Can Lyme Disease Cause Memory Loss and Amnesia?

Memory problems can occur in Lyme disease.
One patient developed severe autobiographical amnesia.
Researchers explored a possible link with PTLDS.

Patients with Lyme disease frequently report cognitive symptoms including brain fog, slowed processing, concentration problems, and memory difficulties.

In a recent case report, investigators described a 41-year-old patient with post-treatment Lyme disease syndrome (PTLDS) who developed severe retrograde autobiographical and semantic amnesia.¹

The case highlights the complex neurologic and psychiatric symptoms that may occur in some patients following Lyme disease.

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Memory Loss in a Patient With PTLDS

In 2015, the patient developed weakness, fatigue, psychomotor slowing, night sweats, and difficulty with attention.

Several months before the onset of symptoms, he experienced a low-grade fever and an erythema migrans rash.

The patient also developed identity loss, dissociative symptoms, specific phobias, and depressed mood.

Testing for Lyme disease was positive, and he was treated with antibiotics. However, psychomotor slowing and depression persisted.

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Symptoms Worsened After Initial Treatment

Six months later, the patient’s condition worsened.

He developed:

• Pain in the upper and lower limbs
• Mobility problems
• More severe headaches
• Learning difficulties
• Progressive cognitive symptoms

According to the authors, “The clinical picture was compatible with PTLDS.”¹

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Severe Retrograde and Semantic Amnesia

In 2019, the patient was admitted to a rehabilitation center because of worsening physical symptoms. At that time, his partner reported significant memory problems.

Neuropsychological testing found impaired intensive attention but preserved selective attention.

According to the authors:

“The patient did not remember any episode of his life prior to the illness and his first memory dated back to about 1 year after the diagnosis of Lyme Disease.”¹

The patient reportedly had difficulty recognizing relatives and recalling autobiographical memories from before the illness.

While short-term and anterograde memory remained intact, retrograde and semantic memory were significantly impaired.

The authors noted that the patient’s pattern of severe autobiographical and semantic memory loss resembled features reported in dissociative amnesia.¹

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What Is Semantic and Retrograde Amnesia?

Semantic memory refers to general knowledge such as facts, concepts, vocabulary, or recognition of familiar people and objects.²

Retrograde amnesia involves impaired memory for events, facts, or experiences that occurred before the onset of illness or injury.³

Most patients with PTLDS do not develop severe amnesia of this type.

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Additional Psychiatric and Neurologic Symptoms

The patient also experienced persistent phobias, including fears involving contamination, germs, insects, weapons, and uniforms.

These symptoms significantly affected daily functioning.

Three years after the PTLDS diagnosis, the patient continued to exhibit marked psychomotor slowing and major deficits in autobiographical and semantic memory.

The authors hypothesized that Lyme disease and its functional sequelae may have contributed to triggering dissociative amnesia.¹

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Neurocognitive Symptoms in Lyme Disease

Cognitive symptoms are commonly reported in Lyme disease and PTLDS.

Patients may describe:

• Brain fog
• Memory impairment
• Difficulty concentrating
• Word-finding problems
• Mental fatigue
• Slowed processing speed

However, severe dissociative or autobiographical amnesia appears to be rare and remains poorly understood.

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FAQ: Lyme Disease and Memory Loss

Can Lyme disease cause memory loss?

Some patients with Lyme disease report memory problems, brain fog, and difficulty concentrating, particularly in neurologic Lyme disease or PTLDS.

What is PTLDS?

Post-treatment Lyme disease syndrome (PTLDS) refers to persistent symptoms that continue after standard Lyme disease treatment.

Can Lyme disease cause dissociative amnesia?

This case report described severe autobiographical and semantic amnesia in a patient with PTLDS, though such presentations appear to be uncommon.

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Final Thoughts

This unusual case highlights the broad range of neurologic and psychiatric symptoms that may occur in some patients following Lyme disease.

While severe autobiographical amnesia appears to be rare, cognitive dysfunction and memory complaints remain common concerns in patients with PTLDS.

Further research is needed to better understand the relationship between Lyme disease, neuroinflammation, cognition, and dissociative symptoms.

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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