CNS Changes Following Amputation

Study Overview
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Brief Summary
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The objective of this study is to better understand the structural and functional changes that the central nervous system (CNS) undergoes following congenital upper limb loss. The focus is on the brain's sensory processing and how neuronal changes may relate to clinical measures. By doing so, the hope is to gain insight into the contribution of critical periods to the plasticity of the sensorimotor processing stream. Both macroscopic and microscopic changes of the brain will be examined in individuals with upper limb amelia and compared to healthy controls. fMRI will be combined with behavioural testing to understand which clinical and behavioural determinants drive somatosensory representations along the entire somatosensory processing stream. Using advanced imaging techniques, the aim is to investigate the contribution of brainstem reorganisation to plasticity observed at the cortical level and, by doing so, gain a better understanding of the mechanistic underpinnings of functional reorganisation. Overall, the hope is to provide the first mechanistic insight into whether early life experiences are crucial for the development of the relay nuclei in the central nervous system and how these changes relate to clinical measures such as adaptive behaviours or pain.

Official Title
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Functional, Structural, and Metabolic Central Nervous System Changes Following Damage of the Central Nervous System

Conditions
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Amputation, Congenital, Upper Limb; Amelia

Intervention / Treatment
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* Diagnostic Test: MRI
* Diagnostic Test: MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria - Patients: Age 18-75 Upper-limb congenital amputees with complete absence of a hand Signed informed consent Exclusion Criteria - Patients: Contraindications to magnetic resonance imaging Neurological impairment of body function impairments not induced by spinal cord injury BMI > 40 Pregnancy Claustrophobia Inclusion Criteria - Healthy subjects: Age 18-75 Signed Informed consent Exclusion Criteria - Healthy subjects: Contraindications to magnetic resonance imaging Pregnancy Neurological illness Impairment of body function induced by a congenital upper-limb amputation Claustrophobia BMI > 40

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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 congenital amputation<br> | Diagnostic Test: MRI<br>* We will examine patients with congenital upper-limb amputations using functional and structural MRI in both the brain and the spinal cord as well as questionnaires and clinical measures of motor function<br>|
| Healthy subjects<br> | Diagnostic Test: MRI<br>* We will examine healthy patients using functional and structural MRI in both the brain and the spinal cord and questionnaires.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of functional MRI (fMRI) parameter between 2 to 4 time points | Change of brain activities is assessed between 2 to 4 time points using fMRI during resting-state or a specific task in patients with congenital amputations and compared to healthy controls | Up to 50 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Conventional magnetic resonance imaging (MRI) parameter | Structural characteristics in the brain and cervical spinal cord are assessed in patients with congenital upper-limb amputations using conventional MRI and compared to healthy controls | Up to 50 weeks | 
| Amputees: Motor Activity Log questionnaire | Evaluation of residual limb and/or prosthesis usage as compared to other body parts via a questionnaire and behavioural assessments. | Up to 50 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Plasticity, Congenital amputee, Upper limb amelia, Somatotopy, Functional MRI, Hand, Reorganisation