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Man presents with homonymous hemianopia, rapidly progressive dementia
Patient underwent stroke workup that showed hyperintensities in the left occipital and inferior parietal cortexes on diffusion-weighted imaging.
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A 66-year-old patient first noticed trouble with his right peripheral vision 2 weeks prior to presentation while he was playing golf. He also complained of more trouble with light to dark adaptation and reading.
The patient had no ocular history. He had had a cardiac ablation for atrial fibrillation in 2011, a right bundle branch block and cardiomyopathy. His family history was notable for Alzheimer’s disease, prostate cancer and myocardial infarction in his father.
The patient was a retired engineer who drank alcohol socially and quit smoking at age 26. He took 81 mg of aspirin, a multivitamin, vitamin C and a magnesium supplement daily.
History
Upon outside ophthalmology exam, the patient’s best corrected visual acuity was 20/30 in his right eye and 20/20 in his left. He had full color vision on Ishihara plates, and his pupils were equal, round and reactive to light with no afferent pupillary defect. His motility exam was reportedly normal, and the slit lamp exam was unremarkable. On dilated fundus exam his cup-to-disc ratio was 0.4, and he had trace extrafoveal drusen in both eyes. Automated perimetry revealed a right homonymous hemianopia (Figure 1).
The patient underwent a stroke workup, including diffusion-weighted MRI, which showed hyperintensities in the left occipital and inferior parietal cortexes that were consistent with a possible early left occipital stroke. Magnetic resonance angiography, transesophageal echocardiography and 24-hour Holter readings were all normal. He was evaluated by a neurologist and cardiologist, and started on Xarelto (rivaroxaban, Janssen).
In the next month, the patient had progressive problems with word finding and memory. His wife prompted him to seek emergency care when he could not compute a simple arithmetic problem. At this point, he was able to perform activities of daily living but was not driving or shaving, which he claimed was due to his visual difficulties.
The patient had another MRI, which demonstrated a single small focus of prolonged T2 hyperintensity in the white matter of the frontal lobe. The previously noted left occipital hyperintensity was no longer noted, and there was no evidence of a previous stroke. Electrocardiogram and routine labs were normal.
The next day, another visual field test that showed possible progression of the right hemianopic field defect into the left visual field but was significantly more unreliable. Two days later, the patient was admitted to our hospital. Neurologic exam documented increased muscle tone, cognitive decline, ataxia, perseveration of speech and myoclonus. He was then admitted for further workup.
Figure 1. Right homonymous hemianopia on automated perimetry at presentation.
Images: Renz J, Hedges TR
Figure 2. Diffusion-weighted MRI showing hyperintensity of the caudate nucleus of the basal ganglia, left greater than right (black arrow), and ribbon-like signal in the frontal and occipital lobes (white arrows).
Examination
Copper, Lyme, erythrocyte sedimentation rate and C-reactive protein, antinuclear antibodies, rapid plasma reagin, and a paraneoplastic panel were all normal. A lumbar puncture was unremarkable, and an electroencephalogram (EEG) showed periodic sharp and slow wave complexes. Yet another MRI noted faint, relatively slow cortical diffusion that was worse in the left frontal temporal and occipital cortex, as well as the persistent hyperintensity in the caudate nucleus of the left basal ganglia (Figure 2).
Upon neuro-ophthalmologic exam, the patient appeared to have visual field loss to confrontation on the right as well as the left. Although visual acuity could not be tested by Snellen chart and he repeatedly stated, “I can’t see,” the patient was able to recognize objects and family members. He was unable to initiate appropriate saccades, made inaccurate saccades, and had perseverated fixation consistent with Balint’s syndrome. His ability to pursue targets was poor. These abnormalities rapidly worsened over the course of several days, and he became minimally verbal.
What is your diagnosis?
Homonymous hemianopia
The first concern in any patient with apparently acute homonymous hemianopia is stroke. Brain tumor with hemorrhage would be the next possibility. However, the differential diagnosis of homonymous hemianopia and rapidly progressive dementia is narrow.
Degenerative dementias, such as Alzheimer’s, Pick’s disease or Lewy body dementia, can rarely be associated with hemianopias when degenerative neurofibrillary tangles are focused primarily in the occipital cortex; however, the clinical course is typically more gradual in these disorders. Occipital seizures typically have autonomic findings, such as tachycardia, and occipital spikes on EEG. Functional vision loss would be difficult to rule out, but is unlikely given the severity of the patient’s cognitive decline and the lack of previous psychosocial abnormalities.
The patient’s homonymous hemianopia, rapidly progressive dementia, later neurologic findings of ataxia, increased muscle tone, perseveration of speech and movement, his MRI showing hyperintensity of his basal ganglia, a ribbon-like signal in the frontal and occipital cortices, and his EEG all lead to the diagnosis of the Heidenhain variant of Creutzfeldt-Jakob disease. He was discharged to hospice and died 12 days later. His cerebrospinal fluid was later found to be positive for 14-3-3 protein.
Discussion
Creutzfeldt-Jakob disease is rare and fatal, with an incidence of one in 2 million people, 75% of whom die within 6 months. There is no sex predilection, and the mean age of onset is in the seventh decade. Symptoms primarily include rapidly progressive dementia, myoclonus, ataxia and personality changes. Pathologically, prion protein accumulates in the brain, resulting in spongiform degeneration, loss of granular cells, astrocytic gliosis and amyloid plaque. Prion protein is stable in high temperature and acid and is thus not destroyed by routine sterilization.
Eighty-five percent of cases are sporadic. Less commonly it is familial, although some small case series noted a strong genetic basis in the Heidenhain variant.
There have been three cases of spongiform encephalopathy after cornea transplant, but no conclusive evidence of transmission from intraocular surgery or ophthalmic procedures. Diagnosis is made clinically but can be confirmed by 14-3-3 protein in cerebrospinal fluid, hyperintense basal ganglia on MRI, EEG with periodic sharp wave complexes, and definitively by brain biopsy.
The Heidenhain variant affects predominantly the occipital lobe. Initial symptoms are primarily visual, with varied complaints including decreased acuity; an altered perception of color, such as a description of “green vision;” visual hallucinations; visual field defects and, in late stages, cortical blindness. MRI findings are ribbon-shaped hyperintensities in the occipital cortex on diffusion-weighted MRI, increased signal in the basal ganglia, and later, occipital atrophy.
A significant number of these cases present first to an eye care provider with vision loss.