Dystonia that is detected in childhood can progress rapidly and interfere in the development of the child's language and mobility, causing a physical disability that will affect them throughout life.

Causes

Dystonia is a very heterogeneous disease, which can occur for a variety of reasons:

• Genetics. Dystonia caused by a defect in a gene. Most genetic forms of dystonia appear in childhood and adolescence. Currently, over 200 genes that cause dystonia have been found. Among the different types of genetic dystonia there are:
  • Recessive hereditary dystonia: Dystonia caused by congenital errors in metabolism or a failure in the production of certain enzymes.
  • Dominant hereditary dystonia: Most isolated forms of dystonia belong to this category, classified according to DYT nomenclature. Myoclonic dystonia is an example. In this case, more than 80% of cases are inherited from the father.
  • De-novo dominant dystonia: These are severe forms of the disease, such as those caused by mutations in the GNAO1 gene, so transmission to offspring is difficult.
  • Mitochondrial hereditary dystonia: These are progressive forms of dystonia that can have very variable degrees of severity. Children with this type of dystonia suffer from a disease called Leigh syndrome: A defect in mitochondrial metabolism that causes the brain not to generate enough energy to function properly and injuries occur in the ganglia of the base.
  • Dystonia linked to the X chromosome: Some examples are dystonia-parkinsonism, also called DYT3 or deafness-dystonia syndrome.
• Degenerative. They also occur due to a defect in a gene but, unlike the previous ones, they produce lesions of progressive character in the central nervous system.
• Idiopathic. Here, there is no genetic cause or event that has been found to cause a lesion in the nervous system.
• Acquired. In this case, the cause is related to damage to the central nervous system due to a lack of oxygen during pregnancy or childbirth, brain trauma or exposure to toxic elements.

Due to its incidence, dystonia is considered a rare disease.

Symptoms

Dystonia in childhood can occur in isolation or associated with other neurological and development problems. It can cause difficulty in everyday tasks such as walking, speaking, feeding oneself and taking care of personal hygiene.

When presented in isolation it is called primary dystonia and often has a genetic origin. Children who suffer from it do not usually have other health problems and their neurological development is normal. At first it manifests itself in actions such as walking, running, or writing and, later, can spread to other parts of the body and cause widespread dystonia.

Myoclonic dystonia is one of the most frequent hereditary forms of dystonia in childhood. It is characterised by the presence of sustained (dystonic) and abrupt (myoclonic) muscle contractions and psychiatric disorders such as anxiety, depression and obsessive-compulsive features. The first symptoms appear in childhood and affect the lower limbs of children, who have difficulties walking, running and with sports. This disease also affects the social relationships of these children, who have problems speaking in public or eating and drinking with friends.

Dystonia can also be associated with other neurological problems, such as spasticity, ataxia, weakness, delay in neurological development and intellectual disability. In this case we call it secondary dystonia and it is necessary to rule out neurometabolic and neurodegenerative causes.

Who is affected by the condition?

It affects children, adolescents, and adults of all ages.

Diagnosis

First of all, patients are subjected to a series of clinical, metabolic, neurophysiological and neuroimaging studies to classify the type of dystonia, before carrying out genetic studies. In patients with myoclonic dystonia, first of all, a Sanger sequencing study is carried out to determine the gene that causes it, and in the other patients, a complete family exome sequencing(parents and patient) is carried out or the index case (patient) based on the DNA samples available.

Being a rare and very heterogeneous disease it is difficult to reach a correct diagnosis and treatment plan. It is important to distinguish hereditary dystonia from childhood cerebral palsy, caused by brain damage at birth, since its diagnosis has very important consequences for treating the disease later.

A diagnosis in time decreases the need to carry out more diagnostic tests, making it possible to form a prognosis and to advise families on avoiding future diseases. It also has a very positive psychosocial impact on the patient and family. And most importantly, an exact diagnosis of the cause that generates the dystonia makes it possible to guide the best possible treatment for each patient, in what we call personalised medicine.

Typical treatment

Dystonia in childhood is progressive and debilitating, but can be prevented with early diagnosis and the use of specific therapies depending on the identified genetic defect.

Levodopa is the treatment of choice in dopa-sensitive dystonia, caused by a defect in the synthesis of dopamine. Botulinum toxin is used to control focal dystonia. In the case of widespread dystonia, different drugs are used to decrease tremors, muscle tone, and painful spasms. And in some cases of paroxysmal dystonia, which is characterised by brief and repetitive involuntary movements during the night, antiepileptic drugs are used.

Surgical alternatives

An intrathecal baclofen pump administers liquid medication through a device that is placed under the skin, and is used to treat generalised secondary forms of dystonia. It reduces pain, decreases muscle tone and spasms. It is a treatment we call symptomatic and palliative, since it does not improve the motor function of the patient.

Deep brain stimulation or globus pallidus stimulation, two electrodes are placed in the globus pallidus using a stereotaxic technique, it is the treatment of choice in primary dystonia, especially if they are widespread and do not respond to conventional medication. In these cases children can recover the function of the area affected by dystonia and improve their quality of life. It can also be useful in patients with secondary forms of dystonia, although its effectiveness is less than in primary forms of dystonia.

Prevention

Performing genetic testing is the best prevention to avoid having more children affected by this disease in the same family.

Causes of cerebral palsy

These can be categorised according to the moment when the brain damage occurs: prenatal, perinatal and postnatal. Currently, the most frequent causes are: extremely premature birth, hypoxia of the brain during birth, and paediatric stroke.

Signs and symptoms

In babies, we see slower psychomotor development, with difficulties in movements or activities. We usually see spasticity, which could be defined as increased tightness in a certain group of muscles. There are major musculoskeletal abnormalities, including spinal deformity, hip dislocation and ankle equinus.

Diagnosis

Fundamentally clinical diagnosis, depending on the patient's history. But confirmation is needed by additional imaging tests such as cranial ultrasound and magnetic resonance imaging. However, these can be normal.

Treatment

Unfortunately, there is no cure for cerebral palsy. However, we can deal with the pathology in different ways, both in prevention and in treatment:

• Psychomotor stimulation treatment, physiotherapy and occupational therapy, depending on the age of the patient, severity and the goals to be reached
• Management of musculoskeletal disorders
• Treatment of musculoskeletal pain
• Indication of orthoses for managing deformities, or technical aids. Indication of wheelchairs or appliances to help with standing or walking
• Indication of medications or botulinum toxin infiltration in order to reduce spasticity
• Treatment of epilepsy symptoms
• Treatment to ensure safe eating and drinking, whether through logopaedic therapy or feeding tubes
• Support in school, both ordinary and special

Prevention

No specific prevention is possible.

Healthcare advice

Apart from the physiotherapy and/or occupational therapy which can be offered or recommended to these patients, physical exercise can always be suggested, depending on the abilities of each person. We also recommend stretching certain muscle groups and trying to correct posture.

Professionals involved

The Child Rehabilitation and Cerebral Palsy Unit is staffed by doctors specialising in caring for these patients, physiotherapists and occupational therapists.

We work with other specialist units, such as Neuropaediatrics, Paediatric Neurosurgery, Orthopaedic Surgery, and Paediatric Traumatology. We are in direct contact with all the paediatric services: Neonatology, Oncohaematology, Nutritional Support, etc.

Hereditary metabolic diseases (HMD) are chronic progressive multi-system illnesses that may appear at any age and that in most cases pose diagnostic and therapeutic challenges. Our Unit has been recognised as a leader within Spain (CSUR) and Europe (ERN) for this pathology and takes part in the neonatal screening programme in Catalonia. We are the only centre in Catalonia to offer complete care from paediatrics to adults with particular expertise in lysosomal storage disorders.

HMDs are divided into:

- Intermediary metabolism HMD: usually with acute symptoms.

- HMD related to the organelles (lysosomal storage disorders, peroxisomal diseases, mitochondrial disorders and endoplasmic reticulum storage diseases): chronic presentation with no decompensations (with the exception of some mitochondrial disorders)

Multiple systems in the body are affected and different organs and systems are involved with varying symptoms depending on the disorder and the patient’s age. These disorders require a coordinated approach to care and programmes to manage the transition to adulthood. 

Symptoms

Many symptoms become evident during childhood in the form of delayed physical growth and delayed psychomotor development. There may be associated heart problems, kidney conditions, and at times decompensations leading to liver or kidney failure and neurological impairment. In the case of organelle disorders, symptoms are chronic and affect the bones and organs of the senses in greater measure. They are more common in adults than intermediary metabolism disorders.   

Diagnosis

Diagnosis is carried out by:

• Laboratory tests: biochemical and enzyme analysis on different tissues according to the suspected diagnosis.
• Specific genetic testing to confirm diagnosis

Treatment 

They are chronic disorders that need to be treated in specialised centres with multidisciplinary teams to provide support for all related health problems.

The following may be necessary, depending on the type of disorder:

• A special and complex diet with different supplements and cofactors
• Pharmaceuticals that help avoid build up of toxic substrates
• Highly complex medication such as enzyme replacement therapy or substrate inhibitors
• Stem cell, liver or kidney transplant 

Prevention

Prevention consists of thorough genetic and reproductive counselling if there is a family history of the disease. Early diagnosis of some diseases through the neonatal screening programme enables effective treatment and improved prognosis.  

Complex paediatric neurosurgery includes:

• Complex brain tumours  
• Alterations in the cerebrospinal fluid (complex cases of hydrocephalus or intracranial hypertension or extremely small children with obstructive or post-haemorrhagic hydrocephalus)
• Craniofacial syndrome malformations (Apert-Crouzon and Carpenter’s syndrome among others)
• Malformations of the fusion of cranio-cervical bones affecting the surrounding structures (such as Chiari malformations combined with anterior spine compression)
• Rare spinal cord disorders 

In general, these are unusual and highly complex diseases. Many are included under the sections for rare diseases. For the best results, they should be treated in large centres that have experience of multiple cases every year and that are equipped with the technology required to treat these disorders. 

Symptoms

Each condition has its own characteristics. In the case of a brain tumour, the child’s symptoms will depend on the area of the brain where the tumour is located.

When there are cases of decompensated hydrocephalus or severe intracranial hypertension, in other words, when there is increased pressure inside the skull, the child may have headaches, visual disturbances and may go into a coma.

Craniofacial malformations are characterised by severe deformities of the bones in the skull and face.

Who is affected by these disorders?

They tend to be rare. It is unusual to treat more than ten cases of each pathology per year.

Diagnosis

Diagnosis of neurosurgical pathologies includes:

• Advanced neuroimaging studies (conventional magnetic resonance imaging and special sequences and vascular studies)
• Neurophysiological tests (evoked potential or sleep studies)
• Collaboration with professionals from other areas (neurologists, ophthalmologists, oncologists, etc.)  

Assessing the results also involves psychologists or other professionals to objectively observe changes in cognitive function and quality of life.

Typical treatment

Treatment of pathologies covered by complex paediatric neurosurgery is usually surgical. This means having an operating room equipped with advanced technology that allows intraoperative monitoring, and specialised anaesthetists and nursing staff.

Prevention

Unfortunately there are no known preventative measure for these disorders. Our principal task is to restore lost function and achieve the best results so that, where possible, the child can develop normally and integrate as much as possible into family life, school and socially.

The main causes of respiratory impairment are hypoventilation due to weak inspiratory muscles and a lack of ability to cough due to weak expiratory muscles. Ventilatory support via non-invasive mechanical ventilation or tracheotomy can prevent or reverse ventilatory failure in these patients.

The loss of expiratory strength means that patients are unable to expel bronchial secretions. If the bulbar muscles are also affected and patients run the risk of inhaling saliva, the contents of the mouth or food, this can induce multiple respiratory infections, pneumonia and atelectasis which results in obstruction of the airway and seriously endangers the patient's life.

The combination of non-invasive mechanical ventilation to assist coughing decreases morbidity and hospital admissions for these patients.

Symptoms

• Respiratory and ventilatory failure
• Unable to expel secretions and ineffective cough
• Dysphagia and dysarthria due to impairment of the bulbar muscles  
• Impairment of peripheral muscles limits function and basic daily activities

 There are currently around 60,000 people with the condition in Spain.

Diagnosis

In the Cardiorespiratory Rehabilitation Unit, we monitor maximal inspiratory and expiratory pressure (MIP and MEP) and peak expiratory flow (PEF), also known as peak cough flow (PCF) and carry out spirometry.

Treatment 

Treatment goals are focused on controlling the evolution of the ventilatory failure and avoiding or improving episodes of respiratory failure. To achieve these objectives, manual techniques or equipment have to be used. These are techniques to encourage pulmonary expansion, manually assist coughing, and others.

Prevention 

One very important objective is to train the main carer in physiotherapy techniques in order to avoid possible complications in the respiratory system.