Gait in Rare Diseases

The aim of this pilot study is to explore whether the knowledge and experience gained during the T-GaiD project (Treatment of Gait Disorders in Dravet Syndrome - NCT03857451) can be transferred to other populations with similar problems, i.e. motor and gait problems as a result of a genetic disorder characterized by epilepsy and developmental delay. In this pilot study, 40 people with Tuberous Sclerosis Complex and 30 people with STXBP1 will be recruited via the Antwerp University Hospital and invited for a gait analysis in the M²OCEAN movement lab. The aim of the pilot study is to evaluate the feasibility of the 3D gait analysis protocol and to determine the sensitivity of the primary (summative measure of the severity of gait abnormalities) and the secondary (spatio-temporal and kinematic gait parameters) outcome measures.

Neurodevelopmental disorders are a group of rare disorders that usually have a genetic cause, each characterized by specific clinical features. Tuberous Sclerosis Complex (TSC or Bourneville's disease), for example, is characterized by the formation of benign tumors, which can develop in almost all organs and tissues. The symptoms vary greatly from person to person, also within one and the same family. Some patients show only limited skin abnormalities, other patients have more affected organs and sometimes become heavily dependent on help. The group of developmental and epileptic encephalopathies (DEE) are genetic neurological disorders that are characterized by epileptic seizures, which usually occur at a (very) young age, and a developmental delay that often leads to an intellectual disability. STXBP1 encephalopathy (STXBP1-E) is an example of an DEE where, in addition to epileptic seizures and developmental delay, motor disorders and gait abnormalities are also frequently seen.

To date, very little is known about motor development in children with TSC and DEE such as STXBP1-RD. Prospective research in the EPISTOP cohort showed that motor development is often delayed in the first years of life, especially in children who also show characteristics of. In clinical practice, we observe progressively increasing gait problems in a number of children that can lead to loss of autonomous steps at a young adult age. A recent study in adult patients with STXBP1-RD showed that about half of the patients were able to walk in adulthood and that those who could walk often had significant gait problems, which appear to be multifactorial in nature.

The ultimate goal of this project is to characterize gait patterns in children, adolescents and young adults with rare genetic disorders, in order to gain new insights into the pathomechanisms of motor and mobility problems. In the long run, these insights will be indispensable for providing an adequate, scientifically substantiated treatment to reduce and, if possible, prevent the gait disorders.

Eligibility Criteria:
Inclusion Criteria:

* diagnosed with tuberous sclerosis complex according to the criteria of Northrup et al. (2012)
* aged 6 years or older
* being able to walk without aids for a minimum distance of 6 meters

Exclusion Criteria:

* severe epileptic seizure (status epilepticus or tonic-clonic insult over 3 min) within the 24 hours before the assessment
* insufficient cooperation to perform 3D gait analysis