usually
performed
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Normal neurological and psychological tests
rarely detect any abnormalities
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Requires careful observation of previous and
current behavior
Tests
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Wisconsin Card Sorting Test
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Stroop Test
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Patient sorts cards into one of four piles based on
clues from instructor
Patients must say the color that the word is written in
rather than reading the word itself
Rhythm Tapping Test
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Patient essentially imitates rhythm that has been
tapped to them (easy to difficult)
Rehabilitation
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Goal Neglect
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Based on the idea that human behavior is controlled
by internal demands in response to the environment
Selection of new actions when previously selected
actions fail to achieve the goal
Brief auditory stimuli also used
Drug Therapy
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Alter the action of the working memory link and
dopaminergic system dysfunction
Rehabilitation
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Reinforcement
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Simple reinforcement and reward techniques
Organizing the executive system
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Targeted to specific areas in which the patient has
problems
Conclusion
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Rehabilitation is difficult
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While there are many similar behaviors, each brain
injury is different
Individuals without brain damage
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Patients with frontal lobe lesions show similar signs to
people without any brain damage (irresponsible,
immoral, and flippant)
Resources
Burgess, P.W. & I. H. Robertson (2002). Principles of the
rehabilitation of frontal lobe function. In D.T. Stuss & R.T.
Knight Principles of Frontal Lobe Function (pp. 557-570).
Oxford, NY: Oxford University Press.
Mesulam, M.-Marsel (2002). The human frontal lobes:
Transcending the default mode through contingent
encoding. In D.T. Stuss & R.T. Knight Principles of Frontal
Lobe Function (pp. 8-28). Oxford, NY: Oxford University
Press.
Tranel, D. (2002). Emotion, decision making, and the ventromedial
prefrontal cortex. In D.T. Stuss & R.T. Knight Principles of
Frontal Lobe Function (pp. 338-353). Oxford, NY: Oxford
University Press.