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Frontal lobe functions and assessmeny 20th july 2013
 

Frontal lobe functions and assessmeny 20th july 2013

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  • Emotional incontinenceTactlessnessIrritabilityUndue familiarityAntisocial behaviorEnvironmental dependencyMood disorders (depression, lability, mania)Obsessive-compuIsive disorder
  • The FAB is a brief tool that can be used at the bedside or in a clinic setting to assist in discriminating between dementias with a frontal dysexecutive phenotype and Dementia of Alzheimer’s Type (DAT). The FAB has validity in distinguishing Fronto-temporal type dementia from DAT in mildly demented patients (MMSE > 24). Total score is from a maximum of 18, higher scores indicating better performance.

Frontal lobe functions and assessmeny 20th july 2013 Frontal lobe functions and assessmeny 20th july 2013 Presentation Transcript

  • FRONTAL LOBE Functions & Assessment Unit 1 , 20 Jul 2013 By: Shahnaz Syeda MPhil M&SP II YEAR TRAINEE LGBRIMH TEZPUR
  • • Commonly described as anatomic seat of human selfawareness, • Most evolutionarily advanced components of the human brain
  • Functional Frontal Lobe Anatomy: A Recap • The frontal lobes have several functional areas – – – – – – Primary motor cortex Supplementary motor cortex Pre motor cortex Frontal eye field Motor speech area Broca Prefrontal cortex (4 parts)  Dorsolateral prefrontal cortex Orbito frontal cortex Anterior cingulate cortex. Ventro medial prefrontal cortex
  • Functional Frontal Lobe Anatomy: Premotor area Primary motor area B4 B6 Central sulcus Supplementary motor area (medially) Frontal eye field B8 Prefrontal area B 9, 10, 11, 12 Lateral sulcus/Sylvian fissure Motor speech area of Broca B 44, 45
  • The primary motor cortex: • It is concerned with muscle contraction, mainly on the opposite side of the body and is responsible for the execution of movement and the maintenance of simple movement. • In short execution of motor movement • In the primary motor area, most of the body is mapped. (Barr and Kiernan, 1983, Gercharind, 1983)
  • Functional Frontal Lobe Anatomy: A recap
  • Primary motor cortex – Function: executes design into movement – Lesions:/ tone;  power;  fine motor function on contra lateral side
  • • Premotor cortex ( area 6) lies immediately anterior to lateral portions of primary motor cortex extends inferiorly to sylvian fissure superiorly about 2/3 of way to the longitudinal fissure
  • • It occupy area anterior to primary motor • Lesion# difficulty in skilled moment • Premotor cortex contributed to motor functioning by influencing the primary motor cortex develop programmes for the motor functions such as routine, necessary skills, and voluntary actions. Thus it is important for motor sequencing. This contribution occurs both when new programmes are formed and when previously established programme are altered. • Premotor area, thus programme skilled motor activities and its execution (Barr and Kiernan, 1983). • In short planning & programming of motor movements and sequencing and organization of movements.
  • Supplementary motor cortex: • Supplementary motor area lies superior to premotor area lying mainly in longitudinal fissure . • According to Stuss and Benson (1986), this area of the frontal lobes seems to provide the drive for the initiation of movement, rather than being involved in the execution of movement. • It is thought to mediate internal needs with external demands in order to initiate motor programme. This coordination refers to both new and previously established programmes including motor speech.
  • • Supplementary motor area – Function: intentional preparation for movement; procedural memory – Lesions: mutism, akinesis; speech returns but it is nonspontaneous
  • Frontal eye field • It is located anterior to the premotor area • Concerned with voluntary eye movement on the opposite side of the stimulus – Selects target and commands movement (saccades)
  • Assessment of frontal eyefield function • Ask the patient to follow the movement of a finger from left to right and up and down. Ask the patient to look from left to right, up and down (with no finger to follow). Note inability to move or jerky movement.
  • Broca’s motor speech area: • Located in left hemisphere(dominant hemisphere) in most right handed persons • Responsible for expressive speech.i.e.it brings formation of words and stimulate larynx, tongue & soft palate lesion# causes broca’s /expressive/motor aphasia-patients can think the words they wish to say but can’t produce speech ,but can write it down.
  • Pre-frontal cortex • Part rest of frontal area excluding motor & premotor area is prefrontal area • Concerned with individual personality. • Also concerned judgment, depth of emotions, social, moral, concentration, abstract ideation& foresightedness. • The prefrontal cortex is concerned with memory, emotions and intellectual functioning (Daubey and Sandok, 1978).
  • The prefrontal cortex • It monitors and contains behaviour through higher order mental functioning i.e. judgement and foresight (Barr and Kiernan, 1989) • According to Luria (1973, 1980), the prefrontal cortex is important in the maintenance and control of cortical tone. It integrates information, both from the individual and the outside environment and subsequently regulates the behaviour of organism, according to the outcome of its action. • The prefrontal areas also select appropriate responses among available possibilities. Thus, this area regulates higher forms of organized conscious activities, be in voluntary movements, memory and cognition. • Lesions lead to inflexibility and stereotypy
  • Attention Concentration Emotion Executive Function Fatigue Guilt Impulses Motor Negative Symptoms Obsessions & Compulsions Pain Ruminations Suicidality Worry (S M S)
  • Recap contd…. PREFRONTAL CORTEX • Dorsolateral prefrontal cortex [DLPFC] Executive, Problem Solving and Analyzing • Ventomedial prefrontal cortex [VMPFC] Role in emotional processing • Orbitofrontal cortex [OFC] Regulate impulses, compulsions and drives • Anterior cingulate cortex [ACC ] Selective Attention (dorsal) Emotions depression and anxiety (ventral)
  • • Dorsolateral pre-frontal lobes together with limbic system is involved in working memory executive functioning abilities, including response inhibition, fluency and retrieval from long term memory. DORSOLATERAL PREFRONTAL CORTEX SYNDROME • Executive dysfunction. • Memory problems: • Defective working memory. • Defective retrieval. • Impaired attention. • Lack of initiative & spontaneity. • Impaired abstract thinking • Impaired problem solving, creativity • Impaired language & verbal fluency.
  • Neuropsychological evaluation ATTENTION Serial subtraction Trail Making A test Digit Symbol of WAIS-R Digit cancellation MEMORY Wechsler Memory Scale –III Digit span Days and months backward PROBLEM SOLVING Block design test, Porteus maze test, Tower of London test Test of abstraction to test abstract thinking ability
  • ORBITOFRONTAL • The orbitofrontal circuit mediates the modulation of social behavior :Emotional life and personality structure, Arousal, motivation, affect. • • • • • • • • • Anatomically synonymous with VMPFC Personality and social changes Silliness Explosive, aggressive bursts Emotional lability Irritability Sexual changes Also known as the “ centre of pleasure” Associated with the feelings of pleasure derived from eating and sex • Dysfunction of this area may result in anhedonia
  • • VENTROMEDIAL PREFRONTAL CORTEX SYNDROME Regulation of emotion: markedly reduced social emotions such as compassion, shame and guilt, poorly regulated anger and frustration tolerance (Michael Koenigs et al.) Decision making: severe impairments in personal and social decision-making Bechara A, Tranel D, Damasio H 2000
  • ANTERIOR CINGULATE SYNDROME Akinetic mutism - patients tending neither to move (akinesia) nor speak (mutism) Disorder of diminished motivation (DDM). Abulia - a lack of will or initiative Apathy - Less extreme (An apathetic individual has an absence of interest in or concern about emotional, social, spiritual, philosophical and/or physical life) Poverty of speech Poor response inhibition
  • Frontal lobe syndrome - Overview A personality and behavior change caused by lesion, stroke, infection, neoplasm or degenerative disorders in the area of frontal lobe are known as frontal lobe syndrome leading to  motor abnormalities  speech and language disorders  impairment of cognitive functions  mood , behavioral as well as personality changes
  • The Case of Phineas Gage (Harlow 1868) Tamping iron blown through skull: L frontal brain injury  Excellent physical recovery  Dramatic personality change ‘no longer Gage’: stubborn, lacked in consideration for others, had profane speech, failed to execute his plans 
  • Frontal lobe syndrome: clinical features • Confabulation: the tendency of the patient to produce erroneous material on being questioned about the past, either recent or remote. • Utilization behaviour: Giving an instrumentally appropriate but exaggerated response to objects that were introduced to them. • Abstract thinking: Impairment of abstraction was maximum with lesions of the frontal lobe (Goldstein,1936)
  • Error utilization difficulty: apparent lack of full awareness of deficits. Luria has referred to this as a lack of ‘self-criticism’ or ‘lack of critical attitude towards one’s own action’ Disinhibition and Impulsiveness: Patient may be disinhibited and influenced by immediacy of situations. Uncontrolled laughter and disinhibited sexuality are found. Apathy and depression: Patients may appear severely apathetic, indifferent, and lethargic, and they may develop Bradykinesia, inertia and mutism
  • • Motor Perseveration:2 types compulsive repetition of a movement and inertia of the programme itself Verbal Behaviour: • Broca’s aphasia • Perseveration or in severe cases echolalia in case of left frontal damage • Impoverishment of spontaneous speech and a reduction in the patient's conversational replies which often shrink to passive responses to questions in case of left frontal lobe damage
  • Neuropsychological Assessment • Neuropsychology is the study of (and the assessment, understanding, and modification of) brain-behavior relationships. • Screening neuropsychological examination is indicated when: 1. Medical or injury condition is suspected to have impacted brain health (for example, compromised circulation, chronically poor nutrition, or drug toxicity); 2. Any relatively sudden, unexpected, and unaccounted for changes appear in mental or cognitive performance that impacts work or daily functioning; 3. Gradual or sudden onset of unusual physical, sensory, or motor changes (an examination by a physician is always indicated in these instances, as well);
  • • Full Neuropsychological examination is indicated when: 1. Screening examination is positive for likelihood of brain disorder; 2. Brain injury or disease is already known and comprehensive understanding of functional impact is desired; 3. Brain injury or disease is highly suspect and comprehensive neurofunctional characteristics are desired to complement neurological examination and diagnostic understanding; 4. Comprehensive diagnostic and functional nature of brain injury or disease is necessary for rehabilitation and life-long planning; 5. Comprehensive diagnostic, functional, and causative nature of brain injury or disease is necessary for forensic application;
  • What Do Neuropsychological Tests Measure? • • • • • • • • • • • • • Attention and Processing Speed – Motor Performance – Sensory Acuity – Working Memory – Learning and Memory Intelligence Language Calculation Visuospatial Analysis Problem Solving and Judgment Abstract Thinking Mood and Temperament Executive Functions
  • Steps • Clinical Diagnostic review of history of present illness • Onset, course and degree of cognitive & personality changes • Premorbid functioning • Test of handedness • Choice of neuropsychological test.
  • Frontal Assessment Battery • • • 1. Similarities (conceptualization) “In what way are they alike?” A banana and an orange • • 2. Lexical fluency (mental flexibility) “Say as many words as you can beginning with the letter ‘S,’ any words except surnames or proper nouns.” • • • • • • • • • If the patient gives no response during the first 5 seconds, say: “for instance, snake.” If the patient pauses 10 seconds, stimulate him by saying: “any word beginning with the letter ‘S.’ The time allowed is 60 seconds. 3. Motor series “Luria” test (programming) “Look carefully at what I’m doing.” The examiner, seated in front of the patient, performs alone three times with his left hand the series of “fist–edge–palm.” “Now, with your right hand do the same series, first with me, then alone.” The examiner performs the series three times with the patient, then says to him/her: “Now, do it on your own.”
  • 4. Conflicting instructions (sensitivity to interference) “Tap twice when I tap once.” To ensure that the patient has understood the instruction, a series of 3 trials is run: 1-1-1. “Tap once when I tap twice.” To ensure that the patient has understood the instruction, a series of 3 trials is run: 2-2-2. The examiner then performs the following series: 1-1-2-1-2-2-2-1-1-2. 5. Go–No Go (inhibitory control) “Tap once when I tap once.” To ensure that the patient has understood the instruction, a series of 3 trials is run: 1-1-1. “Do not tap when I tap twice.” To ensure that the patient has understood the instruction, a series of 3 trials is run: 2-2-2. The examiner then performs the following series: 1-1-2-1-2-2-2-1-1-2.
  • Test of Speed 1. Finger tapping test: This procedure measures motor speed. By examining performance on both sides of the body, inferences may be drawn regarding possible lateral brain damage. [Demo] Please rest your right/left hand comfortably here. Spread out your palm and place your index finger on the tapping key. As soon as I say start tap as fast as you can with your index finger till I say stop. Do not remove your hands, finger or whole body.
  • Test of speed 2. Digit Symbol Substitution test. it is a test of visuo motor co ordination, motor persistence, sustained attention and response speed. Rapid information processing is required in order to substitute the symbols accurately and quickly.
  • Test of Attention It is a precursor to all other neurological/cognitive functions Defined as sustained focus of cognitive resources on information while filtering or ignoring extraneous information 1. Color Trial Test: Developed by WHO Focused Attention: Free from the influence of language. Part 1: Attention, perceptual tracking and simple sequencing. Part 2: Requires metal flexibility in addition to the above. It is considered as a measure of focused attention as in both parts of the test the subject has to ignore irrelevant numbers while scanning for the number which is next in sequence.
  • Trail Making Test 5 A B 4 6 1 C 2 3 D 7 Various levels of difficulty: 1. “Please connect the letters in alphabetical order as fast as you can.” 2. “Repeat, as in „1‟ but alternate with numbers in increasing order”
  • Test of Attention • 2. Digit Vigilance Test: The same level of mental effort or attention deployment is reqiured over a period of time. Inability to sustain and focus attention leads to both increased time to complete the test as well as errors. - 9 and 6 - Time 15 min
  • Test of Executive Functions • EF mediates goal directed behaviour. • Executive functions consist of components such as anticipation, goal selection, planning and monitoring • Ability to - Maintain an appropriate problem solving set - For attainment of future goals. - Inhibit a response or to defer it to a later appropriate time - Prepare plan of action - A mental representation of the task, including - the relevant stimulus information encoded into memory and the desired future goal state
  • Executive Functions 1. 2. 3. 4. 5. 6. 7. 8. 9. Fluency Working memory Set shifting Ability Set maintenance Planning Response Inhibition Error detection Abstraction Organization
  • • 1. Fluency : [ capacity to generate alternatives in a regulated manner] • Verbal fluency – prefrontal cortex in language dominant hemisphere. • Design fluency – bilateral prefrontal areas 1. Phonemic Fluency- Controlled Oral Word Association Test (COWA) • Saying words starting with Letter F – A – S • 3 trials approx 5 min 2. Category Fluency – as many animal names as possible in 1 min exclude names of fish birds and snakes
  • 3. Design Fluency: Visual Fluency is the capacity to generate new visual forms. Free condition: draws novel design Fixed condition: novel design using only four straight or curved lines. - No geometric forms, similar/elaboration of previous design, not meaningful or named. - Found to be sensitive to right frontal-lobe damage - Time 12 min
  • • Example: healthy performance • Novelty Score = 15 Example: right frontal performance R = rule breaking (nameable--triangle) P= perseverative (too similar to others) Novelty Score = 6
  • Working Memory • Put Forth by Baddeley (1986) • Capacity to hold and manipulate information for on going processes. • Mental Sketch pad • Verbal working memory using N back tasks activate Broca’s area and the left supplementary motor and premotor area • 1 back consecutively • 2 back after intervining consonant • Time 12 min
  • • • • • Visual working Memory 1 Back and 2 Back 36 cards black dots 1 back – locations of the dots was consecutively repeated • 2 back – location of dot was repeated after one intervening card.
  • • Planning: has been defined as the identification and organization of the steps and elements needed to carry out an intention or achieve a goal. • left frontal lesions associated with deficits of planning (Shallice 1982) • Components – speed of processing, mental flexibility, working memory, regulation of thought, error correction ability [SMWRE] • Dorsolateral prefrontal cortex is associated with components of generating, selecting, remembering mental moves.
  • Tower of London • Test evaluates the subjects ability to plan and anticipate the results of their actions to achieve a predetermined goal. • Activates wide network consisting of the dorsal prefrontal cortex, premotor cortex, pareital cortex and cerebellum.
  • Set shifting • Ability to change a mental set in response to environmental contingencies. • Ability to adapt responses to a changing environment. • Mental set is formed when the environment does not change, precursor to habit, response to a standard stimulus becomes easy. • Lesions in Dorsolateral prefrontal cortex impair SF ability and increase perseverated response. • Frontal lobe leisons have been ass. with increased errors.
  • Wisconsin Card Sorting Test “Please sort the 60 cards under the 4 samples. I won‟t tell you the rule, but I will announce every mistake. The rule will change after 10 correct placements.” Network of regions activated by this test as seen on PET include bilateral dorsolateral prefrontal cortex, inferior parietal lobule, visual association , cerebellum in additon to the prefrontal cortex.
  • WCST examines – concept formation, abstract reasoning, ability to shift cognitive strategies in response to changing environment. -128 cards -Card 1 : 1 Red triangle (left Hand ) -Card 2 : 2 Green Stars -Card 3 : 3 Yellow Cross -Card 4 : 4 Blue Circles
  • Response Inhibition [E F]: refers to the suppression of actions that are inappropriate in a given context and that interfere with goaldriven behaviour. Stroop Test : Bilateral superior medial prefrontal regions impair performance on Stroop test.
  • RED BLUE ORANGE YELLOW GREEN RED PURPLE RED GREEN YELLOW BLUE RED YELLOW ORANGE RED GREEN BLUE GREEN PURPLE RED 1. Read the words column wise as fast as you can 2. You can correct yourself. 3. Name the color in which the word is printed. 4. Time 20 min Stroop effect Score: Time taken to name – Time taken to read the words.
  • Verbal Comprehension • Ability to understanmd spoken language Token Test (De Renzi & Vignolo 1962)
  • Learning and Memory • Rey’s Auditory Verbal Learning Test (AVLT) • List A – Immediate • List B – After 5 Trials of Immediate recall[interference] List A Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 List B IRecall A DR A Recognition 1 Arm Shoes Mirror 2 Cat Monkey Axe 3 Axe Bowl Hammer 4 Bed Cow Candle 5 Plane Finger Bed 6 Ear Dress Leg 7 Dog Spider Arm
  • VISUO CONSTRUCTIVE ACTIVITIES Complex figure of REY. constructional apraxia occurs due to parietal lesions where the difficulties arise because of the loss of spatial organization of elements. In frontal lobe patients difficulties arise because of disruption of one or more of the steps like intention, programming regulation or verification. The performance of frontal patients may be facilitated if the patients were given a structured sequence of the figure to copy. Immediate Recall - 3 min Delayed Recall – 30 min
  • Logical Memory • Immediate and delayed recall of a meaningful passage.
  • Luria Nebraska and Frontal Lobe Motor functions (C1) Simple and smooth coordinated movements of hand and oral motor area, kinesthetic basis of movement, optic-spatial organization, praxis, selectivity of motor acts, and verbal regulation of motor acts. Visual functions (C4) Visual perception of objects and pictures, visual-spatial orientation and operations in space. Expressive speech (C6) Reflective speech, articulation of speech sounds, repetitive speech, nominative and narrative speech. Memory (C10) New learning, immediate sensory traces, memory with interference, memory for text and logical memory. Left Hemisphere (S2) Left-hand sensory and motor performance Right Hemisphere (S3) Right-hand sensory and motor performance Impairment (S5) Symbolic reasoning, working memory and spatially mediated performance.
  • REFERENCES Reference: 1. Frontal Lobe - LADA A. KEMENOFF, BRUCE L. MILLER, and JOEL H. KRAMER, University of California, San Francisco 2. Neuropsychology of prefrontal cortex, S V Siddiqui et al IJP 3. Neuropsychological Assessment of Frontal Lobe Dysfunction, Goldberg, Bougakov. 4. HUMAN PREFRONTAL CORTEX: PROCESSING AND REPRESENTATIONAL PERSPECTIVES Jacqueline N.Wood and Jordan Grafman 5. Stahl’s Essential Psychopharmacology 6. Walsh(1999),Neuropsychology: A clinical approach (4th edition),Churchil Livingstone