Brain Imaging in Lyme Disease: Can MRI or MRS Detect Cognitive Impairment?

Brain imaging in Lyme disease may provide insight into cognitive symptoms, even when standard tests appear normal.

Patients with Lyme disease frequently report cognitive symptoms such as memory problems, slowed processing, and difficulty concentrating. Yet conventional imaging studies are often unrevealing.

Emerging techniques such as magnetic resonance spectroscopy (MRS) may offer a deeper view into brain metabolism and function.

This disconnect between symptoms and testing reflects the broader diagnostic challenge discussed in Why Lyme Disease Tests the Limits of Medicine, where clinical illness does not always align with available tools.

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What Brain Imaging Shows in Lyme Disease

Brain MRI findings in Lyme disease are often nonspecific. Some patients demonstrate white matter changes similar to those seen in multiple sclerosis, while others have completely normal scans.

Reported abnormalities include lesions in periventricular or subcortical regions associated with cognitive function.

However, normal MRI findings do not exclude neurologic Lyme disease.

This pattern is commonly seen in persistent Lyme disease, where patients experience significant symptoms despite limited objective findings.

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Magnetic Resonance Spectroscopy (MRS): A Metabolic Window

Magnetic resonance spectroscopy (MRS) provides a noninvasive method to evaluate biochemical processes within the brain.

MRS allows measurement of neurotransmitters and metabolites, offering insight into cellular function rather than structure alone.

Advances in imaging technology—including higher field strength MRI systems such as 3 Tesla—have significantly improved the sensitivity of these techniques.

These improvements may allow clinicians to better detect subtle metabolic abnormalities associated with cognitive dysfunction.

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Neurotransmitter Changes and Cognitive Impairment

Studies have shown that neurotransmitter levels may correlate with behavioral outcomes such as memory and reaction time.

In patients with mild cognitive impairment, researchers have identified characteristic metabolic changes, including:

• Decreased gamma-aminobutyric acid (GABA)
• Decreased glutamate (Glu)
• Decreased N-acetylaspartate (NAA)
• Increased myo-inositol (mI)

These findings suggest that altered brain metabolism may contribute to cognitive symptoms.

While not specific to Lyme disease, these patterns raise important questions about whether similar changes occur in patients with Lyme-related cognitive dysfunction.

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Why This Matters in Lyme Disease

Up to 90% of patients with post-treatment Lyme disease syndrome (PTLDS) report cognitive symptoms such as brain fog, memory issues, and slowed processing. Advanced imaging (PET, fMRI, DTI) in these patients shows evidence of inflammation, glial activation, and changes in white matter structure【source: Fallon et al., J Neuropsychiatry Clin Neurosci, 2008】.

These findings suggest that structural imaging alone may underestimate neurologic involvement in Lyme disease.

Functional and metabolic imaging techniques may provide additional insight into these symptoms.

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Clinical Perspective

Brain imaging in Lyme disease remains an evolving field.

While MRI findings are often nonspecific or normal, newer techniques such as MRS may offer valuable insights into brain metabolism and cognitive dysfunction.

At present, imaging results should be interpreted alongside clinical symptoms, exposure history, and laboratory findings.

Future research may clarify whether advanced imaging can improve diagnosis and monitoring of neurologic Lyme disease.

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention