In a patient with recent Epstein‑Barr virus infection who develops new‑onset paresthesia, what is the likely cause and recommended evaluation and management?

EBV and Paresthesia: Neurological Complications

In a patient with recent EBV infection who develops new-onset paresthesia, the most likely causes are post-infectious peripheral neuropathy (including Guillain-Barré syndrome), cranial nerve involvement, or rarely, direct EBV-associated CNS disease such as myelitis or encephalitis.

Likely Etiologies

The paresthesia following EBV infection represents one of several neurological complications:

Peripheral Nervous System Involvement

• Guillain-Barré Syndrome (GBS): EBV is a recognized trigger for GBS, which classically presents with distal paresthesias or sensory loss, followed by progressive bilateral weakness starting in the legs 1. The paresthesias typically precede motor symptoms and are accompanied by areflexia in most patients.

• Focal Neuropathies: EBV can cause brachial plexopathy, radiculoplexopathy, or cranial mononeuropathies 2, 3. These present as pain, paresthesias, and weakness in specific nerve distributions. One case demonstrated cervicobrachial radiculoplexopathy with proximal conduction block following acute EBV infection 2.

• Bilateral Facial Palsy: This can be subtle and may be the presenting feature of GBS in EBV infection. Lack of facial expression may be an early clue 4.

Central Nervous System Involvement (Rare)

• Myelitis: EBV-associated transverse myelitis can present with numbness below a specific dermatome level, followed by weakness and urinary retention 5. MRI shows intramedullary lesions with cord expansion.

• Encephalitis: Severe EBV encephalitis may involve peripheral nerve damage, though this is exceptionally rare 6.

Recommended Evaluation

Initial Assessment

1. Detailed neurological examination:

   • Test for bilateral vs. unilateral involvement
   • Assess deep tendon reflexes (decreased/absent suggests GBS)
   • Check for facial weakness bilaterally (subtle contralateral weakness may indicate GBS)
   • Evaluate for ascending weakness pattern
   • Document sensory level if present

2. Laboratory confirmation of EBV:

   • VCA IgM with or without VCA IgG in absence of EBNA antibodies indicates recent primary infection 7
   • Heterophile antibody test (though false-negative in ~10% of patients, especially children <10 years)

3. Electrophysiological studies:

   • Nerve conduction studies and EMG to identify demyelinating vs. axonal patterns
   • Look for conduction blocks, prolonged F-waves, or absent H-reflexes (GBS features)
   • Can demonstrate focal nerve damage in plexopathies 2

4. CSF analysis (if CNS involvement suspected):

   • Albuminocytologic dissociation (elevated protein with normal cell count) supports GBS
   • EBV PCR on CSF if myelitis or encephalitis suspected 5
   • Metagenomic next-generation sequencing can confirm EBV in CNS disease 6

5. Imaging:

   • MRI of spine if myelitis suspected (look for intramedullary lesions, cord expansion)
   • Brain MRI if encephalitis considered

Management Approach

For GBS (Most Common Serious Complication)

Immediate treatment is critical if GBS is diagnosed:

• Intravenous immunoglobulin (IVIG): 0.4 g/kg daily for 5 days 1
• OR Plasma exchange: 200-250 mL/kg for 5 sessions 1
• These treatments are equally effective; choice depends on availability and patient factors
• Do NOT delay treatment waiting for confirmatory tests if clinical suspicion is high

For Focal Neuropathies

• Supportive care is primary
• Corticosteroids may be considered, though evidence is limited
• Most cases show monophasic course with rapid recovery 2, 3

For Myelitis

• Acyclovir plus corticosteroids 5
• Despite limited evidence for antiviral efficacy in EBV neurological disease, combination therapy is recommended for myelitis

For Encephalitis

• Antiviral therapy (though efficacy is uncertain)
• Corticosteroids
• Supportive care
• Note: Mortality can be high despite treatment 6

Critical Pitfalls to Avoid

1. Missing bilateral facial palsy in GBS: Subtle contralateral weakness may be overlooked. Lack of facial expression is an early clue 4.

2. Assuming benign course: While most EBV infections are self-limited, neurological complications require urgent evaluation and treatment, particularly GBS which can progress to respiratory failure.

3. Delaying GBS treatment: Patients typically reach maximum disability within 2 weeks. Treatment should begin as soon as diagnosis is suspected 1.

4. Overlooking atypical presentations: Young children may present with nonspecific symptoms like refusal to bear weight, irritability, or unsteady gait rather than classic paresthesias 1.

5. Relying solely on heterophile antibody: False-negative results occur in ~10% of patients. Use EBV-specific antibody testing (VCA IgM/IgG and EBNA) when clinical suspicion is high 7.

6. Assuming symptoms after 4 weeks are GBS: If maximum disability occurs >4 weeks after onset, consider alternative diagnoses 1.