Hearing Loss — Sudden Onset

Brief posting — I’m off for a week’s vacation, but didn’t want to leave our Blog completely dry.  So since our next topic will be “Vertigo,” a word about the little known Cranial Nerve 8 syndrome “Sudden Sensorineural Hearing Loss” (SSNHL).

A pregnant woman presented to her obstetrician with sudden onset unilateral hearing loss, & was told, “Go to primary.”  Too late.  By the time I saw her, more than another week had gone by.  Prednisone wouldn’t help any more, & the lady may remain virtually deaf in that ear forever.  A shame, especially since the incidence of SSNHL is increased in pregnancy.

Nobody knows why, nor do they know why the syndrome occurs in the first place.  But SSNHL is a bona fide condition, the abbreviation common among ENT’s.  High-dose Prednisone ASAP for 10 days seems to help.  There’s no good data, the few studies have flaws, and patients with milder symptoms may certainly regain function on their own.  But permanent hearing loss is not uncommon.  There’s no downside to 10 days of steroids; I’d certainly want them.

Whenever I see a case, I page the on-call ENT fellow, who always says, “We need audiometry first, but why don’t you start Prednisone 60 now.”  Then they squeeze the patient in.  One man came to me 3 weeks after onset; I just requested a routine ENT appointment, they expedited him in within a few days, only to lament to the patient that nothing could be done at that point.

So if anyone complains of sudden-onset unilateral hearing loss, often with tinnitus, see them immediately.  Rule out a stroke by excluding other lower cranial nerve symptoms (diplopia, dysarthria, dysphagia), and signs (ipsilateral Horner’s syndrome, EOM deficits, facial palsy, unsteady gait, or loss of pinprick sensation on the opposite side of the face).  Stroke is rare; we’ll discuss it more when we come to “Vertigo.”

Estimate the extent of hearing deficit by a whisper test (or document in decibels if you have a machine).  Determine that it is in fact sensorineural by tuning fork.  Call your local ENT for advice.  If you can’t reach them, start Prednisone 60 mg daily (first dose stat, then every day in the early morning), and call again later.

Distinguish sensorineural (8th nerve disorder) hearing loss from conductive (external or middle ear disease) with the tuning fork tests: Weber & Rinne.  Use a 512 Hz fork (the high-pitched one).  Click here if you don’t understand the test pathophysiology.

1.  Weber  —  Strike the fork hard, place it firmly on top of the patient’s head, & ask, “Do you hear this better in the right ear, the left ear, or the same in both?”

  • If there’s conductive loss, the affected ear hears the vibrations best.
  • With sensorineural loss, the unaffected ear hears best.
  • Determine ahead of time which ear is affected (by history, & whisper test)

2.  Rinne  —  My Way to do it:

a)  Instruct the patient, “Tell me which is louder, ‘One’ or ‘Two’.”

b)   Strike the fork hard, place the handle firmly on pt’s s mastoid bone behind the ear, prongs pointing back, and say “Here’s ‘One’” [bone conduction (BC)].

c)  Then, as it keeps vibrating, hold it so the patient can hear the prongs vibrate directly (like in front of the ear), and say, “Here’s ‘Two’” [air conduction (AC)].

  • If the patient hears the fork better via bone conduction, there’s a conductive deficit in that ear [chart “BC>AC”].
  • If the patient hears it better via air conduction [“AC>BC”], there’s no conductive deficit.  So if that was the affected ear, the deficit is sensorineural (i.e. not conductive).

BUT, before you do the tuning fork tests, look in the ear.  If you see the canal on the affected side is completely occluded with cerumen, lavage it before bothering to test further.

If you see a horrible-looking TM, don’t assume that’s related, because middle-ear disease is conductive, not sensorineural (otitis media usually presents with acute pain; otherwise, what you see is probably chronic).  Eustachian Tube Dysfunction also causes conductive deficits.

Actually, you can even distinguish sensorineural from conductive over the telephone, & call in the Prednisone with confidence.  Have the patient hum, and ask where they hear it best?

  • If heard best in the affected ear, it’s conductive loss (so no Rx)
  • If best on the unaffected side, the loss if sensorineural (call the Rx in with confidence)

Try it yourself.  Stick a finger in your ear (to create a conductive deficit), and hum.

SUMMARY

A patient presents with sudden onset of, say, Left (unilateral) hearing loss of only a few days’ duration.

1.  Look in the ear.  If the canal’s full of wax, clean it out.  Let’s assume both canals & TMs look normal.

2.  Test hearing as best you can (whisper at 6 feet, audiometry if you have it).  Document which ear is affected, & how bad.  Let’s say:

  • Right Ear:  hearing intact to whisper at 6 feet
  • Left Ear:  hearing intact only to loud shout at 6 feet

3.  Perform the Weber & Rinne tests.  If the Left ear has sensorineural loss, you should find:

  • Weber lateralizes to the right
  • AC > BC bilaterally (normal pattern)

4.  Having now Dx’d “Left SSNHL”:

  • Arrange formal audiometry & subsequent ENT consultation ASAP
  • But right away, Rx Prednisone 60 mg in single daily dose in AM for 10-14 days
  • DON’T taper the steroids !!!!!  You can Rx high-doses for ❤ weeks & stop abruptly without any fear.  Adrenal insufficiency won’t occur until at least a month of Tx.

You’ll read about MRIs & all sorts of other possible work-up, but leave that to ENT, since most patients won’t need anything except steroids & time.

And that’s that.  Onto “Vertigo” next posting.

WAIT…. one interesting anecdote that has nothing to do with all this, but worthy of mention [one that I once read about, didn’t witness myself].

What’s in the differential of absolutely sudden onset, fulminant, panicked hysteria  —  the patient began abruptly screaming & writhing uncontrollably, in such distress that they’re unable to explain a single thing?

One possibility:  yellow-jacket flew in the ear [just try to imagine how you might react].  Be sure to examine ears if patients present as such.

Treatment:  flood the canal with lidocaine; it’ll paralyze the bug stat, then kill it.

Nice to know, hope I never see it.

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