Movement disorders are commonly neurological, involving both voluntary and involuntary abnormal, reduced or slowed movement. Ataxia affects the cerebellum, the brain’s coordination centre, causing uncoordinated, clumsy balance and limb movements as well as impaired speech. Dystonia involves sustained involuntary muscle contractions with twisting, repetitive movements. Myoclonus muscle jerks can be lightning-quick, effecting either a single muscle or a whole group of muscles. Chorea is characterized by repetitive, brief, irregular rapid, involuntary movements commonly of the face, mouth, trunk and limbs. HCD Economics has already conducted a large Burden of Illness Study of Huntington’s Chorea, one of the most well know genetic diseases.

Parkinson’s Disease (PD) is a collection of common signs and symptoms including slowness, stiffness, tremor and imbalance. Many sufferers are diagnosed with Idiopathic Parkinson’s as the underlying cause is unknown. 15% of patients, with symptoms suggesting PD, also have atypical parkinsonism disorders. Atypical disorders are usually more difficult to treat, they include symptoms of Multiple System Atrophy (MSA) as well as Progressive Supranuclear Palsy (PSP). As PD progresses, Dementia with Lewy bodies (DLB) can also occur. Whilst approximately 5% of PD is explained by genetic links to specific Parkinson's genes, there are numerous genetic risk variants on many genes which collectively account for perhaps a third of inherited risk.

Gaucher Disease (GD) is a rare genetic disorder yet one of the most common lysosomal storage disorders. Type 3 Gaucher Disease GD has neuronopathic symptoms, combined with an enlarged liver and spleen, as well as blood disorders. Neuropathic issues include seizures, eye movement disorders and poor coordination. People with Gaucher Disease have a 2-4% chance at greater risk of developing Parkinson’s symptoms after age sixty. Rising to an 8% chance by age eighty. Carriers of only one copy of the recessive GD gene also have a lower but still increased risk of developing PD.

Dravet syndrome is a rare genetic epilepsy characterised by multiple, frequent and prolonged seizures which are often treatment resistant. Dravet typically begins in the first year of life in otherwise healthy infants.  Around 85% of Dravet patients survive to reach adulthood, despite risk of sudden unexplained death in Epilepsy. Children with Dravet experience various types seziures, including myoclonic jerks. Sufferers also experience learning difficulties including speech problems and incontinence, features of autism as well as nutritional concerns which can lead to growth issues. Many sufferers also experience sleep disturbances. As the disease progresses towards adulthood more orthopaedic and mobility issues are observed, including gait disturbance, unsteadiness, poor coordination, and muscle tone issues.

Lennox-Gastaut (LGS) syndrome is another rare form of childhood epilepsy, effecting 2-5% of all epileptic children. LGS is characterised by multiple different types of seizure, particularly tonic (stiffening) and atonic (drop) seizures. Most children present with developmental or intellectual problems before LGS is diagnosed, including hyperactivity, agitation, aggression and autism. These seizures persist into adulthood and often occur daily. Cognitive disability worsens over time and most adults with LGS are not able to live and work independently. Patients with LGS may also develop gait instability.

Currently there are a range of molecules focused on treating symptoms of all these conditions. Such as anticonvulsant medications e.g. Levodopa & Cannabidiols. Along with medications that help treat associated sleep disturbances and incontinence. Disease modifying therapies are also emerging, including gene therapy and gene editing.  Especially for Dravet, GD & LGS, where associated genes are more pronounced and more readily targeted.

HCD Economics believes it is now important to increase understanding of socio-economic burden in these inter-related conditions. Evaluating how persistent seizures and movement disorders impact daily life. Both for children and adults, as well as the people who care for them. We recently started a project in Gaucher’s disease, we also aim to begin a study in Parkinson’s later this year. Following this work and having further expanded our working relationships with neurologist across the globe, we plan to evaluate movement disorder issues in younger populations, including rare epilepsy.

For more information on the MOTION Multi-Outcomes of Tremors, Imbalance and Ongoing Neuropathy research programme, including opportunities to join the research community investors partnering in the study, please contact Anthony Woodhead.