Signs and symptoms of Fregoli's:[7] Levodopa, also known as L-DOPA, is the precursor to several catecholamines, specifically of dopamine, epinephrine and norepinephrine.
[9] Research by Feinberg, et al. has shown that significant deficits in executive and memory functions follow shortly after damage in the right frontal or left temporoparietal areas.
Tests performed on patients that have had a brain injury revealed that basic attention ability and visuomotor processing speed are typically normal.
Selective attention tests involving auditory targets were also performed, and brain-injured patients had many errors; this meant that they were deficient in their response regulation and inhibition.
The most profound finding in Feinberg et al.'s paper is that performance tests on the retrieval process of memory was significantly damaged in brain-injured patients.
MRIs of patients exemplifying Fregoli symptoms have shown parahippocampal and hippocampal damage in the anterior fusiform gyrus, as well as the middle and inferior of the right temporal gyri.
In recent years, the P300 auditory component, which forms in response to a detection task that occurs a short time after a stimulus, has acquired a great deal of recognition.
Papageorgio et al.'s paper, psychological evidence for altered information processing in delusional misidentification syndromes, hypothesized that electrophysiological brain activity in the working memory and P300 component can help identify the mechanisms of DMS.
From this result, the researchers implied that shorter P300 amplitudes are highly correlated with gray matter abnormalities; this finding is consistent with the DMS patients' characteristics and the presence of gray-matter deterioration.
The researchers were, thus, able to imply that DMS patients have trouble in focusing their resources to a stimulus; this was hypothesized to be caused by the neurodegeneration of the right hemisphere.
Overall, other research studies have also provided evidence in the correlation of DMS and gray-matter degeneration of the right frontal region, which controls attentional resources.
[15][16][17] The condition is named after the Italian actor Leopoldo Fregoli, who was renowned for his ability to make quick changes of appearance during his stage act.
[1] Delusional misidentification syndromes (DMS) are rooted in the inability to register the identity of something, whether it is an object, event, place or even a person.
In some cases, the patient holds the belief that they exist in both the correct and an incorrect location, a delusion that has been termed reduplicative paramnesia; the latter being a variant of the delusional misidentification syndromes.
An accurate semiological analysis of higher visual anomalies and their corresponding topographic sites may help elucidate the aetiology of Fregoli's and other misidentification disorders.
[22] In March 2020, the delusion was covered in an episode of the BBC medical soap opera Doctors when Lizzie Milton (Adele James) believes she is being stalked by Joe Pasquale.
[24] In Alex Garland’s 2022 folk horror film Men, the protagonist perceives the entire male population of a Herefordshire village (all played by Rory Kinnear) to share the same face.