The cause of<unk>  is unknown, and there are no fully accepted diagnostic criteria for the disease. This is partially due to the gradual onset of<unk>  symptoms, their variety, the rare nature of the disease, and the younger age of onset typically 50–60 years. In 2012, the first international conference on<unk>  was held in Vancouver, Canada. Continued research and testing will hopefully result in accepted and standardized criteria for diagnosis.<unk>  is often initially misdiagnosed as an anxiety disorder or depression. It has been suggested that depression or anxiety may result from the symptoms of decreased visual function, and the progressive nature of the disease. Early visual impairments have often led to a referral to an ophthalmologist, which can result in unnecessary cataract surgery. Due to the lack of biomarkers for<unk> , neuropsychological examinations are advised. Neuroimaging can also assist in the diagnosis of<unk> . For<unk>  and AD neuroimaging is carried out using MRI scans, single-photon emission computed tomography, and positron emission tomography (PET scans). Neuroimages are often compared to those of people with AD to assist diagnosis. Due to the early onset of<unk>  in comparison to AD, images taken at the early stages of the disease will vary from brain images in AD. At this early stage brain<unk>  will be shown to be more centrally located in the right<unk>  lobe and occipital gyrus, while AD brain images show the majority of<unk>  in the medial temporal cortex. This variation within the images will assist in early diagnosis of<unk> ; however, as the years go on the images will become increasingly similar, due to the majority of<unk>  also developing to AD later in life because of continued brain<unk> . A key aspect found through brain imaging of<unk>  patients is a loss of grey matter (collections of neuronal cell bodies) in the<unk>  and occipital temporal cortices within the right hemisphere. For some people with<unk> , neuroimaging may not give a clear diagnosis; therefore, careful observation in relation to<unk>  symptoms can also assist in the diagnosis. The variation and lack of organized clinical testing has led to continued difficulties and delays in the diagnosis of<unk> .
Posterior cortical atrophy
Geographic atrophy
Pellucid marginal degeneration
Hippocampal sclerosis
Polymicrogyria
Cerebral atrophy
Central chromatolysis
Neurofibrillary tangle