פרק 21 Chapter 21: Neurologic Disorders Caused by Lesions in Specific Parts of the Cerebrum Flashcards

1
Q

תסמונת Kluver bucy

A

Kluver-Bucy syndrome: compulsion to attend to all visual stimuli, hyperorality, hypersexuality, blunted emotional reactivity; the full syndrome is rarely seen in humans.

it results from total bilateral temporal lobectomy in adult rhesus monkeys (see also Chap. 21). While these animals were made rather placid and lacked the ability to recognize objects visually (they could not distinguish edible from inedible objects), they had a striking tendency to examine everything orally, were unusually alert and responsive to visual stimuli (they touched or mouthed every object within their visual fields), became hypersexual, and increased their food intake.
This complete constellation of behavioral changes has occurred only infrequently in human beings, for example, after removal of the temporal lobes (Marlowe et al; Terzian and Dalle). Pillieri and Poeck (1969) have collected cases that have come closest to reproducing the syndrome (Fig. 243). Many human examples have occurred in conjunction with diffuse diseases (Alzheimer and Pick cerebral atrophies, meningoencephalitis because of toxoplasmosis, herpes simplex, and AIDS) and hence are of limited value for anatomic analysis. With bitemporal surgical ablations, placidity and enhanced oral behavior were the most frequent consequences; altered sexual behavior and visual agnosia were less frequent. In all patients who showed placidity and an amnesic state, the hippocampi and medial parts of the temporal lobe had been destroyed, but not the amygdaloid nuclei.

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2
Q

נזק לאונות הטמפורליות עלול לגרום לכל הליקויים הבאים פרט ל:
1. cortical deafness
2. agnosia for sounds
3. wernicke-aphasia
4. homonymoua upper quadrant anopsia
5. sympathetic apraxia

A
  1. sympathetic apraxia
    “sympathetic apraxia”. particular, in a right-handed person, a lesion in the left frontal lobe that includes Broca’s area, the left motor cortex, and the deep underlying white matter may cause left-limb apraxia. Clinically, there is a nonfluent aphasia, a right hemiparesis, and clumsiness of the non­ paralyzed left hand.
    (ACA territory involving pre-motor cortex)
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3
Q
A

ד. optic apraxia

Balint Syndrome- Simultagnosia, optic ataxia, occular apraxia
Failure to understand the meaning of an entire picture
even though some of its parts are recognized is referred to
as simultanagnosia, and is found in bilateral lesions of the
occipital-parietal junction
. When combined with deficits
in visual control of eye and hand movements (optic ataxia
and ocular apraxia)
, the resulting condition is referred to
as Balint syndrome and it is strictly speaking, a
bilateral disorder of the parietal lobe

Effects of bilateral disease of the parietal lobes
Balint syndrome: visual-spatial imperception (simultagnosia),
optic apraxia (difficulty directing gaze),
and optic ataxia (difficulty reaching for objects)
In almost all reported cases of the Balint syndrome, the lesions have been bilateral, mainly in the vascular border zones (areas 19 and 7) of the parietooccipital
regions,

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4
Q

מטופל לא מצליח לזהות אותיות ולקרוא. איפה הפגיעה?

A

calcarine + angular gyrus of dominant hemisphere

The ability to recognize visually presented objects and words depends on the integrity not only of the visual pathways and primary visual area of the cerebral cortex (area 17 of Brodmann) but also of those cortical areas that lie just anterior to area 17 (areas 18 and 19 of the occipital lobe and area 39—the angular gyrus of the dominant hemisphere). Blindness that is the result of destruction of both visual and adjacent regions of the occipital lobes is termed cortical or cerebral blindness. Another remarkable condition exists in which the patient denies or is oblivious to blindness despite overt manifestations of the defect (Anton syndrome).

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5
Q

חולה מתלונן שרואה אובייקט מספר רב של פעמים.
איפה הפגיעה?

A

אונה אוקסיפיטלית ימנית

Polyopia, the perception of
multiple images when a single stimulus is presented, is
said to be associated predominantly with right occipital
lesions and can occur with either eye
. Usually there is one
primary and a number of secondary images, and their
relationships may be constant or changing.

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6
Q

מהי תסמונת
GERSTMAN

A
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7
Q

פגיעות טמפורליות

A
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8
Q

פגיעות פריאטליות

A
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9
Q

תיאור של constructional apraxia – איזה מיקום מתאים ?
1. פריאטלי דומיננטי
2. פריאטלי לא דומיננטי
3. טמפורלי דומיננטי
4. פרונטלי דוצ

A

פריאטלי לא דומיננטי

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10
Q

מטופל עם פרכוס שמקורו פריאטלי שמאלי
1. אפרקסיה
2. הזית ריח
3. הזית שמיעה
4. בעיה מרחבית

A

APRAXIA

(הזית ריח ושמיעה= טמפורלי)
(בעיה מרחבית= פריאטלי ימני)

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11
Q

מטופל שלא מצליח להוציא עט מהכיס כמבקשים ממנו וגם לא כשמדגימים לו. מחוץ לחדר הבדיקה הוא נצפה מוציא את העט מהכיס בכדי לחתום על מסמך. בהנחה שלא מדובר בהתחזות, במה מדובר?
1. אפרקסיה Limb Kinetic
2. אפרקסיה Ideational
3. אפרקסיה Ideomotor
4. אפרקסיה Constructional

A

IDEATIONAL APRAXIA-
what to do

בצורה להדיוטות איך להבדיל.
עומד מולי אדם ואני רוצה לבדוק איזו סוג אפרקסיה יש לו אידיומוטור או אידיאשונל.
אני אומרת לו: תסביר לי בבקשה איך מצחצחים שיניים:
ideomotor- יסביר לי בצורה מדוייקת איך מרימים את המברשת שמים עליה משחה מקרבים לפה ומצחצים שיניים
ideational- לא ידע להסביר לי מה השלבים או יסביר לי שלבים לא נכונים.

בשלב הבא אני מניחה מול המטופל מברשת שיניים על השולחן ואומרת לו- תדגים לי איך מצחצחים שיניים
ideomotor- ייקח את מברשת השיניים ויכניס אותה לכיס (כלומר לא יודע מה לעשות או עושה לא נכון)
ideational- ייקח את מברשת השיניים ויכניס אותה לכיס (כלומר לא יודע מה לעשות או עושה לא נכון)

בשלב השלישי לאחר ארוחה טעימה עם הרבה פטרוזיליה ושום המטופל מרגיש שהפה שלו מסריח ושהגיע הזמן לצחצח שיניים.
ideomotor- ייקח את מברשת השיניים ויכניס אותה לכיס (כלומר לא יודע מה לעשות או עושה לא נכון)
ideational- ילך למראה ויבצע את כל השלבים המדוקדקים של צחצוח שיניים.

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12
Q

בבדיקה נוירולוגית של בן 70 המתלונן שמתקשה לפקוח עיניים נמצאו הממצאים הבאים: אינו פוקח את
עיניו לפקודה, אך בפקיחה פסיבית של עיניו הן נותרות פקוחות.
מהי הסיבה לתופעה זו?
א. Conversion disorder
ב. Lid apraxia
ג. Midbrain lesion
ד. Myasthenia gravis

A

LID APRAXIA

common disorder of motor behavior of the eyelids is seen in many patients with large acute lesions of the right parietal lobe. Its mildest form is a disinclination to open the lids when the patient is spoken to. This gives the erroneous impression that the patient is drowsy or stuporous, but it will be found that a quick reply is given to whispered questions. In more severe cases, the lids are held shut and opening them is strongly resisted, to the point of making an examination of the pupils and fundi impossible.

Effects of unilateral disease of the nondominant (right) parietal lobe
A. Visuospatial disorders
B. Topographic memory loss
C. Anosognosia, dressing, and constructional apraxias (these disorders may occur with lesions of either hemisphere but are observed more frequently and are of greater severity with lesions of the nondominant one)
D. Confusion
E. Tendency to keep the eyes closed, resist lid opening, and blepharospasm

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13
Q

פגיעות פרונטליות

A
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14
Q

איזו תופעה מאפיינת פגיעה פרונטלית שמאלית באדם בעל יד דומיננטית ימנית?
א. dressing apraxia
ב. ideational apraxia
ג. ideomotor apraxia
ד. sympathetic apraxia

A

sympathetic apraxia

שאר סוגי האפרקסיות שמתוארות בשאלה הינם ממקור פריאטלי

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15
Q

איזו תופעה עשויה להתאים להתנהגות פרונטלית אצל נבדק בזמן בדיקת Mini-mental
א. לא זוכר אף מילה מרשימה של 3 מילים לאחר השהייה
ב. מדווח על הזיות ראייה בזמן הבדיקה
ג. יזכר בשלוש מילים, וחוזר למטלה של serial 7
ד. מתקשה לצייר מחומשים חופפים ומבקש עזרה

A

WORKING MEMORY – PREFRONTAL ,MEDIAL TEMPORAL LOBES ,DORSOMEDIAL THALAMUS
ב –occipital temporal
ד-constructional -parietal

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16
Q
A

conductive aphasia (supramarginal gyrus or insula)

clinical effects of frontal lobe lesions (1) motor abnormalities related to the prerolandic motor cortex; (2) speech and language disorders related to the dominant frontal lobe,; (3) incontinence of bladder and bowel; (4) impairment of capacity for goal-directed sustained mental activity (abulia), and the ability to shift from one line of thought or action to another, that is, aspects of attention manifest as impersistence and perseveration; (5) akinesia and lack of initiative and spontaneity (apathy and abulia); (6) changes in personality, particularly in mood and self-control (disinhibition of behavior); and (7) an abnormality of gait that has proved difficult to characterize

17
Q

פגיעות טמפורליות

A
18
Q

הזיותשמיעהמאורגנותנמשכותשעותנשמעותכמומקהלהשמכוונתאתהכלים,החולהמודעלכךשזהלאאמיתי,מההפגיעה?
א.דימוםבפונס
ב.AVMפורנטלי
ג.פרכוסיםטמפורלים
ד.פירכוס אוקסיפיטלי

A

דימום בפונס.

19
Q

מטופלהתקבלבתמונהשלאירועיםחוזריםשלניתוקהמלווהבורטיגו,נמשךלזמןקצר.איפההמקורהמוחי:
א.אורביטופרונטלי
ב. קורטקס טמפורלי אחורי
ג. קורטקסאינסולרי
ד. אוקסיפיטלי

A

קורטקס טמפורלי אחורי

20
Q

איזה איזור במוח אחראי על תפיסת תחושת זמן
1. אונה טמפורלית
2. אונה פריאטלית
3. אונה פרונטלית
4. אונה אוקסיפיטלית

A

אונה טמפורלית
The symptoms that arise as a consequence of diseaseof the temporal lobes may be divided into disorders of: (1) special senses (visual, auditory, olfactory, and gustatory), (2), language, (3) memory and time perception, (4) emotion, and behavior.

Clinical Effects of Temporal Lobe Lesions
* Visual Disorders
* Cortical Deafness
* Auditory Agnosia
* Word Deafness (Auditory Verbal Agnosia)
* Auditory Illusions and Hallucinations
* Vestibular Disturbances
* Disturbances of Time Perception
* Disturbances of Smell and Taste
* Other (Nonauditory) Temporal Lobe Syndromes

21
Q

חולה עם הרפס אנצפליטיס ובEEG גלים חדים וזיזים טמפורלי חד צידי. ממה יסבול בנוסף?
1. קוואדרנטאנופיה תחתונה קונטרה-לטרלית
2. אפזיה מוטורית מבודדת
3. קוואדריאנופיה עליונה קונטראלטרלית

A

PIE IN THE SKY

Herpes-temporal –pie in the sky
Aphasia is frontal lobe
Parietal –pie in the floor

22
Q

תיאור של מטופלת שהולכת לרופא אאג כי לא “שומעת “ טוב - לא מבינה מה שאומרים לה. כן מבינה מה שכותבים לה. מצלצל לה הטלפון והיא שומעת שהוא מצלצל ועונה, אבל לא מבינה מה שאומרים לה. איפה הפגיעה?
1. פוזיפורם ג׳ירוס
2. אנגולר ג׳רוס
3. פרה-מוטור קוטרוקס
4. סופריור טמפורל גירוס

A

Pure word deafness
This defect has been attributed to a subcortical lesion of the left temporal lobe, spanning the Wernicke area and interrupting also those auditory fibers that cross in the corpus callosum from the opposite side. Thus, there is a failure to activate the left auditory language area (Wernicke area). Bilateral lesions of the auditory cortex have the same effect.
—–
fusiform gyrus- prosopagnosia
angular gyrus-gerstman

23
Q

a lesion in what lobe will cause
“word deafness, amusia, and auditory agnosia”?

A

left temporal lobe

Auditory Agnosia:
Lesions of secondary zones of auditory cortex area 21,22 – have no effect on perception of sounds or pure tones, however **appreciation of complex combinations severely impaired **– auditory agnosia: inability to recognise sounds, different muscal tones- amusia, word deafness.
Agnosia for sounds: usually associated with word deafness or with amusia
– if pure sounds agnosia – lesion in Right Temporal Lobe Amusia: right temporal lobe – important for recognition of harmony and melody (in the absence of words),
Left temporal and frontal lobe - writing and reading of music- Word deafness: left temporal lobe

Cortical deafness:
Bilateral lesions of temporal lobe (posteriosuperior surface of temporal lobe - gyri of heschl) – central deafness. May also occur in subcortical lesions interrupting fibers from medial geniculate bodies to transverse gyri)

24
Q

איזה צמד מהבאים אינו נכון?
1. פגיעה פריאטלית ימנית גורמת לנגלקט דו”צ
2. פגיעה פריאטלית שמאלית גורמת לנגלקט ימני
3. פגיעה בסופריור פריאטל לוביול גורמת לאנוזוגנוזיה
4. פגיעה באונה טמפורלית גורמת לפגיעה בתפיסת הזמן
5. פגיעה באונה טמפורלית גורמת לסימולטאגנוזיה

A

  • With regards to 1: The question of bilateral sensory deficits as a result of lesions in only one postcentral parietal lobe bilateral disturbances in nearly half of their patients with unilateral lesions, but the deficits were always more severe contralaterally and mainly in the hand and therefore the ipsilateral effect is rarely evident in clinical work.
  • with regards to 2 Unilateral spatial neglect is brought out by having the patient bisect a line, draw a daisy or a clock, or name all the objects in the room. Homonymous hemianopia and varying degrees of hemiparesis may or may not be present and interfere with the interpretation of the lack of application on the left side of the drawing.
    Clinical observations indicate that patients with right parietal lesions show variable but lesser elements of ipsilateral neglect in addition to the striking degree of contralateral neglect, suggesting that, in respect to spatial attention, the right parietal lobe is truly dominant- כלומר זה נכון אבל פחות.
  • With regards to answer 3: The lesion responsible for the various forms of one-sided
    Anosognosia
    lies in the cortex and white matter of the superior parietal lobule. Rarely, a deep lesion of the ventrolateral thalamus and the juxtaposed white matter of the parietal lobe will produce a similar contralateral
    Neglect
    . Unilateral asomatognosia is many times more frequent with right (nondominant) parietal lesions as with left-sided ones. The apparent infrequency of right-sided agnosic symptoms with left parietal lesions is attributable in part, but not entirely, to their obscuration by an associated
    aphasia.
  • Effects of bilateral disease of the parietal lobes ** Balint syndrome**: visual-spatial imperception (simultagnosia), optic apraxia (difficulty directing gaze), and optic ataxia (difficulty reaching for objects).
    Failure to understand the meaning of an entire picture even though some of its parts are recognized is referred to as simultanagnosia, and is found in bilateral lesions of the occipital-parietal junction. When combined with deficits in visual control of eye and hand movements (optic ataxia and ocular apraxia), the resulting condition is referred to as Balint syndrome. A failure to recognize familiar faces is called prosopagnosia and typically results from occipital-parietal lesions
25
Q

איש שרואה פרצופים של אנשים שזה עתה יצאו מהחדר. מה התופעה?
1. הלוצינציות מורכבות
2. פרוזופגנוזיה
3. אליס בארץ הפלאות
4. פאלינופסיה

A

פאלינופסיה

  • Teleposia – הפרעה בעומק התמונה,
  • micropsia - רואים קטן יותר מהרגיל,
  • macropsia – ההיפך.
    במידה ומונאוקולרית יש לחשוד בהפרעה רטינלית. במידה ודו”צ כנראה ומכוונים לפרכוס טמרפורלי
  • Palinopsia – מריחה של התמונה, מתרחש בנגעים פאריטואוקסיפיטליים. ייתכן תוצאה של פרכוס, אך גם בעת גידול או שבץ.
  • Tortosopia – פגיעה בגרעין הוסטיבולרי, גורם לחפצים להיראות מוטים הצידה, או אפילו הפוכים. (ייתכן גם בפגיעה פאריטאלית).

Other cerebral disturbances of vision include various types of distortion in which images seem to recede into the distance (teleopsia), appear too small (micropsia), or, less frequently, seem too large (macropsia). If such distortions are perceived with only one eye, a retinal lesion should be suspected. If perceived with both eyes, they usually signify disease of the temporal lobes, in which case the visual disturbances tend to occur in attacks and are accompanied by other manifestations of temporal lobe seizures. Palinopsia, a persistence of repetitive afterimages, similar to the appearance of a celluloid movie strip, occurs with right parietooccipital lesions; it has been a consequence of seizures in the cases we have encountered, but instances associated with static disorders (tumor, infarction) have been described as well

26
Q
A

הלוצינציות ראייה בהן האדם מודע לכך שאינן אמיתיות
Subthalamic and midbrain lesions may give rise to visual hallucinations that are not unpleasant and are accompanied by good insight (“peduncular hallucinosis” of Lhermitte).

Formed or complex visual hallucinations (of people, animals, landscapes) are observed in a variety of conditions, notably in old age when vision fails (Charles Bonnet syndrome),, in the withdrawal state following chronic intoxication with alcohol and other sedative-hypnotic drugs, in Alzheimer disease, and in infarcts of the occipitoparietal or occipitotemporal regions (release hallucinations) or the diencephalon (“peduncular hallucinosis”).
Electrical stimulation studies of the human cerebral cortex during surgical exploration and studies by positron emission tomography (PET) have emphasized the importance of the temporal lobe in the genesis of complex visual, auditory, and olfactory hallucinations. For reasons not easily explained, with pontine-midbrain lesions, there may be unformed auditory hallucinations.

27
Q

תיאור של הלוצינציה עם חיות זזות. מה מיקום הפגיעה?
א. טמפורלי
ב. אוקסיפיטלי
ג. פרונטלי

A

Formed hallucinations usually temporal

Visual Hallucinations
These phenomena may be elementary or complex, and both types have sensory as well as cognitive aspects. Elementary (or unformed) hallucinations include flashes of light, colors, luminous points, stars, multiple lights (like candles), and geometric forms (circles, squares, and hexagons). They may be stationary or moving (zigzag, oscillations, vibrations, or pulsations). They are much the same as stimulating the calcarine cortex in a conscious patient. Complex (formed) hallucinations include objects, persons, or animals and infrequently, more complete scenes that are indicative of lesions in the visual association areas or their connections with the temporal lobes. They may be of natural size, Lilliputian, or grossly enlarged. With hemianopia, they appear in the defective field or move from the intact field toward the hemianopic one. The patient may realize that the hallucinations are false experiences or may be convinced of their reality. Because the patient’s response is usually in accord with the nature of the hallucination, he may react with fear to a threatening vision or casually if its content is benign.

28
Q

מטופל שלא מזהה פירות וירקות בראיה אבל מזהה לפי הריח, איפה הפגיעה?
1. זרימה ונטרלית מהאונה האקוסיפיטלית.
2. זרימה דורסלית מהאונה האוקסיפיטלית
3. פגיעה דו צידית בקטבים האוקסיפיטליים
4. פגיעה ב- superior longitudinal fasciculus

A

זרימה ונטרלית מהאונה האוקסיפיטלית
טמפורלי the what פריאטלי the where

איך לזכור-
* Parietal dorsal stream the where- I open the door (dorsal) and ask Where (where) the Puck (parietal) am i
* Temporal ventral stream the what- What Temperature does this Vered (ורד) need

29
Q

בת 50 אחרי טראומה מוחית, הפסיקה לזהות פנים מוכרות והפסיקה לברך לשלום אנשים מוכרים. איזה מהמבנים פגוע?
1. hippocampal gyrus
2. fusiform gyrus
3. calcarine
4. cingulate gyrus
5. superior temporal gyrus

A

fusiform gyrus= prosopagnosia

Prosopagnosia This term (from the Greek prosopon, “face,” and gnosis, “knowledge”) type of visual defect in which the patient cannot identify a familiar face by looking at either the person or a picture, cannot learn to recognize new faces. They may also be unable to interpret the meaning of facial expressions or to judge the ages or distinguish the genders of faces. In identifying persons, the patient depends on other data, such as the presence and type of glasses or moustache, the type of gait, or sound of the voice. Similarly, species of animals and birds and specific models or types of cars cannot be distinguished from one another, but the patient can still recognize an animal, bird, or car as such. Other agnosias may be present in such cases (color agnosia, simultanagnosia) and there may be topographic disorientation, disturbances of body schema, and constructional or dressing apraxia. Visual field defects are nearly always present. Some neurologists have interpreted this condition as a simultanagnosia involving facial features. Another view is that the face, though satisfactorily perceived, cannot be matched to a memory store of faces.
The small number of cases that have been studied anatomically and by CT and MRI indicate that prosopagnosia is most often associated with bilateral lesions of the ventromedial occipitotemporal including the inferior occipital or midfusiform gyri, but there are exceptions that are attributable to unilateral damage, almost always on the right side. The notion that there is a “face area” in the fusiform gyrus is expressed uncritically in the literature and seems to be an oversimplification.
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* Damasio has drawn attention to a group of acquired deficits of color perception with preservation of form vision, the result of focal damage (usually infarction) of the visual association cortex, and subjacent white matter. Color vision may be lost in a quadrant, half of the visual field, or the entire field. The latter, or full-field achromatopsia,
is the result of bilateral occipitotemporal lesions
involving the fusiform and lingual gyri, a localization that accounts for its frequent association with visual agnosia (especially prosopagnosia) and some degree of visual field defect.
* A lesion restricted to the inferior
part of the right occipitotemporal region
, sparing both the optic radiations and striate cortex, causes the purest form of achromatopsia (left hemiachromatopsia). With a similar left-sided lesion, alexia may be associated with the right hemiachromatopsia.

30
Q

פגיעות אוקסיפיטליות

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31
Q

מהי ההגדרה של אגנוזיה ויזואלית?

A

the patient cannot understand the meaning of what he sees, i.e., visual agnosia. Primary visual perception is more or less intact, and the patient may accurately describe the shape, color, and size of objects and draw copies of them. Despite this, he cannot identify the objects unless he hears, smells, tastes, or palpates them

32
Q

היכן ממוקמת הפגיעה המוחית בחולה המתקשה לכוון את המבט למיקום מסויים, מתקשה לכוון את היד
לחפץ ולא מסוגל לתאר את מכלול התמונה שיש לה מספר פריטים?
א. Bilateral parieto-occipital lobes
ב. lobe Dominant temporo-occipital
ג. Non dominant parietal lobe
ד. Splenium of corpus callosum

A

bilateral parieto-occipital lobes

An important and not infrequent disorder of visual Agnosia, a disorder of visually directed reaching with the Hand, difficulty directing gaze, and simultanagnosia, is given the name Balint syndrome. It is, strictly speaking, a
bilateral disorder of the parietal lobes.

Balint syndrome-
In this not uncommon syndrome, the appreciation of a coherent and detailed visual world is disrupted and the patient perceives only disconnected individual parts of the scene,
as in the visual simultanagnosia described earlier. While it is due to lesions that span the occipital and parietal Lobes, The defect is noted when the patient describes a complex scene in a disjointed way, single objects being pointed out, others missed entirely, the relationships and context of parts of the picture remaining unappreciated. The entire syndrome consists of (1) a disorder of visual attention mainly to the periphery of the visual field, in which the totality of a scene is not perceived despite preservation of vision for individual elements (visual simultanagnosia as discussed earlier); (2) difficulty in grasping or touching an object under visual guidance, as though hand and eye were not coordinated (called by Balint optic ataxia); and (3) an inability to project gaze voluntarily into the peripheral field and to scan it despite the fact that eye movements are full (termed psychic paralysis of fixation of gaze by Balint, incorrectly called optic apraxia)

33
Q

Figure 21-1. Photograph of the lateral surface of the human brain. (Reproduced by permission from Carpenter MB, Sutin J: Human
Neuroanatomy, 8th ed. Baltimore, Williams & Wilkins, 1982.)

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34
Q

Figure 21-2. Cytoarchitectural zones of the human cerebral cortex according to Brodmann.
A. Lateral surface.
B. Medial surface.
C. Basal inferior surface.
The functional zones of the cortex are illustrated in Fig. 21-3.

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35
Q

Figure 21-3. A and B. Approximate distribution of functional zones on lateral (A) and medial (B) aspects of the cerebral cortex. Abbreviations: A1, primary auditory cortex; AA, auditory association cortex; AG, angular gyrus; CG, cingulate cortex; IPL, inferior parietal lobule; IT, inferior temporal gyrus; M1, primary motor area; MA, motor association cortex; MPO, medial parietooccipital area; MT, middle temporal gyrus; OF, orbitofrontal region; PC, prefrontal cortex; PH, parahippocampal region; PO, parolfactory area; PS, peristriate cortex; RS, retrosplenial area; S1, primary somatosensory area; SA, somatosensory association cortex; SG, supramarginal gyrus; SPL, superior parietal lobule; ST, superior temporal gyrus; TP, temporopolar cortex; V1, primary visual cortex; VA, visual association cortex. (Redrawn by permission from M-M Mesulam.)

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36
Q

Figure 21-4. The basic cytoarchitecture of the cerebral cortex, adapted from Brodmann. The six basic cell layers are indicated on the left, and the fiber layers on the right (see text).

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37
Q

Figure 21-5. Four fundamental types of cerebral cortex and their distribution in the cerebrum. The primary visual cortex has a preponderance of small neurons; hence, it was historically called “granular.” The primary motor cortex, by contrast, has relatively fewer small neurons and was described as “agranular.” (Reproduced with permission from Kandel ER, Schwartz JH, Jessel TM:
Principles of Neural Science, 4th ed.
New York, McGraw-Hill, 2000.)

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38
Q

Figure 21-6. Connections involved in naming a seen object and in reading. The visual pattern is transferred from the visual cortex and association areas to the angular gyrus, which arouses the auditory pattern in the Wernicke area. The auditory pattern is transmitted to the Broca area through the arcuate fasciculus, where the articulatory form is aroused and transferred to the contiguous face area of the motor cortex. With destruction of the left visual cortex and splenium (or intervening white matter), the words perceived in the right visual cortex cannot cross over to the language areas and the patient cannot read.

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