Pure anarthria with predominantly sequencing errors in phoneme articulation: a case report

A 77-year-old left-handed man presented with pure anarthria following cerebral infarction. The lesion was restricted to the right precentral gyrus extending to the immediately underlying subcortical white matter and the frontal part of the insular cortex. Qualitative analysis of anarthria revealed that half of the phonemic-articulatory errors in spontaneous speech were sequencing ones. Sequential errors were detected at the phoneme level in both consonants and vowels, and at the syllable level. Most of the sequential errors were pre-positioning. Sequential errors were observed both within and across words. In clear contrast with anarthria, writing and comprehension was preserved, which suggested the problem was limited to oral expression. Our findings provide further support that the precentral gyrus and/or the insular cortex of the language dominant hemisphere is responsible for the temporal sequencing of the articulatory programming.