Tumor-Related Trigeminal Neuralgia
Summary
Type: Secondary trigeminal neuralgia due to tumor compression or infiltration
Common causes: Schwannoma, meningioma, epidermoid cyst, metastasis, glioma, nasopharyngeal carcinoma
Etiology
- Meningiomas (e.g., cerebellopontine angle meningioma, skull base)
- Intrinsic brainstem tumors (e.g., gliomas)
- Nasopharyngeal carcinoma (invasion through foramen rotundum or ovale)
Clinical Features
- Involvement of one or more branches of the trigeminal nerve (V1, V2, V3)
- Sensory loss: hypoesthesia or paresthesia is common
- Motor deficit: masseter weakness/atrophy if V3 involved
- Other cranial nerve deficits (e.g., CN VI, VII, VIII) may be present
Diagnosis
- MRI with contrast:
- Evaluate the nerve from root entry zone to Meckel’s cave and skull base foramina
- Look for mass lesions, infiltration, or compression
- CT scan:
- Useful for detecting bone erosion or foraminal involvement
Differences from Classical Trigeminal Neuralgia
| Feature | Classical TN | Tumor-Related TN |
|---|---|---|
| Cause | Vascular compression | Tumor compression or invasion |
| Sensory loss | Rare | Common |
| Pain | Paroxysmal, electric-shock | May be constant or atypical |
| Other cranial nerves | Rarely affected | Often involved |
| MRI findings | Often normal | Visible mass lesion |
Important Note
Any trigeminal neuralgia with atypical features or associated neurological deficits should prompt MRI imaging to rule out a tumor or structural lesion.