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Neurology of Delusions Orrin Devinsky

Neurology of Delusions Orrin Devinsky. Delusion. Pathological, fixed idea Cannot be overturned by evidence Not culturally or religious condoned Can be bizarre or non-bizarre Occur in primary psychiatric disorders (schizophrenia, delusional disorders) and secondary neurological disorders.

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Neurology of Delusions Orrin Devinsky

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  1. Neurology of DelusionsOrrin Devinsky

  2. Delusion • Pathological, fixed idea • Cannot be overturned by evidence • Not culturally or religious condoned • Can be bizarre or non-bizarre • Occur in primary psychiatric disorders (schizophrenia, delusional disorders) and secondary neurological disorders

  3. Delusions in Psychiatry • Schizophrenia - often bizarre • Influence, persecution/paranoia, self-significance • Psychosis due to mood disorder • Delusional disorder - prominent non-bizarre delusions lasting > 1 month • Erotomania • Grandiose • Jealous • Persecutory • Somatic • Mixed

  4. Delusions in Neurological Disorders • Generalized Neurological Disorders • Neurosyphilis (grandiose) • Dementia - Alzheimer’s, Multi-infact, Lewy body disease • Parkinson’s disease • Toxic-metabolic • Epilepsy – Postictal & interictal • Focal Neurological disorders • Stroke • Tumor • Head trauma • Epilepsy – Interictal & postictal

  5. Content Specific Delusions in Neurological Disorders • Delusional misidentification syndromes • Reduplicative paramnesia • Capgras • Fregoli (a stranger is believed to be a familiar person) • Othello (delusional jealousy) • De Clerambault (erotomania) • Cotard (belief one is dying or dead)

  6. Content Specific Delusions: Poles of Familiarity • Loss of familiarity • People • Capgras • Mirror sign • Places • Foreign reduplicative paramnesia (home is considered a duplicate in another location) • Disorientation for place (familiar place exists in another location) • Hyperfamiliarity • People • Fregoli (a stranger is believed to be familiar) • Places • Reduplicative paramnesia (foreign place is considered familiar location)

  7. Content Specific Delusions: Neuropsychiatric Pendulum • Before 1975 – psychiatric • Early 1990’s increased awareness of neuro causes - ~40% of cases • ‘02 Mayo Clinic review of Capgras - only 2/47 (4%) psychiatric! (Joseph, Arch Neuro)

  8. Anatomy of Delusions: Bifrontal & Right Hemisphere • R hem plus bifrontal - post-traumatic Capgras • Benson et al, 1976 • Alexander et al, 1979 • Delusions after R stroke (Levine & Grek, 1984) • 9 patients - reduplication of place, distortions/condensations of events • Tendency for frontal & temporal • Most significant finding was baseline atrophy’ • 2 HIT: R focal on diffuse • Faulty reasoning and memory • Misrepresentations of past events

  9. Reduplicative Paramnesia • 1903 - first described by Pick as a memory disorder • A place simultaneously exists in two or more physical locations • Unfamiliar place (hospital) is in home town • Associated with R hemisphere dysfunction • Benson et al 1976 & Ruff & Volpe, 1981. • RHDamage BHDamage LHDamage (Feinberg, 1989) 36 (52%) 28 (41%) 5 (7%) <.0001 (7x) • With neurological lesions – R frontal or parietal

  10. Capgras’ Patient (’23 & ‘24) 53 yo woman, paranoid megaolmaniac (royal lineages, wealth) dress-designer, onset of paranoia after 4/5 children died. Daughter and husband imposters. Filed for divorce. Went to police to report underground children. Police department replaced multiple times with imposters. She was replaced by an imposter. Recognized that it was especially for familiar people Initially postulated an “agnosia of identification”; struggle for all sensory images between poles of familiar and strange. A year later - Oedipal conflict

  11. Capgras Syndrome & Right Hemisphere • Hayman & Abrams 1977 & Alexander et al, 1979 • Review of literature (Feinberg ,1989) RHDamage BHDamage LHDamage 8 (32%) 16 (62%) 2 (7%) <.06 (4X R>L)

  12. Capgras Syndrome: Mechanisms • Opposite of prosopagnosia (Young & Ellis) • Prosopagnosia - no conscious recognition of familiar face but a GSR to familiar face • Capgras - conscious recognition of familiar face but no GSR to familiar face • Hirsten & Ramachandran’s patient • Absence of GSR • Knew his dad was dad by phone • Thought same person in photo was different if gaze different • Disconnection of facial recognition area from emotional area that generates the “glow” or “sparkle”

  13. Capgras and Familiarity: Why • Ramachandran - missing the glow; strangers don’t evoke that - no ‘mismatch’ • If so, why don’t they say - “its my wife, but I don’t feel like its my wife” • Patient X - somatic delusions, emotional disconnection but verbally aware after R Ant TL

  14. Familiarity & The Temporal Lobe • Perirhinal cortex (ant parahippocampal gyrus) - familiarity of faces and objects; • Patient NB - Temporal resection of L perirhinal cortex for epilepsy with sparing of hippocampus. Impaired familiarity, preserved recollection. (Bowles et al, 2007) • Posterior parahippocampal gyrus - familiarity of places

  15. Déjà vu: Familiarity & The Temporal Lobe • Déjà vu – transient feeling of familiarity • Too brief to be a delusion, yet if it persisted… • Déjà vu - temporal lobe foci, R>L

  16. Familiarity & The Temporal Lobe • Lesions outside the right temporal lobe may cause non-delusional hyperfamiliarity syndromes by disinhibiting emotional familiarity • Lesions that destroy or disconnect the right perirhinal cortex may impair familiarity

  17. Capgras and Dementia • Mayo clinic - 10 year review of Capgras and misidentification • 47 cases; 37 (81%) had a degenerative disorder (mean age 72 yo) vs those without (51 yo) • Visual hallucinations - 30/38 with degenerative vs 2/9 (p=0.03) without • Lewy Body Disease - 26 patients!

  18. Capgras & Lewy Body Disease? • Lewy Body Disease • Progressive cognitive decline, often frontal fxn • Marked fluctuations in alertness and attention • Parkinsonian motor syndromes (decreased spontaneity, rigidity) • Visual hallucinations - correlates with Lewy Bodies in amygdala, parahippocampal and inferior temporal cortices • Two key hits • Face and emotional recognition • Impaired self-monitoring to detect errors

  19. Hyperfamiliarity • Patient 1 - left lateral temporal venous infarct & GTC - prosopaganoisa selectively affecting unfamiliar faces. (Vuileumier, 2003) • Patient 2 – 32 yo man, bilateral F-T epilepsy, cluster of >10 CPS, hyperfamiliarity for faces lasting ~48 hrs • Patient GP - 46 yo policeman. Déjà vu, fear for 6 mos. CPS & single GTC. Since then hyperfamiliarity for faces.

  20. Hyperfamiliarity Seven patients reported All had TCS or epilepsy Most with Left hemisphere or bilateral pathology, usually affecting temporal lobe Déjà vu and HFF result from increased activity in right relative to the left medial temporal lobe areas, consistent with the dominant role of the right medial temporal regions in familiarity experiences

  21. Frontal Pathology in Delusions (Feinberg et al, 2005) • 29 patients with misidentification-reduplication syndromes • Exclusively frontal lesions in 10/29 (34.5%) cases • Four with right frontal • Six with bifrontal lesions • None had lesions sparing the frontal lobes

  22. Frontal Pathology in Delusions • Nearly ubiquitous in delusions • Impaired functions: theory of mind, decision and prediction making, time estimation and sequencing & working memory. • Inability to monitor self and recognize and correct inaccurate memories and familiarity assessments. • The resistance of delusions to change despite clear evidence that they are wrong likely reflects frontal dysfunction.

  23. Anosognosia: A Delusional Disorder? • Unawareness of neurological deficit: vision (Anton’s syndrome) or movement (anosognosia for hemiplegia) • Inability of self to recognize blindness or hemiplegia is strikingThe resistance of delusions to change despite clear evidence that they are wrong likely reflects frontal dysfunction. • Often confabulate: “it’s just bad lighting”, “can move fine” • Resists rational explanation or visual demonstration

  24. Anosognosia: A Delusional Disorder? • Some patients deny ownership of their limb (asomatognosia), ? it belongs to someone else. • Asomatognosia - delusion with loss of limb’s relation to self: Capgras affecting the arm. • Other patients personify the limb with names such as “Floppy Joe” or “Silly Jimmy”, hate the limb (misoplegia), or recognize the deficit but show no concern (anosodiaphoria). • Anosognosia for hemiplegia - large R hemisphere strokes; par, front & temp lobes, insula, subcortex

  25. Corpus Callosum and Left Hemisphere in Delusions • Act to disconnect more than connect • Kosslyn – L hem is categorical • Callosotomy studies • The verbal hemisphere - tends to lie • Snow scene R Hem; Chicken claw L Hem • L hand picked shovel, R hand picked chicken • “I saw a claw and I picked the chicken, and you have to clean out the chicken shed with a shovel” • Nude photo • Oh doctor…you have some machine!

  26. The Hemispheres in Delusions • Right lesions disinhibit the left hemisphere; loss of monitoring of: • Reality, self-awareness, emotional familiarity, ego boundaries • Disrupts relation between and monitoring psychic, emotional, and physical self to people, places and even body parts • Excess lying & categorical thinking • Left hemisphere is the delusional hemisphere.

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