Differential Diagnosis

Given the information that the patient's behaviors are not inconsistent with their personality before the cognitive impairment, but rather maximized, we can approach the differential diagnosis as follows:

• Single most likely diagnosis

  • Frontotemporal dementia (FTD): This condition is characterized by changes in personality, behavior, and social conduct, which can be an exaggeration of the patient's pre-existing traits. The fact that the behaviors are "maximized" versions of the patient's previous personality suggests a possible diagnosis of FTD, particularly the behavioral variant.

• Other Likely diagnoses

  • Alzheimer's disease with prominent behavioral symptoms: While Alzheimer's disease is primarily known for its cognitive decline, some patients may exhibit significant behavioral changes, including exaggerations of their pre-existing personality traits.
  • Vascular dementia: This condition can lead to cognitive decline and changes in behavior, depending on the areas of the brain affected by vascular disease. Personality changes can occur, reflecting the patient's previous traits in an exaggerated form.
  • Traumatic brain injury (TBI): Depending on the severity and location of the injury, TBI can result in significant changes in behavior and personality, which might be seen as an exaggeration of pre-existing traits.

• Do Not Miss diagnoses

  • Creutzfeldt-Jakob disease: A rare, degenerative, and fatal brain disorder that can cause rapid cognitive decline and significant changes in behavior. It's crucial to consider this diagnosis due to its severity and the need for prompt identification, even though it's less likely.
  • Normal pressure hydrocephalus (NPH): Characterized by the triad of gait disturbance, dementia, and urinary incontinence. Behavioral changes can occur, and while less common, NPH is a treatable condition, making it a "do not miss" diagnosis.
  • Neurosyphilis: A condition that can cause a wide range of neurological symptoms, including cognitive decline and personality changes. Given its potential for treatment and the severe consequences of missing the diagnosis, it should be considered.

• Rare diagnoses

  • Huntington's disease: An inherited disorder that causes progressive damage to the brain, leading to cognitive, motor, and psychiatric symptoms. Personality changes and behavioral disturbances are common, but the disease's rarity and specific genetic nature make it less likely without a suggestive family history.
  • Wilson's disease: A genetic disorder that leads to copper accumulation in the brain and liver. It can cause neurological symptoms, including personality changes and psychiatric symptoms. However, its rarity and the presence of other systemic symptoms (like liver disease) make it a less common consideration in the differential diagnosis of cognitive impairment with behavioral changes.