History
Ms. Mui was a 50-year-old lady. She was a chronic smoker and non-drinker.
She presented with a 1-year history of episodic facial pain. The episodes were described as brief, electric shock-like sensations involving the cheeks and mandibular regions. They could recur in quick succession, but a refractory period must be present in between attacks. The symptoms initially occurred in the right face, but later involved the left face at an increased frequency. The symptoms were exclusively unilateral each time. Cold wind was usually the triggering factor, if present.
There were no associated autonomic symptoms or focal neurological symptoms.
Physical examination
Neurological examination was normal.
Investigations
No investigations have been performed for her symptoms yet.
Thought process
Ms. Mui presented with a syndrome of chronic, episodic neuropathic facial pain in the distribution of the trigeminal nerve.
The pathology was likely localized to the trigeminal nerve. Given the bilateral symptoms, a pontine localization should be considered.
The etiology was likely to be structural, that is, related to neurovascular compression. Alternative etiologies should be entertained due to the bilateral symptoms. These differential diagnoses included multiple sclerosis, Sjögren’s disease, systemic lupus erythematosus, and a tumor.
Next steps
A contrast MRI brain was arranged to discern the presence of neurovascular compression at the trigeminal exit zone from the pons.
Autoimmune antibodies were checked.