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OUTLINE: FRONTAL LOBE       1.   Evolution       2.   History       3.   Anatomy and connections       4.   Syndromes     ...
MAMMALS FRONTAL LOBE EVOLUTION                        33% of Brain area                        Most recently evolved    ...
HUMAN FRONTAL LOBE EVOLUTIONThe  high, straight forehead that characterizes modern humans,superseding the prominent brow ...
FRONTAL LOBE HISTORY 1600-19001.   1641 – Lateral sulcus of the brain was first defined by     Franciscus de la Boe Sylviu...
FRONTAL LOBE               A.   Lateral surface                    1.   Posterior - Central                         sulcus...
LATERAL SURFACE FRONTAL LOBE                     Precentral  sulcus –                      parallel to central           ...
MEDIAL SURFACE FRONTAL LOBE                     Between   cingulate                      sulcus and superior             ...
ORBITAL SURFACE FRONTAL LOBE                       Divided into four orbital gyri by a                        well-marked...
FUNCTIONAL FRONTAL LOBE ANATOMY                 Premotor area                Primary motor area                  B6       ...
PRIMARY MOTOR CORTEX Input: thalamus, BG,  sensory, premotor Output: motor fibers to  brainstem and spinal  cord Functi...
PRE MOTOR CORTEX Input: thalamus, BG,  sensory cortex Output: primary motor  cortex Function: stores motor  programs; c...
SUPPLEMENTARY MOTOR CORTEX   Input: cingulate gyrus,    thalamus, sensory &    prefrontal cortex   Output: premotor, pri...
FRONTAL EYE FIELDS   Input: parietal / temporal    (what is target); posterior    / parietal cortex (where is    target)...
BROCA‟S SPEECH AREA Input: Wernicke‟s Output: primary motor  cortex Function: speech  production (dominant  hemisphere)...
CONNECTIVITY OF PREFRONTAL REGIONS   input from association cortex    (occipital, parietal, temporal &    olfactory areas...
INTERACTION AMONG ASSOCIATION AREAS
FRONTAL LOBE SYNDROMES
PHINEASE GAGE (1848)                                1. He becomes unreliable and failsOn 13th Sept 1848 a railroad        ...
FRONTAL LOBE ABLATION IN MONKEY ANDDOGS (BIANCHI)   "The frontal lobes are the seat of coordination and fusion of the    ...
FRONTAL LOBE HISTORY 1900-2010Feuchtwanger    (1923)             Jacobson     (1935)  200 case of frontal lobe injury   ...
INFERIOMESIAL FRONTAL LEUKOTOMYEGAS MONIZ 1935Hours                       Weeks   to months     Drowsy                 ...
FROTNAL LOBE SYNDROMES                           executive function                          deficit; disinterest /     ap...
ORBITAL PREFRONTAL CORTEX   Connections:    temporal,parietal, thalamus,    GP, caudate, SN, insula,    amygdala   Part ...
DORSOMEDIAL PREFRONTAL CORTEX   Connections:    temporal,parietal, thalam    us, caudate, GP, substant    ia nigra, cingu...
DORSOLATERAL PREFRONTAL CORTEX Connections: motor /  sensory convergence  areas, thalamus, GP,  caudate, SN Functions: m...
FRONTAL CONVEXITY SYNDROME (APATHETIC)   Apathy (occasional brief         Three-step hand sequence    angry or aggressiv...
UNILATERAL FRONTAL LOBE SYNDROME  1. Contralateral               4. Difficulty in adaptation     hemiplegia               ...
DOMINANT FRONTAL LOBE                             Deficits in tests of categorization1. Loss of motor speech       and fl...
RIGHT HEMIS. PREFRONTAL LESIONS Loss of emotional               Large lesions may exist  speech expression              ...
BILATERAL FRONTAL LOBE LESION1. Pseudodepressed -         6. Active learning,  Apathy, Abulia, akinetic       problem solv...
FRONTAL LOBE SYNDROME MIMICS   Bilateral Caudate nucleus lesion - Dyscontrol   Globus pallidus lesion – Apathy and abuli...
FIVE „FRONTAL SUBCORTICAL CIRCUITS‟1.   Motor2.   Oculomotor3.   Dorsolateral prefrontal4.   Lateral orbitofrontal5.   Ant...
1. FRONTAL SUBCORTICAL MOTOR CIRCUIT                                      SMA,                                  Premotor,M...
2.FRONTAL OCULOMOTOR CIRCUIT                         Frontal                        Eye field           Thalamus          ...
3.DORSOLATERAL PREFRONTAL CIRCUIT                           Lateral Pre-Frontal                   Thalamus                ...
4. LATERAL ORBITOFRONTAL CIRCUIT                             Infero-Lateral                              Pre-Frontal      ...
5. ANTERIOR CINGULATE CIRCUIT                        Ant. Cingulate                                                       ...
NEUROTRANSMITTERS: DOPAMINERGICTRACTS Origin: ventral  tegmental area in  midbrain Projections: prefrontal  cortex (meso...
NEUROTRANSMITTERS: NOREPINEPHRINETRACTS Origin: locus ceruleus  in brainstem and lateral  brainstem tegmentum Projection...
NEUROTRANSMITTERS: SEROTONIN TRACTS Origin: raphe nuclei in  brainstem Projections: number of  forebrain structures Fun...
FRONTAL LOBE FUNCTION Motor         Cognitive Behavior       Arousal Voluntary     Memory     Personality   Attention move...
MOTOR PLANNING1.   Frontal lobe has evolved from being the main     motor planner/organizer to a higher level     behaviou...
“PLANNING NEURONS” IN THE MONKEYFRONTAL CORTEX
FRONTAL LOBE AND AROUSAL Right frontal lobe -> bilateral inhibitory influences  on attention and arousal Left frontal lo...
MEMORY DEFECT Inattentiveness Defect in working memory Defect in sequencing, perseverance Can recall the details of pr...
WORKING MEMORY
WORKING MEMORY IS A SHORT-TERM MEMORY REQUIRED FORBOTH THE ENCODING AND RECALL OF EXPLICIT KNOWLEDGE
NEURON FIRING IN THE PRINCIPAL SULCUSTRACK THE WORKING MEMORY
IMAGING OF WORKING MEMORY
LEARNINGImpaired association     Impaired temporal   learning                 learning1. Reduced response      1. Impaired...
ABSTRACTION AND JUDGMENT Cognitive functions undisturbed Concrete thinking Diminished insight Defect in planning / exe...
PROBLEM SOLVING Unable to think all the option and select appropriate Fails to conceptualize all the demands of the  sit...
PROBLEM SOLVING - LURIANormal                               Frontal lobe lesion   1.    The specification of           1. ...
IMPAIRED DIVERGENT THINKING1.   Decreased consideration of alternative     strategies/behaviors; reduced flexibility2.   D...
Language•   Broca‟s / non-fluent aphasia•   Prefrontal/ transcortical motor aphasia•   Language-motor dissociation•   Akin...
FRONTAL LOBE PERSONALITY Lack of initiative and     Organic driveness:  spontaneity                 brief but intense P...
DECREASED INHIBITION1.   Problems inhibiting incorrect/ineffective     responses & switching to a new strategy2.   Perseve...
DISINHIBITED SEXUALITY   It is not unusual for a             Seizure activity arising    hypersexual, disinhibited      ...
NEUROANATOMIC CORRELATION   Motor                           Attention     Perseveration ->                  Brainstem ...
FRONTAL LOBE HISTORY TAKING Personality changes (over familiar, tactless and  sexual indiscretions) Hyperorality Distra...
FRONTAL LOBE TESTS   1.   Attention   2.   Memory   3.   Abstraction   4.   Judgment   5.   Planning   6.   Language   7. ...
Tests of attention and memoryo Alternative sequence (e.g. copying MNMN)o Luria‟s „fist-edge-palm‟ test (show 3X)o Go/no-go...
Tests of attention and memory cont‟ oDigit span   orepeat 3-52; 3-52-8; 3-52-8-67..” N: >5   o Visual grasp: “look away fr...
Tests of abstraction and judgmento Interpret proverbs (e.g.“the golden hammer  opens iron doors”)o Explain why conceptuall...
Language tests o Thurstone / word fluency test (“recite as many   words beginning with „F‟ in 1 min as you can,   then wit...
MOTOR SEQUENCING: KINETIC MELODY1.   Hand position test (three-step hand sequence)2.   Rhythm tapping tasks3.   Go no go t...
FRONTAL RELEASE SIGN   Grasp reflex                        Snout reflex       Forceful grapping of        object on tou...
Formal Tests• Abstract thinking and set shifting; L>R   • Wisconsin Card Sorting Test• Visuo-motor track, conceptualizatio...
Wisconsin Card Sorting Test“Please sort the 60 cards under the 4 samples.I won‟t tell you the rule, but I will announce ev...
Trail Making Test                           5                           B              A                              4   ...
Stroop Color and Word TestsRED BLUE ORANGE YELLOWGREEN RED PURPLE REDGREEN YELLOW BLUE REDYELLOW ORANGE RED GREENBLUE GREE...
Tower of London TestsVarious levels of difficulty:e.g. “Please rearrange the balls on the pegs, so that each peg hasone ba...
FRONTAL PATHOLOGY          Injury          Tumor          Abscess, infection          Dementia          Epilepsy     ...
TRAUMATIC BRAIN INJURYo   Gunshot woundo   Closed head injury     o Widespread stretching and shearing of fibers       thr...
FRONTAL LOBE INJURYAttention disorder –           Language   •   Distractibility           1.   Dynamic aphasiaMemory     ...
FRONTAL LOBE INJURY CONT.Mood, affect, behavior   1.   Reduced activity   2.   Lack of drive and initiative   3.   Lack of...
FRONTAL LOBE EPILEPSY    Clinical Features                            EEG        Frequent seizure with clustering      ...
FRONTAL LOBE AND PSYCHIATRY   Schizophrenia :                    Personality disorder:       Involving dorsolateral    ...
FRONTAL LOBE DEMENTIA   Trouble in maintaining normal              Language Problems    social and interpersonal        ...
VASCULAR DISEASEo   Common cause especially in elderlyo   ACA territory infarction     o   Damage to medial frontal areao ...
FRONTAL LOBE DISEASE    Degenerative diseases     – Pick‟s disease     – Huntington‟s disease    Infectious diseases    ...
FRONTAL LOBE DISEASE   Tumors    – Gliomas, meningiomas    – subfrontal and olfactory groove meningiomas:      profound p...
FRONTAL LOBE PATHOLOGYFrontal lobe abscess                         Meningioma
FRONTAL PATHOLOGYTuberous sclerosis   Frontal glioblastoma
Frontal lobe 2010
Frontal lobe 2010
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Frontal lobe 2010

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  • Thankyou, this is one of the most helpful things I have seen while trying to live with prefrontal cortex deficits. I have printed out several of the slides to show my doctor so he can understand certain things!
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Frontal lobe 2010

  1. 1. OUTLINE: FRONTAL LOBE 1. Evolution 2. History 3. Anatomy and connections 4. Syndromes 5. Physiology 6. Neurotransmitters 7. Dysfunction 8. Testing 9. Pathology
  2. 2. MAMMALS FRONTAL LOBE EVOLUTION  33% of Brain area  Most recently evolved  Well developed only in primates  Human species is due to frontal lobe  Last to develop in ontogeny from age 1-> 6years  Gives our capacity to feel empathy, sympathy, understand humor and when others are being ironic, sarcastic or even deceptive.
  3. 3. HUMAN FRONTAL LOBE EVOLUTIONThe high, straight forehead that characterizes modern humans,superseding the prominent brow ridges of our ancestors, is dueto the expansion of the cortex, and especially the prefrontalcortex, in our species.1. Australopithecus robustus 2. Homo habilis 3. Homo erectus4. Homo sapiens neanderthalensis 5. Homo sapiens sapiens
  4. 4. FRONTAL LOBE HISTORY 1600-19001. 1641 – Lateral sulcus of the brain was first defined by Franciscus de la Boe Sylvius,2. 1825 - Long before the time of Bouillaud the coexistence of aphasia, with certain forms of paralysis3. 1848 - Beginning with the tragic story of Phineas Gage4. 1861 - The area of the brain responsible for forming language is called Brocas area,5. 1868 - The "prefrontal“ introduced by Richard Owen6. 1890 - Swiss doctor working in a mental institution decided to try a revolutionary treatment. He removed the frontal lobe from six of his patients
  5. 5. FRONTAL LOBE A. Lateral surface 1. Posterior - Central sulcus 2. Inferio-Posterior – sylvian fissure. B. Medial sufface C. Orbital surface
  6. 6. LATERAL SURFACE FRONTAL LOBE  Precentral sulcus – parallel to central sulcus between them precentral gyrus  Sup and inf frontal sulci divide sup, middle and inf frontal gyri
  7. 7. MEDIAL SURFACE FRONTAL LOBE  Between cingulate sulcus and superior medial margin of hemisphere  Posterior part vertical sulcus – paracentral lobule
  8. 8. ORBITAL SURFACE FRONTAL LOBE  Divided into four orbital gyri by a well-marked H-shaped orbital sulcus.  The medial, anterior, lateral, and posterior orbital gyri.  The medial orbital gyrus presents a well-marked antero- posterior sulcus,  the olfactory sulcus, for the olfactory tract;  the portion medial to this is named the straight gyrus, and is continuous with the superior frontal gyrus on the medial surface.
  9. 9. FUNCTIONAL FRONTAL LOBE ANATOMY Premotor area Primary motor area B6 B4 Central sulcus Supplementary motor area (medially) Motor cortex 1. Primary Frontal eye field 2. Premotor B8 3. Supplementary Prefrontal area 4. Frontal eye B 9, 10, 11, 12 field Lateral sulcus/ 5. Broca’s area Sylvian fissurePrefrontal cortex Motor speech 1. Dorsolateral 2. Medial area of Broca 3. Orbitofrontal B 44, 45
  10. 10. PRIMARY MOTOR CORTEX Input: thalamus, BG, sensory, premotor Output: motor fibers to brainstem and spinal cord Function: executes design into movement Lesions: / tone; power; fine motor function on contra lateral side
  11. 11. PRE MOTOR CORTEX Input: thalamus, BG, sensory cortex Output: primary motor cortex Function: stores motor programs; controls coarse postural movements Lesions: moderate weakness in proximal muscles on contralateral side
  12. 12. SUPPLEMENTARY MOTOR CORTEX Input: cingulate gyrus, thalamus, sensory & prefrontal cortex Output: premotor, primary motor Function: intentional preparation for movement; procedural memory Lesions: mutism, akinesis; speech returns but it is non-spontaneous
  13. 13. FRONTAL EYE FIELDS Input: parietal / temporal (what is target); posterior / parietal cortex (where is target) Output: caudate; superior colliculus; paramedian pontine reticular formation Function: executive: selects target and commands movement (saccades) Lesion: eyes deviate ipsilaterally with destructive lesion and contralaterally with irritating lesions
  14. 14. BROCA‟S SPEECH AREA Input: Wernicke‟s Output: primary motor cortex Function: speech production (dominant hemisphere); emotional, melodic component of speech (non-dominant) Lesions: motor aphasia; monotone speech
  15. 15. CONNECTIVITY OF PREFRONTAL REGIONS input from association cortex (occipital, parietal, temporal & olfactory areas) convergence of higher-order input from all modalities. reciprocal connections: prefrontal processing modulates perceptual processing. LIMBIC connections (memory/emotion) Input to premotor areas - controls/programs behavior.
  16. 16. INTERACTION AMONG ASSOCIATION AREAS
  17. 17. FRONTAL LOBE SYNDROMES
  18. 18. PHINEASE GAGE (1848) 1. He becomes unreliable and failsOn 13th Sept 1848 a railroad to come to work and when worker, hard working, present he is "lazy." 2. He has no interest in going to diligent, reliable, church, constantly drinks alcohol, gambles, and "whores about." responsible, intelligent, 3. He is accused of sexually good humored, polite god molesting young children. fearing, family oriented 4. He ignores his wife and children and fails to meet his financial and foreman family obligations. 5. He has lost his sense of humour.Following an explosion iron 6. He curses constantly and does so bar drove into frontal lobe in inappropriate circumstances. 7. Died of status epilepticus in 1861
  19. 19. FRONTAL LOBE ABLATION IN MONKEY ANDDOGS (BIANCHI) "The frontal lobes are the seat of coordination and fusion of the incoming and outgoing products of the several sensory and motor areas of the cortex" (Bianchi, 1895) Loss of "perceptive power", leading to defective attention and object recognition. Reduction in memory. Reduction in "associative power", leading to lack of coordination of the individual steps leading towards a given goal, and thus to severe difficulty solving anything but the most simple problem. Altered emotional attachments, leading to serious changes in "sociality" [one of the main aspects of Phineas Gages post-traumatic behaviour]. Disruption of focal consciousness and purposive behaviour, leading to apathy and/or distractibility [one of the main aspects of Beckys post- operative behaviour]. Bianchi 1922
  20. 20. FRONTAL LOBE HISTORY 1900-2010Feuchtwanger (1923) Jacobson (1935) 200 case of frontal lobe injury  Premotor lobotomy in  Lack of initiative primates ->  Vacillation  Social indifference  Euphoria  Tameness  Inattentiveness  Placidity  Normal intellect and memory  ForgetfulnessEgas Moniz 1935  Difficulty in problem  Prefrontal lobotomies in solving  psychotics Dandy‟s (1936)  following bilateral frontal lobotomy during removal of meningioma
  21. 21. INFERIOMESIAL FRONTAL LEUKOTOMYEGAS MONIZ 1935Hours Weeks to months  Drowsy  Regained memory and  Apathetic intellect  Incontinent  Akinetic  With personality  Mute changesDays  Indifferent to the others  Decreased initiative problem  Lack of concern  No thought to their  Freedom from anxiety conduct  Apathetic  Tactless  Distractible  Socially inept  Euphoria and emotional outburst
  22. 22. FROTNAL LOBE SYNDROMES executive function deficit; disinterest / apathy; emotional reactivity; decreased drive/ attention to relevant awareness/ stimuli spontaneous movements; akinetic-abulic& Lateral mutism emotional lability, Medial disinhibition, distractibility, ‘hyperkinesis’ Orbital
  23. 23. ORBITAL PREFRONTAL CORTEX Connections: temporal,parietal, thalamus, GP, caudate, SN, insula, amygdala Part of limbic system Function: emotional input, arousal, suppression of distracting signals Lesions: Disinhibited, impulsive behaviour (pseudopsychopathic) Inappropriate jocular affect, euphoria ,emotional lability, Poor judgment and insight, Distractibility
  24. 24. DORSOMEDIAL PREFRONTAL CORTEX Connections: temporal,parietal, thalam us, caudate, GP, substant ia nigra, cingulate Functions: motivation, initiation of activity Lesions: Paucity of spontaneous movement and gesture, Sparse verbal output (repetition may be preserved), Lower extremity weakness and loss of sensation, Incontinence
  25. 25. DORSOLATERAL PREFRONTAL CORTEX Connections: motor / sensory convergence areas, thalamus, GP, caudate, SN Functions: monitors and adjusts behavior using „working memory‟ Lesions: executive function deficit; disinterest / emotional reactivity; attention to relevant stimuli
  26. 26. FRONTAL CONVEXITY SYNDROME (APATHETIC) Apathy (occasional brief  Three-step hand sequence angry or aggressive Alternating programs outbursts common) Reciprocal programs Indifference Rhythm tapping Psychomotor retardation Multiple loops Motor perseveration and  Poor word list generation impersistence  Poor abstraction and Loss of self categorization Stimulus-bound behaviour  Segmented approach to Discrepant motor and verbal visuospatial analysis behaviour Motor programming deficits
  27. 27. UNILATERAL FRONTAL LOBE SYNDROME 1. Contralateral 4. Difficulty in adaptation hemiplegia 5. Loss of initiative 2. Conjugate deviation of 6. Loss of kinetic melody eye to side of lesion 7. Unable to solve 3. Personality change problem (Psudopsychotic) 8. Anosmia and blindness a. Mood elevation, talkativeness b. Tendency to joke, lack of tact, silly and childish behavior
  28. 28. DOMINANT FRONTAL LOBE  Deficits in tests of categorization1. Loss of motor speech and flexibility.2. Unable to write  Problems with body schema (autopagnosia) due to problems of3. Sympathetic apraxia scanning, perceptual shifting and postural mechanisms.4. Dysphoria  Marked inactivity affects general intellectual processes and behavior.  Cannot change verbal instructions into acts, especially when the instructions are complex or symbolic.  Decreased spontaneity of speech; may result in complete loss of voluntary speech.  Memory deficits for verbal material; however, deficits may be due to defective registration.
  29. 29. RIGHT HEMIS. PREFRONTAL LESIONS Loss of emotional  Large lesions may exist speech expression without obvious symptoms; serious Euphoria speech disorders usually Constructional apraxia, not seen in right hemisphere lesions. associated with motor rather than perceptual  Difficulty with drawing tasks, though this is difficulties; deficits may associated more with occur as a function of right hemisphere lesions impaired complex (3-D) in general. spatial analysis.  Impaired visual-spatial integration, maze learning, non-verbal visual memory
  30. 30. BILATERAL FRONTAL LOBE LESION1. Pseudodepressed - 6. Active learning, Apathy, Abulia, akinetic problem solving, mutism, judgment2. Impulsiveness and 7. Limitation of utilization irritability behavior3. Inability to sustain attention 8. Frontal release sign a. Snout4. Decomposition of gait b. Suck5. Sphincter disturbance c. Palmomental d. Grasp e. Brow tapping
  31. 31. FRONTAL LOBE SYNDROME MIMICS Bilateral Caudate nucleus lesion - Dyscontrol Globus pallidus lesion – Apathy and abulia Bilateral thalamic infarction MS – Apathy and disinhibition Sjogren‟s syndrome Subcortical stroke Adrenoleukodystrophy Parkinson‟s disease Fahr‟s disease Huntington‟s disease Depression Schizophrenia OCD
  32. 32. FIVE „FRONTAL SUBCORTICAL CIRCUITS‟1. Motor2. Oculomotor3. Dorsolateral prefrontal4. Lateral orbitofrontal5. Anterior cingulate Cummings,„93
  33. 33. 1. FRONTAL SUBCORTICAL MOTOR CIRCUIT SMA, Premotor,Motor Hypo-thalamus Putamen Thalamus Globus VL,VA,CM Pallidus Supplementary Motor & Premotor : planning, initiation & storage of motor programs; fine-tuning of movements Motor : final station for execution of the movement according to the design
  34. 34. 2.FRONTAL OCULOMOTOR CIRCUIT Frontal Eye field Thalamus Central VA, MD Caudate DM Globus Pallidus & Substantia Nigra  Voluntary scanning eye movement  Independent of visual stimuli
  35. 35. 3.DORSOLATERAL PREFRONTAL CIRCUIT Lateral Pre-Frontal Thalamus DL VA, MD Caudate DM Globus Pallidus & Substantia Nigra Executive functions: motor planning, deciding which stimuli to attend to, shifting cognitive sets Attention span and working memory
  36. 36. 4. LATERAL ORBITOFRONTAL CIRCUIT Infero-Lateral Pre-Frontal VM Orbito-Frontal Caudate DM Globus Thalamus Pallidus & VA, MD Substantia Nigra  Emotional life and personality structure  Arousal, motivation, affect  Orbitofrontal cortex: consciousness
  37. 37. 5. ANTERIOR CINGULATE CIRCUIT Ant. Cingulate MD Thalamus Thalamus Ventral Striatum MD RL Globus Pallidus & Substantia Nigra Abulia, akinetic mutism
  38. 38. NEUROTRANSMITTERS: DOPAMINERGICTRACTS Origin: ventral tegmental area in midbrain Projections: prefrontal cortex (mesocortical tract) and to limbic system (mesolimbic tract) Function: reward; motivation; spontaneity; arousal
  39. 39. NEUROTRANSMITTERS: NOREPINEPHRINETRACTS Origin: locus ceruleus in brainstem and lateral brainstem tegmentum Projections: anterior cortex Functions: alertness, arousal, cognitive processing of somatosensory info
  40. 40. NEUROTRANSMITTERS: SEROTONIN TRACTS Origin: raphe nuclei in brainstem Projections: number of forebrain structures Function: minor role in prefrontal cortex; sleep, mood, anxiety, feeding
  41. 41. FRONTAL LOBE FUNCTION Motor Cognitive Behavior Arousal Voluntary Memory Personality Attention movements Planning, Problem Social and Initiation solving sexual Spontaneity Judgment Impulse control Language Abstract Mood and Expression thinking affect Eye movements
  42. 42. MOTOR PLANNING1. Frontal lobe has evolved from being the main motor planner/organizer to a higher level behavioural/strategic planner/organizer.2. Mental model, considering options, selecting behaviours based on context, feedback, stored knowledge3. Making predictions about what will work.
  43. 43. “PLANNING NEURONS” IN THE MONKEYFRONTAL CORTEX
  44. 44. FRONTAL LOBE AND AROUSAL Right frontal lobe -> bilateral inhibitory influences on attention and arousal Left frontal lobe unilateral excitation of arousal Left frontal damage -> unopposed right cerebral inhibition -> akinesia
  45. 45. MEMORY DEFECT Inattentiveness Defect in working memory Defect in sequencing, perseverance Can recall the details of problem, error in trying to solve Could not put them to use in the correction of further performance. Cannot categorizes series of item in group for recall
  46. 46. WORKING MEMORY
  47. 47. WORKING MEMORY IS A SHORT-TERM MEMORY REQUIRED FORBOTH THE ENCODING AND RECALL OF EXPLICIT KNOWLEDGE
  48. 48. NEURON FIRING IN THE PRINCIPAL SULCUSTRACK THE WORKING MEMORY
  49. 49. IMAGING OF WORKING MEMORY
  50. 50. LEARNINGImpaired association Impaired temporal learning learning1. Reduced response 1. Impaired memory for to consequences order, recency2. Impaired on delayed 2. Could affect response tasks problem-solving,3. Impaired planning and impair responsiveness to systematic, social & contextual organized cues behaviours
  51. 51. ABSTRACTION AND JUDGMENT Cognitive functions undisturbed Concrete thinking Diminished insight Defect in planning / executive control
  52. 52. PROBLEM SOLVING Unable to think all the option and select appropriate Fails to conceptualize all the demands of the situation but thinks “concretely” – think and react directly to the stimulus
  53. 53. PROBLEM SOLVING - LURIANormal Frontal lobe lesion 1. The specification of 1. Erroneous analysis of problem and the the condition of the problem condition in which it has arisen 2. The plan of action that is selected quickly 2. A plan of action or loses its regulation strategy for the solution influence on behavior of the problem is as a whole and is formulated replaced by a perseveration of one 3. Execution, including particular link of the implementation and motor act or by the control of the plan influence of some 4. Checking of the results connection established against the original plan during the patients past experience.
  54. 54. IMPAIRED DIVERGENT THINKING1. Decreased consideration of alternative strategies/behaviors; reduced flexibility2. Decreased spontaneity, initiative, may appear lazy, unmotivated3. Knowledge/intelligence may seem intact (e.g. IQ) but its not used to generate strategies or solve problems efficiently
  55. 55. Language• Broca‟s / non-fluent aphasia• Prefrontal/ transcortical motor aphasia• Language-motor dissociation• Akinetic mutism
  56. 56. FRONTAL LOBE PERSONALITY Lack of initiative and  Organic driveness: spontaneity brief but intense Placidity: worry, meaningless activity. anxiety, self concern,  Loss of ego strength: hypochondriasis, and Witzelsucht or moria : pain reduces socially uninhibited and Psychomotor lack aunawerness of retardation: number of their abnormal movements, spoken behavior. words and thought per  Loss of regards to unit of time diminish. social conventions , Mild form abulia and only interested in severe akinetic mutism. personal gratification.
  57. 57. DECREASED INHIBITION1. Problems inhibiting incorrect/ineffective responses & switching to a new strategy2. Perseverates; not responsive to feedback or changes in environment3. Violates rules, expectancies; takes risks4. Not adaptable5. Decreased social inhibitons as well
  58. 58. DISINHIBITED SEXUALITY It is not unusual for a  Seizure activity arising hypersexual, disinhibited from the deep frontal frontal lobe injured regions have also been individual to employ force. associated with spirited physical self- increased sexual defense is probably the best behavior, including strategy of the woman. Her sexual automatisms, husband may have exhibitionism, gential regressed to the cave-man manipulation, and level, and she owes it to him masturbation to be responsive at the cave-women level. It may not be agreeable at first, but she will soon find it exhilarating if unconventional."
  59. 59. NEUROANATOMIC CORRELATION Motor  Attention  Perseveration ->  Brainstem thalamic Posteriolateral frontal system dominant lobe and  Orbitofronal syndrome connection to basal ganglia  Frontolimbic link  Posterior lesion ->  Loss of inhibition of difficulty in organizing parietal lobe  Anterior lesion ->  Echophenomenon and dissociation between environmental behavior and language dependency
  60. 60. FRONTAL LOBE HISTORY TAKING Personality changes (over familiar, tactless and sexual indiscretions) Hyperorality Distractibility Poor motivation Inability to adapt to new situations Poor problem solving skills
  61. 61. FRONTAL LOBE TESTS 1. Attention 2. Memory 3. Abstraction 4. Judgment 5. Planning 6. Language 7. Motor sequencing
  62. 62. Tests of attention and memoryo Alternative sequence (e.g. copying MNMN)o Luria‟s „fist-edge-palm‟ test (show 3X)o Go/no-go: o”tap once if I tap twice, don‟t tap if I tap once” o“tap for A” oread 60 letters at 1/sec; N: < 2 errors
  63. 63. Tests of attention and memory cont‟ oDigit span orepeat 3-52; 3-52-8; 3-52-8-67..” N: >5 o Visual grasp: “look away from stimulus” o Recency test o“recall sequence of stimuli / events” o Imitation (of examiner) / utilization (of objects presented)
  64. 64. Tests of abstraction and judgmento Interpret proverbs (e.g.“the golden hammer opens iron doors”)o Explain why conceptually linked words are the same (e.g. coat & skirt)o Plan & structure a sequential set of activities (“how would you bake a cake?”)o Insight / reaction to own illness
  65. 65. Language tests o Thurstone / word fluency test (“recite as many words beginning with „F‟ in 1 min as you can, then with „A‟, „S‟”); N: >15 o Repetition (Broca‟s vs transcortical) o “Ball” o “Methodist” o “Methodist episcopal” o “No if‟s end‟s or but‟s” o “Around the rugged rock the ragged rascal ran”
  66. 66. MOTOR SEQUENCING: KINETIC MELODY1. Hand position test (three-step hand sequence)2. Rhythm tapping tasks3. Go no go test4. Copying tasks (multiple loops)
  67. 67. FRONTAL RELEASE SIGN Grasp reflex  Snout reflex  Forceful grapping of object on touching palm  Palmomental or sole Sucking reflex  By touching the lips  Glabellar tap Groping reflex  Involuntary following with hand/eye of moving object Stimulus capture  Utilization behavior
  68. 68. Formal Tests• Abstract thinking and set shifting; L>R • Wisconsin Card Sorting Test• Visuo-motor track, conceptualization, set shift • Trail Making• Attention, shift sets; L>R • Stroop Color & Word Test• Planning • Tower of London Test • Block design • Maze lest
  69. 69. 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.”
  70. 70. Trail Making Test 5 B A 4 6 1 C 2 3 D 7Various 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”
  71. 71. Stroop Color and Word TestsRED BLUE ORANGE YELLOWGREEN RED PURPLE REDGREEN YELLOW BLUE REDYELLOW ORANGE RED GREENBLUE GREEN PURPLE RED “Please read this as fast as you can”
  72. 72. Tower of London TestsVarious levels of difficulty:e.g. “Please rearrange the balls on the pegs, so that each peg hasone ball only. Use as few movements as possible”
  73. 73. FRONTAL PATHOLOGY  Injury  Tumor  Abscess, infection  Dementia  Epilepsy  Stroke  Developmental
  74. 74. TRAUMATIC BRAIN INJURYo Gunshot woundo Closed head injury o Widespread stretching and shearing of fibers throughout o Frontal lobe more vulnerableo Contusions and intracerebral hematomas
  75. 75. FRONTAL LOBE INJURYAttention disorder – Language • Distractibility 1. Dynamic aphasiaMemory 2. Normal motor speech • Poor “forgetting to 3. Normal repetition remember” 4. Difficulty inThinking prepositioning  Concrete 5. Difficulty in structuring  Perseveration and sentence stereotypy, 6. Lack of coherence  unable to switch task 7. Socially inappropriate and disinhibited
  76. 76. FRONTAL LOBE INJURY CONT.Mood, affect, behavior 1. Reduced activity 2. Lack of drive and initiative 3. Lack of concern 4. Bouts of restlessness and uncoordinated behavior 5. Apathy, emotional blunting, indifference to the surrounding 6. Bouts of euphoria 7. Disinhibition – irritability and aggression 8. Witzelsucht – inappropriate facetiousness and tendency to pun
  77. 77. FRONTAL LOBE EPILEPSY  Clinical Features  EEG  Frequent seizure with clustering  May show no ictal or interictal  Brief stereotyped seizure abnormality  Nocturnal attacks  May show bilateral spike waves  Sudden onset and cessation  May show focal changes often  Absence of psychic aura widespread  Absence of postictal confusion  Imaging/ pathology  Rapid evolution with awareness  Hemartoma lost at onset  Benign tumors  Prominent complex bilateral motor  Gliomas automatism involving lower limbs  Angioma  Prominent ictal posturing and tonic  Dysplasia spasm  Post traumatic  Versive head and eye turning  Atrophy  Bizarre automatism  Tuberculoma  Frequent secondary generalization  Cysticercosis  Status epilepticus common
  78. 78. FRONTAL LOBE AND PSYCHIATRY Schizophrenia :  Personality disorder:  Involving dorsolateral prefrontal cortex Antisocial Personality  affective changes, disorder with impaired motivation, poor insight. and other impulsivity of frontal "defect symptoms  Evidence : lobe Neuropathologic studies, (23) in EEG studies, (24)  Attention deficit in radiological studies using CT measures, (25) syndrome with with MRI, (26) and in cerebral blood flow distractibility of frontal (CBF) studies. lobe
  79. 79. FRONTAL LOBE DEMENTIA Trouble in maintaining normal  Language Problems social and interpersonal  limited speech output, lack of functioning. speech spontaneity, stereotyping of phrases (ie., use of pat phrases They may violate rules of repeatedly and excessively), politeness and may make perseveration (a meaningless inappropriate remarks. persistence of verbal activity), a They may become emotionally decreased vocabulary, a considerable amount of repetition, aroused very easily. especially of brief words and Insensitivity – lack of consideration phrases. to others.  Often there is jargon and instead of being able to find the word to lack of restraint - stealing or describe an object, the person with unsocial behaviour this disease will give a description Obsession – of it instead (ie., a "watch" referred to as "something you tell the time Sexual misadventures,. with"). This means that the person may not be able to name objects Kluver Bucy Syndrome early in the disease.  hypersexuality, gluttony, and an  Eventually the person becomes obsession to touch and seize any mute for periods and then objects in the persons field of completely mute by the end of the vision. Overeating may lead to disease. considerable weight gain.
  80. 80. VASCULAR DISEASEo Common cause especially in elderlyo ACA territory infarction o Damage to medial frontal areao MCA territory o Dorsolateral frontal lobeo ACom aneurysm rupture o Personality change, emotional disturbance
  81. 81. FRONTAL LOBE DISEASE  Degenerative diseases – Pick‟s disease – Huntington‟s disease  Infectious diseases – Neurosyphilis – Herpes simplex encephalitis
  82. 82. FRONTAL LOBE DISEASE Tumors – Gliomas, meningiomas – subfrontal and olfactory groove meningiomas: profound personality changes and dementia Multiple Sclerosis – Frontal lobes 2nd highest number of plaques – euphoric/depressed mood, Memory problems, cognitive and behavioral effects
  83. 83. FRONTAL LOBE PATHOLOGYFrontal lobe abscess Meningioma
  84. 84. FRONTAL PATHOLOGYTuberous sclerosis Frontal glioblastoma

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