Reply

REPLY:

We thank Drs Lizarazo and Guarnizo for their comment on our article “Stroke Mimics in the Acute Setting: Role of Multimodal CT Protocol.”¹

We acknowledge the comment about the denomination of “functional neurological disorder” (FND) instead of “conversion disorder.” Indeed, in Diagnostic and Statistical Manual of Mental Disorders, 5th ed, 2022 text revision, terminology has been updated.²

FND, previously regarded as a diagnosis of exclusion, is now a rule-in diagnosis that relies on tests with positive findings such as the Hoover test for functional leg weakness and others. Nevertheless, the differential diagnosis versus an acute stroke may be uncertain in the acute setting, leading the clinician to perform an imaging evaluation to rule out stroke.³

FND is now considered a multinetwork brain disorder with impairment within and across the limbic system/salience network, self agency, multimodal integration, attention and sensorimotor circuits. Although FND is a clinical diagnosis, neuroimaging has provided evidence of functional and subtle structural brain changes in patients with this disorder, arguing against a strict functional-structural dichotomy in this condition.⁴ Nevertheless, these subtle abnormalities (ie, smaller volume of the thalamus, increased cortical thickening in the premotor cortex) cannot be evaluated with a multimodal CT protocol such as in our study.