Horizontal gaze palsy as presenting symptom of brainstem encephalitis

A 48-year-old female presented with bilateral paralysis of supranuclear hori zontal conjugated gaze and impairment of various pontine, cerebellar and cervical spinal cord functions. The clinical signs and laboratory work-up indicated myeloencephalitis, probably of viral etiology. Paralysis of supranuclear horizontal conjugated gaze was produced experimentally by damaging the paramedial pontine reticularformation(PPRF). In the human, this a bnor-mality is extremely rare and, to the best of our knowledge, has not been reported previously in reversible encephalitis.