Mudanças reorganizacionais nos córtices somatossensorial e motor em amputados
revisão da literatura
DOI:
https://doi.org/10.34024/rnc.2009.v17.8575Palavras-chave:
Plasticidade Neuronal, Amputação, Membro-fantasma, Dor, ReabilitaçãoResumo
Embora antigamente não se considerava que o córtex sensóriomotor de mamíferos adultos pudesse passar por mudanças em sua organização, sabe-se hoje que essas são possíveis e ocorrem devido a uma série de fatores. Visando compreender melhor a plasticidade cerebral, os objetivos dessa revisão foram identificar as mudanças reorganizacionais que ocorrem nos córtices somatossensorial e motor em amputados, bem como os mecanismos relacionados a essas mudanças e as repercussões funcionais advindas dessas alterações. A análise de estudos realizados em amputados permitiu concluir que a área de representação referente ao membro amputado nos córtices sensitivo e motor não fica inativa, mas passa a se relacionar com áreas corticais vizinhas. Além disso, a reorganização cortical em amputados está freqüentemente relacionada a uma condição conhecida por sensação fantasma e pode algumas vezes estar associada à dor fantasma. Os mecanismos envolvidos com a plasticidade incluem a remoção da inibição cortical local, o reforço de sinapses existentes e a formação de novas sinapses. Entender o processo reorganizacional do córtex cerebral é de fundamental importância na elaboração de estratégias de reabilitação para indivíduos amputados, pois através das intervenções terapêuticas pode-se, possivelmente, promover uma boa recuperação funcional e uma melhora da qualidade de vida.
Referências
Ramachandran VS. Behavioral and magnetoencephalographic correlates of plasticity in the adult human brain. Proc Nat Acad Sci USA 1993;90:10413-20. DOI: https://doi.org/10.1073/pnas.90.22.10413
Lundborg G. Nerve injury and repair – a challenge to the plastic brain. J Perip Nerv Sys 2003;8:209-26. DOI: https://doi.org/10.1111/j.1085-9489.2003.03027.x
Buonomano DV, Merzenich MM. Cortical plasticity: from synapses to maps. Ann Rev Neuroscienc 1998;21:149-86. DOI: https://doi.org/10.1146/annurev.neuro.21.1.149
Chen R, Corwell B, Yaseen Z, Hallett M, Cohen LG. Mechanisms of cortical reorganization in lower-limb amputees. J Neuroscienc 1998;18(9):3443-50. DOI: https://doi.org/10.1523/JNEUROSCI.18-09-03443.1998
Feldman DE, Brecht M. Map plasticity in somatosensory cortex. Science 2005;310:810-5. DOI: https://doi.org/10.1126/science.1115807
Grüsser SM, Mühlnickel W, Schaefer M, Villringer K, Christmann C, Koeppe C, et al. Remote activation of referred phantom sensation and cortical reorganization in human upper extremity amputees. Exp Brain Res 2004;154:97-102. DOI: https://doi.org/10.1007/s00221-003-1649-4
Ilic TV, Ziemann U. Exploring motor cortical plasticity using transcranial magnetic stimulation in humans. Ann NY Acad Sci 2005;1048:175-84. DOI: https://doi.org/10.1196/annals.1342.016
Mogilner A, Grossman JAI, Ribary U, Joliot M, Volkmann J, Rapaport D, et al. Somatosensory cortical plasticity in adult humans revealed by magnetoencephalography. Proceed Nat Acad Sci USA 1993;90:3593-7. DOI: https://doi.org/10.1073/pnas.90.8.3593
Zanette G, Manganotti P, Fiaschi A, Tamburin S. Modulation of motor cortex excitability after upper limb immobilization. Clin Neurophysiol 2004;115:1264-75. DOI: https://doi.org/10.1016/j.clinph.2003.12.033
Ziemann U, Muellbacher W, Hallet M, Cohen LG. Modulation of practice-dependent plasticity in human motor cortex. Brain 2001;124:1171-81. DOI: https://doi.org/10.1093/brain/124.6.1171
Brasil Neto J. Neurofisiologia e plasticidade no córtex cerebral pela estimulação magnética transcraniana repetitiva. Rev Psiquiatr Clín 2004;31(5):216-20. DOI: https://doi.org/10.1590/S0101-60832004000500004
Moore CEG, Schady W. Investigation of the functional correlates of reorganization within the human somatosensory cortex. Brain 2000;123:1883-95. DOI: https://doi.org/10.1093/brain/123.9.1883
Arendt T. Neurodegeneration and plasticity. Inter J Develop Neuroscienc 2004;22:507-14. DOI: https://doi.org/10.1016/j.ijdevneu.2004.07.007
Stefan K, Kunesch E, Cohen LG, Benecke R, Classen J. Induction of plasticity in the human motor cortex by paired associative stimulation. Brain 2000;123:572-84. DOI: https://doi.org/10.1093/brain/123.3.572
Sanes JN, Donoghue JP. Plasticity and primary motor cortex. Ann Rev Neuroscienc 2000;23:393-415. DOI: https://doi.org/10.1146/annurev.neuro.23.1.393
Monfils MH, Plautz EJ, Kleim JA. In search of the motor engram: motor map plasticity as a mechanism for encoding motor experience. Neuroscient 2005;11(5):471-83. DOI: https://doi.org/10.1177/1073858405278015
Braun C, Heinz U, Schweizer R, Wiech K, Birbaumer N, Topka H. Dynamic organization of the somatosensory cortex induced by motor activity. Brain 2001;124:2259-67. DOI: https://doi.org/10.1093/brain/124.11.2259
Schaefer M, Flor H, Heinze HJ, Rotte M. Dynamic shifts in the organization of primary somatosensory cortex induced by bimanual spatial coupling of motor activity. Neuroimage 2005;25:395-400. DOI: https://doi.org/10.1016/j.neuroimage.2004.11.032
Knecht S, Henningsen H, Höhling C, Elbert T, Flor H, Pantev C, et al. Plasticity of plasticity? Changes in the pattern of perceptual correlates of reorganization after amputation. Brain 1998;121:717-24. DOI: https://doi.org/10.1093/brain/121.4.717
Florence SL, Kaas JH. Large-scale reorganization at multiple levels of the somatosensory pathway follows therapeutic amputation of the hand in monkeys. J Neuroscienc 1995;15(12):8083-95.
Pantev C, Engelien A, Candia V, Elbert T. Representational cortex in musicians: plastic alterations in response to musical practice. Ann NY Acad Sci 2001;930:300-14. DOI: https://doi.org/10.1111/j.1749-6632.2001.tb05740.x
Weiss T, Miltner WHR, Liepert J, Meissner W, Taub E. Rapid functional plasticity in the primary somatomotor cortex and perceptual changes after nerve block. Eur J Neuroscienc 2004;20:3413-23. DOI: https://doi.org/10.1111/j.1460-9568.2004.03790.x
Knecht S, Henningsen H, Elbert T, Flor H, Höhling C, Pantev C, et al. Cortical reorganization in human amputees and mislocalization of painful stimuli to the phantom limb. Neuroscienc Let 1995;201:262-4. DOI: https://doi.org/10.1016/0304-3940(95)12186-2
24.Lotze M, Flor H, Grodd W, Larbig W, Birbaumer N. Phantom movements and pain: An fMRI study in upper limb amputees. Brain 2001;124:205-12. DOI: https://doi.org/10.1093/brain/124.11.2268
Elbert T, Sterr A, Flor H, Rockstron B, Knecht S, Pantev C, et al. Input-increase and input decrease types of cortical reorganization after upper extremity amputation in humans. Exp Brain Res 1997;117:161-4. DOI: https://doi.org/10.1007/s002210050210
Flor H, Elbert T, Mühlnickel W, Pantev C, Wienbruch C, Taub E. Cortical reorganization and phantom phenomena in congenital and traumatic upper-extremity amputees. Exp Brain Res 1998;119:205-12. DOI: https://doi.org/10.1007/s002210050334
Woodhouse A. Phantom limb sensation. Clin Exp Pharmacol Physiol 2005;32:132-4. DOI: https://doi.org/10.1111/j.1440-1681.2005.04142.x
Dettmers C, Adler T, Rzanny R, Van Schayck R, Gaser C, Weiss T, et al. Increased excitability in the primary motor cortex and supplementary motor area in patients with phantom limb pain after upper limb amputation. Neuroscienc Lett 2001;307:109-12. DOI: https://doi.org/10.1016/S0304-3940(01)01953-X
Mercier C, Reilly KT, Vargas CD, Aballea A, Sirigu A. Mapping phantom movement representations in the motor cortex of amputees. Brain 2006;129:2202-10. DOI: https://doi.org/10.1093/brain/awl180
Reilly KT, Mercier C, Schieber MH, Sirigu A. Persistent hand motor commands in the amputees’ brain. Brain 2006;129:2211-23. DOI: https://doi.org/10.1093/brain/awl154
Ramachandran VS, Rogers-Ramachandran D. Synaesthesia in phantom limbs induced with mirrors. Proceed Royal Soc Lon 1996;263:377-86. DOI: https://doi.org/10.1098/rspb.1996.0058
Karl A, Birbaumer N, Lutzenberger W, Cohen LG, Flor H. Reorganization of motor and somatosensory cortex in upper extremity amputees with phantom limb pain. J Neuroscienc 2001;21(10):3609-18. DOI: https://doi.org/10.1523/JNEUROSCI.21-10-03609.2001
Schwenkreis P, Maier C, Pleger B, Mansourian N, Dertwinkel R, Malin JP, et al. NMDA-mediated mechanisms in cortical excitability changes after limb amputation. Acta Neurol Scan 2003;108:170-84. DOI: https://doi.org/10.1034/j.1600-0404.2003.00114.x
Nico D, Daprati E, Rigal F, Parsons L, Sirigu A. Left and right hand recognition in upper limb amputees. Brain 2004;127:120-32. DOI: https://doi.org/10.1093/brain/awh006
Montoya P, Ritter K, Huse E, Larbig W, Braun C, Töpfner S, et al. The cortical somatotopic map and phantom phenomena in subjects with congenital limb atrophy and traumatic amputees with phantom limb pain. Eur J Neuroscienc 1998;10:1095-102. DOI: https://doi.org/10.1046/j.1460-9568.1998.00122.x
Byl N, Roderick J, Mohamed O, Hanny M, Kotler J, Smith A, et al. Effectiveness of sensory and motor rehabilitation of the upper limb following the principles of neuroplasticity: patients stable poststroke. Neurorehab Neural Repair 2003;17(3):176-91. DOI: https://doi.org/10.1177/0888439003257137
Churchill JD, Muja N, Myers WA, Besheer J, Garraghty PE. Somatotopic consolidation: a third phase of reorganization after peripheral nerve injury in adult squirrel monkeys. Exp Brain Res 1998;118:189-96. DOI: https://doi.org/10.1007/s002210050271
Dhillon GS, Krüger TB, Sandhu JS, Horch KW. Effects of shortterm training on sensory and motor function in severed nerves of longterm human amputees. J Neurophysiol 2005;93:2625-33. DOI: https://doi.org/10.1152/jn.00937.2004
Garraghty PE, Kaas J. Large-scale functional reorganization in adult monkey cortex after peripheral nerve injury. Proceed Nat Acad Sci USA 1991;88:6976-80. DOI: https://doi.org/10.1073/pnas.88.16.6976
Ziemann U, Hallett M, Cohen LG. Mechanisms of deafferentation-induced plasticity in human motor cortex. J Neuroscienc 1998;18(17):7000-7. DOI: https://doi.org/10.1523/JNEUROSCI.18-17-07000.1998
Weiss T, Miltner WHR, Huonker R, Friedel R, Schmidt I, Taub E. Rapid functional plasticity of the somatosensory cortex after finger amputation. Exp Brain Res 2000;134:199-203. DOI: https://doi.org/10.1007/s002210000456
Pearson PP, Arnold PB, Oladehin A, Li CC, Walers RS. Largescale cortical reorganization following forelimb deafferentation in rat does not involve plasticity of intracortical connections. Exp Brain Res 2001;138:8-25. DOI: https://doi.org/10.1007/s002210100678
Cooke SF, Bliss TVP. Plasticity in the human central nervous system. Brain 2006;129:1659-73. DOI: https://doi.org/10.1093/brain/awl082
Liepert J, Terborg C, Weiller C. Motor plasticity induced by synchronized thumb and foot movements. Exp Brain Res 1999;125:435-9. DOI: https://doi.org/10.1007/s002210050700
Ramanathan D, Conner JM, Tuszynski MH. A form of motor cortical plasticity that correlates with recovery of function after brain injury. PNAS 2006;103(30):11370-5. DOI: https://doi.org/10.1073/pnas.0601065103
Florence SL, Boydston LA, Hackett TA, Lachoff HT, Strata F, Niblock MM. Sensory enrichment after peripheral nerve injury restores cortical, not thalamic, receptive field organization. Eur J Neuroscienc 2001;13:1733-66. DOI: https://doi.org/10.1046/j.0953-816x.2001.01555.x
