• Distinction between central and peripheral vertigo can be made clinically by way of close physical examination of nystagmus.  The chart below describes specific findings for each:

 

• 	PERIPHERAL	CENTRAL
  Nystagmus
  Direction	Fast phase away from lesion; never reverses direction	Sometimes reverses direction if looking in direction of slow phase
  Type	Horizontal with torsional component, never purely torsional or vertical	Can be in any direction
  Other neurologic signs	Absent	Often present
  Postural instability	Unidirectional instability, walking preserved
  Effect of visual fixation	Suppressed	Not Suppressed
  Deafness or tinnitus	May be present	Absent

References

• www.uptodate.com