Frontotemporal Dementia

Frontotemporal dementia (FTD) or frontotemporal degeneration is a group of disorders characterized by progressive loss of nerve cells in the frontal and temporal lobes of the brain, which are responsible for behavior, personality, language production, and comprehension.

About

Frontotemporal dementia is caused by the degeneration of nerve cells in the frontal and temporal lobes, leading to the deterioration of behavior, personality, and language skills. There are various diseases that can cause frontotemporal degeneration, with two prominent groups involving the proteins tau and TDP43. These diseases preferentially affect the frontal and temporal lobes, resulting in dementia.

Types

Frontotemporal dementia encompasses different subtypes, including:

Behavioral variant frontotemporal dementia (bvFTD): This subtype is characterized by prominent changes in behavior and personality. It typically occurs in people in their 50s and 60s, but can manifest as early as the 20s or as late as the 80s. Nerve cell loss in areas that control judgment, empathy, conduct, and foresight is most prominent in this subtype.

Primary progressive aphasia (PPA): PPA primarily affects language skills, including speaking, writing, and comprehension. It usually develops before the age of 65 but can occur in late life as well. PPA has two distinct forms:

Semantic variant: Individuals lose the ability to understand or formulate words in spoken sentences.
Nonfluent/agrammatic variant: Speech becomes hesitant, laborious, or ungrammatical.
In addition to these subtypes, there are also disorders that affect motor function, such as amyotrophic lateral sclerosis (ALS), corticobasal syndrome, and progressive supranuclear palsy (PSP). These disorders can involve changes in muscle or motor functions along with behavioral or language problems.

Causes and Risk Factors

Inherited factors play a role in about one-third of all cases of frontotemporal degeneration. Genetic counseling and testing are available for individuals with a family history of the disorder. Other than a family history or a similar disorder, there are no known risk factors for frontotemporal degeneration.

Diagnosis

Diagnosing behavioral variant frontotemporal dementia and PPA requires a thorough evaluation by a knowledgeable doctor. The diagnosis is based on the patient’s symptoms and neurological examinations. Additional tests, including magnetic resonance imaging (MRI) and glucose positron emission scans, can provide valuable information but should be interpreted alongside the patient’s history and neurological exam.

Outcomes and Treatment

Currently, there are no specific treatments for the different subtypes of frontotemporal dementia. Medications can be used to manage symptoms such as agitation, irritability, and depression, aiming to improve quality of life. Frontotemporal dementia progressively worsens over time, and the rate of decline varies among individuals. Muscle weakness and coordination problems often arise, leading to mobility issues and the potential need for a wheelchair or bed confinement. Swallowing, chewing, and bladder/bowel control can also be affected. Eventually, physical changes can result in infections that may contribute to the individual’s death.

Long-term outcomes for individuals with Korsakoff syndrome, with or without a preceding Wernicke encephalopathy episode, are not extensively studied. Available data suggest that approximately 25% of individuals eventually recover, around 50% experience some improvement but not full recovery, and approximately 25% remain unchanged. Research indicates that those who recover and abstain from alcohol may have a normal life expectancy.

For individuals at risk of thiamine deficiency, such as heavy drinkers, thiamine and other vitamin supplements may be recommended under medical supervision. Injectable thiamine is often administered to those with a history of heavy alcohol use who exhibit symptoms of Wernicke encephalopathy. After acute symptoms improve, a comprehensive evaluation is conducted to assess if the person’s medical history, alcohol use, and memory problems align with Korsakoff syndrome. Extended treatment with oral thiamine, other vitamins, and magnesium may enhance symptom improvement. If no progress occurs, addressing comorbid deficiencies and medical conditions and considering long-term residential care or supportive accommodation should be explored.

Abstaining from alcohol and maintaining a healthy diet are crucial aspects of long-term treatment. Individuals with Korsakoff syndrome have reduced alcohol tolerance and are at a higher risk of developing additional alcohol-related health problems.