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Ppt parietal lobe

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Ppt parietal lobe

  1. 1. PARIETAL LOBE Presented by Abdul Qavi ANATOMY AND FUNCTIONAL CORRELATION
  2. 2. INTRODUCTION  The parietal cortex is considered as one of the most complex region of human brain which is responsible for the integration of various stimuli .  Have undergone a major expansion in the course of human evolution, largely in the inferior parietal region  Receives, correlates, analyze primary sensory information to interpret stimulus and aid in discrimination and recognition.
  3. 3. Lobe of the hand
  4. 4. Defining thelobes central (rolandic) sulcus sylvyan (lateral) sulcus frontal lobe temporal lobe occipital lobe parietal lobe
  5. 5. BOUNDARIES OF THE PARIETAL LOBE
  6. 6. BOUNDARIES OF THE PARIETAL LOBE – Anterior border - Central Fissure – Ventral border - Sylvian Fissure – Dorsally by the cingulate gyrus – Posterior border - Parieto-occipital sulcus
  7. 7. SULCI AND GYRI ON THE SUPERO LATERAL SURFACE superolateral medial
  8. 8. SULCI AND GYRI ON THE VARIOUS SURFACE OF PARIETAL LOBE SUPERO LATERAL SURACE • Post central gyrus( area 1,2,3) • Superior parietal lobule (area 5,7) • Inferior parietal lobule • Supra marginal gyrus - lies around the upturned end of sylvian fissure. • Angular gyrus – lies around the upturned end of superior temporal gyrus. MEDIAL SURFACE • Supra splenial sulcus – separate the precuneus from cingulate gyrus • Precuneus - lies between parieto occipital sulcus and paracentral lobule • Isthmus – Separates the splenium of corpus callosum from calcarine sulcus
  9. 9. Parietal lobe sulci and gyri  Post central sulcus – posterior boundary of somatosensory cortex.  Intraparietal sulcus behind post central sulcus which divides the parietal lobe into sup. & inf. Parietal lobule  Posterior end of sylvian fissure curves upwards to terminates into inf.parietal lobule – surrounding cortex supramarginal gyrus[SMG 40]Parietal lobe
  10. 10. Parietal lobe sulci and gyri • Posterior end of sup. Temporal sulcus – angular gyrus[AG 39] • SMG & AG =Ecker’s inf Parietal Lobule • Ecker’s IPL & post. Third of first temporal gyrus constitute the wernicke’language area • 3,1,2-primary sensory areas • 5- somatosensory association area • 7-somatosensory or somatosensory/visual
  11. 11. Parietal Topography •Postcentral Gyrus (1,2,3) •Superior Parietal Lobule (5 , 7) •Supramarginal Gyrus (40) •Angular Gyrus ( 39)
  12. 12. Subdivisions of the Parietal Lobes Functional zones Anterior zone -1,2,3, •Somatosensory cortex Posterior zone -remaining areas •Posterior parietal cortex von Economo: Posterior parietal areas •PE (5) •PF(7b) •PG -Polymodal and asymmetric larger in right hemisphere
  13. 13. • Visual processing areas – Intraparietal sulcus (cIPS) • Control of saccadic eye movements – Saccade - involuntary abrupt and rapid small movements made by the eyes when changing the fixation point • Visual control of grasping – Parietal reach regions (PRR) • Visually guided grasping movements Subdivisions of the Parietal Lobes
  14. 14. Somatosensory strip To area PE -Tactile recognition To motor regions -sensory information about limb position and movement •Area PE is somatosensory –Inputs from the somatosensory strip –Outputs to primary motor cortex, supplementary motor cortex, premotor regions, and area PF •Area PF Input from somatosensory, primary motor cortex, premotor cortex, and small visual input through area PG •Area PG –Receives complex connections including visual, somesthetic, proprioceptive, auditory, vestibular, oculomotor, and cingulate connections –Parieto-temporo-occipital crossroads –Part of the Dorsal Stream •Close relation between the posterior parietal connections and the prefrontal Connections of the Parietal Lobes
  15. 15. Connections of the Parietal Lobes
  16. 16. • Anterior zones - process somatic sensations and perceptions • Posterior zones - integrate information from vision with somatosensory information for movement • Spatial Map in the Brain? A Theory of Parietal Lobe Function
  17. 17. NP/MGH NEURO-IMAGING NORMAL CORTICAL ANATOMY • The Central Sulcus • Sagittal • Axial • Coronal
  18. 18. NP/MGH The Central SulcusThe Central Sulcus
  19. 19. NP/MGH • superior frontal sulcus - pre CS sign • sigmoidal Hook sign • pars bracket sign • Bifid post-CS sign • thin postcentral gyrus sign • intraparital sulcus - post-CS • midline sulcus sign The Central Sulcus (CS)* *Naidich & Brightbill. Int J Neurorad 1996;2:313-338*Naidich & Brightbill. Int J Neurorad 1996;2:313-338
  20. 20. NP/MGH • Superior frontal sulcus - preCS sign – the posterior end of the superior frontal sulcus joins the precentral sulcus in 85% The Central Sulcus (CS) Precentral sulcus Superior frontal sulcus Precentral gyrus Central sulcus Superior frontal gyrus Superior frontal sulcus Precentral sulcus Precentral gyrus
  21. 21. NP/MGH • pars bracket sign – The paired pars marginalis form a “bracket” to each side of the interhemispheric fissure at or behind the central sulcus (96%). The Central Sulcus (CS) Precentral sulcus Superior frontal sulcus Precentral gyrus Central sulcus Pars bracket Paracentral lobule
  22. 22. NP/MGH Sigmoid “Hook” – hooklike configuration of the posterior surface of the precentral gyrus – the “hook” corresponds to the motor hand area. – The “hook” is well seen on CT (89%) and MRI (98%). The Central Sulcus (CS)The Central Sulcus (CS) Precentral sulcus Central sulcus
  23. 23. NP/MGH • Bifid post-CS sign – the post-CS is bifid (85%). – The bifid post-CS encloses the lateral end of the pars marginalis (88%). The Central Sulcus (CS) Precentral sulcus Precentral gyrus Central sulcus Postcentral sulcus Pars bracket
  24. 24. NP/MGH Central sulcus Postcentral sulcus Central sulcus Central sulcus Postcentral sulcus Postcentral sulcus Pars bracketPars bracket
  25. 25. NP/MGH Thin post-CG sign – the postcentral gyrus is thinner than the precentral gyrus (98%). The Central Sulcus (CS)The Central Sulcus (CS) Precentral gyrus Postcentral gyrus
  26. 26. NP/MGH Intraparietal Sulcus (IPS) and the post-CS – in axial MRI, the IPS intersects the post-CS (99%). The Central Sulcus (CS)The Central Sulcus (CS) Pars bracket IPS Postcentral sulcus IPS Pars bracket
  27. 27. NP/MGH Postcentral sulcus IP S Postcentral sulcus IP S Postcentral sulcus IP S
  28. 28. NP/MGH SFS-preCS sign Hook sign Pars bracket sign Bifid post-CS sign Thin postcentral gyrus sign IPS - postCS sign The Central Sulcus (CS)The Central Sulcus (CS)
  29. 29. NP/MGH AxialAxial NeuroanatomyNeuroanatomy
  30. 30. NP/MGH Superior Temporal gyrus Middle Temporal gyrus Inferior Temporal gyrus Fusiform gyrus
  31. 31. NP/MGH Superior occipital gyrus Intra-occipital sulcus Middle occipital gyrus Cingulate gyrus Parieto-occipital fissure Calcarine sulcus Cuneus Middle temporal gyrus Superior temporal sulcus Superior temporal gyrus Insula Inferior frontal gyrus, pars orbitalis Superior frontal gyrus Middle frontal gyrus Inferior frontal gyrus, pars opercularis Lateral fissure Lateral fissure Inferior parietal gyrus
  32. 32. NP/MGH Middle occipital gyrus Superior temporal gyrus Intra-occipital sulcus Superior frontal gyrus Central sulcus Superior occipital gyrus Parieto-occipital sulcus Superior temporal sulcus Lateral fissure Inferior parietal gyrus Postcentral gyrus Lateral fissure Middle frontal gyrus Inferior frontal gyrus
  33. 33. NP/MGH Postcentral sulcus Superior frontal sulcus Central sulcus Intraparietal sulcus Superior frontal gyrus Middle frontal gyrus Superior parietal gyrus Centrum semiovale Parietooccipital sulcus Precuneus Angular gyrus Central sulcus Inferior frontal gyrus Supramarginal gyrus Postcentral sulcus
  34. 34. NP/MGH Central sulcus Postcentral sulcus Superior frontal sulcus Precentral sulcus Pars marginalis Intraparietal sulcus Superior frontal gyrus Middle frontal gyrus Precuneus Paracentral lobule Superior parietal gyrus
  35. 35. NP/MGH CoronalCoronal NeuroanatomyNeuroanatomy
  36. 36. NP/MGH Olfactory bulb Gyrus rectus Medial Orbital gyrus Inferior Frontal gyrus Superior Frontal gyrus Middle Frontal gyrus Interhemispheric Fissure Inferior Frontal gyrus
  37. 37. NP/MGH Superior Frontal gyrusSuperior Frontal sulcus Middle Frontal gyrus Superior Temporal Sulcus Sylvian Fissure Amygdala Precentral sulcus Anterior commissure Cingulate sulcus Superior Temporal gyrus Middle Temporal gyrus Inferior Temporal gyrus Precentral gyrus
  38. 38. NP/MGH Paracentral lobule Superior Temporal gyrus Middle Temporal gyrus Inferior Temporal gyrus Central Sulcus Postcentral gyrus Cingulate gyrusIntraparietal sulcus Fusiform gyrus Collateral sulcus Parahippocampal gyrus Supramarginal gyrus Intraparietal sulcus
  39. 39. NP/MGH Superior Temporal gyrus Middle Temporal gyrus Inferior temporal gyrus Fusiform gyrus Central sulcus Paracentral lobule
  40. 40. NP/MGH Lingual gyrus Calcarine sulcus Superior parietal lobule precuneus Cingulate gyrus Tentorium cerebelli Fusiform gyrus Inferior parietal lobule Middle occipital gyrus Inferior occipital gyrus Lingual gyrus Collateral sulcus
  41. 41. NP/MGH SagittalSagittal NeuroanatomyNeuroanatomy
  42. 42. NP/MGH Subcallosal gyrus Gyrus rectus Parietooccipital sulcus Fastigium, fourth ventricle Cingulate gyrus Calcarine sulcus Marginal ramus of Cingulate sulcus precuneus Paracentral lobule Cingulate sulcusSuperior frontal gyrus Cuneus Lingual gyrus
  43. 43. NP/MGH Parietooccipital sulcus Calcarine sulcus Superior parietal lobule Marginal ramus of Cingulate sulcus Central sulcus Precentral sulcus Precuneus Corona radiata Superior frontal gyrus Lingual gyrus Inferior occipital gyrus
  44. 44. NP/MGH Central sulcus Inferior Temporal gyrus Middle Temporal gyrus uperior Temporal gyrus
  45. 45. NP/MGH Gyrus rectus Parietooccipital sulcus Cingulate gyrus Calcarine sulcus Lingual gyrus Marginal ramus of Cingulate sulcus Superior parietal lobule Cingulate sulcus Caudothallamic groove Precuneus Central sulcus Cuneus Precentral gyrus Frontomarginal gyrus Superior frontal gyrus
  46. 46. NP/MGH Inferior Temporal gyrus Superior Temporal sulcus Superior Temporal gyrus Anterior occipital sulcus Superior frontal sulcus Precentral sulcus Central sulcus Postcentral sulcus Angular gyrus Lateral fissure, posterior segment Inferior frontal gyrus, pars orbitalis Middle Temporal gyrus Inferior occipital gyrus Middle occipital gyrus Inferior frontal gyrus, pars triangularis
  47. 47. BLOOD SUPPLY
  48. 48. BLOOD SUPPLY
  49. 49. Primary somatosensory area Location : Post central gyrus(ant parietal lobule) on lateral surface and dorsal aspect of paracentral lobule on medial serface. Broadman area (3 ,1, 2) Representation : contralatral half of body inverted Function: initial reception center for afferent impulses, especially for tactile, pressure, and position sensations. necessary for discriminating finer, more critical grades of sensation and for recognizing intensity. Afferent connections: VP nucleaus of thalamus Outputs: primary motor cortex, contralateral S1,association somatosensory cortex(area 5 & 7), thalamus Deficit: Postural sensation (proprioception), passive movement (kinesthesis), Tactile sensation, Two point discrimination, Astereognosis,High sensory thresholds Functional areas
  50. 50. Somatosensory Homunculus Body presentation
  51. 51. Secondary Somatosensory area Location : superior lip of lateral fissure (parietal operculam) Representation :contralateral side dominant, Bilateral representation Afferent: Intralaminar nuclei and posterior group of nuclei of thalamus Function: not well described, ? Involved in less discriminative aspects of sensation. Lesions: none ascribed, rarely inability to appreciate pain(asymbolia)
  52. 52. Somato-sensory association area: Location : superior parietal lobule. broadmann’s area(5,7) Function : interpretation; similarities and differences, spatial relationships and 2D qualities, variations in form and weight, and localization of sensation • Area 5-, Manipulation of objects Tool use/body image • Area 7- Integration of visual and somato-sensory stimuli, Hand-eye coordination, reaching and grasping,, • Afferent: primary somato-sensory area • Deficit : Impair gnostic (knowing, recognition) aspects of sensation , stereognosis, graphesthesia, two-point discrimination, and tactile localization , poor hand eye coordination, (appreciation of primary sensations remains, but assoc. functions impaired)
  53. 53. Inferior parietal lobule • Location: supramarginal gyrus (40) and angular gyrus (39) • Function:.  Left hemisphere – language ,maths, reading, writing, understanding of symbols.  Right hemisphere—visuo-spatial orientation. • Lesions Aphasia, agnosia, and apraxia and visuspatial defects • A deeply placed parietal lesion may cause either an inferior quadrantic or hemianopic visual field defect
  54. 54. Clinical assesment and testing
  55. 55. Post-Central Gyrus,Dominant or Non-Dominant 1. Impaired Postural sensation (proprioception), passive movement (kinesthesis). 2. Astereognosis 3. Impaired Two point discrimination 4. Agraphesthesia 5. Weight discrimination
  56. 56.  Inability to discriminate size and shape of objects and identify them by touch alone. Tests  Patient identifies by touch such common objects as a coin, paperclip, pencil, or key (each hand tested separately)  Patient judges the relative size of a series of coins  Patient judges the texture of a series of objects, such as cloth, wire, sandpaper Astereognosis (tactile agnosia)
  57. 57. Astereognosis
  58. 58. Graphesthesia  Ability to recognise letters or numbers written on skin with pencil,or dull pin  Testing is often done over the finger pads, palms, or dorsum of the feet  Letters or numbers about 1 cm in height are written on the finger pads, larger elsewhere  clear figures as 8, 4 5 used first, more difficult 6, 9 ,3 can be used as finer tests  Tactile movement sense, directional cutaneous kinesthesia- Ability to tell the direction of movement of a light scratch stimulus drawn for 2 cm to 3 cm across the skin which may be a sensitive indicator of function of the posterior columns and primary somatosensory cortex  Loss of graphesthesia or the sense of tactile movement with intact peripheral sensation implies a cortical lesion, particularly when the loss is unilateral.
  59. 59. Two point discrimination  Ability to differentiate, eyes closed, cutaneous stimulation by one point from stimulation by two points. Instruments: two-point discriminator, electrocardiogram calipers,compass, paper clip bent into “v,” adjusting the two points to different distances. Method  Either one-point or two-point stimuli are delivered randomly, and the minimal distance that can be discerned as two points is determined.  The result is taken as the minimum distance between two points that can be consistently felt separately.  Normal 2-point discrimination - 1 mm (tip of the tongue), 2 mm to 3 mm ( lips), 2 mm to 4 mm ( fingertips), 4 mm to 6 mm (dorsum of the fingers), 8 mm to 12 mm( palm), 20 mm to 30 mm( back of the hand), and 30 mm to 40 mm ( dorsum of the foot).  The findings on the two sides of the body must always be compared.
  60. 60. Superior Parietal Lobule,Dominant or Non-Dominant  cannot reach for objects (optic ataxia) -Balint syndrome  Poor visual guidance of hands, fingers, eyes, and limbs, head (hard time catching a ball)  Hard time directing movement in space (trouble flying a kite)  Hard time distinguishing left from right
  61. 61. Dominant inferior parietal lobule 1. Acalculia 2. Agraphia 3. Left-right confusion 4. Finger agnosia 5. Conductive aphasia 6. Alexia 7. Ideomotor apraxia Gerstmann’s syndrome
  62. 62. Ideomotor apraxia:  failure to perform previously learned motor acts accurately. Results from left hemisphere lesion Usually affects both sides, may be worse on right side Can affect the face (buccofacial) and/or the limbs Tests Carrying out motor acts to command: Buccofacial (blow out a match, protrude tongue, drink through a straw) Limb (salute, use a toothbrush, flip a coin, hammer a nail, comb hair,,snap fingers, kick a ball, crush out a cigarette) Whole body commands(stand like a boxer, swing a baseball bat)
  63. 63. 1. wernicke area 2. Arcuate fasciculus 3. Lt premotor area 4. Lt motor cortex 5. Corpus callosum 6. Rt premotor area 7. Rt motor cortex Ideomotor apraxia:
  64. 64. Ideational apraxia:  Able to carryout individual components of a complex motor act but can not perform the entire sequence properly leading to a goal. Results from left hemisphere lesion ( temporo-parietal)  also seen in generalised cognitive impairment. Tests Carrying out complex motor acts to command: Opening tooth paste, taking tooth brush from holder, and placing toothpaste on brush. How to mail a letter How to drive a car.
  65. 65.  Results from left hemisphere supramarginal gyrus lesion if the underlying arcuate fasciculus is cut  Fluent speech with word finding pauses  Severely defective repetition  Paraphasia in repetition and in spontaneous speech  Normal comprehension and reading  Impaired writing, spontaneous and to dictation, errors in spelling, word choice,  Naming may be mildly impaired Tests  Repetition of words, phrases, & sentences  Write to dictation (letters, words, sentences)  Ask patient to write sentences describing a Job, the weather, or a picture  Confrontation naming of objects, clothing, body parts, parts of objects, colors Conduction aphasia
  66. 66. Finger agnosia:  Inability to recognize, name, and point to individual fingers on self and others  Usually associated with lesion of dominant hemisphere  Lt handed pts may have finger agnosia with lesions of either hemisphere  Limited clinical utility for localisation Tests • Non verbal finger recognition: pt eyes closed, touch pt finger, then ask pt to point same finger on examiner hand • Identification of named fingers on examiner’s hand: examiner’s hand placed in various positions. Ask pt “point to my middle finger” • Verbal identification (naming) of finger on self and examiner: hand placed in various positions, ask pt “what is the name of this finger”
  67. 67. Right-left disorientation  Inability to distinguish right from left on self or env.  More common with left hemisphere lesion  Normal population (9%males, 17% females ) can have difficulty in rt - lt testing Tests • Identification on self(show me your rt foot), • Crossed commands on self(With your rt hand touch your lt shoulder) • Identification on examiner(point to my lt elbow) • Crossed command on examiner(with ur rt hand point to my lt eye)
  68. 68. Acalculia  Loss of ability to understand & order numbers  More severe with left hemisphere lesion  Also note errors in borrowing, alignment , error to particular calculation, Tests Verbal examples(addition, subtraction, multiplication, and division) Eg. 4+6, 8-5, 9*7, 9 /3 Verbal complex problems (allow 20 sec for response) Eg. 14+17, 43-38, 21*5, 128/8 Written complex problems(allow 30 sec for response) 108 605 108 559 +79 -86 *36 /43
  69. 69. Calculation errors Rt hemispheric lesion with lt neglect Rt parietal bleed , poor alignment, calculation errors Alzeimers ds, rote multiplication good but basic arithmatic disturbed
  70. 70.  Diagnosed when pt demonstrate basic language errors, gross spelling errors, or use of paragraphias (word or syllable substitution) Test First, ask patient to write letters and numbers to dictation. Second , ask the pt write names of common objects or body parts Third , if pt can successfully write single words , ask them to write sentence describing his job , whether, or picture from magazine Agraphia Results from damage to the angular gyrus itself and renders the patient unable to understand the written words and write. Pt are not appreciably aphasic but anomia may be present Alexia
  71. 71. Non-dominant inferior parietal lobule 1. Constructional apraxia 2. Dressing apraxia 3. Contralateral Neglect 4. Topographic disorientation 5. Phonagnosia- 6. Amusia . 7. Somatoperceptual disorders(Asomatognosia, Anosagnosia) 8. Sensory extinction or inattention
  72. 72.  Inability to draw or construct 2 or 3D figures or shapes in presence of normal strength, coordination, sensation , comprehension.  More common and severe with right non dominant parietal lesion than left. Tests  Reproduction drawings (both 2D and 3D drawings as vertical diamond, 2D cross, 3D block, 3D pipe, triangle within triangle are used). Scoring done from poor (0) to excellent (3)  Drawings to command(clock with numbers and hands, daisy in flowerpot, house with 2 sides and roof). Constructional apraxia
  73. 73. Constructional apraxia Scoring Interpretation Poor (0) Non recognizable,gross distortion Fair(1) Mod distorted or rotated 2D and loss 3Dimensionality Good(2) Minimal distortion Excellent(3) Perfect or near perfect Rating 0 is 100% probability and Rating 1 is 80% prob of brain damage Vertical diamond
  74. 74. Constructional apraxia Reproduction drawings 2D cross test 3 D cube test 3 D pipe test Triangle within triangle
  75. 75. Drawings to command Constructional apraxia clock Flower pot House in perspective
  76. 76. Constructional apraxia Block designs Common errors Rt lt rotation Near far rotation Figure ground or color reversal
  77. 77. Interpretation Specific errors pathognomic of brain damage (non retarded, age > 10 yrs) 1. Rotation by >45 degree 2. Perseveration or repitition of figure 3. FragmentatIon of design Constructional apraxia
  78. 78. Dressing apraxia Unable to properly clothe themselves Most often leaves lt side partly undressed MC with Rt nondominant parietal lesions Associated with impaired tactile and visuospatial coordination Considered as part of neglect syndrome
  79. 79. Contralateral Neglect and denial Neglect for visual, auditory, and somesthetic stimulation on one side of the body or space Examples: 1.pt draw clock ,house flower with missing lt side 2.If pt asked to read foot ball or ice cream he will read “ ball” and“cream” 3.May shave only the right side of his face 4.May not use one side of body even if no weakness May be associated with denial disorder 1.Anosognosia-Unawareness or denial of illness in presence of obvious disability
  80. 80. Sensory extinction or inattention Loss of the ability to perceive two simultaneous sensory stimuli Double simultaneous light touch stimuli at homologous sites on the two sides of the body . Extinction can also be done on one side. In general the more rostral area is the dominant one; (the face hand test). It may be normal to extinguish the hand stimulus. Most commonly occurs with lesions of the inferior parietal lobule but may also occur with lesions of the temporoparietaloccipital junction, thalamus, and mesencephalic reticular formation .These areas have shown activation in attentional tasks Lesions causing hemispatial neglect are similar to those causing inattention and extinction
  81. 81. Sensory extinction or inattention
  82. 82. Topographic disorientation Inability to find way to familiar environments, localize places on maps, and find his way to new environment Evaluation History obtained from family- 1.Does pt lost at neighbourhood, or home? 2.Has pt lost travelling less frequent location? 3.Does pt have difficulty orienting new environment?  Localizing places on maps Ask pt to draw map of India, if pt can’t draw, doctor should draw map Ask pt to locate cities on map eg. Delhi, mumbai, calcutta 1.Are cities located in appropriate states, ? 2.Are cities located on one half of map(either east or west)? Ability to orient self in hospital environment ask nurses staff regarding pt capacity to find their bed, ward, bathroom
  83. 83. Clinical syndromes Either hemisphere 1. Cortical -sensory syndrome & sensory extinction 2. Total hemi anesthesia may occur 3. Mild hemiparesis, unilateral muscular atrophy in children, hypotonia, slowness of movements, hemiataxia, pseudoathetosis of opposite side 4. Homonymous hemianopia, visual inattention , anosognosia, hemineglect (with right>left lesion) 5. Abolition of optokinetic nystagmus with target moving towards
  84. 84. Right hemisphere Left Hemisphere Topographic disorientation Visuospatial disorders Gerstman’s syndrome (Angular gyrus) Acalculia, Finger agnosia, Lt/rt disorientation, Agraphia Hemi inattention Tactile agnosia (bimanual asteriognosis) Anosognosia Bilateral Ideomotor & ideational apraxia Constructional apraxia, /dressing apraxia Disorder of language especially alexia
  85. 85. Take home message  Both parietal lobes have equal processing capabilities for light touch, tactile localization, 2-point discrimination, joint position sense, passive movement sense, and stereognosis. Language and sequential analysis ability are strongly lateralized to the left inferior parietal lobe Spatial abilities are strongly lateralized than language. Both parietal lobes have substantial spatial abilities, with the right being superior Lesions to the parietal lobe are seldom localized to one particular quadrant (e.g. inferior, superior), or even restricted to the parietal lobe. Even after assessment of clinical symptom and signs it is difficult to ascertain all signs to particular area of the parietal lobe.
  86. 86. Questions and Answers
  87. 87. 1- Which one is not a part of parietal lobe a) Angular gyrus b) Gyrus rectus c) Supramarginal gyrus d) Precuneus Ans: b) Gyrus rectus
  88. 88. 2- Supramarginal gyrus corresponds to Brodmans area- a) 39 b) 40 c) 44 d) 42 Ans: b) 40
  89. 89. 3- Sigmoid Hook sign denotes- a) Central sulcus b) Precentral sulcus c) Calcarine sulcus d) Parieto-occipital sulcus Ans: a) Central sulcus
  90. 90. 4- All are functions of parietal lobe except- a) Stereognosis b) Proprioception c) Two point discrimination d) Prosody Ans: d) Prosody
  91. 91. 5- Inferior quadrantanopia occurs in lesion of- a) Frontal lobe b) Occipital lobe c) Parietal lobe d) Temporal lobe Ans: c) Parietal lobe
  92. 92. 6- Normal two point discrmination for the ‘tip of tongue’ is- a) 2-3 mm b) 4-6 mm c) 1 mm d) 6-8 mm Ans: a) 2-3 mm
  93. 93. 7- Gerstman syndrome include all except- a) Finger agnosia b) Agraphia c) Acalculia d) Aphasia Ans: d) Aphasia
  94. 94. 8- Conduction aphasia occurs in lesion of- a) Cuneus b) Paracentral lobule c) Angular gyrus d) Arcuate facsiculus Ans: d) Arcuate facsiculus
  95. 95. 9- Which one is not seen in lesion of non- dominant inferior parietal lobule lesion - a) Ideomotor apraxia b) Dressing apraxia c) Constructional apraxia d) Atopographia Ans: a) Ideomotor apraxia
  96. 96. 10- Unawareness or denial of illness (hemiplegia) is called as- a) Anosognosia b) Asomatognosia c) Anosodiaphoria d) Autotopagnosia Ans: a) Anosognosia

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