Tuberous sclerosis - Symptoms of tuberous sclerosis

The non-cancerous (benign) tumours caused by tuberous sclerosis can develop almost anywhere in the body.

However, the areas most commonly affected include the: 

  • brain – occurring in an estimated 9 out of 10 cases
  • skin – occurring in an estimated 9 out of 10 cases
  • kidneys – occurring in an estimated 8 out of 10 cases
  • heart – occurring in an estimated 7 out of 10 cases
  • eyes – occurring in an estimated 8 out of 10 cases 
  • lungs – occurring in an estimated 4 out of 10 cases in women

These are described in more detail below.

Neurological conditions and complications

Tumours that develop in the brain can affect its ability to function normally, and can cause a range of neurological conditions and complications. "Neurological" is a term used to describe the nervous system, which includes the brain.

Epilepsy

Epilepsy is the most common neurological symptom of tuberous sclerosis, affecting up to 9 out of 10 people with the condition. The condition causes repeated seizures (fits) and a temporary loss of consciousness.

Read more information about epilepsy.

Infantile spasms

Around a third of children will develop a more severe form of epilepsy known as infantile spasms. They usually develop during the first three months of life.

Infantile spasms occur when the baby has multiple seizures in a short space of time. Each seizure often only lasts for a few seconds. A baby usually has a "run" or "cluster" of around 20 seizures, although some babies can have up to 100 seizures over a short period of time.

Infantile spasms usually disappear by the time a child is three years old, but the condition often causes permanent brain damage. An estimated 7 out of 10 children who experience infantile spasms will go on to develop some degree of brain damage and impaired intelligence, such as very slow co-ordination or speech.

It is important to diagnose infantile spasms as early as possible as research has shown that early treatment can greatly improve the outlook of the condition.

Learning disabilities

Nearly half of all children with tuberous sclerosis will have a learning disability. In some cases, the learning disability could be quite mild. In other cases, it could be severe and result in profound disability.

Possible difficulties include: 

  • poor memory
  • low attention span
  • difficulty making plans or organising activities
  • learning much more slowly than other people

Read more about learning disabilities.

Behavioural and developmental disorders 

Around half of all children with tuberous sclerosis may also have behavioural or developmental disorders because of the way the condition affects their brain. These include: 

  • autistic spectrum disorders – a range of related developmental disorders that can cause problems with language, social interaction and behaviour
  • hyperactivity 
  • impulsive behaviour
  • aggression 
  • anxiety 
  • extreme shyness
  • depression 
  • schizophrenia – a condition that causes hallucinations and delusions (seeing or believing things that are not real or untrue) 
  • sleep disorders, such as finding it difficult to get to sleep or frequently waking up during the night, are common and often difficult to control; they can also be caused by epileptic seizures at night and may last for many years

Subependymal giant cell astrocytomas (SEGAs)

A small number of children with tuberous sclerosis will develop multiple types of brain tumours during brain development up until the age of five. These tumours then remain stable, but are thought to cause the other brain problems described above.

A small number of people develop large benign brain tumours. These are known as subependymal giant cell astrocytomas (SEGAs). SEGAs can develop at any age, but they most commonly occur after the teenage years.

In about 1 in 20 people who have these tumours the SEGAs grow too big and risk obstructing the flow of cerebrospinal fluid through the brain. Cerebrospinal fluid surrounds and protects the brain and spine.

If the flow of cerebrospinal fluid is blocked, it can cause pressure to build up in the brain. This is known as hydrocephalus. Symptoms can include:

  • headache
  • nausea and vomiting
  • lack of appetite
  • increased irritability, lethargy or drowsiness
  • personality changes
  • disorientation 
  • visual problems, such as double vision or blurred vision
  • fits and seizures
  • a sudden change in bladder or bowel control, such as urinary incontinence

In cases of hydrocephalus, emergency surgery is required to drain away excess fluid from the brain. If left untreated, hydrocephalus can cause brain damage or, in the most serious cases, death.

SEGAs can be picked up before they cause hydrocephalus through regular MRI scans. Pre-emptive treatment, such as an mTOR inhibitor or surgery, may be used to prevent problems occurring.

Read more about hydrocephalus.

Skin lesions

Around 9 out of 10 of people with tuberous sclerosis will develop skin lesions. They usually occur during early childhood and can take the form of:

  • patches of light-coloured skin
  • areas of thickened skin
  • growths of skin under or around the nail

Red acne-like spots and blemishes are also common, especially on the face.

Kidney tumours

Up to 8 out of 10 children with tuberous sclerosis will develop multiple benign tumours inside their kidneys, usually by the age of five. The kidney tumours are called angiomyolipomas (AMLs) and are made up of blood vessels, muscle and fat.

Kidney tumours bigger than 3cm can rupture (split) and cause internal bleeding. This causes sudden pain and may require surgery. This is the most common kidney problem and occurs in up to two to three out of 10 people with tuberous sclerosis.

If the kidney tumours become too large, they can interfere with eating or occasionally with the workings of the kidneys. This can cause symptoms similar to kidney disease, such as:

  • tiredness
  • swollen ankles, feet or hands caused by water retention
  • shortness of breath
  • blood in the urine
  • protein in the urine 
  • an increased need to urinate, particularly at night
  • itchy skin
  • feeling sick

Polycystic kidneys

Some people with tuberous sclerosis are also born with polycystic kidneys. This is when multiple cysts (small fluid-filled sacs) develop in the kidneys.

Polycystic kidneys can cause symptoms of high blood pressure (hypertension) and kidney disease. Polycystic kidneys are also the most common cause of kidney failure in people with tuberous sclerosis, which occurs in 1 in 20 people. 

About two or three out of 10 children with tuberous sclerosis can also develop multiple simple cysts in their kidneys, but these kidney cysts usually cause no symptoms.

Read more about autosomal dominant polycystic kidney disease.

Kidney cancer

Less than 3 in 100 people with tuberous sclerosis will develop a type of kidney cancer called renal cell carcinoma.

Read more about kidney cancer.

Heart tumours

Up to two-thirds of infants born with tuberous sclerosis will develop one or more tumours inside their heart. These tumours are usually very small and do not cause any symptoms. Unlike the other types of tumour caused by tuberous sclerosis, heart tumours will usually shrink and become much more difficult to detect as a child gets older.

However, in a small number of children, the tumours can block the flow of blood inside the heart or cause it to beat irregularly (arrhythmia).

Heart problems can also cause associated symptoms, including:

  • palpitations (an irregular heartbeat or the sensation of skipped or extra heartbeats)
  • dizziness
  • fainting
  • breathlessness
  • chest pains

Eye tumours

An estimated three-quarters of people with tuberous sclerosis will develop one or more tumours inside their eyes. The tumour grows on the surface of the retina, which is the thin layer of nerve cells that line the inside of the back of the eye. However, they rarely grow large enough to affect a person's vision.

Lung tumours

An estimated 40-60% of women with tuberous sclerosis will develop tumours and cysts inside their lungs. This is a condition called lymphangioleiomyomatosis (LAM). The condition usually develops at around 20 to 40 years of age. It is unclear why women are particularly vulnerable to lung tumours while men are rarely affected.

In most cases, these cysts and tumours do not cause a problem. Around half of all women with tuberous sclerosis may have lung tumours that show up when their lungs are scanned, but do not cause any symptoms.

However, around 1 in 20 women experience symptoms from their lung tumours. The tumours can cause shortness of breath and can feel like asthma. In some cases, one or more of the tumours can rupture, resulting in a collapsed lung. A collapsed lung can be life threatening. It occurs when air leaks out from inside the lung.

In the most serious cases, women with tuberous sclerosis and lung tumours can develop progressive lung failure.

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