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					                       Tinnitus                                    Tinnitus
       Central Causes of Tinnitus                                   Auditory phantom sensation
                 Associate Professor Somsak Tiamkao
                                 Division of Neurology              Ringing of the ear when no
                              Department of Medicine                external sound is present
                                   Faculty of Medicine
                                 Khon Kaen University
                                 Khon Kaen, Thailand




               Classification of Tinnitus                          Central tinnitus
               Pathology        : normal, pathological
                                                                    Primary central
               Severity         : acceptable, unacceptable
               Duration         : temporary, permanent              Secondary central
               Site             : middle ear, peripheral neural,       peripheral       brain
                                  central neural                       phantom tinnitus
               Etiology         : tumour, stroke,etc




                  Secondary tinnitus
Conductive            Sensorineural                     Central
Vibration in     Type I Type II          Type III                  Anatomy
middle ear      motor     transduction transformation   Brain
                OHC      IHC             auditory N.               Auditory brain stem
                  Extrasensory structures
                          Type IIV
                                                                   Auditory midbrain
                                                                   Auditory thalamus and cortex




                                                                                                  1
Single Photon Emission Computerized          Positron Emission Tomography
Tomography: SPECT
  Perfusion abnormality                       Aberrant neural links between the
  Mesial temporal lobe                        somatosensory and motor system
    Hippocampal                               and auditory system
    Amygdala
  Frontal                                     Abnormal neural link between limbic
  Temporal                                    system and emotional centre and
  Parietal cortex                             auditory system




 Central Tinnitus:causes                     Central Tinnitus:causes
    Cerebellopontien angle lesion
                                               Dural AVM
    Vertebral artery: dissection, aneurysm
    Brains stem/cerebellar lesion
                                               Dural AVF
    Benign intracranial hypertension           Inferior olivary hypertrophy




 Physical examination                          Dural AVM
                                               10-15% of intracranial AVM
  General examination
                                               AVM at dura
  Head and neck                                Male: Female = 1:3
  Neuro-otologic examination                   Noise in head (bruit)
                                               Pulsatile tinnitus
     Brain stem
                                               Stroke-like symptoms
     Cerebellar                                Headache
     Palatal myoclonus                         Seizure




                                                                                    2
 Cause of Dural AVM                                 Dural AVF
  Congenital                                         Most common at transverse and
  Secondary                                          sigmoid sinus
      trauma
                                                     Tinnitus
      infection : syphilis
      intracranial surgery                           Cause is the same AVM
      pregnancy                                      Risk of bleeding




Benign intracranial Hypertension                        Cause
  Pseudotumor cerebri                                    Pregnancy
  Increased ICP without neurological deficit             Obesity
  CN VI palsy or papilledema                             Thyroid
  Pulsatile tinnitus headache, visual disturbance
                                                         Anemia
                                                         Cushing
                                                         Drug




 Hydrocephalus                                      Palatal myoclonus
                                                    Rhythmic involuntory jerking movement of soft palate
  Pulsatile tinnitus can be first sign of           Clicking sound
  increased ICP                                     1-2 Hz
                                                    Lesion in triangle of Gullain Molleret which composed of
  Pulse synchronous tinnitus is through to          Inferior olivary nucleus in brain stem
                                                    Central tegmental tract
  be due to vascular pulsations in CSF                     Connects olive to red nucleus in midbrain
  transiently compressing the dural venous          Superior olivary peduncle to contralateral dentate nucleus of
                                                    cerebellum
  sinus resulting in turbulent blood




                                                                                                                    3
 Inferior olive is provided with a massive                 GABA-Benzodiazepine-Chloride Receptor-Targeted
 inhibitory (GABA)                                         Therapy for Tinnitus Control
 Stroke 40%                                                   Central pathway in medial temporal system
 Tumour 7%                                                    SPECT
 Trauma 8%                                                    Irregular and reduced chemical binding GABA
                                                              receptor
 MS 8%                                                        Deficiency of GABA receptor is direct related to
 Encephalitis 2%                                              worsening of tinnitus
                                                              Impairment of GABA function has been
 Essential 27%                                                considered to lead convulsion
 Degenerative 2%                                              Tinnitus is an epileptic-like auditory phenomenon
                                                              Gabapentin




Vertigo, dizziness, and tinnitus after otobasal fracture
L Heid and et al. Int Tinnitus J 2004;10:94-100.            Unusual Cause of Tinnitus
  41% complained of tinnitus                                  Central giant cell granuloma of skull base
                                                              Leber s optic atrophy which involved brain
  53% complained of hearing loss
                                                              stem
                                                              Superficial siderosis of CNS
                                                              Spontaneous intracranial hypotension
                                                              syndrome




Anterior Inferior Cerebellar Artery Infarction              Complex partial seizure
  AICA ischemic stroke
  Vertigo, hearing loss, facial palsy, ataxia,                Female 21 yr
  nystagmus                                                   Episodic of vertigo and click in the brain
  Tinnitus, hearing loss
     Cochlea                                                  No palatal myoclonus
     Auditory nerve                                           MRI-brain : normal
     Cochlear nuclei                                          EEG : epileptic discharge
  Hearing loss
     non        severe




                                                                                                                  4
HEMIFACIAL SPASM: 44%




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