Unit 3 Syndromes

Question 1

Scotomas

Answer 1

• Blind spots in opposite visual field
• Caused by small lesions of V1 in occipital lobe

Question 2

Quadrantopsia

Answer 2

• Loss of contralateral visual field quadrant
• Caused by medium lesions of V1 in occipital lobe

Question 3

Hemianopsia

Answer 3

• Whole contralateral visual field loss
• Caused by large lesions of V1 in occipital lobe

Question 4

Visual Form Agnosia

Answer 4

• Inability to recognize objects, discriminate between simple geometric shapes and orientation
• Caused by lesions to the ventral stream
• More specifically, lesions of ventromedial occipitotemporal cortex (fusiform and lingual gyri)
  
  • LEFT posterior IT lesion: alexia with agraphia
    
    • Alexia = unable to understand written words (reading)
    • Agraphia = loss in ability to communicate through writing
  • RIGHT IT cortex (fusiform gyrus): prosopagnosia
    
    • Unable to recognize faces

Question 5

Balint’s Syndrome

Answer 5

• Lesions to dorsal steam (where)
• Caused by bilateral lesion of posterior parietal cortex near temporoparietooccipital junction
  
  • Watershed area, damage can be caused by MCA/PCA infarct leading to posterior cortical atrophy
• Symptoms:
  
  • Simultanagnosia: inability to perceive more than a single object at a time
  • Ocular apraxia/saccadic initiation failure (SIF): absence of defect of controlled, voluntary, purposeful eye movement
  • Optic ataxia: lack of coordination between visual inputs and hand movements, resulting in inability to reach and grab objects

Question 6

Temporal lobe lesions

Answer 6

may lead to loss of awareness of sound, but reflexes involving sound remain intact

Question 7

Sensory Aphasia

Answer 7

• AKA Wernicke’s
• Inability to understand/comprehend language in written or spoken form
• Speech is fluent, effortless, melodic, but jumbled and unintelligible
• Speech has normal grammar, syntax, rate, and intonation but they can’t express themselves meaningfully using language.
• Due to damage of Wernicke’s on left

Question 8

Sensory Aprosodia

Answer 8

• Inability to detect prosodic elements (humor, sarcasm) in speech
• Lesion in Wernicke-like area on RIGHT side

Question 9

Anomia

Answer 9

• Naming defect
• Lesion to left inferior temporal pole

Question 10

Postcentral Gyrus Lesions

Answer 10

• Loss of 2-point discrimination
• Agraphesthesia: inability to recognize written letters or numbers traced on skin
• Astereognosis: inability to identify an object by active touch of the hands without other sensory input

Question 11

Tactile Agnosia

Answer 11

• Lesion to ventrolateral zone (somatosensory association, parietal lobe)
• Inability to recognize, name objects by touch

Question 12

Constructional apraxia

Answer 12

• Lesion to dorsomedial zone (somatosensory association, parietal lobe)
• Difficulty with simple drawing, building blocks

Question 13

Hemispatial Neglect

Answer 13

• Lesion to right inferior parietal lobule (IPL)
  
  • Common from R-sided MCA strokes
• Neglect of left side of body and left visual field

Question 14

Gerstmann’s Syndrome

Answer 14

• Lesions of left supramarginal AND angular gyri
• Agraphia: loss of ability to write
• Acalculia: loss of ability to understand math
• Right-left disorientation
• Finger agnosia: inability to distinguish own fingers and fingers of others

Question 15

Supramarginal gyrus lesion

Answer 15

• Wernicke’s-like aphasia and impairment in verbal working memory

Question 16

Lesion to Frontal Eye Field

Answer 16

• Deviation of the eyes to the ipsilateral side during the acute phase
  • FEF on each side controls voluntary conjugate gaze to the contralateral visual field
  • So when FEF is damaged, signaling from FEF on the intact side is unopposed and both eyes deviate toward the side of the lesion

Question 17

Broca’s Aphasia

Answer 17

• Central feature: impaired fluency (speech)

Question 18

Conduction Aphasia

Answer 18

• Preserved understanding and fluency
• Central feature: impaired repetition

Question 19

M1 Infarct Signs

Answer 19

• Hemiparesis of lower half of contralateral face
• Hemiparesis of contralatera upper and lower extremities
• Sensory loss from contralateral face and arm, minor leg
• Ataxia of contralateral extremities (minor leg)
  
  • Lack of muscle control/coordination
• Gaze preference to side of lesion
• Contralateral visual field defects
• LEFT: Speech impairments (global aphasia)
• RIGHT: perceptual impairments (hemispatial neglect)

Question 20

Superior M2 Infarcts

Answer 20

• Hemiparesis of the lower half of contralateral face
• Hemiparesis of contralateral upper extremities (no leg!)
• Sensory loss from contralateral face and arm (no leg!)
• Ataxia of contralateral upper extremity
  
  • Lack of motor control/coordination
• Gaze preference to side of lesion
• LEFT: Broca’s aphasia
• *No visual loss

Question 21

Inferior M2 Infarct Signs

Answer 21

• Contralateral tactile agnosia
• Contralateral visual field defects
• LEFT:
  
  • Wernicke’s aphasia
  • Gerstmann’s syndrome
    
    • Agraphia, acalculia, R/L disorientation, finger agnosia
• RIGHT: perceptual impairments
  
  • Hemispatial neglect, constructional apraxia

Question 22

M3 Infarct Signs

Answer 22

Specific to territory in pie-slice shaped wedge of infarction

Question 23

ACA Infarct Signs (A2)

Answer 23

• Hemiparesis of the contralateral leg, pelvic floor
• Incontinence
• Sensory loss from contralateral leg, perineum
• Ataxia of contralateral leg (motor control/coordination)
• Apraxia (difficulty motor planning)
• Slowness and lack of spontaneity
• Akinetic mutism
  
  • No effort to communication (superior PFC)

Question 24

PCA Cortex Infarct Signs

Answer 24

• Contralateral visual field defects
• Cortical blindness if bilateral
• Visual form agnosia
• Memory and naming deficits, disorientation
• LEFT: alexia with agraphia
  
  • Alexia: inability to read
  • Agraphia: inabiity to write
• RIGHT: Prosopagnosia

Question 25

Central PCA Infarct Signs

Answer 25

• Thalamic syndromes
• Involuntary movements
  
  • Chorea
  • Intentional tremor
  • Hemiballismus
    
    • lesion in subthalamic nucleus
    • Hyperkinetic disorder like the choreas, but affecting more proximal limb movements
    • Very intense movements
• Contralateral hemiparesis
• 3rd nerve palsy: down + out