Block 3

• Presbycusis - hearing loss due to age starts at high frequencies
• Frequency of the basilar membrane:

  • high - small apex
  • low - wider
• Inner hair cell – all work of transforming wave energy into useful brain information
• Outer hair cell – modulate the basilar membrane vibration by stretching in response to signal pulling between the tectorial and basilar membrane
• Cochlear nerve are ipsilateral to cochlear nuclei then all bilateral
• Wernicke's (receptive) aphasia - BA number - 22, 39, 40
• Broca (expressive) aphasia - BA number - 44, 45
• Wernicke's (receptive) aphasia - Poor comprehension of speech, speak fluently but word salad
• Broca (expressive) aphasia - Good comprehension but difficulty forming words and slow
• Transverse gyrus of heschl - BA 41
• auditory association cortex - BA 42
• which lobe of the brain is affected in auditory hallucination?

  middle and superior temporal gyrus
• Herpes simplex 1 encephalitis - affects temporal lobe resulting in auditory hallucination
• which diseases can have hallucination?

  schizophrenia and temporal lobe epilepsy
• Sound Localization - Lateral input direction

  • Interaural level difference - which of ear side is louder
  • Interaural time difference - which side of ear does sound reaches first
• Superior olivary complex - for sound localization

  • Time difference detection
  • Coincidence detector needs to signal from both right and left in order to fire
• tinnitus caused by lack of dampening of sound

  • can be idiopathic
• bell's palsy can cause hyperacusis - increase sensitivity to sound 

  • because facial nerve innervates stapedius
•  

  Two types of hearing loss

  1. Conduction - before cochlea
  2. Sensorineural - past or at the cochlea
•  

  Medications that can cause hearing loss

  • Salicylates - aspirin - reversible
  • NSAID - advil or aleve - reversible
  • Antibiotics - aminoglycoside - lead to irreversible loss of inner hair cells
• Sound Localization

  • >1600 Hz interaural level difference
  • <800 Hz, interaural time difference
• Someone comes in with Wernickies encephalopathy that progresses to Korsakoff syndrome, MRI image is done. What do you expect to be additionally damaged?

  Dorsomedial Nucleus affected immediately and The Anterior Nucleus of Thalamus which leads to the memory problems later on
• Question about someone staring at the screen for 30secs and they were lost for 30secs, what type of epilepsy is it?

  You can’t tell because you need an EEG test
• A Hal Pikes Dixie test that was negative, they kept doing the test till they went hyperventilation

  Vestibular Schwannoma
• Spinning around, what makes you stumble?

  Lateral Vestibular
• Bilateral MLF lesion, which will they have a problem with?

  No adduction of eye towards nose
• Simple vs. Complex cells, cells in V1 respond to specific orientation and have excitatory/inhibitory zones and in any of the several parallel positions. What kind of cell is it?

  Complex Cells (V1 and V2)
• High electrical activity is least likely to be where?

  Prefrontal
• Question about MRI contraindications where a patient had an insulin pump which has a metallic parts to it?

  you don’t do an MRI on them without removing the pump and all metallic objects
• What is the vascular theory of Migraine?

  First is Intracranial Vasoconstriction Neurological Phase then Extracranial Vasodilation Headache Phase
• Question about epilepsy where you have tingling in the face and its going down the arm

  Jacksonian March (Simple Focal) then it goes Gran-Mal - Secondary Generalized Seizure
• Question about addiction, what is making you go outside to smoke, what is the control porting in charge of this

  Prefrontal (Anterior Cingulate)
• Rock n’ Roll musician has no problem with the look of his ears, you suspect sensorineural loss from a Rinne test because right ear is having problems, what would the weber test tell you?

  The sound would be louder in the left ear
• Kid with a bad haircut and hearing is out of range, Weber is louder in the left, you get a positive Rinne on the left and negative on the right, what is the problem?

  Really bad sensorineural
• Question about the picture with a baby’s eardrum had bubbles in it and asked what kind of infection

  Serous

  
• In light, what are photoreceptors doing?

  They are releasing less glutamate and relatively depolarize the on centers
• Sleep is concomitant with what?

  Increase in GABA (Both REM and NREM)
• The LHAPH and VPLO are compromised by huge types of hypothalamic, which can cause double narcolepsy and insomnia


  LHAPH uses Orexin and VPLO uses GABA
• Fear and memory leaves in a different place and it overlays with Extinction. Where is this located?

  Infralimbic prefrontal cortex
• Question about a patient in between stages and close to end stage of Wernike-korsokoff, what part of the brain is affected the most?

  Anterior Nucleus of the Thalamus and Cortical Atrophy