bs_bs_banner
Geriatr Gerontol Int 2014; 14: 1003–1007
LETTERS TO THE EDITOR CASE REPORT
Visual field defect as an uncommon presentation of posterior cortical atrophy
Dear Editor, Visual field defect in the form of homonymous hemianopia is rarely caused by a neurodegenerative condition. We report the first Chinese patient with visual field defect as a result of posterior cortical atrophy (PCA). Our patient was a 61-year-old man, with a university degree. He presented with “blurring of vision” and gradual deterioration in his native language ability. Fundoscopic examination was normal, and visual field perimetry showed right homonymous hemianopia. Over the past 7 years, he developed alexia, anomia, agnosia, prosopagnosia and achromatopsia. In the past 2 years, he also had anterograde episodic memory
impairment with problems in judgment. He did not have any stereotyped behavior, motor symptoms or visual hallucinations. Physical examination was unremarkable, and he did not have hemi-neglect. His Mini-Mental State Examination score was 29, with impairment in the intersecting pentagon construction. The patient showed significant deficits in word recognition, naming and word recall in the Alzheimer’s Disease Assessment Scale Cognitive Subscale, which was 13. Magnetic resonance imaging of the brain showed bilateral parietal lobes atrophy (Fig. 1a), but normal hippocampi (Fig. 1b). 11C-Pittsburgh compound B positron emission tomography of the brain (Fig. 1c,d) showed generalized heavy amyloid loading
Figure 1 (a) Axial T1 weighted magnetic resonance imaging of the brain showing bilateral parietal lobes atrophy. (b) Coronal section of fluid attenuated inversion recovery sequences magnetic resonance imaging noted relative preservation of bilateral hippocampi. (c) Positron emission tomography of the brain showing hypometabolism over the bilateral temporoparietal lobes. (d) 11C-Pittsburgh compound B imaging showed amyloid depositions, especially over the bilateral frontal lobes, parietal lobes, temporal lobes, occipital lobes, posterior cingulate gyrus and precuneus.
© 2014 Japan Geriatrics Society
doi: 10.1111/ggi.12203
| 1003
YF Shea and L-W Chu
with hypometabolism over the bilateral temporoparietal lobe. He refused lumbar puncture for the measurement of cerebrospinal fluid biomarkers (i.e. Aβ42, total tau and phosphorylated tau). In summary, our patient fulfilled the proposed diagnostic criteria for PCA.1,2 He was started on rivastigmine and later, added on memantine. He was advised against driving because of his impaired vision. He continued to report visuospatial impairment (e.g. problem in seeing the bus number), acalculia and agraphia over a 2-year follow-up period. PCA, which is a rare form of dementia, is clinically characterized by Balint’s syndrome, Gertsmann’s syndrome, visual agnosia, alexia, agraphia and transcortical sensory aphasia.1–3 In the vast majority (>80%) of PCA cases, amyloid plaques and neurofibrillary tangles are the underlying pathological substrate, as in Alzheimer’s disease.1,2 PCA also accounted for 20.6% of AD with atypical presentations.4 Although visual defects had been reported to occur in 47.5% of PCA subjects, it could easily be missed unless tested by formal perimetry measurements. 75% of these visual field defects are hemianopia or quadranopia.2 The visual field defects are caused by significantly higher cortical pathologies; that is, neurofibrillary tangles and senile plaques in the primary and visual association cortices.3,5 The hypometabolism over the left temporoparietal regions on the positron emission tomography scan (Fig. 1c) correlated with the presentation of right homonymous hemianopia in the present patient. Clinicians should be alerted that neurodegenerative disease could be a cause of visual field defect, especially in the setting of relatively normal structural imaging findings other than cerebral atrophy and normal fundoscopy. The mean delay between symptom onset and the diagnosis of PCA is 4 years.3 After a diagnosis of PCA, referral for proper perimetry measurement should be made, as this could have significant implications for driving safety.2 A total of 78% of PCA patients reported difficulty in driving.2 As the most common underlying pathological substrate is Alzheimer’s disease, further
1004 |
investigations, such as 11C-Pittsburgh compound B positron emission tomography or lumbar puncture for measurements of cerebrospinal fluid biomarkers, can confirm the underlying pathology.1,5,6 Medications, such as acetylcholinesterase inhibitor and memantine, are helpful to slow the cognitive decline.
Acknowledgments Informed consent was obtained from the patient
Disclosure statement The authors declare no conflict of interest. Yat Fung Shea and Leung-Wing Chu Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, China
References 1 Crutch SJ, Schott JM, Rabinovici GD et al. Shining a light on posterior cortical atrophy. Alzheimers Dement 2013; 9: 463– 465. 2 Tang-Wai DF, Graff-Radford NR, Boeve BF et al. Clinical, genetic, and neuropathologic characteristics of posterior cortical atrophy. Neurology 2004; 63: 1168–1174. 3 Pelak VS, Smyth SF, Boyer PJ, Filley CM. Computerized visual field defects in posterior cortical atrophy. Neurology 2011; 77: 2119–2122. 4 Alladi S, Xuereb J, Bak T et al. Focal cortical presentations of Alzheimer’s disease. Brain 2007; 130: 2636–2645. 5 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. 6 Shea YF, Chu LW, Zhou L et al. Cerebrospinal fluid biomarkers of Alzheimer’s disease in Chinese patients. A Pilot study. Am J Alzheimers Dis Other Demen 2013; Oct 1. [Epub ahead of print] doi:10.1177/1533317513504615
© 2014 Japan Geriatrics Society
Geriatr Gerontol Int 2014; 14: 1003–1007
LETTERS TO THE EDITOR CASE REPORT
Visual field defect as an uncommon presentation of posterior cortical atrophy
Dear Editor, Visual field defect in the form of homonymous hemianopia is rarely caused by a neurodegenerative condition. We report the first Chinese patient with visual field defect as a result of posterior cortical atrophy (PCA). Our patient was a 61-year-old man, with a university degree. He presented with “blurring of vision” and gradual deterioration in his native language ability. Fundoscopic examination was normal, and visual field perimetry showed right homonymous hemianopia. Over the past 7 years, he developed alexia, anomia, agnosia, prosopagnosia and achromatopsia. In the past 2 years, he also had anterograde episodic memory
impairment with problems in judgment. He did not have any stereotyped behavior, motor symptoms or visual hallucinations. Physical examination was unremarkable, and he did not have hemi-neglect. His Mini-Mental State Examination score was 29, with impairment in the intersecting pentagon construction. The patient showed significant deficits in word recognition, naming and word recall in the Alzheimer’s Disease Assessment Scale Cognitive Subscale, which was 13. Magnetic resonance imaging of the brain showed bilateral parietal lobes atrophy (Fig. 1a), but normal hippocampi (Fig. 1b). 11C-Pittsburgh compound B positron emission tomography of the brain (Fig. 1c,d) showed generalized heavy amyloid loading
Figure 1 (a) Axial T1 weighted magnetic resonance imaging of the brain showing bilateral parietal lobes atrophy. (b) Coronal section of fluid attenuated inversion recovery sequences magnetic resonance imaging noted relative preservation of bilateral hippocampi. (c) Positron emission tomography of the brain showing hypometabolism over the bilateral temporoparietal lobes. (d) 11C-Pittsburgh compound B imaging showed amyloid depositions, especially over the bilateral frontal lobes, parietal lobes, temporal lobes, occipital lobes, posterior cingulate gyrus and precuneus.
© 2014 Japan Geriatrics Society
doi: 10.1111/ggi.12203
| 1003
YF Shea and L-W Chu
with hypometabolism over the bilateral temporoparietal lobe. He refused lumbar puncture for the measurement of cerebrospinal fluid biomarkers (i.e. Aβ42, total tau and phosphorylated tau). In summary, our patient fulfilled the proposed diagnostic criteria for PCA.1,2 He was started on rivastigmine and later, added on memantine. He was advised against driving because of his impaired vision. He continued to report visuospatial impairment (e.g. problem in seeing the bus number), acalculia and agraphia over a 2-year follow-up period. PCA, which is a rare form of dementia, is clinically characterized by Balint’s syndrome, Gertsmann’s syndrome, visual agnosia, alexia, agraphia and transcortical sensory aphasia.1–3 In the vast majority (>80%) of PCA cases, amyloid plaques and neurofibrillary tangles are the underlying pathological substrate, as in Alzheimer’s disease.1,2 PCA also accounted for 20.6% of AD with atypical presentations.4 Although visual defects had been reported to occur in 47.5% of PCA subjects, it could easily be missed unless tested by formal perimetry measurements. 75% of these visual field defects are hemianopia or quadranopia.2 The visual field defects are caused by significantly higher cortical pathologies; that is, neurofibrillary tangles and senile plaques in the primary and visual association cortices.3,5 The hypometabolism over the left temporoparietal regions on the positron emission tomography scan (Fig. 1c) correlated with the presentation of right homonymous hemianopia in the present patient. Clinicians should be alerted that neurodegenerative disease could be a cause of visual field defect, especially in the setting of relatively normal structural imaging findings other than cerebral atrophy and normal fundoscopy. The mean delay between symptom onset and the diagnosis of PCA is 4 years.3 After a diagnosis of PCA, referral for proper perimetry measurement should be made, as this could have significant implications for driving safety.2 A total of 78% of PCA patients reported difficulty in driving.2 As the most common underlying pathological substrate is Alzheimer’s disease, further
1004 |
investigations, such as 11C-Pittsburgh compound B positron emission tomography or lumbar puncture for measurements of cerebrospinal fluid biomarkers, can confirm the underlying pathology.1,5,6 Medications, such as acetylcholinesterase inhibitor and memantine, are helpful to slow the cognitive decline.
Acknowledgments Informed consent was obtained from the patient
Disclosure statement The authors declare no conflict of interest. Yat Fung Shea and Leung-Wing Chu Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, China
References 1 Crutch SJ, Schott JM, Rabinovici GD et al. Shining a light on posterior cortical atrophy. Alzheimers Dement 2013; 9: 463– 465. 2 Tang-Wai DF, Graff-Radford NR, Boeve BF et al. Clinical, genetic, and neuropathologic characteristics of posterior cortical atrophy. Neurology 2004; 63: 1168–1174. 3 Pelak VS, Smyth SF, Boyer PJ, Filley CM. Computerized visual field defects in posterior cortical atrophy. Neurology 2011; 77: 2119–2122. 4 Alladi S, Xuereb J, Bak T et al. Focal cortical presentations of Alzheimer’s disease. Brain 2007; 130: 2636–2645. 5 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. 6 Shea YF, Chu LW, Zhou L et al. Cerebrospinal fluid biomarkers of Alzheimer’s disease in Chinese patients. A Pilot study. Am J Alzheimers Dis Other Demen 2013; Oct 1. [Epub ahead of print] doi:10.1177/1533317513504615
© 2014 Japan Geriatrics Society
