Childhood dementia

Childhood dementia is an umbrella group consisting of over 100 rare neurodegenerative conditions. These are typically genetic, that cause progressive cognitive decline and the loss of previously acquired skills (e.g: talking, walking, reading/writing, etc). The group of conditions has a very poor prognosis on average, as the progression of cognitive decline and other symptoms/complications have a very significant impact on the life expectancy and quality of those affected. Neuronal ceroid lipofuscinoses, a group of lysosomal storage disorders, are the most common cause of childhood dementia.

Childhood dementia
Other names	Pediatric dementia
Specialty	Neurology, Psychiatry, Pediatrics
Symptoms	Loss of previously acquired developmental skills, seizures, cognitive decline
Usual onset	Childhood or adolescence
Duration	Progressive
Causes	Genetic disorders, neurodegenerative diseases
Diagnostic method	Biochemical testing, genetic testing
Treatment	Most constituent disorders are untreatable and patients receive symptom management (medication, )
Prognosis	Severely reduced life expectancy as a whole. Median life expectancy of 9 years

Classification and terminology

Childhood dementias are a heterogenous group of genetic neurodegenerative disorders, that present symptoms before the age of 18. They are typically monogenic (caused by mutations of a single gene).

Their main characteristics are chronic and widespread cognitive decline; loss of previously acquired developmental skills after a period of typical development; and behaviours and psychological symptoms of dementia (BPSD).

Childhood dementias are distinct from sources of intellectual disability in childhood that are non-progressive (e.g traumatic brain injury) or acquired (e.g nutritional deficiencies or encephalitis).

Prognosis

The prognosis for childhood dementia is generally poor, with most children experiencing a significant decline in cognitive and motor function. Life expectancy varies depending on the underlying cause, but it is often significantly reduced. Studies show that only 25–29% of affected individuals survive to adulthood, and only 10% reach the age of 50.

The median life expectancy is around 9 years, whereas the average life expectancy is 16.3 years.

Signs and symptoms

By their usual definitions, childhood dementias always cause global neurocognitive decline, typically beginning after a period of seemingly normal development.

This progressive decline causes difficulty concentrating, memory loss, confusion, and learning difficulties, in addition to the loss of developmental skills acquired previously, such as: walking, talking, writing, reading, and playing. Eventually the body loses its ability to function, leading to an early death.

Other symptoms and complications can occur depending on the subtype.

Other symptoms:

• Behavioral changes: Personality shifts, aggression, and hyperactivity.
• Motor decline: Loss of coordination, balance, and movement abilities.
• Seizures: Frequent in many forms of childhood dementia.

Other complications:

• Loss of vision or hearing.
• Cardiovascular, respiratory, and/or digestive problems
• Bone or joint problems.

Causes

The majority of childhood dementia cases are caused by genetic mutations that lead to neurodegenerative diseases. The most frequent cause is neuronal ceroid lipofuscinoses (NCL), a family of lysosomal storage disorders. Other causes include mitochondrial diseases, peroxisomal disorders, and other genetic disorders affecting brain function.

Diagnosis

Diagnosis typically involves a combination of biochemical testing and genetic testing, often performed around the age of four. Early diagnosis is crucial for managing symptoms and improving the quality of life for those affected. In most cases, childhood dementia is diagnosed after developmental regression is observed.

Management

There is no treatment for most forms of childhood dementia. For these untreatable conditions, treatment focuses on managing symptoms and improving quality of life.

This can include:

• Medications: Anti-seizure medications, behaviour-modifying drugs, and muscle relaxants.
• Therapies: Physiotherapy, occupational therapy, and speech therapy are used to maintain physical function for as long as possible.
• Supportive care: This includes comprehensive care to address complications related to mobility, feeding, breathing, and communication. Supportive care measures are customized for each patient and may include:

• Respiratory support, to manage breathing difficulties in advanced stages.
• Nutritional support, including the use of feeding tubes when swallowing becomes difficult.
• Palliative care to ensure comfort and quality of life as the disease progresses.

Epidemiology

Current estimates place the incidence of childhood dementias at 1 in 1186 births. This is higher than the incidence of some diseases with more widespread awareness, such as cystic fibrosis (affecting around 1 in 3000-4000 births) and spinal muscular atrophy (around 1 in 11000 births).

Meanwhile, the estimates for the prevalence are lower, at 1 in 3484 people in the general population and 1 in 1715 among children.

History

The concept of childhood dementia gained recognition in the early 20th century with the identification of Batten disease, one of the first known forms of childhood dementia, by British neurologist Frederick Batten in 1903.

See also

• Neuronal ceroid lipofuscinosis
• Batten disease
• Lysosomal storage disease
• Neurodegenerative disease

External links

• Dementia Australia: Childhood Dementia
• Childhood Dementia Initiative