Pharyngeal-cervical-brachial (PCB) variant is a rare localized variant of Guillain-Barré syndrome that presents with a rapidly progressive oropharyngeal and cervicopharyngeal weakness associated with areflexia in the upper limb. Here, we are describing a case of a 20-year-old female who had a preceding history of fever with thrombocytopenia that was found to be dengue ELISA positive. This was followed by rapidly progressive weakness of cervical, bulbar, and bilateral facial muscles along with areflexia of upper limb. Nerve conduction study showed a reduced compound muscle action potential amplitude in the upper limb, and the CSF examination showed albuminocytological dissociation. The patient was given intravenous immunoglobulin, and she started improving within 3 days of commencing the treatment.

Fisher syndrome (FS) may overlap with Guillain-Barré syndrome (GBS), in particular the pharyngeal-cervical-brachial variant form (PCB-GBS), or Bickerstaff brainstem encephalitis (BBE). Our aim was to elucidate the frequency of this overlap and the patterns of clinical progression in patients with FS. Sixty consecutive patients with FS were studied. FS/PCB-GBS was diagnosed when the patients developed pharyngeal, cervical and/or brachial weakness. Patients with flaccid tetraparesis were diagnosed as having FS/conventional GBS. FS/BBE was defined as the development of consciousness disturbances. All 60 patients initially developed the FS clinical triad alone (pure FS). Of these, 30 (50%) patients had pure FS throughout their course, whereas the remaining 50% of patients showed an overlap: PCB-GBS in 14 (23%) patients, conventional GBS in nine (15%) patients and BBE in seven (12%) patients. The median (range) durations from FS onset to progression to FS/PCB-GBS, FS/GBS or FS/BBE were 5 (1-7), 3 (1-4) and 3 (1-5) days, respectively. Patients with overlap syndromes more frequently received immune-modulating treatment, and the outcomes were generally favourable. The frequencies of positivity for anti-GQ1b, GT1a, GD1a, GD1b, GalNAc-GD1a and GM1 antibodies were not significantly different amongst the four groups. Of the patients with pure FS, 50% later developed an overlap with PCB-GBS, conventional GBS or BBE. The overlap occurred within 7 days of FS onset; thus, physicians should pay attention to the possible development of this overlap during the first week after FS onset.