Questions:
44. Where is the lesion usually located in the Balint Syndrome?
45. What are the findings of the Balint Syndrome?
46. What is the Gerstmann syndrome and where is its lesion?
47. Where the lesion is usually located in Hemineglect?
48. Are patients with Hemineglect aware of their defect?
49. Are patients with Hemianopia aware of their defect?
50. What is the response when a patient with a left homonymous hemianopia with unilateral spatial neglect is asked to bisect a line?
51. What is the response when a patient with a right homonymous hemianopia without unilateral spatial neglect is asked to bisect a line?
52. What is the response when a patient with a left Hemianopia with unilateral spatial neglect is asked to draw a clock?
53. What is the response when a patient with a right Hemianopia without unilateral spatial neglect is asked to draw a clock?
54. In a patient with left homonymous hemianopia with unilateral spatial neglect is the exploration of space increased or decreased?
55. In a patient with right homonymous hemianopia without unilateral spatial neglect is the exploration of space increased or decreased?
56. In a patient with left homonymous hemianopia with unilateral spatial neglect are contralesional saccades increased or decreased?
57. In a patient with right homonymous hemianopia without unilateral spatial neglect are contralesional saccades increased or decreased?
58. What differences will be observed between hemineglect and hemianopia in searching for objects?
59. What are the differences between lesion location of hemineglect and hemianopia?
60. What are common factors in cerebral disturbances of vision?

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Questions with answers:
44. Where is the lesion usually located in the Balint Syndrome?
Balint syndrome results most frequently from bilateral parieto-occipital cortical or white matter injury, such as from watershed infarctions, progressive multifocal leukoencephalopathy, Alzheimer disease, and Creutzfeldt–Jakob disease.

45. What are the findings of the Balint Syndrome?
(1) ocular apraxia (deficit in shifting gaze), (2) optic ataxia (defect in reaching under visual guidance), and (3) simultagnosia (inability to grasp the entire meaning of a picture despite an intact capacity to recognize the picture’s individual constituent elements). Affected patients may be unable to identify a picture of a landscape, but they may be able to identify a small tree within the picture; alternatively, they may be able to read the individual 20/20 letters on the Snellen chart but may not be able to identify a whole word.

46. What is the Gerstmann syndrome and where is its lesion?
Gerstmann syndrome is a combination of right–left confusion, finger agnosia, acalculia, and agraphia. It is caused by lesions in the dominant parietal lobe.

47. Where the lesion is usually located in Hemineglect?
Hemineglect usually occurs from lesions of the nondominant (right) hemisphere, inferior parietal lobe, the frontal cortex, and the thalamus. Patients with hemineglect do not notice or respond to stimuli on the contralateral side. Hemineglect can affect not only vision but also other sensory and motor modalities.  

48. Are patients with Hemineglect aware of their defect?
No

49. Are patients with Hemianopia aware of their defect?
Yes

50. What is the response when a patient with a left homonymous hemianopia with unilateral spatial neglect is asked to bisect a line?
Patients with a left homonymous hemianopia with unilateral spatial neglect never search to the left (hemianopic) side. Once they fixate a certain point on the right part of the line, they persisted with this point and mark the subjective midpoint.

51. What is the response when a patient with a right homonymous hemianopia without unilateral spatial neglect is asked to bisect a line?
Hemianopic patients without unilateral spatial neglect see the whole line by searching to the endpoint on the hemianopic side, and bisect it correctly. In contrast, patients with a left homonymous hemianopia with unilateral spatial neglect never search to the left hemianopic side. Once these patients fixate a certain point on the right part of the line, they persisted with this point and mark the subjective midpoint.

52. What is the response when a patient with a left Hemianopia with unilateral spatial neglect is asked to draw a clock?
Their drawing might show only the numbers 12 to 6, or all 12 numbers might be on one half of the clock face (the right side in this case) with the other half distorted or blank.

53. What is the response when a patient with a right Hemianopia without unilateral spatial neglect is asked to draw a clock?
Clock drawing in acute stroke. Friedman PJ, Age and Ageing. 1991:20:140-145. Impaired clock drawing after stroke can reflect either cognitive impairment or spatial neglect. Only one-quarter of our subjects with impaired clock drawing demonstrated neglect of one side of the clock. These subjects almost invariably had non-dominant hemisphere strokes. Number omission was also associated with non-dominant hemisphere stroke whereas other abnormal patterns were not. Nearly half of our subjects had, as their major error, number omission or duplication without spatial neglect, errors which principally reflect cognitive impairment.

54. In a patient with left homonymous hemianopia with unilateral spatial neglect is the exploration of space increased or decreased?
Decreased

55. In a patient with right homonymous hemianopia without unilateral spatial neglect is the exploration of space increased or decreased?
Increased

56. In a patient with left homonymous hemianopia with unilateral spatial neglect are contralesional saccades increased or decreased?
Decreased

57. In a patient with right homonymous hemianopia without unilateral spatial neglect are contralesional saccades increased or decreased?
Increased

58. What differences will be observed between hemineglect and hemianopia in searching for objects?
Object search test: Hemineglect Contralesional neglect, Hemianopia Contralateral emphasis.

59. What are the differences between lesion location of hemineglect and hemianopia?
Side of hemispheric lesion: Hemineglect more often right (nondominant hemisphere), Hemianopia right or left.

60. What are common factors in cerebral disturbances of vision?
Cerebral disturbances of vision can be caused by any condition that affects the visual association cortices or subcortical white matter. They commonly result from bilateral cerebral lesions and are most often found in patients with cerebral hypoxia resulting in bilateral watershed infarctions or with bilateral infarctions in the territory of the posterior cerebral arteries, diffuse encephalopathy and encephalitis, and degenerative disorders producing dementia.

The information below is from Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

10.2 Clinical and Radiologic Findings of Specific Disorders
10.2.1 Balint Syndrome
Balint syndrome results most frequently from bilateral parieto-occipital cortical or white matter injury, such as from watershed infarctions, progressive multifocal leukoencephalopathy, Alzheimer disease, and Creutzfeldt–Jakob disease. It associates (1) ocular apraxia (deficit in shifting gaze), (2) optic ataxia (defect in reaching under visual guidance), and (3) simultagnosia (inability to grasp the entire meaning of a picture despite an intact capacity to recognize the picture’s individual constituent elements). Affected patients may be unable to identify a picture of a landscape, but they may be able to identify a small tree within the picture; alternatively, they may be able to read the individual 20/20 letters on the Snellen chart but may not be able to identify a whole word.

10.2.2 Gerstmann Syndrome
Gerstmann syndrome is caused by lesions in the dominant parietal lobe, and therefore, aphasia is often (but not always) present as well, which can make the diagnosis difficult or impossible.
Gerstmann syndrome is a combination of right–left confusion, finger agnosia (loss in the ability to distinguish, name, or recognize the fingers), acalculia (acquired difficulty performing simple mathematical tasks), and agraphia (acquired inability to communicate through writing).

10.2.3 Hemineglect
Hemineglect usually occurs from lesions of the nondominant (right) hemisphere. Patients with hemineglect do not notice or respond to stimuli on the contralateral side. Hemineglect can affect not only vision but also other sensory and motor modalities. It is associated with damage to various components of a cerebral attentional network, which includes the inferior parietal lobe, the frontal cortex, and the thalamus.

Reference:
1. Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme
2. Clock drawing in acute stroke. Friedman PJ, Age and Ageing. 1991:20:140-145.

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