The syndrome of progressive posterior cortical dysfunction: A multiple case study and review

Areza-Fegyveres, Renata; Caramelli, Paulo; Porto, Claudia Sellitto; Ono, Carla Rachel; Buchpiguel, Carlos Alberto; Nitrini, Ricardo

doi:10.1590/S1980-57642008DN10300014

Abstract

Dementia presenting with prominent higher order visual symptoms may be observed in a range of neurodegenerative conditions and is often challenging to diagnose. Objectives: To describe cases of progressive dementia presenting with prominent visual cortical symptoms. Methods: We conducted a retrospective search of cases of progressive dementia with predominant visual symptoms, seen at our dementia unit from 1996 to 2006. Results: Twelve patients (5 men, 7 women) were identified, with ages ranging from 49 to 67 years. At the first examination, the duration of the symptoms ranged from one to ten years and the Mini-Mental State Examination scores from 7 to 27. Eleven patients presented with predominant visuospatial symptoms (partial or complete Balint syndrome) and one with visuoperceptive impairment. Other reported manifestations were: constructional apraxia in 11 patients, partial or complete Gerstmann syndrome in ten, ideomotor apraxia in nine, hemineglect or extinction in four patients, alien hand phenomenon in three, and prosopagnosia in one patient. Memory loss was reported by ten patients, but was not the main complaint in any of these cases. Insight was relatively preserved in five patients even after a long period following the onset of symptoms. Six patients developed parkinsonism during evolution. Clinical diagnoses were possible or probable AD in seven patients, cortico-basal degeneration in four, and dementia with Lewy body in one. Conclusions: Clinicians should consider this condition especially in presenile patients with slowly progressive higher-order visual symptoms. Although described in association with different conditions, it may also occur in Alzheimer disease.

Key words:
posterior cortical atrophy; syndrome of progressive posterior cortical dysfunction; Alzheimer disease; visual symptoms.

Resumo

As demências que se apresentam predominantemente com sintomas visuais associativos podem ser observadas em diferentes condições neurodegenerativas, sendo seu diagnóstico muitas vezes desafiador. Objetivos: Descrever as principais características clínicas de pacientes com demência progressiva que se apresentam com sintomas visuais proeminentes. Métodos: Conduzimos estudo retrospectivo de casos com demência progressiva com sintomas visuais predominantes vistos no nosso ambulatório de demência, no período de 1996 até 2006. Resultados: Doze pacientes (5 homens e 7 mulheres) foram identificados, com idades variando entre 49 e 67 anos. Na primeira consulta, duração de sintomas variou de um a dez anos e a pontuação do Mini-Exame do Estado Mental variou de 7 a 27 pontos. Onze pacientes apresentaram sintomas visuoespaciais predominantes (Síndrome de Bálint parcial ou completa) e um apresentou alteração visuoperceptiva. Outras manifestações relatadas foram: apraxia construtiva em 11 pacientes, síndrome de Gerstmann parcial ou completa em 10 pacientes, apraxia ideomotora em nove, heminegligência ou extinção em 4 pacientes, fenômeno da mão alienígena em 3 e prosopagnosia em um paciente. Queixa de perda de memória foi referida em 10 pacientes, mas em nenhum deles como queixa principal. Juízo crítico era preservado em cinco pacientes até estágios moderados da doença. Seis pacientes desenvolveram parkinsonismo ao longo da evolução. O diagnóstico clínico foi DA possível ou provável em sete pacientes, degeneração corticobasal em quatro e demência com corpos de Lewy em um paciente. Conclusões: Os clínicos devem ter em mente essa condição especialmente em pacientes pré-senis com queixas visuais complexas e lentamente progressivas. Apesar de descritas em diferentes condições, pode ocorrer na doença de Alzheimer.

Palavras-chave:
atrofia cortical posterior; síndrome de disfunção cortical posterior progressiva; doença de Alzheimer; sintomas visuais.

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References

¹
Benson F, Davis J, Snyder BD. Posterior cortical atrophy. Arch Neurol 1988;45:789-793.
²
Damasio AR. Disorders of complex visual processing: agnosias, achromatopsias, Balint's syndrome and related difficulties of orientation and construction. In: Mesulam MM, editor. Principles of behavioral neurology, Philadelphia: F.A. Davis Company; 1985:259-288.
³
Tang-Wai DF, Graff-Radford NR, Boeve BF, et al. Clinical, genetic and neuropathological characteristics of posterior cortical atrophy. Neurology 2004;63:1168-1174.
⁴
Mendez MF, Ghajarania M, Perryman KM. Posterior cortical atrophy: clinical characteristics and differences compared to Alzheimer's disease. Dement Geriatr Cogn Disord 2002;14:33-40.
⁵
Purvin V, Bonnin J, Goodman J. Palinopsia as a presenting manifestation of Creutzfeldt-Jacob disease. Am J Neuro-Ophtalmol 1989;9:242-246.
⁶
Vargas ME, Kupersmith MJ, Savino, et al. Homonymous field defect as first manifestation of Creutzfeldt-Jacob disease. Am J Neuro-Ophtalmol 1995;119:497-504.
⁷
Victoroff J, Ross W, Benson F, Verity A, Vinters HV. Posterior cortical atrophy. Neuropathologic considerations. Arch Neurol 1994;51:269-274.
⁸
Wenning GK, Litvan I, Jankovic J, et al. Natural history and survival of 14 patients with autopsy-confirmed corticobasal degeneration. J Neurol Neurosurg Psychiatry 1998;64:184-189.
⁹
Tang-Wai DF, Josephs KA, Boeve BF, Dickson DW, Parisi JE, Petersen RC. Pathologically confirmed corticobasal degeneration presenting with visuospatial dysfunction. Neurology 2003;61:1134-1135.
¹⁰
Renner JA, Burns JM, Hou CE, McKeel DW, Storandt M, Morris JC. Progressive posterior cortical dysfunction. A clinicopathologic series. Neurology 2004;63:1175-1180.
¹¹
McKhann G, Drachman D, Folstein M, et al. Clinical diagnosis of Alzheimer's disease: Report of the NINCDS-ADRDA work group under the auspices of department of health and human services task force on Alzheimer's disease. Neurology 1984;34:939-44.
¹²
Litvan I, Bhatia KP, Burn DJ, et al. Movement Disorders Society Scientific Issues Committee. Movement Disorders Society Scientific Issues Committee report: SIC Task Force appraisal of clinical diagnostic criteria for Parkinsonian disorders. Mov Disord 2003;18:467-486.
¹³
McKeith IG. Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the Consortium on DLB International Workshop. J Alzheimers Dis 2006;9(3 Suppl):417-423
¹⁴
Folstein MF, Folstein SE, McHugh PR. Mini-Mental State: a practical method for grading the cognitive state for the clinician. J Psychiatr Res 1975;12:189-198.
¹⁵
Brucki SMD, Nitrini R, Caramelli P, Bertolucci PHF, Okamoto IH. Sugestões para o uso do mini-exame do estado mental no Brasil. Arq Neuropsiquiatr 2003; 61:777-781.
¹⁶
Nitrini R, Lefevre BH, Mathias SC, et al. Neuropsychological tests of simple application for diagnosing dementia. Arq Neuropsiquiatr 1994;52:457-465.
¹⁷
Nitrini R, Caramelli P, Herrera Junior E, et al. Performance of illiterate and literate nondemented elderly subjects in two tests of long-term memory. J Int Neuropsychol Soc 2004;10:634-638.
¹⁸
Takada LT, Caramelli P, Fichman HC, et al. Comparison between two tests of delayed recall for the diagnosis of dementia. Arq Neuropsiquiatr 2006;64:35-40.
¹⁹
Miller E. Verbal fluency as a function of a measure of verbal intelligence and in relation to different types of cerebral pathology. Br J Clin Psychol 1984;8:385-394.
²⁰
Brucki SMD, Rocha MSG. Category fluency test: effects of age, gender ad education on total scores, clustering and switching in Brazilian Portuguese-speaking subjects. Braz J Med Biol Res 2004; 37:1771-1777.
²¹
Lesak MD. Neuropsychological assessment. 3rd ed. Nova York: Oxford University Press; 1995.
²²
Weintraub S. Neuropsychological assessment of mental state. In: Mesulam MM, editor. Principles of behavioral neurology , Philadelphia: F.A. Davis Company ;1985:121-173.
²³
Baddley A. Working memory. Science 1992;255:556-559.
²⁴
Croisile B, Trillet M, Hibert O, et al. Désordres visuo-constructifs et alexie-agraphie associés à une atrophie corticale postérieure. Rev Neurol (Paris) 1991;147:138-143.
²⁵
Leiguarda R, Merello M, Balej J. Apraxia in corticobasal degeneration. In: Litvan I, Goetz CG, Lang AE, editors. Corticobasal degeneration. Philadelphia: Lippincott Williams & Wilkins; 2000:103-121.
²⁶
Graham NL, Bak TH, Patterson K, Hodges JR. Language function and dysfunction in corticobasal degeneration. Neurology 2003;61:493-499.
²⁷
Graham NL, Zeman A Young AW, Patterson K, Hodges JR. Dyspraxia in a patient with corticobasal degeneration: the role of visual and tactile inputs of action. J Neurol Neurosurg Psychiatry 1999;67:334-344.
²⁸
Hodges JR, Spatt J, Patterson K. "What" and "how": evidence for the dissociation of object knowledge and mechanical problem solving skills in the human brain. Proc Natl Acad Sci USA 1999;96:9444-9448.
²⁹
Spatt J, Bak T, Bozeat S, Patterson K , Hodges JR. Apraxia, mechanical problem-solving and semantic knowledge: contribution to object usage in corticobasal degeneration. J Neurol 2002;249:601-608.
³⁰
Mendez MF. Corticobasal ganglionic degeneration with Bálint's syndrome. J Neuropsychiatry Clin Neurosci 2000;12: 273-275.
³¹
McMonagle P, Deering F, Berliner Y, Kertesz A. The cognitive profile of posterior cortical atrophy. Neurology 2006;66:331-338.
³²
Josephs KA, Whitwell JL, Boeve BF, et al. Visual hallucinations in posterior cortical atrophy. Arch Neurol 2006;63:1427-1432.
³³
Nodera H, Mori A, Izumi Y, Sakamoto T, Kaji R. Creutzfeldt-Jakob disease manifesting as posterior cortical dementia. Neurology 2005;65:330.
³⁴
Snowden JS, Mann DM, Neary D. Distinct neuropsychological characteristics in Creutzfeldt-Jakob disease. J Neurol Neurosurg Psychiatry 2002;73:686-694.
³⁵
Hof PR, Bouras C, Constantinidis J, Morrison JH. Balint's syndrome in Alzheimer's disease: specific disruption of the occipito-parietal visual pathway. Brain Res 1989;493:368-375.
³⁶
Hof PR, Bouras C, Constantinidis J, Morrison JH. Selective disconnection of specific visual association pathways in cases of Alzheimer's disease presenting with Bálint's syndrome. J Neuropathol Exp Neurol 1990;49:168-184.
³⁷
Morrison JH, Hof PR, Bouras C. An anatomic substrate for visual disconnection in Alzheimer's disease. Ann N Y Acad Sci 1991;640:36-43.
³⁸
Hof PR, Bouras C. Object recognition deficit in Alzheimer's disease: possible disconnection of the occipito-temporal component of the visual system. Neurosci Lett 1991;122:53-56.
³⁹
Hof PR, Archin N, Osmand AP, et al. Posterior cortical atrophy in Alzheimer's disease: analysis of a new case and re-evaluation of a historical report. Acta Neuropathol (Berl) 1993;86:215-23.
⁴⁰
Hof PR, Vogt BA, Bouras C, Morrison JH. Atypical form of Alzheimer's disease with prominent posterior cortical atrophy: a review of lesion distribution and circuit disconnection in cortical visual pathways. Vision Res 1997;37:3609-3625.
⁴¹
Giannakopoulos P, Gold G, Duc M, Michel JP, Hof PR, Bouras C. Neuroanatomic correlates of visual agnosia in Alzheimer's disease: a clinicopathologic study. Neurology 1999;52:71-77.
⁴²
Mendez MF, Cherrier MM. The evolution of alexia and simultagnosia in posterior cortical atrophy. Neuropsychiatry Neuropsychol Behav Neurol 1998;11:76-82.
⁴³
Attig E, Jacquy J, Uytdenhoef P, Roland H. Progressive focal degenerative disease of the posterior associative cortex. Can J Neurol Sci 1993;20:154-157.
⁴⁴
Levine DN, Lee JM, Fisher CM. The visual variant of Alzheimer's disease: a clinicopathologic case study. Neurology 1993;43:305-313.
⁴⁵
Schmitdke K, Hüll M, Talazko J. Posterior cortical atrophy: a variant of Alzheimer's disease? A case series with PET findings. J Neurol 2005;27:27-35.
⁴⁶
Flament S, Delacourte A, Delaère P, Duyckaertz C, Haw JJ. Correlation between microscopical changes and tau 64 an 69 biochemical detection in senile dementia of the Alzheimer's type. Tau 64 and 69 are reliable markers of the neurofibrillary degeneration. Acta Neuropathol 1990;80:212:215.
⁴⁷
Freedman L, Selchen DH, Black SE, Kaplan R, Garnett ES, Nahmias CN. Posterior cortical dementia with alexia: neurobehavioral, MRI, and PET findings. J Neurol Neurosurg Psychiatry 1991;54:443-448.
⁴⁸
Wakai M, Honda H, Takaha A, Kato T, Ito K, Hamanaka T. Unusual findings on PET study of a patient with posterior cortical atrophy. Acta Neurol Scand 1994;89:458-461.
⁴⁹
Ross SJM, Graham N, Stuart-Green L, et al. Progressive biparietal atrophy: an atypical presentation of Alzheimer's disease. J Neurol Neurosurg Psychiatry 1996:61:388-395.
⁵⁰
Nestor PJ, Caine D, Fryer TD, Clarke J, Hodges JR. The topography of metabolic deficits in posterior cortical atrophy (the visual variant of Alzheimer's disease) with FDG-PET. J Neurol Neurosurg Psychiatry 2003;74:1521-1529.

Publication Dates

Publication in this collection
Jul-Sep 2007

This is an open-access article distributed under the terms of the Creative Commons Attribution License

[1] ¹
Benson F, Davis J, Snyder BD. Posterior cortical atrophy. Arch Neurol 1988;45:789-793.

[2] ²
Damasio AR. Disorders of complex visual processing: agnosias, achromatopsias, Balint's syndrome and related difficulties of orientation and construction. In: Mesulam MM, editor. Principles of behavioral neurology, Philadelphia: F.A. Davis Company; 1985:259-288.

[3] ³
Tang-Wai DF, Graff-Radford NR, Boeve BF, et al. Clinical, genetic and neuropathological characteristics of posterior cortical atrophy. Neurology 2004;63:1168-1174.

[4] ⁴
Mendez MF, Ghajarania M, Perryman KM. Posterior cortical atrophy: clinical characteristics and differences compared to Alzheimer's disease. Dement Geriatr Cogn Disord 2002;14:33-40.

[5] ⁵
Purvin V, Bonnin J, Goodman J. Palinopsia as a presenting manifestation of Creutzfeldt-Jacob disease. Am J Neuro-Ophtalmol 1989;9:242-246.

[6] ⁶
Vargas ME, Kupersmith MJ, Savino, et al. Homonymous field defect as first manifestation of Creutzfeldt-Jacob disease. Am J Neuro-Ophtalmol 1995;119:497-504.

[7] ⁷
Victoroff J, Ross W, Benson F, Verity A, Vinters HV. Posterior cortical atrophy. Neuropathologic considerations. Arch Neurol 1994;51:269-274.

[8] ⁸
Wenning GK, Litvan I, Jankovic J, et al. Natural history and survival of 14 patients with autopsy-confirmed corticobasal degeneration. J Neurol Neurosurg Psychiatry 1998;64:184-189.

[9] ⁹
Tang-Wai DF, Josephs KA, Boeve BF, Dickson DW, Parisi JE, Petersen RC. Pathologically confirmed corticobasal degeneration presenting with visuospatial dysfunction. Neurology 2003;61:1134-1135.

[10] ¹⁰
Renner JA, Burns JM, Hou CE, McKeel DW, Storandt M, Morris JC. Progressive posterior cortical dysfunction. A clinicopathologic series. Neurology 2004;63:1175-1180.

[11] ¹¹
McKhann G, Drachman D, Folstein M, et al. Clinical diagnosis of Alzheimer's disease: Report of the NINCDS-ADRDA work group under the auspices of department of health and human services task force on Alzheimer's disease. Neurology 1984;34:939-44.

[12] ¹²
Litvan I, Bhatia KP, Burn DJ, et al. Movement Disorders Society Scientific Issues Committee. Movement Disorders Society Scientific Issues Committee report: SIC Task Force appraisal of clinical diagnostic criteria for Parkinsonian disorders. Mov Disord 2003;18:467-486.

[13] ¹³
McKeith IG. Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the Consortium on DLB International Workshop. J Alzheimers Dis 2006;9(3 Suppl):417-423

[14] ¹⁴
Folstein MF, Folstein SE, McHugh PR. Mini-Mental State: a practical method for grading the cognitive state for the clinician. J Psychiatr Res 1975;12:189-198.

[15] ¹⁵
Brucki SMD, Nitrini R, Caramelli P, Bertolucci PHF, Okamoto IH. Sugestões para o uso do mini-exame do estado mental no Brasil. Arq Neuropsiquiatr 2003; 61:777-781.

[16] ¹⁶
Nitrini R, Lefevre BH, Mathias SC, et al. Neuropsychological tests of simple application for diagnosing dementia. Arq Neuropsiquiatr 1994;52:457-465.

[17] ¹⁷
Nitrini R, Caramelli P, Herrera Junior E, et al. Performance of illiterate and literate nondemented elderly subjects in two tests of long-term memory. J Int Neuropsychol Soc 2004;10:634-638.

[18] ¹⁸
Takada LT, Caramelli P, Fichman HC, et al. Comparison between two tests of delayed recall for the diagnosis of dementia. Arq Neuropsiquiatr 2006;64:35-40.

[19] ¹⁹
Miller E. Verbal fluency as a function of a measure of verbal intelligence and in relation to different types of cerebral pathology. Br J Clin Psychol 1984;8:385-394.

[20] ²⁰
Brucki SMD, Rocha MSG. Category fluency test: effects of age, gender ad education on total scores, clustering and switching in Brazilian Portuguese-speaking subjects. Braz J Med Biol Res 2004; 37:1771-1777.

[21] ²¹
Lesak MD. Neuropsychological assessment. 3rd ed. Nova York: Oxford University Press; 1995.

[22] ²²
Weintraub S. Neuropsychological assessment of mental state. In: Mesulam MM, editor. Principles of behavioral neurology , Philadelphia: F.A. Davis Company ;1985:121-173.

[23] ²³
Baddley A. Working memory. Science 1992;255:556-559.

[24] ²⁴
Croisile B, Trillet M, Hibert O, et al. Désordres visuo-constructifs et alexie-agraphie associés à une atrophie corticale postérieure. Rev Neurol (Paris) 1991;147:138-143.

[25] ²⁵
Leiguarda R, Merello M, Balej J. Apraxia in corticobasal degeneration. In: Litvan I, Goetz CG, Lang AE, editors. Corticobasal degeneration. Philadelphia: Lippincott Williams & Wilkins; 2000:103-121.

[26] ²⁶
Graham NL, Bak TH, Patterson K, Hodges JR. Language function and dysfunction in corticobasal degeneration. Neurology 2003;61:493-499.

[27] ²⁷
Graham NL, Zeman A Young AW, Patterson K, Hodges JR. Dyspraxia in a patient with corticobasal degeneration: the role of visual and tactile inputs of action. J Neurol Neurosurg Psychiatry 1999;67:334-344.

[28] ²⁸
Hodges JR, Spatt J, Patterson K. "What" and "how": evidence for the dissociation of object knowledge and mechanical problem solving skills in the human brain. Proc Natl Acad Sci USA 1999;96:9444-9448.

[29] ²⁹
Spatt J, Bak T, Bozeat S, Patterson K , Hodges JR. Apraxia, mechanical problem-solving and semantic knowledge: contribution to object usage in corticobasal degeneration. J Neurol 2002;249:601-608.

[30] ³⁰
Mendez MF. Corticobasal ganglionic degeneration with Bálint's syndrome. J Neuropsychiatry Clin Neurosci 2000;12: 273-275.

[31] ³¹
McMonagle P, Deering F, Berliner Y, Kertesz A. The cognitive profile of posterior cortical atrophy. Neurology 2006;66:331-338.

[32] ³²
Josephs KA, Whitwell JL, Boeve BF, et al. Visual hallucinations in posterior cortical atrophy. Arch Neurol 2006;63:1427-1432.

[33] ³³
Nodera H, Mori A, Izumi Y, Sakamoto T, Kaji R. Creutzfeldt-Jakob disease manifesting as posterior cortical dementia. Neurology 2005;65:330.

[34] ³⁴
Snowden JS, Mann DM, Neary D. Distinct neuropsychological characteristics in Creutzfeldt-Jakob disease. J Neurol Neurosurg Psychiatry 2002;73:686-694.

[35] ³⁵
Hof PR, Bouras C, Constantinidis J, Morrison JH. Balint's syndrome in Alzheimer's disease: specific disruption of the occipito-parietal visual pathway. Brain Res 1989;493:368-375.

[36] ³⁶
Hof PR, Bouras C, Constantinidis J, Morrison JH. Selective disconnection of specific visual association pathways in cases of Alzheimer's disease presenting with Bálint's syndrome. J Neuropathol Exp Neurol 1990;49:168-184.

[37] ³⁷
Morrison JH, Hof PR, Bouras C. An anatomic substrate for visual disconnection in Alzheimer's disease. Ann N Y Acad Sci 1991;640:36-43.

[38] ³⁸
Hof PR, Bouras C. Object recognition deficit in Alzheimer's disease: possible disconnection of the occipito-temporal component of the visual system. Neurosci Lett 1991;122:53-56.

[39] ³⁹
Hof PR, Archin N, Osmand AP, et al. Posterior cortical atrophy in Alzheimer's disease: analysis of a new case and re-evaluation of a historical report. Acta Neuropathol (Berl) 1993;86:215-23.

[40] ⁴⁰
Hof PR, Vogt BA, Bouras C, Morrison JH. Atypical form of Alzheimer's disease with prominent posterior cortical atrophy: a review of lesion distribution and circuit disconnection in cortical visual pathways. Vision Res 1997;37:3609-3625.

[41] ⁴¹
Giannakopoulos P, Gold G, Duc M, Michel JP, Hof PR, Bouras C. Neuroanatomic correlates of visual agnosia in Alzheimer's disease: a clinicopathologic study. Neurology 1999;52:71-77.

[42] ⁴²
Mendez MF, Cherrier MM. The evolution of alexia and simultagnosia in posterior cortical atrophy. Neuropsychiatry Neuropsychol Behav Neurol 1998;11:76-82.

[43] ⁴³
Attig E, Jacquy J, Uytdenhoef P, Roland H. Progressive focal degenerative disease of the posterior associative cortex. Can J Neurol Sci 1993;20:154-157.

[44] ⁴⁴
Levine DN, Lee JM, Fisher CM. The visual variant of Alzheimer's disease: a clinicopathologic case study. Neurology 1993;43:305-313.

[45] ⁴⁵
Schmitdke K, Hüll M, Talazko J. Posterior cortical atrophy: a variant of Alzheimer's disease? A case series with PET findings. J Neurol 2005;27:27-35.

[46] ⁴⁶
Flament S, Delacourte A, Delaère P, Duyckaertz C, Haw JJ. Correlation between microscopical changes and tau 64 an 69 biochemical detection in senile dementia of the Alzheimer's type. Tau 64 and 69 are reliable markers of the neurofibrillary degeneration. Acta Neuropathol 1990;80:212:215.

[47] ⁴⁷
Freedman L, Selchen DH, Black SE, Kaplan R, Garnett ES, Nahmias CN. Posterior cortical dementia with alexia: neurobehavioral, MRI, and PET findings. J Neurol Neurosurg Psychiatry 1991;54:443-448.

[48] ⁴⁸
Wakai M, Honda H, Takaha A, Kato T, Ito K, Hamanaka T. Unusual findings on PET study of a patient with posterior cortical atrophy. Acta Neurol Scand 1994;89:458-461.

[49] ⁴⁹
Ross SJM, Graham N, Stuart-Green L, et al. Progressive biparietal atrophy: an atypical presentation of Alzheimer's disease. J Neurol Neurosurg Psychiatry 1996:61:388-395.

[50] ⁵⁰
Nestor PJ, Caine D, Fryer TD, Clarke J, Hodges JR. The topography of metabolic deficits in posterior cortical atrophy (the visual variant of Alzheimer's disease) with FDG-PET. J Neurol Neurosurg Psychiatry 2003;74:1521-1529.

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