An 32-year-old alcoholic, malnourished male with a traumatic…

An 32-year-old alcoholic, malnourished male with a traumatic brain injury is brought to the ED one hour after an automobile accident.  A hypertonic saline infusion is started to decrease intracranial pressure.  However, he develops spastic quadriplegia, pseudobulbar palsy, and coma from acute, noninflammatory demyelination centered within the basis pontis.  What is the most likely diagnosis?