Echolalia in patients with primary progressive aphasia

Area of Science:

• Neuroscience
• Neurology
• Linguistics

Background:

• Primary progressive aphasia (PPA) is a neurodegenerative disorder affecting language abilities.
• Echolalia, the repetition of speech, is a less-studied symptom in PPA.
• Understanding echolalia's characteristics and neural correlates can aid in PPA diagnosis and management.

Purpose of the Study:

• To investigate the occurrence of echolalia in patients with PPA.
• To identify associated clinical symptoms and neurological findings in PPA patients with echolalia.
• To explore the relationship between echolalia and brain activity patterns in PPA.

Main Methods:

• Forty-five PPA patients (including nonfluent/agrammatic variant PPA - nfvPPA) were assessed for echolalia during conversations.
• Evaluated language function, parkinsonism, grasp reflex, imitation behavior, and disinhibition.
• Measured regional cerebral blood flow (rCBF) using single-photon emission computed tomography (SPECT).

Main Results:

• Echolalia was present in 14 PPA patients (12 nfvPPA, 2 unclassified), all exhibiting mitigated forms.
• Echolalia group showed significantly lower age and poorer auditory comprehension compared to non-echolalia group.
• Higher prevalence of imitation behavior and significantly lower rCBF in the medial frontal cortex were observed in the echolalia group.

Conclusions:

• Echolalia is characteristic of nfvPPA, particularly in patients with impaired comprehension.
• Reduced inhibition in the medial frontal cortex may underlie echolalia.
• Findings suggest a neural basis for echolalia involving frontal lobe dysfunction in PPA.