on neurological examination, characteristic features are the reduced strength of muscles and reduced or absent tendon reflexes (hypo- or areflexia, respectively). however, a small proportion have normal reflexes in affected limbs before developing areflexia, and some may have exaggerated reflexes. in the miller fisher variant of guillain–barré syndrome (see below), a triad of weakness of the eye muscles, abnormalities in coordination, as well as absent reflexes can be found. the level of consciousness is normally unaffected in guillain–barré syndrome, but the bickerstaff brainstem encephalitis subtype may feature drowsiness, sleepiness, or coma.