MRI is the modality of choice to structurally image the brain, however, there are no easily identifiable features to specifically support the diagnosis of dementia with Lewy bodies.
Brain scans
Your doctor might order an MRI or CT scan to identify a stroke or bleeding and to rule out a tumor. While dementias are diagnosed based on the medical history and physical examination, certain features on imaging studies can suggest different types of dementia, such as Alzheimer's or Lewy body dementia.
There are no tests that can definitively diagnose LBD. Currently, only a brain autopsy after death can confirm a suspected diagnosis.
Magnetic resonance imaging (MRI)
Repeat scans can show how a person's brain changes over time. Evidence of shrinkage may support a diagnosis of Alzheimer's or another neurodegenerative dementia but cannot indicate a specific diagnosis. MRI also provides a detailed picture of brain blood vessels.
MRI can be used to rule out other causes, find characteristic patterns of brain damage, and differentiate between types of dementia. Brain scans do not always show abnormalities in people diagnosed with dementia, as sometimes there are no visible changes in the brain.
About a third of them converted to Alzheimer's disease dementia, and the others did not or developed other types of dementia. We found that MRI is not accurate enough to identify people with MCI who will develop dementia due to Alzheimer's disease.
CT scans are the most common type of brain scan used in dementia diagnosis. They are useful for ruling out other conditions that cause similar symptoms to dementia and at showing changes to brain structure that occur in diseases like Alzheimer's.
Who can diagnose dementia? Visiting a primary care doctor is often the first step for people who are experiencing changes in thinking, movement, or behavior. However, neurologists — doctors who specialize in disorders of the brain and nervous system — are often consulted to diagnose dementia.
Increased numbers and size of the intense-white spots seen on the mostly gray images of the brain have long been linked to memory loss and emotional problems, especially as people age.
LBD is frequently misdiagnosed as Alzheimer's disease, especially in the early stage. Over time, changes in movement, hallucinations, or RBD can help distinguish LBD from Alzheimer's disease.
80% of LBD patients are misdiagnosed
Lack of a diagnostic test and the fact that LBD presents so many symptoms that are associated with other conditions means the disease is very difficult to spot.
Frontal and temporal lobe atrophy on magnetic resonance imaging (MRI), with relative preservation of posterior areas, represent the imaging hallmark of frontotemporal lobar degeneration (the neuropathological changes underlying FTD) (Neary et al. 1998).
Memory problems
Difficulties with memory are the most well-known first signs of dementia. For example, a person may not recall recent events or may keep losing items (such as keys and glasses) around the house. Memory loss is often the first and main symptom in early Alzheimer's disease.
White matter lesions (WMLs) are areas of abnormal myelination in the brain. These lesions are best visualized as hyperintensities on T2 weighted and FLAIR (Fluid-attenuated inversion recovery) sequences of magnetic resonance imaging. They are considered a marker of small vessel disease.
The Mini-Cog test.
A third test, known as the Mini-Cog, takes 2 to 4 minutes to administer and involves asking patients to recall three words after drawing a picture of a clock. If a patient shows no difficulties recalling the words, it is inferred that he or she does not have dementia.
Introduction: The five-word test (5WT) is a serial verbal memory test with semantic cuing. It is proposed to rapidly evaluate memory of aging people and has previously shown its sensitivity and its specificity in identifying patients with AD.
Depression, nutritional deficiencies, side-effects from medications and emotional distress can all produce symptoms that can be mistaken as early signs of dementia, such as communication and memory difficulties and behavioural changes.
The clock test is a non-verbal screening tool that may be used as part of the assessment for dementia, Alzheimer's, and other neurological problems. The clock test screens for cognitive impairment. The individual being screened is asked to draw a clock with the hour and minute hands pointing to a specific time.
The five-minute cognitive test (FCT) was designed to capture deficits in five domains of cognitive abilities, including episodic memory, language fluency, time orientation, visuospatial function, and executive function.
Routine use of high field MRI has greatly contributed to the clinical diagnosis of neurodegenerative disorders, because MRI enables to visualize degenerative process showing either atrophy of the specific areas or degeneration of specific structures.
Early symptoms typically involve personality or mood changes such as depression and withdrawal, sometimes obsessive behavior and language difficulties. Many patients lose their inhibitions and exhibit antisocial behavior.
In Radiology, patients pose this question often. “Can MRI show if I have dementia?” In fact, we scan patients every day with a diagnosis of dementia, memory loss, Alzheimer's, and confusion, among a variety of other neurological disorders. The truth is that MRI is NOT the test to formally diagnose dementia.
Unlike Alzheimer's disease, which tends to progress gradually, this disease often starts rapidly, with a fast decline in the first few months. Later, there may be some leveling off but Lewy body dementia typically progresses faster than Alzheimer's. A patient can survive from five to seven years with the disease.
Persons living with dementia (PLwD) have increasing problems with memory and overt changes in personality. The person in the middle stage of dementia has increasing difficulties with instrumental activities of daily living (IADL).