Frontotemporal Dementia (FTD) encompasses a group of neurodegenerative disorders characterized by atrophy of the frontal and temporal lobes of the brain. Each disorder or syndrome presents with a unique set of symptoms. Below is a description of the syndromes which fall under the umbrella of FTD. It is important to remember that as the diseases progress symptoms can overlap between the variants.
Behavioral Variant FTD
The behavioral variant (bvFTD) accounts for the majority of the cases of FTD. BvFTD is defined by symptoms of disinhibition, apathy, lack of empathy, compulsive behaviors, alteration in dietary habits, and reduced executive function. Practically, individuals with bvFTD experience changes in their personality, struggle with decision-making, and engage in socially unusual or inappropriate behaviors. They may also develop obsessive tendencies and a preference for sweets.
Primary Progressive Aphasia (PPA)
The PPA branch of FTD syndromes encompasses disorders with predominantly language issues. There are three versions of PPA detailed below each with its own form of speech impairment.
- Semantic Variant - The semantic variant of PPA is characterized by difficulty with naming and word comprehension. Individuals will be unable to name specific objects they once knew or not fully understand the significance of words. Their speech will often sound normal but may be meaningless in its content.
- Non-fluent/ agrammatic Variant - Individuals with the non-fluent variety of PPA have difficulty with pronunciation and production of words. They will often speak slowly in an effortful manner with grammatical errors.
- Logopenic Variant - The logopenic variant leads to difficulty with finding the right word. Individuals with this variety will often pause frequently during conversation or have difficulty with repeating phrases. Unlike the two variants listed above, they are still able to recall the specific meaning of words and do not typically have issues with the motor aspects of speech.
Corticobasal Syndrome
This disorder primarily affects movement. People with corticobasal syndrome will have difficulty moving their muscles or completing familiar tasks such as using utensils or a phone. Sometimes it may seem as if movements happen that are not under the patient’s control. People with this disorder may also have frequent falls, slow and stiff movements, or muscle spasms.
Progressive Supranuclear Palsy
Similar to corticobasal syndrome, progressive supranuclear palsy (PSP) affects the muscles. A hallmark of PSP is changes in eye movement resulting in blurry vision as well as difficulty walking down stairs or maintaining eye contact. Individuals with PSP may also experience changes in their walking and stiff muscles with frequent falls. These individuals may also experience some of the behavioral symptoms found in bvFTD.
FTD with ALS
Upwards of 15% of patients with FTD have a concurrent motor neuron disease such as Amyotrophic Lateral Sclerosis (ALS). They will experience difficulty with muscle movement, involuntary twitches, and coordination in addition the behavioral symptoms of FTD. This overlap of disorders is often attributed to the C9orf72 gene mutation.
*The text above is a summary of the information provided by the AFTD. Please see www.theaftd.org for reference.