Differential Diagnosis
- Single most likely diagnosis
- Frontotemporal dementia: This diagnosis is considered the most likely due to the patient's drastic change in behavior 2 years ago, lack of insight into his current situation, fixation on food, and disorientation in time and space. The presence of myoclonus also supports this diagnosis, as it can be a feature of frontotemporal dementia.
- Other Likely diagnoses
- Alzheimer's disease: Although less likely than frontotemporal dementia, Alzheimer's disease is still a possibility given the patient's age, disorientation, and memory impairments. However, the prominent behavioral changes and fixation on food are more characteristic of frontotemporal dementia.
- Traumatic brain injury: The patient's history of prison and domestic violence order suggests a potential for head trauma, which could contribute to his cognitive and behavioral impairments.
- Chronic substance abuse: The patient's homelessness and non-adherence to diabetes treatment suggest potential substance abuse, which could contribute to his cognitive and behavioral impairments.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cerebral vasculitis: Although rare, cerebral vasculitis can present with cognitive decline, behavioral changes, and myoclonus. Missing this diagnosis could lead to delayed treatment and potentially fatal outcomes.
- Infectious encephathy (e.g., HIV, syphilis): The patient's history of prison and potential for high-risk behaviors increases the risk of infectious diseases that can affect the brain. Missing these diagnoses could lead to delayed treatment and potentially fatal outcomes.
- Hypoactive delirium: The patient's disorientation, fixation on food, and myoclonus could also be indicative of a delirium, which requires immediate attention to identify and treat the underlying cause.
- Rare diagnoses
- Creutzfeldt-Jakob disease: This rare prion disease can present with rapid cognitive decline, myoclonus, and behavioral changes. Although unlikely, it is essential to consider this diagnosis due to its fatal outcome and potential for transmission.
- Whipple's disease: This rare infectious disease can present with cognitive decline, behavioral changes, and myoclonus. Although unlikely, it is essential to consider this diagnosis due to its potential for treatment and fatal outcome if missed.