Hippocampal neurometabolic and structural changes from pre-to post-COVID-19: A case-series study

Area of Science:

• Neurology
• Neuroimaging
• Infectious Diseases

Background:

• COVID-19 infection can lead to neurological complications potentially caused by undetectable neurochemical and structural brain abnormalities.
• This study focused on elderly individuals who experienced mild COVID-19 symptoms.

Purpose of the Study:

• To examine within-subject neurometabolic and structural brain alterations in the hippocampus before and after COVID-19 infection.
• To investigate potential links between COVID-19 and changes in brain chemistry and structure.

Main Methods:

• Utilized whole-brain magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (¹H-MRS) of the left hippocampus.
• Collected data from three elderly individuals (aged 63-68) pre- and post-COVID-19 infection.
• Compared post-infection measures with pre-infection baselines and Minimal Detectable Change (MDC) values from a control group.

Main Results:

• Observed significant reductions in glutamate-glutamine (Glx) in two patients post-COVID-19 (≥ 42.0%).
• Detected elevations in myo-inositol (mIns) and N-acetyl-aspartate (NAA) in one patient post-COVID-19 (≥ 36.4%).
• MRI revealed increased hippocampal volume in two patients and unchanged volume in one patient.

Conclusions:

• Mild COVID-19 infection may be associated with localized hippocampal neuroinflammation and decreased glutamate levels.
• ¹H-MRS findings offer potential clinical value for understanding chronic neurological and psychological issues in COVID-19 long-haulers.