Question

A boy met with a motorbike accident. CT brain shows injury to the posterior end of the superior temporal gyrus. He is likely to suffer from

• A. Fluent aphasia
• B. Non-fluent aphasia
• C. Conduction aphasia
• D. None of the above

Answer 1

The Correct Option is A

Localisation-to-syndrome angle. Pin the lesion first: the posterior end of the superior temporal gyrus in the dominant hemisphere is Wernicke area (Brodmann 22), the brain region that decodes the meaning of language. Damage there breaks comprehension while leaving the speech motor apparatus in the frontal lobe untouched, so the patient talks readily and smoothly, just nonsensically, often with word substitutions and made-up words, and cannot understand others. That smooth but empty output is what we label fluent aphasia, also called receptive or sensory aphasia. Contrast it with the other patterns to confirm: a halting, effortful, agrammatic output points to Broca (inferior frontal gyrus) non-fluent aphasia, and an isolated repetition deficit with preserved comprehension points to conduction aphasia from arcuate fasciculus injury. The posterior superior temporal gyrus matches fluent (Wernicke) aphasia. Reference: BDC, 7e, Vol 4, p 129.