This article was downloaded by: [Universitat Politècnica de València] On: 23 October 2014, At: 01:53 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Neurocase: The Neural Basis of Cognition Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/nncs20 Hemispatial visual defect in Alzheimer's disease a b Haruhiko Oda , Shingo Ohkawa & Kiyoshi Maeda a a Department of Psychiatry and Neurology , Kobe University Graduate School of Medicine, Kusunoki-cho, Chuou-ku , Kobe, Japan b Department of Aging Brain and Cognitive , Hyogo Brain and Heart Center at Himeji, Saisho-Ko , Himeji, Japan Published online: 19 Jun 2008. To cite this article: Haruhiko Oda , Shingo Ohkawa & Kiyoshi Maeda (2008) Hemispatial visual defect in Alzheimer's disease, Neurocase: The Neural Basis of Cognition, 14:2, 141-146, DOI: 10.1080/13554790802032226 To link to this article: http://dx.doi.org/10.1080/13554790802032226 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. 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Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions NEUROCASE 2008, 14 (2), 141–146 NNCS Hemispatial visual defect in Alzheimer’s disease Hemispatial Visual Defect in Alzheimer’s Disease Haruhiko Oda,1 Shingo Ohkawa,2 and Kiyoshi Maeda1 1 Downloaded by [Universitat Politècnica de València] at 01:53 23 October 2014 Department of Psychiatry and Neurology, Kobe University Graduate School of Medicine, Kusunoki-cho, Chuou-ku, Kobe, Japan 2 Department of Aging Brain and Cognitive, Hyogo Brain and Heart Center at Himeji, Saisho-Ko, Himeji, Japan We describe a 56-year-old woman with Alzheimer’s disease with left hemispatial neglect and left homonymous hemianopsia with macular sparing considered a manifestation of Alzheimer’s disease resulting from severe degenerative change in the right primary visual cortex. Hemispatial neglect normally results from brain damage to the right cerebral hemisphere. Homonymous hemianopsia is commonly the result of localized brain disease, especially cerebral infarction or hemorrhage. To our knowledge, a patient with Alzheimer’s disease showing hemispatial neglect and homonymous hemianopsia with macular sparing has not previously been reported. Keywords: Dementia; Alzheimer; Macular sparing; Neglect; Hemianopsia. INTRODUCTION CASE REPORT Hemianopsia is a primary sensory dysfunction due to unilateral involvement of the visual pathways or cortex (Miller & Newman, 1998). This neurological sign is commonly the result of localized brain disease, especially cerebral infarction or hemorrhage, and is only rarely reported in patients with degenerative dementias such as Alzheimer’s disease (AD) and dementia with Lewy bodies (Bashir, Elble, Ghobrial, & Struble, 1998; Shuren & Heilman, 1993). Hemispatial neglect is a deficit in attention to the one side of the visual space normally after damage to the opposite hemisphere of the brain. We report here a patient with AD who showed a left hemispatial neglect and a left homonymous hemianopsia with macula sparing. To our knowledge, this type of visual defect has not previously been reported in a patient with AD. A 56-year-old right-handed woman was hospitalized with a 2-year history of slowly progressing memory impairment and topographic disorientation. She had no history of stroke or transient ischemic attacks, and no episode of confusion, agitation, hallucinations, delusions, or depression. Results of physical examination were normal. On neurological examination, a left homonymous hemianopsia was detected on visual field testing by confrontation technique, though the patient herself was unaware of it. This deficit was also present when she rotated her head or trunk and looked into the right or left hemispace. Visual acuities were right 20/25, left 20/25, without correction. Saccades and smooth pursuit eye movements were normal. There were no other neurological abnormalities: notably, the extrapyramidal system was intact. An ophthalmologist noted no findings of retinal or ocular We are greatful to Kazunari Ishii for advice on radiologic findings. Address correspondence to Haruhiko Oda, Department of Psychiatry and Neurology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuou-ku, Kobe 650-0017, Japan (E-mail: oda72742@yahoo.co.jp). © 2008 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business http://www.psypress.com/neurocase DOI: 10.1080/13554790802032226 142 ODA ET AL. pathology. Goldman perimetry (kinetic perimetry) revealed a left homonymous hemianopsia, with sparing of the central field of each eye (Figure 1). Automatic perimetry was not performed. On the Mini-Mental State Examination (Japanese version), she scored 16 of 30 with errors in orientation, attention, verbal memory, and construction (visuospatial function). She was poorly Downloaded by [Universitat Politècnica de València] at 01:53 23 October 2014 (a) (b) Figure 1. Goldman perimetry: (a) right eye; (b) left eye. There is a left homonymous hemianopsia with macular sparing. Downloaded by [Universitat Politècnica de València] at 01:53 23 October 2014 HEMISPATIAL VISUAL DEFECT IN ALZHEIMER’S DISEASE oriented to time, recalled 0 of 3 words at 3 min, and failed to copy the left side of a cube. She scored 15 on the Alzheimer’s Disease Assessment Scale-cognition (ADAS-cog) (Japanese version), and had a full IQ of 72 on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) (Japanese version) (Table 1). She was neither aphasic nor apraxic. In a horizontal bisection test of a 200-mm black line on a sheet of white paper, her subjective midpoint was shifted 36 mm to the right from the true midpoint. In a line cancellation test, she omitted five of 41 lines in the left fifth of the test sheet (Figure 2). In copying a picture of a flower, she failed to draw the left halves of petals and leaves (Figure 3). Color identification was preserved. Her brain magnetic resonance imaging (MRI) showed cerebral atrophy bilaterally in the frontal and right temporo-parietal lobes, and ventricular enlargement predominantly in the right inferior horn. A fluid attenuated inversion recovery (FLAIR) images revealed very mild ischemic changes in the subcortical white matter (Figure 4). There were no lesions of cerebral arteries on a magnetic resonance angiography. A single photon emission computed tomography (SPECT) scan showed bilateral global reduction of regional 143 Figure 2. Line cancellation test. The subject omitted five of 41 lines in the left fifth of the test sheet. TABLE 1 The profile of Mini Mental State Examination and Alzheimer Disease Assessment Scale Score Mini Mental State Examination Total score Orientation in time Orientation in place Registry Attention Recall Language Construction Alzheimer Disease Assessment Scale-Cognitive scale Total score Word recall Spoken language ability Comprehension Word finding difficulty Following commands Naming objects/fingers Construction Praxis Orientation Word recognition Recall of test instructions 16 2 3 3 1 0 7 0 15.67 5 0 0 0 1 0 1 4 3 1.67 0 Figure 3. Copy of the picture. Failure to copy the left side of petals and leaves. Downloaded by [Universitat Politècnica de València] at 01:53 23 October 2014 144 ODA ET AL. Figure 4. FLAIR of the brain. FLAIR shows an enlarged Sylvian fissure predominantly in the right side. Ischemic change is not noted in the subcortical white matter. Figure 5. SPECT images reveal bilateral global reduction in regional blood flow that is most pronounced in the right temporo-occipital and parieto-occipital lobes. blood flow predominantly in the right temporooccipital and parieto-occipital lobes (Figure 5). Lumbar puncture yielded cerebrospinal fluid with normal findings. She was diagnosed with AD and given a therapeutic trial of donepezil. However, the treatment demonstrated no clinical change including her memory impairment, hemispatial neglect and homonymous hemianopsia with macula sparing. DISCUSSION This report shows that homonymous hemianopsia with macular sparing can be a rare manifestation of AD. Our patient exhibited slowly progressive decline of global cognitive function, including episodic memory and topographic orientation. Neuroimaging studies revealed cerebral atrophy and Downloaded by [Universitat Politècnica de València] at 01:53 23 October 2014 HEMISPATIAL VISUAL DEFECT IN ALZHEIMER’S DISEASE hypoperfusion that were most pronounced in the right temporo-occipital and parieto-occipital regions. The left hemianopsia and remarkable asymmetry of SPECT perfusion image patterns led to some uncertainty in diagnosis, since the former is commonly associated with localized brain disease, while the latter is commonly associated with corticobasal degeneration. However, her brain MRI revealed no localized lesions responsible for the hemianopsia, and there was no parkinsonism or cortical signs (apraxia or alien hand) suggestive of corticobasal degeneration. A clinical diagnosis of AD was therefore made, and the hemianopsia was considered attributable to the severe degenerative change in the right primary visual system. Our case’s visual field loss is very unique in that the center of field of vision of each eye was preserved. This pattern is termed macular sparing, and is quite typical of posterior cerebral artery infarction (Miller & Newman, 1998). Though the occipital lobe is supplied by the posterior cerebral artery, the macular cortex (occipital pole) has an independent blood supply derived from the middle cerebral artery. This unique blood supply of the occipital lobe often accounts for macular sparing, though not in the present case. Hemianopsia is a primary sensory dysfunction caused by geniculocalcarine lesions. Hemispatial visual inattention, however, may masquerade as hemianopsia. Kooistra and Heilman (1989) emphasized that the failure to report a stimulus presented in a visual field may also result from hemispatial neglect as well as hemianopsia. Hemispatial neglect is a type of cognitive impairment associated with involvement of the right temporo-parietal associative cortex and is rarely reported in AD patients (Heilman & Valenstein, 1979; Levine, Lee, & Fisher, 1993; Ryan, Duffy, & Tariot, 2000). Our patient failed to copy the left side of a cube and a picture of a flower (Figure 3), and omitted lines in the left fifth of the line cancellation test sheet. These findings revealed the presence of hemispatial neglect. Therefore, differentiation from attentional visual impairment was necessary. Kooistra and Heilman (1989) reported that the attentional visual half-field refers to the corporeal and extracorporeal space to the right or left of a midsagittal plane through the head and body, and that an attentional visual defect is present when the eyes are directed either straight ahead or toward the hemianopic hemispace but 145 improves when they are directed to the nonhemianopic hemispace. Ryan et al. (2000) reported a case that appeared to have left homonymous hemianopsia on automatic perimetry and intact visual field on Goldman perimetry. The discrepant results between automatic and Goldman perimetry reflect the slower pace of the latter. Neglect is time-dependent, with an ipsilesional stimulus extinguishing awareness of a subsequent contralesional stimulus for more than 1 s; therefore a patient with hemispatial neglect may show a hemianopsia on automatic perimetry caused by its faster pace. Goldman perimetry is performed with slower pace and thus it is less affected by a visual neglect. Ryan’s case showed intact visual field on Goldman perimetry and be considered to have hemispatial neglect but homonymous hemianopsia. We applied these useful techniques to our case. On confrontational testing, the left visual defect did not change when her eyes were directed to the right or left hemispace, and in addition she had an obvious visual defect consistent with homonymous hemianopsia on Goldman perimetry. Macular sparing, especially, revealed the presence of homonymous hemianopsia. These findings indicate the comorbidity of the left hemispatial neglect and the left homonymous hemianopsia. Our patient’s visual defect could be due to both the hemianopsia and the neglect. A clinical diagnosis of AD was made and thus histological confirmation is required. In conclusion, our case illustrates that some patients with AD can exhibit unilateral involvement of the primary visual system, resulting in homonymous hemianopsia with macular sparing. Degenerative change might be another cause of this type of visual field defect. Further findings are needed to determine the precise mechanism responsible for the changes observed in this patient. 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