Validation of a Clinical Assessment Scale Specific to Alternating Hemiplegia

Study Overview
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Brief Summary
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Alternating Hemiplegia of Childhood (AHC) is a very rare neurological disorder of genetic origin, combining paroxysmal episodes and neurodevelopmental impairment. The disease is generally sporadic, and its incidence has been estimated at 1 in 100,000 births, with around 500 cases published worldwide. The true prevalence of AHC may be underestimated due to a lack of understanding of the disease and a high degree of phenotypic heterogeneity. It should be noted that, to date, it is difficult to assess the clinical characteristics of AHC patients in a homogeneous way. The lack of disease-specific clinical outcome measures therefore constitutes a critical node for advancing AHC research. In addition, recognition of the pattern of movement disorders and the ability to classify their severity are very important and useful for the clinician. Homogeneous disease assessment will help plan rehabilitative and pharmacological interventions, facilitate monitoring of treatment outcomes, and predict prognosis. This is why an AHC assessment scale have been developed in collaboration with clinical teams from the IAHCRC consortium. The scale has already been tested and validated on Italian and Spanish patients. The aim of this study is therefore to validate the use of this same scale on our French population of AHC patients. The hypothesis of the study is that the practical use of this scale specific to alternating hemiplegia is reproducible. To this end, all the items on the scale will be scored independently for each patient by 4 neuropediatricians with expertise in the disease, in order to observe the reproducibility of the results obtained with this scale. The scale will be used for twenty AHC patients of all ages.

Official Title
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Validation of a Clinical Assessment Scale Specific to Alternating Hemiplegia

Conditions
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Alternating Hemiplegia

Intervention / Treatment
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* Other: interview with neurologist


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient with confirmed diagnosis of AHC, unrestricted age range 0-99 years At least one parent and/or legal guardian who understands and speaks the national language Adult patients : Gathering of the non-opposition of the patient and/or his legal representative Minor patients : Collection of non-opposition from parents/guardians Exclusion Criteria: Patient's refusal to participate in the study Patient under court protection, unable to give consent

Ages Eligible for Study
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Minimum Age: 0 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with alternating hemiplegia<br>Patients with alternating hemiplegia, from 0 to 99 years old | Other: interview with neurologist<br>* interview with neurologist<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Composite primary endpoint : - missing data from the scale <5 - mean scores compared between the 4 neurologists are close to the scale's mid-point, i.e. floor and ceiling effects are < 20%, and skewness statistics are between 21 and 11 | All statistical tests will be performed using SPSS version 24.0 statistical software, and P < 0.05 will be considered significant. Validation of the use of the scale based on the results obtained independently by the 4 expert neurologists using a composite primary endpoint consisting of three criteria: missing data from the scale <5 mean scores compared between the 4 neurologists are close to the scale's mid-point, i.e. floor and ceiling effects are < 20%, and skewness statistics are between 21 and 11. | At inclusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Alternating Hemiplegia of Childhood, rating scale