Case 5: Fluent Nonsense
This patient spoke fluently and seemed fairly normal so long as conversation was confined to social pleasantries like responding to "How are you today?" However, as soon as conversation went beyond stock phrases to matters of substance, spontaneous speech became progressively more devoid of meaning. The patient seemed totally unaware that he was talking nonsense. Verbal instructions were not understood unless they were reinforced with non-verbal visual cues. The patient showed no reaction to any visual stimulus (including visual threat) given in the upper right visual fields. Other aspects of the neurologic exam were normal, including eye movements, somatic sensation (so far as it could be tested) and movements of the face, arm, and leg.
Diagrams
Dx
Occlusion of inferior branches language-dominant hemisphere
Note
Expert Note
Case 5.
This patient's fluent, melodic spoken language with little meaningful content, combined with an inability to comprehend spoken language, is characteristic of Wernicke's aphasia. The stroke, which affected the posterior part of the superior temporal gyrus and neighboring cortex, has disrupted the circuitry essential for comprehending sounds as being part of language. These patients do not understand what is being said to them. Additionally, they cannot correct errors in their own use of language, which may be filled with sound-alike words, words used incorrectly or made-up, meaningless words.
Part of the visual radiations representing the contralateral superior quadrants loop forward into the temporal lobe, where they lie lateral to the ventricle before turning and running posterior to the medial occipital lobe. These fibers may therefore be at special risk from an inferior branch occlusion. Detailed visual field testing in a patient who cannot understand even simple directions is difficult. However, where the patient does and doesn't see can be roughly determined by whether or not s/he responds to threatening gestures in each of the visual quadrants ('visual threat').
The normal eye movements and normal motor and somatosensory components of the neurologic exam reinforce the idea that cortical regions supplied by the superior branch of MCA are intact in this patient.