Clinical Trial: Transient Global Amnesia (TGA). Exploratory Study of the Default Mode Network During the Acute Phase

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Transient Global Amnesia (TGA) Exploratory Study of the Default Mode Network in Resting State Functional MRI (fMRI) During the Acute Phase

Brief Summary:

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 dur

Detailed Summary:

Background:

The transient global amnesia is a transient, massive and pure memory disorder. Its pathophysiology is poorly known, but the disease process involves the Papez circuitry, and more specifically the medial part of the temporal lobes (hippocampi). It involves 3-8 per 100,000 people per year. The age of patients affected is between 50 and 70 years. Structural MRI can confirm the diagnosis by revealing a focal and selective lesion located on the CA1 region of the hippocampus better observed between 48h and 72h after onset of the episode.

Main purpose:

The main aim of this study is to identify neuronal functional impairment in a group of patients vs. a group of healthy subjects during the acute phase of transient global amnesia (TGA) using resting state fMRI imaging.

Secondary purpose:

  • Show correlations between functional activity observed in resting state fMRI at the acute phase and cognitive performance in the patient group.
  • Describe the evolution of functional impairment in resting state fMRI between the acute phase (visit 1) and post-acute phases (visit 2 and 3) in the patient group compared to the control group subjects.

Study design:

Monocentric, pilot, prospective, controlled study including consecutive patients admitted to the emergency department of the CHU of Toulouse for transient global amnesia. investigators will compare two independent groups: patients and controls We expect three months between the signing of consent and the end of the study. The total duration of the study will not ex
Sponsor: University Hospital, Toulouse

Current 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. [ Time Frame: 3 months ]

Original 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. [ Time Frame: 3 mounth ]

Current Secondary Outcome: memory performance tests and functional activity [ Time Frame: 3 months ]

The correlation coefficient between memory performance tests and functional activity observed in resting state fMRI in the group of patients.


Original Secondary Outcome: memory performance tests and functional activity [ Time Frame: 3 mounths ]

The correlation coefficient between memory performance tests and functional activity observed in resting state fMRI in the group of patients.


Information By: University Hospital, Toulouse

Dates:
Date Received: December 4, 2013
Date Started: December 2013
Date Completion:
Last Updated: March 12, 2017
Last Verified: March 2017