Bickerstaff's encephalitis is a rare inflammatory disorder of the central nervous system, first described by Edwin Bickerstaff in 1951. It may also affect the peripheral nervous system, and has features in common with both Miller Fisher syndrome and GuillainâBarrÃ© syndrome. 1  1 Signs and symptoms.  2 Pathophysiology.
Pathophysiology. Tears are produced in the lacrimal gland and drain through the upper and lower puncta into the canaliculi and then into the lacrimal sac and nasolacrimal duct (see Figure: Anatomy of the lacrimal system. ). Obstruction of tear drainage can lead to stasis and infection.
1 The superior duct, the smaller and shorter of the two, at first ascends, then bends at an acute angle, and passes medialward and downward to the lacrimal sac.2  The inferior duct at first descends, then runs almost horizontally to the lacrimal sac.utside the latter is a layer of striped muscle, continuous with the lacrimal part of the Orbicularis oculi; at the base of each lacrimal papilla, the muscular fibers are circularly arranged and form a kind of sphincter.