3.10.4 Frontotemporal dementia and Pick’s disease

3.10.4 Frontotemporal dementia and Pick’s disease

The Neuropathology Frontotemporal Dementia

Frontotemporal dementia (FTD) is a degenerative brain disease that is an early-onset disorder that mostly occurs before the age of 65. FTD encompasses several types of dementia involving the progressive degeneration of the frontal and temporal lobes (Miller, 2010).

FTD refers to a clinical syndrome of 3 types:

  • Behavioural variant (bvFTD) previously known as Pick’s disease
  • Progressive non-fluent aphasia
  • Semantic dementia

Frontotemporal dementia (FTD) is a neurodegenerative disorder that primarily affects the frontal and temporal lobes of the brain. It is characterized by a progressive decline in behaviour, language, and/or executive function, leading to a decline in the individual’s ability to engage in activities of daily living and care for themselves. FTD is a relatively uncommon form of dementia, accounting for approximately 10-15% of all cases (Josephs, 2011).

The neuropathology of FTD is characterized by the progressive degeneration of specific regions of the brain, including the frontal and temporal lobes, as well as the anterior cingulate cortex and basal ganglia. At the cellular level, FTD is characterized by the presence of abnormal protein aggregates, including tau and TDP-43, which can lead to the formation of neurofibrillary tangles and other pathological inclusions. In addition, there may be evidence of neuronal loss, glial activation, and oxidative stress, which can further contribute to the degeneration of brain cells (Snowden, 2010).

Roughly 10-15% of people suffering from FTD will suffer from neurone failure. This is referred to as FTD with motor neurone disease.

The Neuropathology of Pick’s Disease

bvFTD is what was previously referred to as Pick’s disease. Today, however, specialists only refer to a condition as Pick’s when certain requirements are met. Pick’s disease is the prototype of frontotemporal lobe degeneration tauopathy.

Pick’s disease, also known as frontal temporal lobar degeneration, is a rare neurodegenerative disorder characterized by the progressive deterioration of specific regions of the brain, including the frontal and temporal lobes. The disease primarily affects individuals in their 40s to 60s and leads to a decline in behaviour, language, and executive function. The hallmark of Pick’s disease is the presence of abnormal protein inclusions in the affected brain regions, including tau and TDP-43, which can contribute to the degeneration of brain cells. The onset and progression of Pick’s disease can vary greatly from one individual to another, and there is currently no cure for this condition. However, various treatments and therapies are available to help manage the symptoms and improve quality of life, including speech and language therapy, occupational therapy, and support for caregivers.

The most frequent type of FTD is behavioural variant frontotemporal dementia (BvFTD), often known as Pick’s disease.

Symptoms:

FTD’s broadly present as behavioural or language disorders with gradual onsets. Characteristic social display patterns include dissociation from family, strong oniomania, vulgar speech characteristics, yelling, and inability to control emotions, behaviour, personality, and temperament. It has been observed that the gradual beginning and progression of changes in behaviour or language deficiencies began several years before referral to a neurologist or psychiatrist.

Pick’s disease can display itself in two different ways. One way is that it results in frontotemporal dementia’s behavioural variation (bvFTD). The second is when it damages your brain’s language centres, leading to a disorder called primary progressive aphasia.

Cause:

Frontotemporal dementia with a highly specific cause includes Pick’s disease. A particular protein called tau is present in all nerve and brain cells (named for a Greek alphabet letter). Tau and other proteins must have a certain structure in order to function effectively.

When tau proteins break down and clump together, they accumulate inside neurons, causing harm and eventual death to those cells. These dead neurons, called “Pick cells,” resemble bulging balloons. Pick bodies, which are tangles of tau proteins found inside cells, can also be seen under a microscope. Other conditions don’t cause Pick bodies or Pick cells (Neary & Snowden, 1996).

References:

(1) Josephs, K. A., & Ahlskog, J. E. (2011). Frontotemporal dementia and parkinsonism linked to chromosome 17: a review. Mayo Clinic Proceedings, 86(3), 297-305.

(2) Miller, B. L., & Darby, E. (2010). Frontotemporal dementia. The Lancet Neurology, 9(7), 708-719.

(3) Neary, D., & Snowden, J. (1996). Fronto-temporal dementia: nosology, neuropsychology, and neuropathology. Brain and Cognition, 31(2), 176-187.

(4) Snowden, J. S., & Neary, D. (2010). Frontotemporal lobar degeneration. The Lancet Neurology, 9(6), 171-180.