What is Frontotemporal Dementia?
Frontotemporal dementia (FTD) is the name for a group of brain disorders that cause changes in the sufferer’s personality, behavior, or language abilities. All of the disorders are caused by loss of function in the brain’s frontal and/or temporal lobes, the parts of the brain that control planning, judgment, emotion, social behavior, and language.
Frontotemporal dementia most commonly affects people between the ages of 45 and 60, although it can occur in people who are older or younger. It differs from other types of dementia such as Alzheimer’s disease, which usually has a significantly later onset. frontotemporal dementia disorders are some of the most common causes of dementia in younger people.
Frontotemporal dementia also differs from dementias like Alzheimer’s because the sufferer’s memory usually remains unaffected throughout the course of the disease.
The symptoms of frontotemporal dementia vary depending on which parts of the brain are affected. The disorders can be broadly divided into two categories: those that primarily have behavior-related symptoms, and those that have primarily language-related symptoms. Some rares types of frontotemporal dementia have movement-related symptoms.
Symptoms of Behavioral Frontotemporal Dementia
This is the most common type of frontotemporal dementia, making up about half of all cases. Behavior-related symptoms include:
- Inappropriate social behavior (including rudeness, inappropriate touching, or engaging in taboo behaviors)
- Loss of consideration for other people’s feelings
- Loss of affection for loved ones
- Loss of inhibition
- Poor judgment or decision making
- Loss of interest in daily activities and social situations
- Unusual, repetitive behaviors
- Poor hygiene
- Changes in appetite or eating behaviors (including eating too quickly or trying to eat inedible items)
Symptoms of Language-Related Frontotemporal Dementia
These types of frontotemporal dementia primarily affect the sufferer’s ability to use and understand language, both spoken and written. Disorders in this category include primary progressive aphasia, semantic dementia, and agrammatic aphasia.
Symptoms of these disorders include:
- Problems with spoken languages, such as having trouble finding the right word to use
- Difficulty understanding written and/or spoken language
- Problems with grammar, such as leaving words out of sentences or putting words in the wrong order
- Using extremely simplified language
- Difficulty recognizing familiar objects or people
If parts of the brain that control movement is also affected, frontotemporal dementia can produce movement-related symptoms. This happens most often in cases of behavioral frontotemporal dementia. Some doctors also consider movement-related brain disorders such as amyotrophic lateral sclerosis (ALS), corticobasal degeneration, and progressive supranuclear palsy to be types of frontotemporal dementia.
Movement-related symptoms of frontotemporal dementia can include:
- Muscle weakness in the limbs
- Muscle stiffness
- Muscle weakness in the lips, tongue, and throat (which may cause difficulty swallowing)
- Tremors or uncontrollable shaking
- Muscle spasms or involuntary jerking movements
- Difficulties with balance or walking
All of the symptoms of frontotemporal dementia get progressively worse over time. Although the symptoms themselves are not directly life-threatening, they may put the sufferer at risk of health complications, dangerous behavior, or self-harm. Many sufferers eventually need constant care to keep them healthy and safe.
What Causes Frontotemporal Dementia?
Frontotemporal dementia occurs when abnormal proteins accumulate in brain tissue. Over time, these proteins interfere with the function of brain cells, and eventually, the cells die. As more cells die, the affected part of the brain shrinks and the functions controlled by that part of the brain is impaired.
Frontotemporal dementia affects the frontal and/or temporal lobes of the brain. The frontal lobes are behind the forehead, directly above the eyes on both sides of the brain. They help control thought processes such as planning, judgment, and emotional responses. The frontal lobes also play a role in some language skills (such as sentence-building) and some movement functions. The temporal lobes are below and to each side of the frontal lobes. They play a vital role in processing language, as well as being responsible for some memory functions.
The symptoms experienced by an individual frontotemporal dementia sufferer vary depending on which parts of the brain are affected, and the progression of the symptoms varies according to the pattern of degeneration in the brain.
Scientists are not sure what causes frontotemporal dementia disorders. More than one abnormal protein seems to be involved in the development of the diseases, and it’s not clear what causes the proteins to accumulate in the brain.
Is Frontotemporal Dementia Hereditary?
The majority of frontotemporal dementia cases are not inherited. In about 60% of cases, the disorders occur spontaneously in patients who don’t have a family history of related disorders. In about 40% of frontotemporal dementia cases, the patient does have a strong family history of frontotemporal dementia or other degenerative neurological disorders. In about half of those apparently inherited cases, genetic testing is able to detect a specific genetic cause.
Frontotemporal dementia is associated with variations in several different genes, each of which plays a role in the production of the proteins that are thought to be the cause of the disorders. Scientists don’t know exactly how these genetic variations trigger the disease, but it’s possible that different genetic factors might contribute to different types of FTD disorders or different symptom patterns.
If you have a family history of frontotemporal dementia or other degenerative neurological disorders, a genetic counselor can help you assess the risks you face.
How Is Frontotemporal Dementia Detected?
There is no cure for frontotemporal dementia, and there is no treatment that will stop the progression of its symptoms. Early detection of the disorders, however, can help sufferers seek interventions that will keep them safe.
Early signs of frontotemporal dementia often include:
- Loss of interest in daily activities
- Withdrawal from social interaction
- Shifts in mood or depressive behavior
- Changes in personality
- Loss of social inhibition
- Sudden onset of inappropriate behavior
- Obsessive or repetitive behaviors
- Binge eating or rapid weight gain
How Is Frontotemporal Dementia Diagnosed?
There is currently no test or exam that will definitively detect frontotemporal dementia. The disorders are often misdiagnosed because their early symptoms look similar to the symptoms of other disorders. Common misdiagnoses include depression, schizophrenia, and Alzheimer’s disease.
As part of the diagnostic process, doctors will typically administer physical exams, neurological exams, and laboratory tests to rule out conditions other than frontotemporal dementia that could be causing the symptoms. The process will include interviews with the patient and with loved ones or caregivers in an attempt to get a complete picture of the pattern of symptoms.
Brain imaging scans such as magnetic resonance imaging (MRI) and positron emission tracer (PET) scans may also be used to look for evidence of other brain disorders. The physical effects of frontotemporal dementia itself are not always detectable on scans, especially in the early stages.
PLEASE CONSULT A PHYSICIAN FOR MORE INFORMATION.
How Is Frontotemporal Dementia Treated?
There is no treatment that will slow, stop, or reverse the effects of frontotemporal dementia. Medications that show promise in treating other forms of dementia appear to be ineffective at treating frontotemporal dementia, and some may even make symptoms worse. The course of treatment for frontotemporal dementia is focused on directly treating symptoms and attempting to manage their effects.
- Antidepressants such as citalopram, paroxetine, or sertraline may be used to treat symptoms such as depression or mood changes.
- Antipsychotics such as olanzapine or quetiapine may be used to treat behavioral symptoms. These medications carry the risk of severe and potentially life-threatening side effects, so they must be used with caution.
Speech therapy may help sufferers cope during the early stages of language-related FTD disorders.
How Does Frontotemporal Dementia Progress?
The symptoms of frontotemporal dementia become progressively worse over time, and in some cases, symptoms become so severe that sufferers require full-time care. The symptoms themselves are not life-threatening, but they can become so debilitating that the sufferer is at risk of serious medical and behavioral complications. The time from the initial appearance of symptoms until the disorder reaches its peak impact can be as short as 2 years or as long as 20 years.
Potential long-term complications of frontotemporal dementia include:
- Infections or illnesses such as pneumonia
- Accidents or falls
- Risky behavior that can endanger the sufferer or others
- Total loss of the ability to communicate
How Is Frontotemporal Dementia Prevented?
There is no known way to prevent frontotemporal dementia. The cause of sporadic cases of frontotemporal dementia (those that occur without a family history) remain unknown, so there are no avoidable risk factors associated with frontotemporal dementia disorders.
If you have a family history of frontotemporal dementia or degenerative neurological disorders, a genetic counselor can help you decide if you should undergo genetic testing. Genetic tests can identify whether or not you’ve inherited one of the genetic variants that have been associated with frontotemporal dementia disorders.
Frontotemporal Dementia Caregiver Tips
Taking care of a loved one with frontotemporal dementia is extremely taxing, both physically and emotionally. To help yourself and your loved one cope with the effects of the disease, keep these tips in mind:
- Learn all you can about FTD. Some of the symptoms of frontotemporal dementia can be shocking, and you’ll be better equipped to deal with them if you understand their cause. Your loved one may exhibit agitation, aggression, or socially unacceptable behavior. It’s important that you not take this behavior personally and understand that it is part of the disease.
- Create soothing surroundings. The symptoms of both behavior- and language-related FTD can be easier to manage if your loved one has a calm, distraction-free environment. Work to identify situations that seem to trigger problematic behavior, and try to limit those situations as much as you can.
- Take care of yourself. Caregivers for people with FTD are at particular risk of physical and mental health issues themselves. Don’t hesitate to take time for yourself away from your loved one when you can, and seek help from a support group, either locally or online.
Frontotemporal Dementia Brain Science
Frontotemporal dementia is caused by the buildup of abnormal proteins in the brain. As these proteins accumulate in the brain’s nerve cells, they impede the function of the cells and eventually cause the cells to die. Scientists have identified several genes and more than one protein associated with the various FTD disorders. Normally, the genes control the production of proteins that play an important role in proper brain function. Certain abnormal changes (mutations) in the genes, however, seem to be the trigger for abnormal protein formation.
Some of the genes associated with FTD include:
- C9orf72. This gene was discovered relatively recently, but its mutations seem to be the most common cause of FTD. C9orf72 mutations have been associated with about a quarter of all inherited cases of FTD and with about 6% of non-inherited cases. Scientists are currently studying the role this gene plays in protein production.
- Microtubule-associated protein tau (MAPT). Mutations in this gene are associated with 5-10% of FTD cases. The gene is associated with the production of a protein called tau, which is vital for proper nerve-cell function and health.
- Progranulin (GRN or PGRN). This gene plays a role in the production of a protein called progranulin. The protein helps nerve cells resist and recover from inflammation and injury. The GRN gene is associated with 5-10% of FTD cases.
These gene mutations may be passed from parents to their children, and inherited mutations are responsible for about 40% of FTD cases. The remainder of cases result from spontaneous gene mutations that occur sometime later in life. Scientists are still unsure what causes these spontaneous mutations.
Frontotemporal Dementia Research
Title: Low-Dose Lithium for the Treatment of Behavioral Symptoms in frontotemporal dementia (Lithium)
Contact: Edward Huey, MD
Columbia University Medical Center
New York, NY
Behavioral symptoms of frontotemporal dementia (FTD), including agitation, aggression, and inappropriate repetitive behaviors are common, distressing to patients and caregivers, often lead to institutionalization, and can be very difficult and expensive to treat. There is a dearth of medication for treating these symptoms in FTD. Typically, antidepressants and antipsychotic medications are prescribed – which have low efficacy and, with the latter class, carry serious adverse effects such as parkinsonism and increased cardiovascular-related mortality. The investigators propose a study of the efficacy of lithium carbonate compared to placebo in the treatment of agitation, aggression, and inappropriate repetitive behaviors in 60 patients with FTD in a randomized, double-blind, two-arm parallel 12-week trial. Lithium is a highly effective treatment for mania and symptoms of agitation or aggression in bipolar disorder. It also inhibits tau aggregation and phosphorylation, leading to considerable interest in its use as a disease-modifying treatment for tauopathies such as FTD and Alzheimer’s disease. Unfortunately, earlier trials using typical doses (i.e., doses prescribed for treatment of bipolar disorder) showed high incidence of serious adverse effects (including confusion and delirium). For the study proposed the investigators will: 1) use lower doses and lower target serum concentrations than preceding trials (shown in preliminary data from a Columbia study and data from other labs to be well-tolerated) and 2) target behavioral symptoms rather than cognitive outcomes.
Title: Rehabilitating and Decelerating Language Loss in Primary Progressive Aphasia With tDCS Plus Language Therapy
Principal investigator: Argye E Hillis, MD, MS
Johns Hopkins School of Medicine
Primary Progressive Aphasia (PPA) is a debilitating disorder characterized by the gradual loss of language functioning, even though cognitive functioning is relatively well preserved until the advanced stages of the disease. There are three main PPA variants classified based on the pattern of language impairments and areas of atrophy, but ammonia is present across all variants in the earliest stages. While there is a significant amount of research investigating multiple treatment approaches for individuals with aphasia resulting from stroke, individuals with PPA have far fewer treatment options to choose from. Recently, a growing body of literature of treatment in stroke-based aphasia has found promising results for pairing traditional language therapy with non-invasive neurostimulation via transcranial direct current stimulation (tDCS). The small number of studies of the effects of tDCS applied to left inferior frontal gyrus (IFG) in PPA also yield promising results that show tDCS can enhance generalization to untreated structures. Research in stroke-based aphasia has also shown that language outcomes significantly improve when participants are treated with more complex language stimuli because this treatment approach results in enhanced generalization. For example, a therapy that has participants build sentences around verbs has been found to improve word-level verb and noun naming. The current proposal aims to investigate whether combining the benefits of tDCS while providing verb retrieval therapy that uses sentence building to improve word-level retrieval deficits, will enhance word retrieval deficits in PPA and slow the loss of language functioning. It is hypothesized that Furthermore, the proposed study will investigate the atrophy patterns at baseline, to determine which atrophy patterns are predictive of improved word retrieval. Specifically, this proposal aims 1) to determine whether tDCS to left IFG coupled with therapy promoting verb retrieval within sentences improve noun and verb retrieval in treated and untreated items in individuals with PPA, and 2) To investigate which patterns of atrophy are predictive of maintenance and generalization of word-retrieval in individuals with PPA following tDCS+therapy vs. sham+therapy. This proposed research will allow the investigators to evaluate the potential benefits and sustainability of tDCS in PPA, the generalization of trained items to untrained items, as well as the deceleration of language loss.
Title: TMS for the Treatment of Primary Progressive Aphasia
Principal investigator: Alexandra Touroutoglou, PhD
Massachusetts General Hospital
Primary Progressive Aphasia (PPA) is a progressive syndrome in the family of Alzheimer’s disease and related disorders involving devastating language impairments caused by selective neurodegeneration of the brain’s language network. Unfortunately, there is no treatment for PPA. An exciting possibility for treatment is non-invasive repetitive transcranial brain stimulation (rTMS), which induces electric currents in degenerating brain networks, making them in some cases more efficient.
Therapeutic benefits from rTMS have been demonstrated when it is applied in many sequential sessions. For example, repeated sessions of rTMS to the left dorsolateral prefrontal cortex (dlPFC) is approved by the US Food and Drug Administration as a treatment for major depressive disorder. With respect to language, high-frequency rTMS increases the response rate for picture naming in healthy individuals and in patients with Alzheimer’s disease. Further, in a sham-controlled study, Cotelli and colleagues demonstrated that in a group of 10 non-fluent PPA patients, high-frequency rTMS over the left and right dlPFC improved the percent of correct responses for action naming. When rTMS was applied for five consecutive days in a sham-controlled single case study, Finocchiaro and colleagues showed lasting improvements in language (up to 1 week) in a patient with non-fluent PPA. Trebbastoni and colleagues further showed the same lasting improvements in language (up to 1 week) in a patient with logopenic PPA. Recently, in a sham-controlled single case study, Bureau and colleagues applied a more intense rTMS protocol for ten consecutive days and demonstrated significant linguistic improvements in a logopenic PPA patient that lasted for 1 month. These studies have contributed valuable insights into the potential use of rTMS in treating the language symptoms of PPA patients.