Case 44 Answers

Basic Human Neuroanatomy

A Clinically Oriented Atlas

Case 44 Answers

1. What is the term describing the patient’s indifference to, and to some extent denial of, her clinical signs and symptoms?

Anosognosia

2. What is the term describing the patient’s inability to persist with activities requiring sustained effort?

Motor impersistence

3. What is the term describing the patient’s inability to copy complex geometric figures?

Constructional apraxia

4. What is the term describing the patient’s failure to recognize the stimulus on the left side of the body or the left side of space, when presented with bilateral simultaneous sensory (visual or tactile) stimuli?

Sensory extinction

5. How would you describe this patient’s visual field deficit?

Left homonymous inferior quadrantanopsia

6. What specific structures are involved by the pathologic process in this case to produce the mental status, visual, and sensory findings noted on the examination?

Signs or Symptoms	Site of Lesion
Mild Anosognosia	Right inferior parietal lobule**
Motor impersistence	Right parietal lobe**
Constructional apraxia	Right inferior parietal lobule
Sensory extinction	Right superior and inferior parietal lobules**
Left homonymous inferior quadrantanopsia	Right inferior parietal lobule (deep)
Left UMN facial weakness (mild)	Right corticonuclear (corticobulbar) fibers above the lower pons
Left hemiparesis (mild)	Right corticospinal fibers
Decreased touch, pinprick, vibration on the left	Right postcentral gyrus
Decreased joint position sense, two-point discrimination, stereognosis on the left	Right superior parietal lobule

** See question #7 below.

7. Considering her entire neurological picture, in what region of the brain would you place the epicenter of her neurologic lesion?

Right superior and inferior parietal lobules (plus surrounding structures:
postcentral gyrus, precentral gyrus, subcortical white matter)

** While in this case, these higher-order, complex behavioral signs and symptoms arise from a destructive lesion in the right parietal lobe, they can also be present with disruption of any part of the “parietofrontal network for spatial orientation” located in the right (nondominant) cerebral hemisphere. The major cortical nodes of this network are the parietal association cortex (for a sensorimotor representation of personal and extrapersonal space), the frontal eye fields and adjacent cortex (for motor aspects of exploratory and attentional behaviors), and the cingulate cortex (for motivational aspects of attentional behaviors). For a concise explanation of this and other networks subserving focal cortical disorders, please refer to reference #5 below.

8. In general, what type of pathologic process do you think was involved in this case?

Vascular – Right parietal infarct, involving the cortical and subcortical branches of the middle cerebral artery

9. What diagnostic procedure(s) would you undertake at this point?

References:
1. Fisher M. J Nerv Ment Dis 1956;123:201-218.
2. Hier DB, Mondlock J, Caplan LR. Neurology 1983;33:337-344.
3. Hier DB, Mondlock J, Caplan LR. Neurology 1983;33:345-350.
4. Kertesz A, Nicholson I, Cancelliere A, Kassa K, Black SE. Neurology 1985;35:662-666.
5. Mesulam MM. Aphasia, memory loss, and other focal cerebral disorders. Chapter 18 in Harrison’s Neurology in Clinical Medicine, 3rd ed. Editor, SL Hauser. New York: McGraw-Hill Education, 2013.

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