Atormac
Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 1479  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Search
 
  
 Resource Links
  ╗  Similar in PUBMED
 ╗  Search Pubmed for
 ╗  Search in Google Scholar for
  ╗  Article in PDF (672 KB)
  ╗  Citation Manager
  ╗  Access Statistics
  ╗  Reader Comments
  ╗  Email Alert *
  ╗  Add to My List *
* Registration required (free)  

 
  In this Article
   References
   Article Figures
   Article Tables

 Article Access Statistics
    Viewed4246    
    Printed99    
    Emailed2    
    PDF Downloaded90    
    Comments [Add]    
    Cited by others 4    

Recommend this journal

 


 
Table of Contents    
LETTER TO EDITOR
Year : 2011  |  Volume : 59  |  Issue : 2  |  Page : 297-299

Posterior cortical atrophy: A rare visual variant of Alzheimer's disease


Department of Neurology, Medical College, Calicut 8, Kerala, India

Date of Submission28-Nov-2010
Date of Decision28-Nov-2010
Date of Acceptance21-Dec-2010
Date of Web Publication7-Apr-2011

Correspondence Address:
K Saifudheen
Department of Neurology, Medical College, Calicut 8, Kerala
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0028-3886.79154

Rights and Permissions



How to cite this article:
Gafoor V A, Jose J, Saifudheen K, Musthafa M. Posterior cortical atrophy: A rare visual variant of Alzheimer's disease. Neurol India 2011;59:297-9

How to cite this URL:
Gafoor V A, Jose J, Saifudheen K, Musthafa M. Posterior cortical atrophy: A rare visual variant of Alzheimer's disease. Neurol India [serial online] 2011 [cited 2019 Aug 18];59:297-9. Available from: http://www.neurologyindia.com/text.asp?2011/59/2/297/79154


Sir,

The term posterior cortical atrophy (PCA) refers to a clinical syndrome characterized by progressive disruption of higher order visual processing owing to a neurodegenerative disorder. It was first described by Franck Benson in 1988. [1] The complex visual disorders seen in PCA patients include elements of Balint's syndrome, apperceptive visual agnosia, alexia, environmental disorientation, simultagnosia, prosopagnosia, and left hemineglect. It is twice common in females. Senile plaques and neurofibrillary tangles constitute the characteristic pathologic findings of PCA and for this reason; some authors use the term "visual variant of Alzheimer's disease (AD)."

A 56-year-old female presented with a 5-year history of insidious onset of difficulty in recognizing familiar faces including that of her family members. However, she could identify them by their voices. Subsequently she developed difficulty in identifying some common objects like household articles. Her speech and writing were normal but she was unable to read. Later, three years into her illness, her family members noticed that she had disregard to objects in the left half of her visual field and for the last 6 months she had difficulty in dressing up by herself. Her behavior and memory were normal and she did not have any dysexecutive symptoms or visuospatial problems. She did not have any hallucinations, weakness, extra pyramidal symptoms, or ataxia. Her past, family and personal histories were insignificant. On examination, she was a right handed, conscious, cooperative, attentive, and cheerful lady. Her Mini Mental Status Examination score was 26/30. Neuropsychological examination revealed marked impairment in the ability to recognize familiar faces, but she was able to provide semantic information about them when their identity was disclosed to her. She also had left hemineglect and constructional apraxia. Elements of Gerstmann's syndrome were present namely, acalculia, alexia, and finger agnosia. She also had Balint's syndrome (simultagnosia, optic ataxia, and ocular motor apraxia). Her visual acuity was 20/100 in both eyes and visual field examination by confrontation revealed left hemineglect. Color vision and funduscopic examination were normal. Her pupils reacted briskly to light and eyes accommodated well to near vision. She did not have any motor or cortical sensory deficits or alien hand phenomenon. Routine blood, urine, serum chemistry, liver, and renal function tests were normal. Magnetic resonance imaging showed marked atrophy of both parietal lobes, with more severe atrophy on right side along with atrophy of both occipital and right temporal lobes [Figure 1]. Electroencephalogram was normal.
Figure 1: (a) Sagittal T1-weighted image shows right side parietoccipital atrophy, (b) Axial T1-weighted image shows marked occipital and parietal cortical atrophy with more severe atrophy on right side

Click here to view


In our patient the first and most disabling symptom was progressive prosopagnosia followed by visual object agnosia. This indicates a disorder affecting the bilateral occipitotemporal (ventral visual stream) cortices. Prosopagnosia has also been described in unilateral lesions affecting the right occipitotemporal cortex or more precisely the right fusiform cortex. [2] Subsequent development of Balint's syndrome and components of Gerstmann's syndrome points to the involvement of the bilateral occipitoparietal cortices (dorsal visual stream). Of late, she developed dressing apraxia and left hemi neglect which could suggest right parietal lobe affection. This constellation of findings is suggestive of posterior cortical atrophy or Benson's syndrome, a rare presenile dementia. The diagnostic criteria for PCA have been proposed [3] [Table 1]. The most common pathologic findings of PCA are senile plaques and neurofibrillary tangles predominantly affecting visual association areas. [4] But the focal distribution of these changes distinguishes them from typical AD. Magnetic resonance imaging of our patient showed atrophy of occipitoparietal and occipitotemporal cortex with right side being affected more severely. Our patient had prominent atrophy of the right temporal lobe, but she did not have any impairment of episodic memory. Right temporal variant frontotemporal dementia has been described which can also be associated with prosopagnosia. [5] But the other manifestations of involvement of visual association areas of brain like Balint syndrome and Gerstmann syndrome are not features of this entity and almost 100% of patients develop inappropriate behaviors as the disease progresses. [5] Our patient did not develop any behavioral alterations even after five years of disease duration which argues against a diagnosis of right temporal variant of FTD. Therefore, it can be postulated that the right mesial temporal involvement in our patient is only an extension of the focal cortical degeneration which is a hallmark of PCA.
Table 1: Proposed diagnostic criteria


Click here to view


 
 ╗ References Top

1.Benson DF, Davis RJ, Snyder BD. Posterior cortical atrophy. Arch Neurol 1988;45:789-93.  Back to cited text no. 1
[PUBMED]  [FULLTEXT]  
2.Joubert S, Felician O, Barbeau E, Sontheimer A, Barton JJ, Ceccaldi M, et al. Impaired configurational processing in a case of progressive prosopagnosia associated with predominant right temporal lobe atrophy. Brain 2003;126:2537-50.  Back to cited text no. 2
[PUBMED]  [FULLTEXT]  
3.Tang-Wai DF, Graff-Radford NR, Boeve BF, Dickson DW, Parisi JE, Crook R, et al. Clinical, genetic, and neuropathologic characteristics of posterior cortical atrophy. Neurology 2004;63:1168-74.  Back to cited text no. 3
[PUBMED]  [FULLTEXT]  
4.Levine DN, Lee JM, Fisher CM. The visual variant of Alzheimer's disease: A clinicopathologic case study. Neurology 1993;43:305-13.  Back to cited text no. 4
[PUBMED]    
5.Josephs KA, Whitwell JL, Knopman DS, Boeve BF, Vemuri P, Senjem ML, et al. Two distinct subtypes of right temporal variant frontotemporal dementia. Neurology 2009;73:1443-50.  Back to cited text no. 5
[PUBMED]  [FULLTEXT]  


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1]

This article has been cited by
1 Visuospatial perception: An emerging biomarker for AlzheimerŠs disease
Mandal, P.K. and Joshi, J. and Saharan, S.
Journal of AlzheimerŠs Disease. 2012; 31(SUPPL. 3): S117-S135
[Pubmed]
2 Posterior cortical atrophy
Crutch, S.J., Lehmann, M., Schott, J.M., Rabinovici, G.D., Rossor, M.N., Fox, N.C.
The Lancet Neurology. 2012; 11(2): 170-178
[Pubmed]
3 Posterior cortical atrophy
Sebastian J Crutch,Manja Lehmann,Jonathan M Schott,Gil D Rabinovici,Martin N Rossor,Nick C Fox
The Lancet Neurology. 2012; 11(2): 170
[Pubmed] | [DOI]
4 Posterior cortical atrophy: A rare visual variant of AlzheimerŠs disease
Arora, A., Sharma, C.M., Kumawat, B.L., Khandelwal, D.
Neurology India. 2011; 59(3): 482-484
[Pubmed]



 

Top
Print this article  Email this article
   
Online since 20th March '04
Published by Wolters Kluwer - Medknow