0:04

This is Dr. Samantha Shapiro,

0:06

executive editor of Harrison's Principles

0:08

of Internal Medicine. Harrison's

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Podglass is brought to you by

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McGraw-Hill's Access Medicine, the online medical

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resource that delivers the latest trusted

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content from the best minds in

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medicine. And now, on to the

0:21

episode. Hi,

0:28

everyone. Welcome back to Harrison's Podglass.

0:30

We're your co-hosts. I'm Dr. Kathy

0:32

Handy. And I'm Dr. Charlie Weiner, and

0:34

we're joining you from the Johns Hopkins School of

0:36

Medicine. Welcome to

0:39

episode 118, the 24-year-old with facial weakness. Kathy,

0:44

today we're talking about a 24-year-old

0:46

graduate student with no past medical

0:48

history. He presents today

0:50

with an abrupt left-sided facial weakness

0:52

and difficulty closing his left eye.

0:55

He says that he went to sleep last night after working

0:57

in the library, denies any fever, chills,

1:00

or night sweats. He did notice

1:02

a mild pain behind his left ear yesterday, but he

1:04

was thinking he had a bug bite or something. He

1:07

goes to school in Florida and does not

1:10

spend much time outside. He

1:12

uses alcohol and legal cannabis sparingly.

1:15

He's sexually active with a number of

1:17

female partners and usually does not use

1:19

any barrier methods of contraception. He

1:22

does not use illicit drugs or cigarettes, and

1:24

he takes no medications. On

1:26

examination, he has a left facial droop, an

1:29

asymmetric smile, and diminished

1:31

forehead creases. When asked

1:33

to close his eyes, his right eye is normal, but

1:35

his left eye remains 30% open. This

1:40

sounds like acute Bell's palsy. I'm

1:43

listening. Tell me more. Okay.

1:45

Remember the seventh cranial nerve innervates

1:47

the face. Bell's palsy is the

1:49

most common cause of facial paralysis

1:52

and involves a unilateral facial

1:54

nerve palsy. The onset

1:56

of Bell's palsy is fairly abrupt

1:58

with maximal weakness. typically being attained

2:01

by about the 48-hour mark. Pain

2:04

behind the ear may precede the paralysis for a

2:06

day or two, which is, it sounds like

2:08

what happened in our patient. And

2:10

taste sensation may be lost unilaterally

2:12

and hyperacusis may also be present.

2:16

Do we need more testing or can we just call

2:18

this spells? The diagnosis

2:20

can usually be made clinically in

2:22

patients who have the

2:24

typical presentation, no risk factors

2:26

or preexisting symptoms for other causes

2:29

of facial paralysis, an

2:31

absence of any cutaneous lesions of herpes

2:33

zoster in the external ear canal, and

2:36

a normal neurologic examination with the exception

2:38

of the facial nerve. Approximately

2:40

80% of patients will

2:42

recover within a few weeks or months. And

2:45

this sounds like a typical case. Okay,

2:47

well the question is asking, which

2:50

of the following pathologic entities is the most

2:52

common cause of his findings? So it's getting

2:54

at the underlying cause of his Bell's Palsy.

2:57

The options are A, a cerebral neoplasm,

3:00

B, herpes simplex type 1,

3:03

C, Lyme disease, D, trauma,

3:06

or E, varicella zoster virus?

3:10

The best answer is B, HSV1,

3:12

but varicella zoster is also a

3:15

good answer. In

3:17

acute Bell's Palsy, there's inflammation of

3:19

the facial nerve with mononuclear cells

3:21

consistent with an infectious or immune

3:23

cause. HSV type

3:25

1 DNA has frequently been

3:27

detected in endoneural fluid and

3:29

posterior erychular muscle, suggesting that

3:31

a reactivation of this virus

3:33

in the geniculate ganglion may be

3:36

responsible for most cases. Reactivation

3:39

of VZV is also associated with Bell's

3:41

Palsy in up to one-third of cases

3:44

and may represent the second most frequent cause.

3:47

And there are a variety of other

3:49

viruses that have also been implicated less commonly.

3:52

What about the other options? Yeah, the

3:54

differential of acute facial palsy is broad,

3:56

although this seems like a classic case

3:59

of Bell's. Lyme disease

4:01

can cause unilateral or bilateral

4:03

facial palsies, and in

4:05

endemic areas, over 10% of

4:07

cases of facial palsy are likely due

4:09

to Lyme disease. Facial

4:12

palsy that is often bilateral

4:14

occurs in sarcoidosis and in

4:16

Guillain-Barré syndrome. Leprosy

4:19

frequently involves a facial nerve, and facial

4:21

neuropathy may also occur in diabetes, connective

4:24

tissue diseases, including showgrins and

4:26

amyloidosis. Given that,

4:28

depending on the patient and the rest of

4:30

the history, you should think about things like

4:33

cerebral infarcts or demyelinating lesions in MS and

4:35

even pontine tumors. The question

4:38

mentions cerebral neoplasms, so I'll just

4:40

highlight that acoustic neuromas frequently do

4:42

involve the facial nerve by local

4:44

compression. Okay, well, this

4:46

is a two-part question, so let's keep moving

4:48

on. The next question asks,

4:51

which of the following is the next

4:53

most reasonable therapeutic step? A,

4:56

focus muscle electrical stimulation. B,

4:59

IV immunoglobulin infusion. C,

5:02

L-dopotherapy. D,

5:04

prednisone. Or E, vallecyclovir.

5:08

Usually in an uncomplicated case, you

5:11

can advise symptomatic measures such as

5:13

using paper tape to

5:15

depress the upper eyelid during sleep

5:17

and just to prevent corneal

5:19

drying. Or you can suggest

5:21

artificial tears or massage of the weakened

5:23

muscles. Yeah, but those were not choices

5:25

I could get you. Alright,

5:28

fair enough. So of the answer choices,

5:31

the best one to go with would be D,

5:33

which is a short course of prednisone. So

5:36

as I mentioned before, acute belts, palsy, this

5:38

inflammation of the facial nerve with

5:40

mononuclear cells. So a course of

5:42

glucocorticoids given as prednisone 60 to 80

5:45

milligrams daily during the first five days

5:47

and then tapered usually over the

5:49

next five days, modestly shortens

5:51

the recovery period and improves the

5:53

functional outcome. Although large

5:55

and well controlled randomized trials found

5:57

no added benefit of the antiviral agents,

6:00

valcyclovir or acyclovir, compared

6:02

with glucocorticoids alone. Some earlier

6:05

data suggests a combination therapy with

6:07

prednisone plus valacyclovir might be marginally

6:09

better than prednisone alone, especially

6:12

in patients who have severe clinical presentations.

6:16

For patients with permanent paralysis from belt

6:18

palsy, a number of cosmetic surgical procedures have

6:20

been used to restore a relatively

6:23

symmetric appearance to the face. But

6:25

the best answer choice listed is prednisone.

6:29

Okay, so today's teaching points are that

6:31

belt palsy manifests as an acute facial

6:33

paralysis due to inflammation of the facial

6:35

nerve. It likely represents reactivation

6:37

of virus such as HSV or VZV,

6:41

although you have to think of Lyme disease in

6:43

endemic areas. No other workup

6:45

is necessary in typical cases and treatment

6:48

is symptomatic with the consideration of a

6:50

short course of prednisone, which may hasten

6:52

recovery. And you can read

6:54

more about this in the Harrison's chapter on

6:56

cranial nerve palsies. Thanks

6:59

for listening to Harrison's Pod Class.

7:02

You can listen to this episode

7:04

and more on accessmedicine.com, which

7:06

includes the complete Harrison's Principles of

7:08

Internal Medicine text, Harrison's review questions,

7:10

which compliment and expand upon the

7:12

questions in this episode, and much

7:14

more. accessmedicine.com may already

7:17

be available to you via your

7:19

academic institution. Check it out. Thank

7:29

you.