What is Frontotemporal Lobe Dementia?
Frontotemporal dementia (FTD) refers to a group of disorders that cause the cells in the frontal and anterior temporal areas of the brain to deteriorate. To put it simply, these are the parts of your brain that influence your personality, behavior, ability to learn language, motivation, abstract thinking, and decision-making abilities. FTD is the third most common cause of dementia in people aged 65 and above. For those under 65, it’s the second most common cause and often affects people between 45 and 65 years old.
The first record of FTD-related syndromes was made back in 1892 by Arnold Pick. Initially, the condition was named “Pick’s disease” in 1926 when Onari and Hugo Spatz noticed the shrinkage of the frontotemporal lobe of the brain accompanied by the presence of abnormal substances, called Pick bodies in the brain. However, in 1994, a research group from the United Kingdom and Sweden introduced the term “FTD” to better classify the different symptoms and physical changes in the brain related to this disorder.
FTD results in behavior changes and/or difficulties with language, which are usually the first noticeable signs. As the condition progresses, it can also lead to impairment in decision-making abilities and general thinking skills, also known as cognitive abilities. There are two main types of FTD; one affects behavior, and the other primarily impacts language skills. The language type of FTD can further be divided into two subtypes, depending on which parts of the frontal and temporal lobes are most affected. These subtypes include non-fluent variant primary progressive aphasia (nfvPPA), where speech becomes effortful and grammatically incorrect, and semantic variant primary progressive aphasia (svPPA), where one experiences difficulty understanding or naming words.
What Causes Frontotemporal Lobe Dementia?
Frontotemporal dementia, often, happens randomly. But genetics do play a role in this disease. Around 40% of cases actually run in the family. Within those family cases, about 13.4% are passed down directly from parent to child.
Scientists have discovered over 20 genes that could potentially be involved in frontotemporal dementia development. Three genes that are commonly involved are named microtubules associated protein tau, granulin, and a slightly more complicated one known as chromosome 9 open-reading-frame 72 (or C9orf72 for short). These three genes are responsible for maintaining the structure of our cells.
Some researchers think that if C9orf72 is mutated, it could lead to both frontotemporal dementia and another disease called amyotrophic lateral sclerosis.
In addition to genetics, certain circumstances or conditions like a head injury or thyroid disease have also been associated with an increased risk of developing frontotemporal dementia. If you’ve experienced a head trauma, your risk of getting this disease is about 3.3 times higher. If you have a thyroid disease, your risk is 2.5 times higher.
Risk Factors and Frequency for Frontotemporal Lobe Dementia
This condition most often affects people in their late middle age, with an average age of 58 at the time of diagnosis. The incidence of the disease varies with age: it’s 2.2 cases per 100,000 people between ages 40-49, 3.3 per 100,000 between 50-59, and 8.9 out of 100,000 between 60-69. Out of every 100,000 people, 15-22 are likely to have this condition. Interestingly, men are more likely to exhibit behavior and semantic variants while women predominantly show a non-fluent variant. On average, people live for 7.5 years after being diagnosed.
Signs and Symptoms of Frontotemporal Lobe Dementia
Diagnosing frontotemporal dementia (FTD) can be tricky. At first, it might be confused with mental health disorders or even a stroke. Due to this, it’s crucial to gather a detailed health history and carry out a thorough physical examination. Those who care for the person with potential FTD can often provide vital information. FTD can present differently depending on the areas of the brain it affects. Regardless of the type, FTD makes daily activities and tasks more challenging over time.
There are several types of FTD, including:
- Behavior variant-type FTD (bvFTD): The most common type. People with bvFTD may have altered behavior and personality changes, such as disinhibition, emotional blunting, apathy, and impaired thinking. Their memory typically remains intact until the late stages of the disease.
- Semantic variant FTD: Those with this type of FTD struggle with language. They might struggle to remember words or understand their meaning and fail to recognize unfamiliar faces or objects. Although their speech is fluent, it often lacks coherency.
- Non-fluent variant Primary Progressive Aphasia (nfvPPA): Patients with nfvPPA often exhibit halted speech, word jumbling, and difficulties in understanding complex sentences. However, they usually maintain memory, abstract thinking, and calculating abilities in the early stages of the disease.
If a doctor suspects someone has FTD, they can perform different tests, including:
- Go-no-go test: This checks a patient’s impulse control. The patient must perform an action in response to a particular stimulus and then refrain from performing that action in response to a different stimulus.
- Letter fluency test: This tests for semantic variant FTD by asking the patient to say as many words as possible that start with a certain letter, excluding proper nouns, in a minute.
- Attention test: This test, which includes subtracting seven from a hundred several times or spelling “world” backward, assesses attention span.
- Similarities and differences: To check for impaired abstract thinking, the patient must compare different items and discuss how they are alike or different.
Testing for Frontotemporal Lobe Dementia
For people who may have frontotemporal dementia, a number of tests and evaluations are usually carried out by the doctors.
Lab tests can often involve investigating certain proteins called neurofilament light chains, which function as building blocks of your brain’s nerve fibers. Doctors have noticed that people with frontotemporal dementia often possess high levels of these particular proteins in their blood and cerebrospinal fluid (the fluid which surrounds the brain and spinal cord).
Doctors also employ various imaging techniques like magnetic resonance imaging (MRI), computed tomography (CT) scans, or single-photon emission tomography. These are used to picture the brain in detail and can help reveal any signs of atrophy (shrinkage) and lowered blood flow in the front and sides of the brain. However, these signs are not exclusive to frontotemporal dementia and can be seen in other diseases as well. Hence, imaging tests can be helpful in making a diagnosis or excluding other possible causes for the symptoms.
An electroencephalogram (EEG), a test that measures electrical activity in the brain, can also be carried out. While it is not as useful for diagnosing frontotemporal dementia as it is for Alzheimer’s disease, it can still indicate changes in brain activity that might be indicative of the disease. For example, some people with frontotemporal dementia may show a reduction in fast brain activities (alpha, beta1- beta3 waves), while their slow activities (delta & theta waves) are not significantly affected.
Lastly, doctors may evaluate the cognitive functioning of a patient through various assessments such as the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment, and Functional Cognitive Assessment. These tests assess different aspects of your thinking abilities, such as memory, language, attention, and decision-making skills. For general practice, the MMSE and the Informant Questionnaire for Cognitive Disorders in the Elderly are commonly used. As with the Imaging and EEG tests, these are also useful tools that doctors use to help determine the presence of frontotemporal dementia.
Treatment Options for Frontotemporal Lobe Dementia
Managing a condition called Frontotemporal Dementia (FTD) involves a multi-faceted approach. This includes providing genetic counseling to patients and their families, where a healthcare professional will discuss genetic testing and make certain suggestions about dealing with the condition.
Treatment usually involves a combined effort from multiple healthcare professionals and can constitute what’s called non-pharmacologic treatment. This means treatment that does not involve medication. This can include things like social support services, physical therapy, and occupational therapy to help with everyday activities. Speech therapy can assist with communication while cognitive behavior therapy can help manage thoughts and behaviors. Rehabilitation services can help individuals regain lost skills and caregivers’ education aids families in understanding and managing the condition. It’s important to consistently monitor the patient’s behavior, as well as tasks such as managing finances, driving, modifying the living environment, and eating habits.
Medication-based or pharmacological treatment for FTD is also an option, although its effectiveness varies. Certain drugs known as acetylcholinesterase inhibitors and N-methyl-D-aspartate inhibitors have not been proven definitively effective. Meds known as selective serotonin reuptake inhibitors (SSRIs), often used to treat depression, can play a role in managing specific behaviors, but won’t necessarily improve cognitive ability. Antipsychotic medications show mixed results and may have detrimental side effects, which is why they have not been approved by the U.S. Food and Drug Administration for treating FTD. Medications that antagonize, or counteract, dopamine can potentially improve motivation and reduce apathy symptoms. There are some potential treatments like salsalate, which attempts to inhibit a protein implicated in dementia, and gosuranib, a type of antibody that targets this same protein. However, scientific research hasn’t advanced enough to formulate recommendations about these treatments. There are ongoing trials that look at other potentially promising medications.
What else can Frontotemporal Lobe Dementia be?
Frontotemporal dementia is a condition that can sometimes be confused with other mental health issues. As a result, it’s important for doctors to take a detailed health history and conduct a full-body exam to differentiate each distinct condition. A neurological exam is particularly important in helping doctors understand the situation. Doctors should also consider whether a drop in cognitive abilities could be the result of bodies’ hormone levels and metabolism disorders.
Other potential causes of a decline in cognitive function can include:
- Alzheimer’s disease
- Vascular dementia
- Lewy body dementia
- Parkinsonism
- Supranuclear palsy
- Alcoholism
- Bipolar disorders
- Schizophrenia
- Borderline personality disorder
- Obsessive-compulsive disorder
What to expect with Frontotemporal Lobe Dementia
When someone is diagnosed with Frontotemporal Dementia (FTD), a type of brain disorder that affects specific areas of the brain causing problems with behavior and language, at a younger age, it can lead to a delay in diagnosis. This delay can negatively affect patients, families, and caregivers emotionally, financially, and socially.
FTD carries a risk of death that is six times higher compared to Alzheimer’s disease, which itself carries a risk four times higher than average. On average, individuals diagnosed with FTD live for about 7.5 years.
Possible Complications When Diagnosed with Frontotemporal Lobe Dementia
Reports suggest that 33%-76% of patients suffering from Frontotemporal Dementia (FTD) may experience sleep disturbances or abnormal behaviors at night. Such issues are more commonly reported in patients diagnosed with Primary Progressive Aphasia (PPA) than in those with Behavioral Variant Frontotemporal Dementia (bvFTD). Not surprisingly, caregivers of PPA patients often report this issue too. It’s essential that anyone experiencing sleep problems maintains good sleep hygiene and sticks to a regular sleep schedule.
Furthermore, FTD might coexist with other disorders like motor neuron disease, progressive supranuclear palsy, and amyotrophic lateral sclerosis. Treating such combined conditions usually involves both medication and non-medical interventions, in addition to addressing the underlying disease.
Sleep-related problems reported by patients include the following:
- Insomnia: found in about 48% of cases
- Sleep-disordered breathing: found in approximately 68% of cases
- Excessive daytime sleepiness: found in around 64% of cases
- Restless leg syndrome: found in roughly 8% of cases
In addition, some FTD patients may face a heightened risk of falling. Altered sexual behaviour and eating disorders (like overeating/binge eating, loss of appetite, or specific food cravings) have also been reported.
Preventing Frontotemporal Lobe Dementia
Frontotemporal dementia (FTD) is a type of dementia that includes three different forms. All of these forms of FTD can seriously affect a person’s social life, ability to work, and daily functioning. The condition requires that individuals get the right information about the disease and have strong family support. They might also need help with everyday tasks and benefits from comprehensive rehabilitation services. Regular assistance and updates should be given to those who care for them due to the heavy demands of managing the condition.
Genetics plays a significant role in this condition as about 40% of cases have a family history, and 13.4% are passed down directly from a parent. This means that if a family member has the disease, other family members should be closely watched for early warning signs and symptoms.
