What are the causes and treatment options for perioral numbness?

Causes and Treatment of Perioral Numbness

Perioral numbness is most commonly caused by vertebrobasilar arterial insufficiency, but can also result from medication side effects, cerebrovascular events, or peripheral nerve disorders. Proper evaluation and targeted treatment are essential to address the underlying cause.

Common Causes of Perioral Numbness

Neurological Causes

• Vertebrobasilar arterial insufficiency: Atherosclerotic stenosis affecting vertebral arteries can cause perioral numbness along with other symptoms like dizziness, vertigo, diplopia, blurred vision, and ataxia 1
• Cerebrovascular events:
  • Thalamic lacunar infarcts (cheiro-oral syndrome) 2
  • Pontine tegmental hemorrhage 3
  • Brain tumors 4
• Peripheral nerve disorders:
  • Charcot-Marie-Tooth disease with GJB1 mutation 5
  • Trigeminal nerve compression or injury

Medication-Related Causes

• Lidocaine toxicity: Intravenous lidocaine administration can cause perioral numbness as an early sign of toxicity 1
• Other medications: Various medications affecting peripheral nerves or central nervous system

Other Causes

• Trauma: Perioral injuries in both adults and children 6
• Allergic reactions: Contact dermatitis or angioedema
• Hyperventilation: Can cause transient perioral numbness
• Vitamin deficiencies: B12 deficiency neuropathy

Evaluation of Perioral Numbness

Initial Assessment

1. Detailed history:

   • Duration of symptoms (acute vs. chronic)
   • Associated symptoms (dizziness, vertigo, visual changes)
   • Recent medication use, especially IV lidocaine
   • History of trauma or dental procedures

2. Physical examination:

   • Neurological examination focusing on cranial nerves
   • Assessment for other neurological deficits
   • Evaluation of symmetry of numbness (unilateral vs. bilateral)

Diagnostic Testing

• Neuroimaging:

  • MRA or CTA is recommended for evaluation of vertebral arteries when symptoms suggest posterior cerebral or cerebellar ischemia 1
  • Brain MRI with contrast to evaluate for stroke, tumors, or demyelinating lesions

• Additional testing based on clinical suspicion:

  • Blood tests for vitamin levels, inflammatory markers
  • Nerve conduction studies if peripheral neuropathy is suspected

Treatment Approach

For Vertebrobasilar Insufficiency

1. Medical management:

   • Antiplatelet therapy (aspirin, clopidogrel)
   • Risk factor modification (smoking cessation, blood pressure control, diabetes management)
   • Statins for hyperlipidemia

2. Revascularization for severe symptomatic stenosis:

   • Consider catheter-based angiography to define vertebral artery pathoanatomy when noninvasive imaging is inconclusive 1
   • Surgical or endovascular interventions in selected cases

For Medication-Induced Perioral Numbness

1. Lidocaine toxicity:
   • Immediate discontinuation of lidocaine infusion
   • Supportive care
   • Monitoring for progression of symptoms
   • Prevention by using ideal body weight for dosing calculations and setting upper infusion rate limits 1

For Cerebrovascular Events

1. Acute management:

   • Prompt neurological evaluation
   • Thrombolysis or thrombectomy if indicated for acute ischemic stroke
   • Blood pressure management for hemorrhagic stroke

2. Secondary prevention:

   • Antiplatelet or anticoagulant therapy as appropriate
   • Risk factor modification
   • Regular follow-up imaging

Special Considerations

Bilateral vs. Unilateral Perioral Numbness

• Bilateral perioral numbness may occur even with unilateral pontine lesions 3
• Unilateral perioral numbness (especially with ipsilateral hand numbness) should raise suspicion for cheiro-oral syndrome, often due to thalamic or pontine lesions 2

Red Flags Requiring Urgent Evaluation

• Sudden onset of perioral numbness
• Accompanying weakness, speech changes, or visual disturbances
• Progressive symptoms
• Associated headache or altered mental status

Prevention

• Regular cardiovascular risk assessment
• Proper medication dosing and monitoring
• Avoidance of triggers (excessive alcohol in susceptible individuals) 5
• Protective equipment for activities with risk of facial trauma

Remember that perioral numbness, while sometimes benign and transient, can be an early warning sign of serious neurological conditions requiring prompt evaluation and treatment.