Bilateral diaphragmatic weakness due to syringomyelia.

A lady in her late 50s presented with a 25-year history of intermittent severe neck and arm pain due to a syrinx extending from C4-T3 with suspended sensory loss but no other symptoms. She developed acute-onset bilateral diaphragmatic weakness requiring nocturnal non-invasive ventilation following an episode of severe neck and arm pain.Although rare, neurogenic diaphragmatic weakness has previously been reported with syringomyelia presumably due to involvement of the motor nuclei supplying the phrenic nerve and thoracic intercostal muscles that reside medially in the ventral cord.