Amnesia | Transient Global Amnesia (TGA). Exploratory Study of the Default Mode Network During the Acute Phase
Amnesia research study
What is the primary objective of this study?
The transient global amnesia, in which the memory disorder is massive, transient and pure, offers a unique model for exploring episodic memory. Topographic MRI can reveal a focal and selective lesion located on the CA1 region of the hippocampus better visible between 48h and 72h after onset of the episode. There is therefore a real dissociation between structural lesions witch are minimal or non-existent and the massive memory disorder. This suggests that functional impairment goes far beyond the structural damage in this condition. To our knowledge, no study has been performed to identify this functional impairment using resting state fMRI. Thus, investigators wish to study the neural networks involved in memory impairment during the acute phase of transient global amnesia using resting state imaging. This technique appears to be modern and adapted to these patients population. Investigators hypothesize that despite limited structural lesions, a large functional network is impaired compared to that observed in a group of healthy subjects. investigators believe that the alteration of the functional network will explain the depth of memory impairment observed. The main aim of this study will be to identify functional impairment in the patient group vs. control group during the acute phase of transient global amnesia (TGA) using resting state imaging. Patients potentially eligible will be informed during their arrival to the emergency unit. If the patient is eligible and would like to participate, information will be given. For the patients willing to participate, inclusion and exclusion criteria will be verified. Two imaging exams (topographic MRI and resting state fMRI) and neuropsychological assessment will be performed during three visits.
Who is eligible to participate?
Inclusion Criteria: Patient group Clinical criteria of definition of transient global amnesia: Acute disorder of anterograde memory observed by a witness. Respect of the other cognitive functions. No exclusion criteria for this diagnosis (see exclusion criteria section). Hippocampal lesion in DWI MRI performed at 72h Clinical resolution of memory disorder within 24 hours Control group No cognitive complaint No history of transient amnesia Both groups Age between 40 and 80 years old Exclusion Criteria: Patient group Disturbance of consciousness or loss of identity Argument in favor of seizure disorders Presence of a neurological deficit focused Both groups Recent head trauma Acute intoxication ethyl Taking drugs influencing memory processing Severe hypoglycemia Psychiatric disorder altering capacity for judgment Progressive neurological disorder with cognitive alteration Indication against MRI French language level insufficient to be appropriately involved in neuropsychological assessment, Administrative issues: unable to give informed about information, not covered by a social security system, refusal to sign the consent, patient under curators. Pregnant Woman
Which medical condition, disease, disorder, syndrome, illness, or injury is researched?
Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.
Other:IRMfevaluation in resting state fMRI during three successive visits: During the acute phase within 24 hours In 72 hours In 3 months
Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.
patienteach patient TGA will receive an evaluation in resting state IRMf during three successive visits: During the acute phase within 24 hours In 72 hours In 3 months
controleach control will receive an evaluation in resting state IRMf during three successive visits: During the acute phase within 24 hours In 72 hours In 3 months
Start Date: December 2013
Completed Date: December 2015
Primary Outcome: The primary judgment criteria will be the difference in activation probabilistic resting state maps between patient and control groups during the acute phase.
Secondary Outcome: memory performance tests and functional activity
Study sponsors, principal investigator, and references
Principal Investigator: PrJérémie Pariente, PHD
Lead Sponsor: University Hospital, Toulouse