Background: Mitigated echolalia (ME), a symptom of aphasia, involves deliberate repetition of just-heard words or phrases, possibly to aid auditory comprehension. Its functional basis remains largely unexplored.
Aims: This study examined (a) ME through modern neuroscience; (b) the effects of Constraint-Induced Aphasia Therapy (CIAT) and memantine on ME in a fluent aphasia patient (CCR); and (c) ME's brain correlates using multimodal neuroimaging.
Methods: Verbal and auditory tasks assessed ME in CCR across phases: placebo (weeks 0–16), placebo + CIAT (weeks 16–18), placebo alone (weeks 18–20), washout (weeks 20–24), and memantine (weeks 24–48). CIAT included instructions to reduce ME. Follow-up testing occurred 10 years post-treatment.
Results: At baseline, ME occurred in spontaneous speech and difficult words, suggesting meaning access issues, short-term memory deficits, and impaired inhibitory control. CIAT reduced ME immediately and 2 weeks after treatment, with sustained improvement under memantine. No changes were observed during placebo or washout. ME returned to baseline after 10 years. Imaging linked ME to residual left dorsal stream activity and intact right white matter after left ventral stream damage.
Conclusions: ME hindered communication due to deficits in sound-meaning mapping, memory, attention, and inhibition. Therapy and drugs may help manage ME in similar cases.
