Alzheimer’s disease (AD) is the most common cause of dementia in the world. The most common symptom of AD is memory loss. However, some patients with AD may present with lesser-known symptoms too. It is important to recognize these symptoms to enable early diagnosis of AD.
Loss of smell:
Impaired sense of smell is an early feature of AD. Clinical observations suggest that approximately 85% of patients with early-stage AD exhibit olfactory dysfunction. It is important to detect patients with olfactory deficit (via odour identification test), as this will help in early diagnosis of AD. Therapies for AD are most effective in early stage.
In some cases of AD, memory impairment may not be the first or the most important complaint. Instead, they present themselves with difficulty in finding appropriate words while speaking and impaired comprehension while talking to others. They may also have difficulty in naming objects and repeating words or sentences. This variant of AD is known as logopenic variant of AD.
Prominent and early visual disturbances:
Patients may have visuospatial disorientation. They may find it difficult to locate the toilet or kitchen in their own homes or may not be able to locate a Kirana store or friend’s home that they often visited earlier. They may have difficulty in identifying objects or understanding their functions despite having normal vision. These visual symptoms occur in a variant of AD, known as posterior cortical atrophy.
Early personality and behavioral changes
Early personality and behavioral changes such as disinhibition, apathy or compulsiveness. This is seen in “frontal variant” of AD.