Lyme Disease Brachial Plexopathy: Arm Weakness and Radicular Pain
ARM WEAKNESS
SHOCK-LIKE PAIN?
COULD THIS BE LYME DISEASE?
Lyme disease brachial plexopathy can present as progressive arm weakness, neck pain, and shock-like pains radiating from the shoulders. A 76-year-old man developed left arm weakness following what he believed was a mosquito bite. He was initially treated for presumed cellulitis with temporary improvement. However, he returned 24 days later with bilateral paroxysmal “shock-like” pains and worsening weakness. MRI later revealed meningoradiculitis involving the brachial plexus and spinal cord, and Lyme testing confirmed neuroborreliosis requiring IV ceftriaxone for recovery.
Initial Presentation: Arm Weakness and Neck Pain
In their article “Early Lyme neuroborreliosis manifesting as brachial plexopathy and meningitis in Northwestern Ontario, Canada,” Gu and colleagues describe a case of Lyme disease presenting as brachial plexopathy and meningitis.
The 76-year-old man was initially admitted with left arm weakness, neck pain, body aches, and headaches after what he believed was a mosquito bite. Without recognizing the possibility of a tick exposure, Lyme disease was not initially considered.
Lyme Disease Brachial Plexopathy Explained
Brachial plexopathy is a form of peripheral neuropathy involving the nerve network from the neck to the arm. Damage can lead to:
- Arm and shoulder weakness
- Radiating pain from neck to arm
- Numbness or tingling
- Loss of reflexes
- Muscle atrophy if chronic
Causes include trauma, autoimmune disease, tumors, and infections such as Lyme disease.
Misdiagnosed as Cellulitis
The patient was diagnosed with cellulitis and treated with cephalexin. His symptoms temporarily improved.
This improvement may reflect partial antibiotic effect or natural fluctuation as Lyme disease progresses—leading to a false sense of resolution.
Return 24 Days Later: Shock-Like Pains
He returned with bilateral paroxysmal “shock-like” pains radiating from the shoulders to the arms and chest.
These symptoms reflect radiculitis—inflammation of nerve roots causing electric, stabbing pain. This is a hallmark feature of neuroborreliosis.
Progressive Arm Weakness
Over the following days, weakness progressed despite prior treatment. This suggested inadequate therapy, as cephalexin does not adequately treat neurologic Lyme disease.
MRI Reveals Polyradiculitis
MRI showed inflammation along the spinal cord and brachial plexus, consistent with polyradiculitis. Lyme testing was positive by ELISA and Western blot.
Diagnosis and Treatment
The patient was diagnosed with early Lyme neuroborreliosis with meningoradiculitis and treated with IV ceftriaxone.
He experienced gradual recovery over the following year.
Why Lyme Disease Causes Brachial Plexopathy
Lyme disease can affect nerve roots through:
- Direct bacterial invasion
- Immune-mediated inflammation
- Meningeal spread through cerebrospinal fluid
- Nerve root swelling and compression
- Demyelination
The Diagnostic Challenge
This case highlights how Lyme disease may be missed when neurologic patterns are not recognized—especially when tick exposure is unclear.
Clinical Perspective
Shock-like pain, progressive weakness, and neurologic symptoms should prompt consideration of Lyme neuroborreliosis—even without a known tick bite.
Recognizing this pattern early may prevent delayed diagnosis and prolonged illness.
Clinical Takeaway
Lyme disease brachial plexopathy is often missed when symptoms are mistaken for cellulitis or nonspecific nerve pain. Electric, shock-like pain with progressive weakness should raise suspicion for neuroborreliosis—even when tick exposure is not recognized. Early diagnosis and appropriate treatment are critical to prevent long-term neurologic complications.
Frequently Asked Questions
Can Lyme disease cause brachial plexopathy?
Yes. Infection can affect nerve roots in the cervical spine, leading to inflammatory radiculoneuritis.
What are shock-like pains in Lyme disease?
They are electric or stabbing pains caused by inflamed nerve roots in neuroborreliosis.
Can cellulitis antibiotics treat Lyme disease?
They may provide temporary improvement but are often inadequate for neurologic Lyme disease.
How long does recovery take?
Recovery may take months to a year after appropriate treatment.
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
