Advertisement

The Italian Journal of Neurological Sciences

, Volume 19, Supplement 6, pp S403–S407 | Cite as

Memory and executive functions in healthy subjects and patients with multiple sclerosis: the role of PET and SPECT

  • C. Pozzilli
  • A. Pisani
  • M. Gherardi
  • S. Cannoni
  • O. Ciccarelli
Cognitive Dysfunction IN MS

Abstract

Despite extensive research, the precise role of different brain areas in modulating attentional and mnemonic processes is still controversial. Using positron emission tomography (PET) or single photon emission computed tomography (SPECT), we can measure changes which are associated with the level of neuronal activity in normal subjects and in patients. We describe the pattern of activation in attentional processes, with respect to three basic components: vigilance, selective attention and attentional processing capacity. Furthermore, we underline the predominant role of frontal and temporal cortices that mediate different activities associated with memory function.

Functional techniques have substantially contributed to a better understanding of the cognitive deficits associated with multiple sclerosis (MS), suggesting that cortical- subcortical disconnection is the most likely cause of the neuropsychological deficits. The difficulties in attempting to attribute specific cognitive abnormalities to focal brain pathology in presence of widespread disease such as MS will probably be attenuated by functional neuroimaging studies.

Key words

Memory Executive functions PET SPECT Multiple sclerosis 

Sommario

Nonostante le molteplici ricerche, non è ancora ben chiaro il ruolo preciso delle differenti aree cerebrali nei processi mnesici ed attenzionali. L'uso di tecniche funzionali come la tomografia ad emissione di positroni (PET) e la tomografia ad emissione di singoli fotoni (SPECT) ha reso possibile valutare le singole diverse strutture the sono coinvolte in tali processi. In questo lavoro, abbiamo preso in considerazione gli study effettuati mediante PET e SPECT mirati ad approfondire il substrato neuroftsiologico alla base dei processi attenzionali. Per quanto riguarda la memoria, è stato esaminato il ruolo delle diverse aree corticali, con particolare riguardo alla corteccia frontale e temporale. Nell'umbito della sclerosi multipla, gli study funzionali hanno messo in luce l'importanza delle strutture sottocorticali per le funzioni mnesiche ed esecutive, contribuendo a chiarire il ruolo della disconnessione tra strutture corticali e sottocorticali.

References

  1. 1.
    Chertkow H, Bub D (1994) Functional activation and cognition: The 15O PET subtraction method. In: Kertesz A (ed) Localization and neuroimaging in neuropsychology. Academic Press, San Diego, CA, pp 152–180Google Scholar
  2. 2.
    Montaldi D, Mayes A, Branes A, Wilson L, Hadley DM, Patterson J, Wyper DJ (1997) Use of HMPAO SPECT to investigate memory function in patients with amnesia. In: SPECT in neurology and psychiatry. John Libbey & Company, London, pp 57–67Google Scholar
  3. 3.
    Cohen RM, Semple WE, Gross M, Holcomb HJ, Dowling SM and Nordahl TE (1988) Functional localization of sustained attention. Neuropsychiatry Neuropsychol Behav Neurol 1:3–20Google Scholar
  4. 4.
    Nobre AC, Sebestyen GN, Gitelman DR, Mesulam MM, Frackowiak RS, Frith CD (1997) Functional localization of the system for visuo spatial attention using position emission tomography. Brain 120:515–533Google Scholar
  5. 5.
    Corbetta M, Miezen FM, Shulman GL, Petersen SE (1991) PET studies of spatial attention: Direction vs. visual hemifield. J Cereb Blood Flow Metab 11:S435Google Scholar
  6. 6.
    Posner MI, Petersen SE, Fox P, Raichle ME (1988) Localization of cognitive operations in the human brain. Science 240:1627–1631Google Scholar
  7. 7.
    Berman KF, Ostrem JL, Randolph C, Gold J, Goldberg TE, Coppola R, Carson RE, Hescovitch P, Weinberger DR (1995) Physiological activation of a cortical network during perfor mance of the Winsconsin card sorting test: A positron emission tomography study. Neuropsychologia 33:1027–1046Google Scholar
  8. 8.
    Shallice T, Fletcher P, Frith CD, Grasby P, Frackowiak RS, Dolan RJ (1994) Brain regions associated with acquisition and retrieval of verbal episodic memory. Nature 368:633–635Google Scholar
  9. 9.
    Calabrese P, Markowitsch HJ, Durwen HF, Widlitzek H, Haupts M, Holinka B, Gehlen W (1996) Right temporofrontal cortex as critical locus for the ecphory of old episodic memories. J Neurol Neurosurg Psychiatry 61:304–310Google Scholar
  10. 10.
    Rugg MD, Fletcher PC, Frith CD, Frackowiak RS, Dolan RJ (1997) Brain region supporting intentional and incidental memory: A PET study. Neuroreport 8:1283–1287Google Scholar
  11. 11.
    Fletcher PC, Shallice T, Frith CD, Frackowiak RS, Dolan RJ (1996) Brain activity during memory retrieval. The influence of imagery and semantic cueing. Brain 119:1587–1596Google Scholar
  12. 12.
    Hazeltine E, Grafton ST, Ivry R (1997) Attention and stimulus characteristics determine the locus of motor-sequence encoding. A PET study. Brain 120:123–140Google Scholar
  13. 13.
    Grasby PM, Frith CD, Friston KJ, Bench C, Frackowiak RS, Dolan RJ (1993) Functional mapping of brain areas implicated in auditory-verbal memory function. Brain 116:1–20Google Scholar
  14. 14.
    Evans J, Wilson B, Wraight EP, Hodges JR (1993) Neuropsychological and SPELT scan findings during and after transient global amnesia: Evidence for the differential im pairment of remote episodic memory. J Neurol Neurosurg Psychiatry 56:127–130Google Scholar
  15. 15.
    Tanabe H, Hashikawa K, Nakagawa Y, Ikeda M, Yamamoto H et al (1991) Memory loss due to transient hypoperfusion in the medial temporal lobes including hippocampus. Acta Neurol Scand 84:22–27Google Scholar
  16. 16.
    Nyberg L, McIntosh AR, Houle S, Nilsson LG, Tulving E (1996) Activation of medial temporal structures during episodic memory retrieval. Nature 380:715–717Google Scholar
  17. 17.
    Fujii T, Okuda J, Kawashima R, Yamadori A et al (1997) Different roles of the left and right parahippocampal regions in verbal recognition: A PET study. Neuroreport 8:1113–1117Google Scholar
  18. 18.
    Schacter DL, Uecker A, Reiman E, Yun LS et al (1997) Effects of size and orientation change on hippocampal activation during episodic recognition: A PET study. Neuroreport 8:3993–3998Google Scholar
  19. 19.
    Jonides J, Smith EE, Koeppe RA, Awh E, Minoshima S, Mintun MA (1993) Spatial working memory in humans as revealed by PET. Nature 636:623–625Google Scholar
  20. 20.
    Smith EE, Jonides J (1997) Working memory: A view from neuroimaging. Cognit Psychol 33:5–42Google Scholar
  21. 21.
    Salmon E, Van der Linden M, Collette F, Delfiore G, Maquet P, Delgueldre C, Luxen A, Franck G (1996) Regional brain activity during working memory tasks. Brain 119:1617–1625Google Scholar
  22. 22.
    Paulesu E, Frith CD, Frackowiak RS (1993) The neural correlate of the verbal component of working memory. Nature 362:342–345Google Scholar
  23. 23.
    Coull JT, Frith CD, Franckoviak RS, Grasby PM (1996) A fronto-parietal network for rapid visual information process ing: a PET study of sustained attention and working memory. Neuropsychologia 34:1085–1095Google Scholar
  24. 24.
    Faillenot I, Sakata H, Costes N, Decety J, Jeannerod M (1997) Visual working memory for shape and 3D-orientation: A PET study. Neuroreport 8:859–862Google Scholar
  25. 25.
    Feinstein A, Kartsounis LD, Miller DH, Youl BD, Ron MA (1992) Clinically isolated lesion of the type seen in multiple sclerosis: A cognitive, psychiatric and MRI follow-up study. J Neurol Neurosurg Psychiatry 55:869–876Google Scholar
  26. 26.
    Rao SM (1995) Neuropsychology of multiple sclerosis. Curr Opin Neurol 8:216–220Google Scholar
  27. 27.
    Brooks DJ, Leenders KL, Head G, Marshall J, Legg NJ, Jones T (1984) Studies on regional cerebral oxygen utilisation and cognitive function in multiple sclerosis. J Neurol Neurosurg Psychiatry 47:1182–1191Google Scholar
  28. 28.
    Pozzilli C, Passafiume D, Bernardi S, Pantano P, Incoccia C, Bastianello S, Bozzao L, Lenzi GL, Fieschi C (1991) SPELT, MRI and cognitive functions in multiple sclerosis. J Neurol Neurosurg Psychiatry 54:110–115Google Scholar
  29. 29.
    Pozzilli C, Fieschi C, Perani D, Paulesu E, Comi G, Bastianello S et al (1992) Relationship between corpus callosum atrophy and cerebral metabolic asymmetries in multiple sclerosis. J Neurol Sci 112:51–57Google Scholar
  30. 30.
    Pozzilli C, Gasperini C, Anzini A, Grasso MG, Ristori G, Fieschi C (1993) Anatomical and functional correlates of cognitive deficit in multiple sclerosis. J Neurol Sci 115S:55–58Google Scholar
  31. 31.
    Frackowiak RS, Pozzilli C, Legg NJ et al (1981) Regional cerebral oxygen supply and utilization in dementia: A clinical and physiological study with oxygen-15 and positron tomography. Brain 104:785–799Google Scholar
  32. 32.
    Blinkenberg M, Rune K, Jonsson A, Holm S, Jensen CV, Paulson OB, Sorensen PS (1996) Cerebral metabolism in a case of multiple sclerosis with acute mental disorder. Acta Neurol Scand 94:310–313Google Scholar
  33. 33.
    Paulesu E, Perani D, Fazio F, Comi G, Pozzilli C, Martinelli V, Filippi M, Bettinardi V et al (1996) Functional basis of memory impairment in multiple sclerosis: A [18F] FDG PET study. Neuroimage 4:37–96Google Scholar
  34. 34.
    Perani D, Bressi S, Cappa SF, Vallar G, Alberoni M, Grassi F et al (1993) Evidence of multiple memory systems in the human brain. Brain 116:903–919Google Scholar

Copyright information

© Springer-Verlag 1998

Authors and Affiliations

  • C. Pozzilli
    • 1
  • A. Pisani
    • 1
  • M. Gherardi
    • 1
  • S. Cannoni
    • 1
  • O. Ciccarelli
    • 1
  1. 1.Department of Neuroslogical SciencesUniversity of RomaRomaItaly

Personalised recommendations