Clinical Analysis: 50-year-old Female with Left Cheek Pain + Constant Bilateral Gaze Deviation to the Left Upper Quadrant

Parsing the Clinical Presentation

1. Left cheek pain - suggests involvement of the left trigeminal nerve (V2 - maxillary division, which covers the cheek)
2. Constant (tonic) conjugate gaze deviation of both eyes toward the left upper quadrant - this is a sustained, non-paroxysmal deviation, not a gaze palsy (she cannot be brought back to midline by effort)

Neuroanatomical Localization

Step 1: Which direction are the eyes going?

• Left upper quadrant = left horizontal + upward vertical components

Step 2: The "eyes toward the lesion" rule

• Frontal eye field (FEF) lesion (left hemisphere): The left FEF normally drives eyes to the right. If it is destroyed, the intact right FEF drives eyes to the LEFT (ipsiversive deviation). Eyes look TOWARD the lesion (left). This matches.
• Left PPRF/abducens nucleus (pontine) lesion: Also causes gaze failure to the left, but in pontine lesions the doll's-eye maneuver CANNOT overcome the deviation (vs. frontal lesions where it can). Eyes look toward the HEMIPARESIS (toward the side of the lesion = left), but it is OPPOSITE to a frontal pattern anatomically.
• "Wrong-way eyes" (thalamic hemorrhage): Deep thalamic hemorrhage (especially medial thalamus) causes eyes to deviate CONTRALATERALLY (toward the hemiparesis, AWAY from the lesion). Eyes look left = lesion is on the RIGHT side in this scenario.

Step 3: Why the upward component?

• Seizure activity (ictal deviation): A focal seizure originating from the left frontal or parieto-occipital cortex causes CONTRALATERAL eye/head deviation (away from the focus) - but a left frontal seizure would drive eyes to the RIGHT, not left. A RIGHT frontal/posterior seizure could drive eyes to the left-upper quadrant.
• Oblique gaze deviation: Can occur with posterior fossa or brainstem lesions affecting both horizontal and vertical gaze centers simultaneously.
• Skew deviation: Combined vertical and torsional misalignment from posterior fossa lesions - but skew is usually disconjugate.

Synthesis: Most Likely Diagnoses

1. LEFT Hemisphere Cortical/Subcortical Stroke (Most Likely)

• Tonic gaze deviation to the LEFT (ipsiversive = toward the lesion)
• The upward component can occur with involvement of the corona radiata/frontal-parietal circuits
• Left facial pain may reflect a thalamic pain component if the stroke extends medially, OR may be a referred pain from involvement of the left corticobulbar/trigeminal pathways
• This is the most common cause of acute tonic conjugate gaze deviation

"Transient gaze deviation, usually of the head and eyes, occurs in about 20% of patients with acute hemisphere stroke... patients with left-sided lesions (gaze deviation to the left) have a worse prognosis." - Bradley and Daroff's Neurology in Clinical Practice

"In general, the larger the lesion, the more persistent the conjugate gaze deviation." - Localization in Clinical Neurology, 8e

2. LEFT Pontine Lesion (Foville Syndrome variant)

• Foville syndrome: ipsilateral horizontal gaze palsy (eyes cannot move to the LEFT) + ipsilateral peripheral facial palsy + contralateral hemiplegia
• The left cheek pain could represent ipsilateral trigeminal (V) involvement at the pons
• However, in a true Foville syndrome, the eyes deviate TO THE RIGHT (away from the pons lesion, toward the hemiparesis), not to the LEFT
• Unless it is an irritative (early) pontine lesion where eyes are transiently driven TOWARD the pons

"The Foville syndrome results from pontine tegmental lesions interrupting the fascicles of the facial nerve, the PPRF, and the corticospinal tract and is characterized by: (1) ipsilateral peripheral facial paralysis; (2) paralysis of conjugate gaze to the side of the lesion; (3) contralateral hemiplegia." - Localization in Clinical Neurology, 8e

3. Cerebellopontine Angle (CPA) Mass (Subacute)

• Left trigeminal nerve → left cheek/facial pain
• Left pons/PPRF → ipsilateral gaze palsy
• Left CN VII → facial weakness
• Cerebellar peduncles → ataxia

"CPA lesions frequently involve neighboring structures, including the pons (nystagmus or ipsilateral gaze palsy), trigeminal nerve (ipsilateral facial pain and/or sensory changes)." - Localization in Clinical Neurology, 8e

4. RIGHT Thalamic Hemorrhage ("Wrong-Way Eyes")

• Eyes deviated to the LEFT (wrong-way = toward hemiparesis, away from the lesion on the right)
• Thalamic pain or referred sensory symptoms potentially in the left face
• Often accompanied by tonic downward + inward gaze ("peering at the nose")

"Hemorrhages deep in a cerebral hemisphere, particularly those involving the medial thalamus, can cause eye deviation to the side of the hemiparesis, opposite the lesion ('wrong-way eyes')." - Localization in Clinical Neurology, 8e

5. Focal Seizure (Ictal Gaze Deviation)

Differential Diagnosis Summary Table

Immediate Workup

1. Urgent non-contrast CT brain - to rule out hemorrhage (thalamic, hemispheric, CPA mass effect)
2. MRI brain with DWI - acute infarct (diffusion restriction), CPA mass, pontine lesion
3. MRA/CTA of Circle of Willis - if vascular event suspected
4. EEG - if seizure is suspected (especially if "constant" deviation is actually ongoing ictal activity)
5. Blood pressure, glucose, CBC, coagulation - standard stroke workup
6. Neurological exam: Check if doll's-eye maneuver overcomes the gaze deviation (if yes = supranuclear/frontal; if no = pontine nuclear)

Key Clinical Clue: Overcoming the Gaze Deviation

• Doll's-eye maneuver (oculocephalic reflex): Turn head to the right → if eyes go to the right (i.e., they now look straight or right) = the brainstem gaze centers are INTACT = the lesion is SUPRANUCLEAR (frontal cortex/hemisphere)
• If eyes stay deviated to the left despite head turning = pontine/brainstem nuclear lesion (e.g., Foville)
• Caloric stimulation (cold water in left ear) is also useful in comatose patients

Bottom Line