Visuospatial dysgnosia is the loss of a sense of "place" in relation to oneself, one's surroundings, objects, and each other. Visuospatial dysgnosia is often associated with topographic agnosia. The same symptoms of the syndrome rarely occur in every patient. Some examples of symptoms that may occur include: Studies have identified the brain region that, if damaged, causes visuospatial dysgnosia: the temporoparietal-occipital region. Lesions are most commonly found in the angular gyrus of the right hemisphere, and are usually unilateral, meaning that they occur in one hemisphere. Unilateral lesions produce more complex cognitive signs such as loss of object naming, prosopagnosia, alexia, apraxia of wearing, and memory deficits in addition to the symptoms of visuospatial dysgnosia. Visuospatial dysgnosia shares many symptoms with Balint syndrome and may be present simultaneously. Visuospatial dysgnosia, along with Balint syndrome, is associated with Alzheimer's disease as an early sign of the disease. Generally, memory loss is the first symptom of Alzheimer's disease, but visual impairment or visuospatial impairment is the presenting symptom in some cases and is common in later stages of the disease. In 1979, David J. Cogan published a lengthy paper describing 17 cases of visuospatial impairment. Here are some examples of patients with visuospatial impairment from Cogan's study: It is clear that visuospatial impairment does not present in the same way, although all of these cases were diagnosed with the disease in conjunction with other comorbidities. For patients with visuospatial impairment, input information can be augmented by adding tactile, kinesthetic, or verbal perceptual input. This is achieved with a general occupational therapy approach of teaching clients with intellectual impairment to use the most effective appropriate perceptual input, which may enable them to complete a task.