Miller-Fisher syndrome in 78 year-old woman presenting as a stroke mimic – a rare case report

Abstract

Background Miller-Fisher syndrome (MFS) is a rare neurological disorder and a clinical variant of Guillain-Barré syndrome (GBS), typically characterized by ophthalmoplegia, ataxia and areflexia. In elderly patients with an atypical presentation without limb weakness and preceding infection the diagnosis is often delayed. The aim of this report is to present a case of MFS and analyze characteristic symptoms that may be helpful in the diagnosis of rare neurological diseases. Case Report A 78-year-old female (negative for SARS-CoV-2) was admitted to the Neurology Department with an acute focal neurologic signs like unsteady gait and partial left ptosis. Acute brainstem stroke was suspected. Brain CT at onset and after few days was performed to confirm cerebrovascular disease, however no ischemic changes were found. Brain MRI also didn’t show evidence of stroke. Later, due to patient’s worsening neurological condition (bilateral external ophthalmoplegia, diminished deep tendon reflexes) and observed progression of respiratory failure (RF), she was referred to Intensive Care Unit. Based on these findings, a MFS was suspected. Diagnosis was confirmed with decreased distal motor and sensory amplitudes on electroneuromyography and elevated protein with a normal white blood cell count in CSF. Patient was successfully treated with intravenous immunoglobulin along with rehabilitation and permanent tracheostomy due to persistent RF. Conclusions Our patient presented with the classic triad of clinical features in MFS with gradually progressive RF. This case highlights that patients with this syndrome may present with progressive RF needing intensive care therefore early diagnosis is crucial for successful treatment. Furthermore, MFS may be complicated to diagnose as the syndrome is rare. However, it is important to include this syndrome in the differential diagnosis of anyone presenting with ataxia, ophthalmoplegia and areflexia. The gradual onset and progressive nature of MFS symptoms may help to distinguish from an acute brainstem stroke.