Confabulation and other delusional syndromes

Confabulation is usually associated with memory (medial temporal or diencephalic) and executive (bifrontal) dysfunction.^7-9

 

7. Benson DF, Djenderedjian A, Miller BL, et al. Neural basis of confabulation. Neurology 1996;46:1239–1243.[Abstract/Free Full Text]
8. Moscovitch M, Melo B. Strategic recall and the frontal lobes: evidence from confabulation and amnesia. Neuropsychologia 1997;35:1017–1034.[Medline]
9. Johnson MK, Hayes SM, D'Esposito M, Raye CL. Confabulation. In: Grafman J, Boller F. Handbook of Neuropsychology,

The anterior parahippocampal cortex (perirhinal cortex, Brodmann areas 35 and 36) is activated by familiarity, while the hippocampus and posterior parahippocampal cortex mediate recollection.⁴⁹ Perirhinal cortex stimulation evokes déjà vu and déjà vécu (already experienced).⁵⁰ Further, the right hemisphere dominates in familiarity decisions^14,48; déjà vu is more common with right than left temporal lobe seizures or stimulation.^48,51 Lesions that destroy or isolate stimuli from right perirhinal cortex may lead to loss of familiarity (e.g., Capgras syndrome) while hyperfamiliarity (i.e., misidentifying strange people as familiar [Fregoli syndrome]) may result from overactivity in right perirhinal cortex from stimulation or disinhibition. Two cases of nondelusional hyperfamiliarity for faces resulted from left-sided lesions (lateral temporal-occipital and anterior cingulate),^52,53 possibly disinhibiting right hemisphere areas that imbue faces or places with familiarity.

48. Gainotti G. Face familiarity feelings, the right temporal lobe and the possible underlying neural mechanisms. Brain Res Rev 2007;56:214–235.[Medline]
49. Bowles B, Crupi C, Mirsattari SM, et al. Impaired familiarity with preserved recollection after anterior temporal-lobe resection that spares the hippocampus. Proc Natl Acad Sci 2007;104:16382–16387.[Abstract/Free Full Text]
50. Vignal J-P, Maillard L, McGonigal A, Chauvel P. The dreamy state: hallucinations of autobiographic memory evoked by temporal lobe stimulations and seizures. Brain 2007;130:88–89.[Abstract/Free Full Text]
51. Mullan S, Penfield W. Illusions of comparative interpretation and emotion. Arch Neurol Psychiatry 1959;81:269–284.[Abstract/Free Full Text]
52. Vuilleumier P, Mohr C, Valenza N, Wetzel C, Landis T. Hyperfamiliarity for unknown faces after left lateral temporo-occipital venous infarction: a double dissociation with prosopagnosia. Brain 2003;126:889–907.[Abstract/Free Full Text]
53. Nente F, Carrillo-Mezo R, Mendez MF, Ramirez-Bermudez J. Pathological hyperfamiliarity for others from a left anterior cingulate lesion. J Neuropsychiatry Clin Neurosci 2007;19:345–346.[Free Full Text]

Hughlings Jackson and right hemisphere expression, and callosal syndromes

56. Jackson JH. Evolution and dissolution of the nervous system. In: Taylor J, ed. Selected Writings of John Hughlings Jackson, Volume 2. New York: Basic Books; 1884/1958:45–75.
57. Sperry RW, Zaidel E, Zaidel D. Self recognition and social awareness in the deconnected minor hemisphere. Neuropsychologia 1979;17:153–166.[Medline]
58. Gazzaniga MS. Cerebral specialization and interhemispheric communication. Brain 2000;123:1296–1326.
59. Gazzaniga MS. The split brain revisited. Sci Am 1998;279:50–55.[Medline]

ego boundaries response to next patient syndrome

55. Bogousslavsky J, Regli F. Response-to-next-patient-stimulation: a right hemisphere syndrome. Neurology 1988;38:1225–1227.[Abstract/Free Full Text]