Miller Fisher syndrome after internal carotid artery stenting: A case report

Introduction: Internal carotid artery (ICA) stenosis is one of the important causes of ischemic stroke, and carotid artery stenting is used as an effective revascularization option in suitable patients. Here we present a patient who underwent stenting for right ICA stenosis, presented to us about one month after the procedure with difficulty walking and swallowing, and was diagnosed with Miller Fisher syndrome during inpatient follow-up.Case: An 80-year-old man had presented to another center 5 months earlier with a brief episode of unresponsiveness; imaging there showed 80% stenosis of the right ICA, and after predilation a 10×7×40 mm Protégé XR stent was placed (Figure 1). One month after stenting, he presented with general weakness and decreased oral intake for 3 weeks, drooping eyelids for 2 days, and a fall after loss of balance 2 days earlier. On admission neurological examination, he was alert, oriented, and cooperative; muscle strength was 4/5 in all four extremities, and bilateral ptosis was present, more prominent on the right. Vibration sense was normal. The upper and lower extremities were areflexic bilaterally. During follow-up he remained areflexic and developed bilateral ptosis, limited abduction and adduction of the right eye, mild limitation of adduction of the left eye, and bilateral miosis; the gag reflex was absent. Electromyography (EMG) performed for Miller Fisher syndrome was consistent with a mixed-type polyneuropathy syndrome (Figure 2, Figure 3). Lumbar puncture could not be performed because the patient was receiving dual antiplatelet therapy for the stent. Intravenous immunoglobulin (IVIG) treatment was started. After treatment, the neurological examination showed that he was alert, oriented, and cooperative, with muscle strength of 4/5 in all four extremities, hyporeflexia in the bilateral upper and lower extremities, limited adduction and downward gaze of the right eye, and full movements of the left eye. His ptosis improved minimally compared with admission, and half of the conjunctiva was spontaneously visible. Anti-GQ1b positivity was detected. On discharge neurological examination, adduction and downward gaze of the right eye were limited, left eye movements were full, and ptosis had improved minimally compared with admission. Muscle strength in the bilateral upper and lower extremities was 4+/5 with hyporeflexia. Plantar reflexes were flexor bilaterally (Figure 1–3).Discussion/Conclusion: In our patient, Miller Fisher syndrome, a rare neurological disease with an incidence of 1–2 per million, developed within the first month after the stenting procedure. Inflammatory polyneuropathies and other neurological diseases should also be kept in mind in neurological presentations that develop after angiographic procedures.Keywords: