What condition presents with unilateral left‑sided tinnitus and sharp shooting pain in the left temporal region?

Trigeminal Neuralgia with Auditory Symptoms

The combination of unilateral left-sided tinnitus and sharp shooting temporal pain most strongly suggests trigeminal neuralgia (Type 2) or a trigeminal autonomic cephalalgia (SUNCT/SUNA), and requires urgent MRI evaluation to exclude secondary causes including multiple sclerosis, tumors, or vascular compression. 1

Key Diagnostic Features

Pain Characteristics That Point to Trigeminal Neuralgia

• Sharp, shooting temporal pain is the hallmark of trigeminal neuralgia, typically involving the maxillary (V2) or mandibular (V3) divisions, with each attack lasting seconds to minutes followed by a mandatory pain-free refractory period. 1
• Type 2 trigeminal neuralgia presents with prolonged continuous pain between the characteristic sharp shooting attacks, which may explain persistent symptoms rather than purely paroxysmal ones. 1
• The temporal region corresponds to the V2 (maxillary) distribution of the trigeminal nerve, making this anatomically consistent with trigeminal neuralgia. 1

Critical Distinction: Trigeminal Autonomic Cephalgias

• SUNCT/SUNA syndromes must be excluded because they present with sharp temporal pain plus prominent autonomic features (tearing, conjunctival injection, rhinorrhea, facial redness) and can have up to 200 attacks daily without refractory periods. 1
• If the patient has any autonomic symptoms (red eye, tearing, nasal congestion, facial flushing), this shifts the diagnosis away from pure trigeminal neuralgia toward SUNCT/SUNA. 1

The Tinnitus Component

• Unilateral tinnitus in the context of facial pain raises concern for a shared pathophysiology involving the trigeminal nerve and auditory system, which converge in the dorsal cochlear nucleus. 2
• Acoustic shock injury can produce both tinnitus and temporal/neck pain through a loop involving middle ear muscles, peripheral inflammation, and trigeminal nerve activation—though this typically follows a clear acoustic trauma. 3
• Neurovascular compression of the vestibulocochlear nerve can cause tinnitus, and when a vessel also compresses the trigeminal nerve, both symptoms may coexist. 4, 5

Immediate Diagnostic Algorithm

Step 1: Characterize the Pain Pattern

• Ask specifically: Are the shooting pains brief (seconds to minutes) with complete pain-free intervals between attacks, or is there continuous background pain with superimposed sharp attacks? 1
  • Brief attacks with refractory periods = Classical trigeminal neuralgia
  • Continuous pain with sharp attacks = Type 2 trigeminal neuralgia
  • Very frequent attacks (>100/day) without refractory periods = SUNCT/SUNA 1

Step 2: Screen for Autonomic Features

• Examine for: Tearing, conjunctival injection, rhinorrhea, nasal blockage, facial redness, or ear fullness during pain attacks. 1
• If present: Diagnosis is SUNCT/SUNA, not trigeminal neuralgia, and treatment differs (lamotrigine is particularly effective for SUNCT/SUNA). 1

Step 3: Assess for Red Flags Requiring Urgent Imaging

• Continuous pain (rather than purely paroxysmal) mandates MRI to rule out secondary causes including multiple sclerosis, tumors, or structural lesions. 1
• Sensory deficits in the trigeminal distribution require urgent imaging to exclude secondary causes. 1
• Unilateral tinnitus itself warrants imaging to exclude retrocochlear pathology (vestibular schwannoma, meningioma). 6

Step 4: Order Appropriate Imaging

• MRI brain with contrast including high-resolution thin-cut sequences through the trigeminal nerve and internal auditory canals to evaluate for:
  • Neurovascular compression at the trigeminal root entry zone 1
  • Multiple sclerosis plaques 1
  • Cerebellopontine angle tumors (vestibular schwannoma, meningioma) 6
  • Vascular malformations 1
• If SUNCT/SUNA is suspected, include pituitary fossa views on MRI. 1

Step 5: Obtain Comprehensive Audiometry

• Pure tone audiometry, speech audiometry, and acoustic reflex testing should be performed within 4 weeks for any unilateral tinnitus to document asymmetric hearing loss and guide further evaluation. 6, 7

Treatment Approach Based on Diagnosis

If Classical or Type 2 Trigeminal Neuralgia

• Start carbamazepine (gold standard first-line treatment) or oxcarbazepine (equally effective with fewer side effects). 1
• Second-line options include gabapentin combined with ropivacaine, pregabalin, lamotrigine, or baclofen. 1
• Surgical microvascular decompression is considered when medications fail. 1

If SUNCT/SUNA

• Lamotrigine is particularly effective for SUNCT/SUNA and should be the first-line agent. 1

If Neurovascular Compression Confirmed on MRI

• Microvascular decompression surgery may address both the trigeminal pain and tinnitus if a vessel is compressing both the trigeminal and vestibulocochlear nerves. 5
• Timing matters: Surgery for tinnitus is more successful when performed within 2–10 years of symptom onset, before irreversible auditory brainstem changes occur. 5

Critical Pitfalls to Avoid

• Do not dismiss this as "just tinnitus" without evaluating the temporal pain, as the combination suggests a specific neurological syndrome requiring targeted treatment. 1
• Do not miss giant cell arteritis in patients over 50 with temporal pain—check for scalp tenderness, jaw claudication, visual symptoms, and elevated inflammatory markers, as this requires immediate high-dose corticosteroids to prevent blindness. 1
• Do not confuse SUNCT/SUNA with trigeminal neuralgia—the presence of autonomic features fundamentally changes the diagnosis and treatment. 1
• Do not delay imaging when continuous pain is present, as this may indicate a secondary cause (tumor, MS) requiring urgent intervention. 1
• Do not order imaging for bilateral, symmetric, non-pulsatile tinnitus—but unilateral tinnitus with facial pain absolutely requires MRI. 6, 7