Frontotemporal Dementia _____________________________________________________________________
EARLY SIGNS AND SYMPTOMS OF FTD VERSUS ALZHEIMER DISEASE
Clinical Features
FTD
Alzheimer Disease
Hallmark
Decline in behavior, language, and/or movement; memory is retained initially May involve speech production, understanding words and recognizing familiar objects, or retrieving words
Decline in memory; socially appropriate behavior is retained initially
Initial language problems
Word-finding or name recall
Age at onset
Usually 45 to 64 years of age
Usually 65 years of age or older
Movement problems
May have early movement disorder, with gait and balance problems, rigidity, apraxia, or muscle weakness
Usually no movement problems early in disease
Source: [3; 8; 15]
Table 3
The neurologic examination typically includes assessment of the patient’s general appearance and speech, mental status, cranial nerves, motor system, sensation, reflexes, and cerebellar function (coordination and balance). Consulting a neurologist who has knowledge and experience in FTD can be valuable when reaching a definitive diagnosis. The neuropsychologic examination assesses brain function and may identify areas of the brain that have been damaged. It typi- cally involves an interview and the administration of written tests. These tests may focus on attention and concentration, memory, orientation, language, visual-spatial abilities, and/ or executive functions (e.g., reasoning, planning, organizing, problem solving). Patients with FTD may show deterioration in the areas of attention and concentration, language, and executive function, but may do relatively well on memory and visual-spatial tests. The Neuropsychiatric Inventory (NPI) may be administered to caregivers of patients with suspected FTD. This survey helps assess behavior and psychopathology by inquiring about the patient’s delusions, hallucinations, agitation/aggression, dys- phoria, anxiety, euphoria, apathy, disinhibition, irritability, unusual motor activity, nighttime behavioral problems, and eating abnormalities. Brain scans are important tools in the diagnosis of FTD. Com- puted tomography (CT) may be done to determine if there is a tumor, hemorrhage, or other brain injury that could account for the symptoms. Magnetic resonance imaging (MRI) provides better visualization of the brain than CT and is often done to evaluate brain atrophy when FTD is suspected. Patients with FTD have progressive frontal and anterior temporal atrophy apparent on MRI. Typically, in bvFTD, there is atrophy of the frontal lobe (involved in personality, judgment, and executive function) and the anterior temporal lobe. In nfvPPA, there is left frontal lobe atrophy (involved in speech production). In svPPA, the atrophy is focused in the anterior temporal lobe (involved in language and face recognition). In specialty or research centers, positron emission tomography (PET),
single photon emission computed tomography (SPECT), or functional MRI (fMRI) brain scans may be done to further evaluate brain functioning. While there is no laboratory test that can diagnose FTD, some tests may be ordered to rule out other diseases with symptoms similar to those of FTD. Blood work may be ordered to identify dehydration, thyroid disease, vitamin B12 deficiency, or infec- tions affecting the brain. An electroencephalogram (EEG) may be done if there is concern that seizures might be causing the patient’s symptoms. In the early stages of FTD, EEG findings are usually normal or have non-specific findings. Lumbar punc- ture may be done to evaluate cerebral spinal fluid and rule out rare brain infections or cancer. Electromyography may be used to identify muscle weakness or myoclonus if MND (or ALS) is being considered as a possible diagnosis. In addition, language evaluation by a speech pathologist can be an important tool in diagnosing patients with nonfluent/agrammatic, semantic, or logopenic variant PPA. It may be challenging to clinically differentiate FTD from early AD ( Table 3 ). The only way to establish an unquestionable diagnosis of FTD is through a brain autopsy after a patient has died. Examination of the brain tissue will show the precise location and severity of the brain atrophy, and microscopic studies can determine the protein composition of the inclu- sions in affected neurons. For families, brain autopsy can confirm the diagnosis (or identify a different cause of the dementia) and bring a measure of closure. Accurate diagnosis may be especially important if there is concern about genetic risk to other family members. Discussion about brain autopsy should be handled delicately and with compassion at a time that is appropriate for the fam- ily; the subject may be emotionally difficult for some families. Introducing the topic ahead of time allows families to consider their feelings about brain autopsy aside from the emotional crisis of the death of a loved one and the immediate time pres- sure of funeral arrangements. Families may then discuss the topic among themselves and come to a consensus.
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MDRI2026
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