Cerebellum lesion
Nystagmus
Not suppressed with visual fixation
May be other than horizontal or horizontal-torsional
May change direction with gaze
Ataxia
Patient may have limb dysmetria, dysarthria, or headache
Head impulse test usually normal
Brainstem infarction
Usually associated with other symptoms of Wallenberg syndrome (lateral medulla infarct)
Ipsilateral Horner's, loss of corneal reflex, dysphagia, contralateral loss of pain/temp
Nystagmus
Not suppressed with visual fixation
May be other than horizontal or horizontal-torsional
May change direction with gaze
Ataxia
Patient may have limb dysmetria, dysarthria, or headache
Head impulse test usually normal
Not suppressed with visual fixation
May be other than horizontal or horizontal-torsional
May change direction with gaze
Usually associated with other symptoms of Wallenberg syndrome (lateral medulla infarct)
Ipsilateral Horner's, loss of corneal reflex, dysphagia, contralateral loss of pain/temp
Ipsilateral Horner's, loss of corneal reflex, dysphagia, contralateral loss of pain/temp<unk> /otologic
Benign paroxysmal positional vertigo (BPPV)
Traumatic (following head injury)
Infection
Labyrinthitis<unk> 
Ramsay Hunt syndrome
Ménière's disease
Ear foreign body
Otic barotrauma
Otosclerosis
Neurologic
Cerebellar stroke
Vertebrobasilar insufficiency
Lateral Wallenberg syndrome
Anterior inferior cerebellar artery syndrome
Neoplastic: cerebellopontine angle tumors
Basal ganglion diseases
Vertebral Artery Dissection
Multiple sclerosis
Infections: neurosyphilis, tuberculosis
Epilepsy
Migraine (basilar)
Other
Hematologic: anemia, polycythemia, hyperviscosity syndrome
Toxic
Alcohol
Aminoglycosides
Chronic renal failure
Metabolic
Thyroid Disease
Hypoglycemia
Benign paroxysmal positional vertigo (BPPV)
Traumatic (following head injury)
Infection
Labyrinthitis<unk> 
Ramsay Hunt syndrome
Ménière's disease
Ear foreign body
Otic barotrauma
Otosclerosis
Labyrinthitis<unk> 
Ramsay Hunt syndrome
Cerebellar stroke
Vertebrobasilar insufficiency
Lateral Wallenberg syndrome
Anterior inferior cerebellar artery syndrome
Neoplastic: cerebellopontine angle tumors
Basal ganglion diseases
Vertebral Artery Dissection
Multiple sclerosis
Infections: neurosyphilis, tuberculosis
Epilepsy
Migraine (basilar)
Hematologic: anemia, polycythemia, hyperviscosity syndrome
Toxic
Alcohol
Aminoglycosides
Chronic renal failure
Metabolic
Thyroid Disease
Hypoglycemia
Alcohol
Aminoglycosides
Thyroid Disease
Hypoglycemia
Vestibular neuritis
Cerebellum lesion
Labyrinthitis
Nystagmus
Benign paroxysmal positional vertigo
Not suppressed with visual fixation
Optic neuritis
May be other than horizontal or horizontal-torsional