Delusional Misidentification Syndromes (DMS)
Capgras and Fregoli syndromes are both rare Delusional Misidentification Syndromes. While they involve similar neuroanatomical deficits—often linked to right-hemisphere, frontal, and temporal-limbic disconnections—they present with distinct delusional “themes.”
| Syndrome | Primary Delusion | Core “Feel” |
|---|---|---|
| Capgras | Familiar people have been replaced by identical impostors. | Loss of emotional familiarity despite correct visual recognition. |
| Fregoli | Different people are actually a single person in disguise. | Hyper-familiarity: feeling that a persecutor is everywhere. |
Clinical Distinctions
- Capgras: Often involves a lack of the “emotional spark” (affective significance) usually triggered by a loved one’s face. The patient recognizes the visual appearance but perceives an “unheimlich” (uncanny) disconnect.
- Fregoli: Named after an Italian actor famous for quick-change impersonations. The patient sees someone new (a stranger or authority figure) and is convinced it is an emotionally significant person (often a persecutor) disguised.
High-Yield Clinical Notes:
- Etiology: Both are commonly seen in neurodegenerative conditions (Alzheimer’s, Lewy Body Dementia), Parkinson’s disease, epilepsy, or post-traumatic brain injury, as well as primary psychotic disorders (Schizophrenia).
- Neuroanatomy: Strongly associated with damage to the right temporal lobe and fusiform gyrus (crucial for facial recognition) and the disconnection between these areas and the limbic system (responsible for emotional processing).
- Treatment: Primarily focused on the underlying cause (e.g., antipsychotics for psychosis, adjusting medications for Parkinson’s). Cognitive therapy is often supportive, but patients rarely gain full insight while in an active state.