Visual anosognosia or Anton-Babinski syndrome is a rare neurological condition related to cortical blindness. The patients deny their blindness and affirm adamantly that they are capable of seeing. The clinical presentation includes confabulations and sometimes confusional states. In this article we report two patients with anosognosia related to ischemic stroke in two different sets of etiology and pathogenesis. We describe the major clinical manifestations of this syndrome and review the current medical literature. Two patients were identified, a 96-year-old male with visual anosognosia secondary to a right posterior cerebral artery thrombosis, and a 56-year-old female with the same syndrome but related to central nervous system angiitis in relation with multiple sclerosis and Hashimoto’s thyroiditis. Visual anosognosia or Anton-Babinski syndrome is a rare neurological condition, however the ischemic vascular cerebral disease is a frequent etiology. We believe that this is the first report of this syndrome in relation to angiitis with a clear autoimmune pathogenesis.
Cortical blindness matches several clinical criteria [
We herein describe two cases and a review of the literature about the visual anosognosia.
A 96-year-old man was admitted to Emergency Room with severe headache and sudden loss of vision. He had a cutaneous carcinoma resected about three years ago, and he was currently on treatment for hypertension.
On admission he was awake and oriented. Blood pressure was 180/100, and he had a mild paresia on his left arm. Ophthalmologic exam confirmed a severe vision loss, ocular movements, as well as photo motor reflex, were preserved. Fundoscopic examination revealed changes secondary to chronic hypertension. The patient sustained that he was able to see, despite the objective evidence of vision loss.
The diffusion images on the brain MRI of the brain demonstrated ischemic areas on the occipital lobes, specially on the right side (
During hospitalization the patient denied his visual deficit. He would fabulate about the landscape across the window on a room with no windows, and made wrong statements about the physician’s tie (for example, referring to the tie’s color when the doctor wasn’t wearing one).
Visual loss remained stable during hospitalization, high blood pressure was controlled. The patient was discharged with secondary prevention treatment for stroke.
A 56-year-old woman with history of Hashimoto’s thyroiditis and multiple sclerosis currently on interferon beta-1a was admitted to the Emergency Room with confusional state and significant psychomotor agitation that required sedation and ventilator support. Acute encephalitis was suspected, but cerebrospinal fluid studies, as well as herpes serology were negative.
Once sedation was discontinued and ventilatory support was retired, it became evident that the patient was not capable of identifying objects, neither perceiving light changes. Ocular movements and pupil reflexes were present. Fundoscopic examination was normal. Thyroid studies revealed suppressed TSH (0.006 uU/mL) and high titers of antithyroid antibodies (79.83 UI/mL). Thyroxine levels were 1.34 ng/dL. Erythrocyte sedimentation rate was high also (65mm/2h)
MR images demonstrated acute ischemic lesions with total compromise of left occipital lobe (
During hospitalization, patient was not aware of her visual deficit. She would mistakenly describe the color of her husband’s suit, or she would take the newspaper and pretended she was reading it.
The patient was put on methylprednisolone boluses, and later she received intravenous cyclophosphamidewith partial recovery of her deficit.
Cortical blindness matches the following clinical criteria [
Visual anosognosia, or Anton-Babinski syndrome, is a rare complication of cortical blindness, where the patients deny their visual deficit [
Theories that try to explain the unawareness of deficit on the Anton-Babinsky syndrome describe disconnection phenomena. The first theory describes a conscious awareness system (CAS) located on the parietal lobes, which monitors all the information received from the senses. This system connects with other, located on the frontal lobes, which integrates the information, in order to perform complex cognitive tasks. In Anton-Babinski syndrome, damage of association pathways between visual cortex and CAS would be responsible for the lack of awareness of the visual deficit [
In addition the disconnection phenomena, other neuropsychologic mechanisms have been described, such as the signal transmission to the visual monitor (located on the visual association cortex) from a secondary visual system, located on the superior colliculus, pulvinar and temporoparietal regions [
Ischemic cerebrovascular disease, as a cause of cortical blindness, is the most common etiology of AntonBabinski syndrome [4,7]. Other diseases described as causes are MELAS [
The first description of visual anosognosia was made by Renaissance French writer Michel de Montaigne (1533-1592). In the second book of his Essais, near the final of the twelfth chapter, he describes a nobleman who denied his own blindness [
We haven’t found cases of visual anosognosia related to angeitis of the central nervous system [
Visual anosognosia, or Anton-Babinski syndrome is a rare neurological condition, with well defined clinical criteria. Neuroimaging studies, along with a complete clinical evaluation, are of great value for the prognosis of the patients. We think our case related with central nervous system vasculitis is one of the first described in literature. Identifying the cause of visual anosognosia is important in establishing de prognosis of the patients.