Can Lyme Disease Cause Double Vision? Third Cranial Nerve Palsy Case

Can Lyme disease cause double vision?
Third cranial nerve palsy is an uncommon manifestation of neuroborreliosis
Prompt recognition and antibiotic treatment may lead to recovery

Can Lyme disease cause double vision? Yes. Although uncommon, Lyme disease can affect the cranial nerves that control eye movement and lead to diplopia (double vision). This case describes a 69-year-old man whose Lyme meningitis presented with an isolated third cranial nerve palsy rather than the much more common seventh cranial nerve palsy.

In this Inside Lyme Podcast, I discuss the case of a 69-year-old man who developed double vision from Lyme meningitis. His case illustrates an uncommon neurologic complication of Lyme disease that improved following antibiotic treatment.

Dixit and colleagues described this case in Case Reports in Neurological Medicine in 2018.

A 69-year-old man presented to a New York City emergency department in August complaining of headache and diplopia. Diplopia is the perception of two images of a single object.

Double vision can result from disorders affecting the eye muscles, cranial nerves, brainstem, blood vessels, or brain. Because some causes are medical emergencies, new-onset diplopia requires prompt evaluation.

The patient had a history of type 2 diabetes and hypertension, both of which can cause microvascular ischemia involving the cranial nerves. These conditions therefore represented important alternative explanations for his symptoms.

He had recently been hiking in rural New York but did not recall a tick bite or notice an erythema migrans rash.

The authors described the progression of his illness: “His headache abruptly began one week ago, was localized to the right occipital region, and gradually moved to his right orbit.”

Within five days he developed diplopia.

“He had double vision when opening both eyes; however, if he covered his right eye, his vision normalized,” the authors wrote.

This pattern is characteristic of binocular diplopia, which results from misalignment of the eyes and typically disappears when either eye is covered.

Third cranial nerve palsy and double vision

Neurologic examination revealed a left third cranial nerve palsy. The third cranial nerve, also known as the oculomotor nerve, controls most of the muscles responsible for eye movement.

It also elevates the upper eyelid and helps constrict the pupil. Injury or inflammation affecting this nerve can therefore produce double vision, abnormal eye positioning, drooping of the eyelid (ptosis), and pupillary abnormalities.

Neurologic Lyme disease may involve several cranial nerves. However, most Lyme-associated cranial neuropathies affect the seventh (facial) nerve. Isolated third cranial nerve palsy is a distinctly uncommon manifestation of Lyme neuroborreliosis.

Evaluation for Lyme meningitis

The patient underwent an extensive diagnostic evaluation. Blood testing showed a strongly positive Lyme antibody titer with 2 of 3 IgM Western blot bands and 5 of 10 IgG Western blot bands.

A lumbar puncture demonstrated 74 white blood cells in the cerebrospinal fluid, consistent with pleocytosis. Pleocytosis reflects inflammation within the central nervous system and supports a diagnosis of meningitis when interpreted in the appropriate clinical setting.

The authors also reported elevated Lyme antibodies in the cerebrospinal fluid. Interpretation of cerebrospinal fluid Lyme antibody testing generally relies on comparing antibody levels in the cerebrospinal fluid and serum to determine whether intrathecal antibody production has occurred.

Taken together, the patient’s headache, third cranial nerve palsy, cerebrospinal fluid pleocytosis, and Lyme serologic findings supported the diagnosis of Lyme meningitis with oculomotor nerve involvement.

Treatment and recovery

The patient was initially treated with acyclovir while clinicians considered other infectious causes of meningitis, including herpesvirus infection. Once Lyme neuroborreliosis became the favored diagnosis, treatment focused on four weeks of intravenous ceftriaxone.

His diplopia resolved, and he remained symptom-free two months after beginning treatment.

This favorable outcome demonstrates that cranial neuropathies caused by Lyme disease may improve with appropriate antibiotic therapy. Recovery, however, varies depending on the affected nerve, the duration of illness before treatment, and the extent of neurologic involvement.

Why facial nerve palsy is more common

Facial nerve palsy is by far the most common cranial neuropathy associated with Lyme disease. It affects the seventh cranial nerve and causes weakness or paralysis of one side of the face.

Although often called Bell’s palsy, Bell’s palsy technically refers to facial paralysis without an identified cause. When Lyme disease is responsible, the more accurate diagnosis is Lyme-associated facial nerve palsy.

Lyme disease may occasionally affect both facial nerves, producing bilateral facial weakness. Other cranial nerves—including the third, fourth, sixth, and less commonly others—may also be affected, although these presentations are considerably less frequent.

Other eye symptoms associated with Lyme disease

Double vision represents only one of several reported ocular manifestations of Lyme disease. Published reports have described conjunctivitis, keratitis, optic neuritis, uveitis, retinal vasculitis or chorioretinitis, and palsies affecting the cranial nerves responsible for eye movement.

Patients may report blurred vision, eye pain, light sensitivity, difficulty focusing, abnormal eye movements, or diplopia. These symptoms are not specific to Lyme disease and may also occur with vascular, inflammatory, autoimmune, metabolic, or other neurologic disorders.

For a broader discussion of these manifestations, see Eye Symptoms of Lyme Disease.

Clinical discussion

Third cranial nerve palsy is an uncommon manifestation of Lyme disease

This case demonstrates that Lyme neuroborreliosis can occasionally affect the third cranial nerve and produce binocular diplopia. Although rare, Lyme disease should be considered when cranial neuropathy occurs in conjunction with headache, meningitis, possible tick exposure, or other compatible clinical findings.

Other causes of third cranial nerve palsy must be excluded

Third cranial nerve palsy has many potential causes, including microvascular ischemia related to diabetes or hypertension, intracranial aneurysm, stroke, tumors, trauma, inflammatory disorders, and other infections.

Because some of these conditions require urgent treatment, neuroimaging and appropriate neurologic evaluation remain essential. In this patient, cerebrospinal fluid pleocytosis together with Lyme serology supported an infectious cause.

Absence of a tick bite or rash does not rule out Lyme disease

The patient did not remember a tick bite or erythema migrans despite hiking in a Lyme-endemic region. Many patients with Lyme disease never recall a tick bite, and the characteristic rash may be absent, atypical, or simply unnoticed.

Clinicians should therefore integrate exposure history, symptoms, examination findings, laboratory studies, and alternative diagnoses when evaluating possible Lyme neuroborreliosis.

Frequently Asked Questions

Can Lyme disease cause double vision?

Yes. Lyme disease can occasionally affect the cranial nerves responsible for eye movement and cause diplopia, or double vision. In this case, Lyme meningitis was associated with a third cranial nerve palsy.

Can Bell’s palsy cause double vision?

Bell’s palsy affects the seventh cranial nerve, which controls facial movement rather than eye alignment. It does not typically cause true binocular diplopia. However, incomplete eyelid closure may cause eye dryness, exposure-related irritation, or blurred vision that a patient may describe as a visual disturbance.

Which cranial nerves can cause double vision?

Palsies involving the third, fourth, or sixth cranial nerves can cause double vision because these nerves control the muscles responsible for eye movement and alignment. The direction and pattern of the diplopia depend on which nerve and eye muscles are affected.

How is Lyme disease with double vision diagnosed?

Diagnosis requires consideration of the clinical presentation, neurologic and eye examination, possible tick exposure, Lyme disease testing, and alternative causes of cranial nerve palsy. When Lyme meningitis is suspected, cerebrospinal fluid testing may provide additional evidence of nervous system involvement.

Can double vision from Lyme disease improve with treatment?

Recovery is possible. In this case, the patient’s diplopia resolved following treatment, and he remained symptom-free two months after beginning therapy. Outcomes may vary depending on the cause, severity, duration, and extent of neurologic involvement.

Clinical Takeaway

New-onset double vision requires prompt medical evaluation because it may result from neurologic, vascular, structural, metabolic, inflammatory, or infectious conditions.

This case illustrates that Lyme neuroborreliosis may occasionally involve the third cranial nerve and cause diplopia, even when the patient does not recall a tick bite or erythema migrans rash.

Although uncommon, Lyme disease should be included in the differential diagnosis of new-onset diplopia in patients with possible tick exposure or other findings suggestive of neuroborreliosis.

Related Articles

Additional articles explore Lyme disease symptoms, diagnostic challenges, and related neurologic manifestations.

Lyme disease symptoms guide
Can early Lyme disease tests be negative?
Why Lyme disease may be misdiagnosed
Persistent Lyme disease overview

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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