To make a diagnosis of frontotemporal dementia, you may need to go through the following tests: As assessment of the symptoms, this is done by speaking to people that know you well and can see a difference in your behavourial habits. An assessment of your mental capabilities may also be undertaken which will involve a number of everyday tasks and questions. Blood tests can help rule out any changes with similar symptoms. Lumbar puncture which is where they test the spinal fluid an help rule out Alzheimer's desease, which can be a cause of the symptoms. Brain Scans can detect signs of dementia, it can also identify the parts of the brain which are most affected. This is under taken using a MRI Scanner, CT Scan or a PET Scan.