Impairment only on the fluency subtest of the Frontal Assessment Battery after prefrontal lesions

Abstract

The Frontal Assessment Battery is a set of six subtests that is used widely to assess frontal cortical executive dysfunction. Performance on the Frontal Assessment Battery has been shown to be sensitive to various neurodegenerative diseases, but it has never been shown to be sensitive to damage restricted to the frontal cortex. Thus, despite its wide use, it has never been validated on an appropriate population of patients with frontal lesions. The present study shows that, of the six subtests that comprise the Frontal Assessment Battery, only performance on the verbal fluency subtest (mental flexibility) was specifically sensitive to injury restricted to the frontal cortex. Performance of patients with damage to the dorsal part of the medial frontal region in the language-dominant left hemisphere was impaired. None of these patients was aphasic at the time of testing. The critical region in the dorsomedial frontal cortex includes the supplementary speech zone but is not restricted to it: it extends into the cingulate motor region and the paracingulate cortex as well as the medial prefrontal areas 8 and 9. The results indicate that the Frontal Assessment Battery is not a sensitive measure of prefrontal cortical dysfunction, except for the verbal fluency subtest.

Ventrolateral and dorsomedial frontal cortex lesions impair mnemonic context retrieval

“…The critical region for verbal fluency found by Chapados & Petrides [32] in the DMFC included the supplementary speech zone, the cingulate motor region, the paracingulate cortex and the medial prefrontal areas 8 and 9. This dorsomedial frontal region, which is linked with the hippocampal/parahippocampal region [47], may play a central role in episodic memory retrieval.…”

“…7 min), patients with lesions that invaded the right ventrolateral prefrontal region were impaired selectively on the unstable context retrieval condition despite the low number of stimuli presented during the encoding phase (three stimuli) and the very short delays between stimulus presentation and memory testing (2 s). Here it is important to note that patients with frontal cortical lesions that spared the ventrolateral prefrontal region and the left dorsomedial verbal fluency retrieval region [32] were not impaired on either of the two context retrieval conditions, emphasizing the regional specificity of frontal cortical impairments. Thus, consistent with the hypothesis tested in the present experiment, the patients who had lesions that included the right VLPFC were impaired on the context memory retrieval task in which stimulus-to-context relations were unstable, but were not impaired when these relations were stable ( figure 3).…”

“…cytoarchitectonic areas 45 and 47/12 as defined by Petrides & Pandya [37]. In addition, these lesions had to spare the dorsomedial frontal cortex (DMFC) that in Chapados & Petrides [32] reduced verbal fluency: the DMFC anterior to the SMA, including the pre-SMA, the cingulate motor areas and medial areas 8, 9 and 32. Note that no patient had a lesion to the right dorsomedial frontal region analogous to the one found to be critical for verbal fluency.…”

Comparison of animal, action and phonemic fluency in aphasia

“…In this paper, we will refer to this task as phonemic fluency. Phonemic fluency performance differentiates individuals with focal frontal lesions from neurologically healthy individuals (Chapados and Petrides , Jurado et al . ).…”

Olfactory and executive dysfunctions following orbito-basal lesions in traumatic brain injury

“…This may confirm for the first time an association between anosmia and executive functions in the early post-traumatic phase of recovery, as assessed with a measure of mental flexibility. Further evidence to support this notion are the finding that normosmic patients outperformed hyposmic patients on three cognitive tasks (problem-solving, verbal fluency and TMT B) measuring executive functions [34,35]. In contrast to the executive function measures, no relationship was noted between scores on the Beck Depression Inventory and olfactory dysfunction.…”