LID LAG AS A SIGN OF HYPERTHYROIDISM

A patient presents with tachycardia. You notice the eyes seem wide. Is this the lid lag of hyperthryoidism?

The terminology of the opthalmologic signs of hyperthyroidism is sometimes excessively parsed. It is lagophthalmos when the eye does not close, von Grafe’s sign when the act of looking down causes a temporary lid retraction, and lid lag when the lid appears persistently retracted while looking down.(Harvey Opthalm Surg 1981)

It is probably sufficient to use the term lid lag for any of these conditions. The pathophysiology is the opposite of the ptosis of Horner’s syndrome. The sympathetically-innervated Mueller’s muscle has an increase rather than a decrease in the tone. As for its sensitivity and specificity, most studies neglect to record this sign.

We are not discussing here the other opthalmologic findings specific to Grave’s disease, which result from myxedema/swelling.

Take Home Points:

Hyperthyroidism causes increased tone in Mueller’s muscle, which causes lid lag

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HORNER’S SYNDROME: FINDINGS ARE SUBTLE

Ptosis, miosis, and anhidrosis. The pathological term for the disease is “oculosympathetic paresis.” The term explains some of the other findings, including ipsilateral conjunctival injection, ipsilateral nasal congestion, upside down ptosis, and harlequin sign. It also explains why the presentation is subtle.

 

Unlike third nerve palsy, it is not the levator palpebrae superioris that is affected. Instead, it is the sympathetically-innervated Mueller’s muscle, which causes only 1-2mm of lid droop. Do an online images search of Horner’s syndrome, and you will see how subtle this can appear. Probably the best we can do is notice slight asymmetries and investigate further.

 

The miosis is easily missed too. If we typically examined patients in the dark, the miosis would stand out. But we see them in bright lights, where both eyes show a relative degree of miosis. If you notice anisocoria, turn the lights out. The Horner’s pupil will remain small. Even if it does eventually dilate, a delay to dilation is characteristic.

 

In summary, Horner’s syndrome is subtle. The ptosis is only 1-2mm, unlike the more dramatic ptosis of third nerve palsy. Miosis is less noticeable in the bright lights of the emergency department.

 

Take Home Points:

-Due to the sympathetically-innervated Mueller’s muscle, the ptosis of Horner’s syndrome is 1-2mm

-Miosis of Horner’s syndrome is best appreciated in the dark

PENETRATING NECK TRAUMA REQUIRES DETAILED EXAMINATION

A patient presents with a stab wound to the neck. You examine the wound and see a 1 cm laceration. The patient reports no other symptoms. How can we best identify injuries?

 

Through the neck run longitudinal blood vessels, nerves, as well as organs of the respiratory and gastrointestinal systems. The mechanism is important – what is the direction of the wound tract?

 

Below is a template of a thorough examination of penetrating neck trauma, with more detail on pertinent items. This is based on the 1997 article by Demetriades et al.

 

Airway: No subcutaneous emphysema, hoarseness, or stridor, no bubbling from wound

Esophagus: No odynophagia, no pharyngeal blood, no hematemesis

Vascular: Normal pulses, no bruit, no hematoma, no active bleeding

Neurologic:

Motor/Sensory/Reflexes normal

Cranial nerves:

II – pupils equally reactive (no Horner’s syndrome)

III, IV, VI – EOMI

V – normal facial sensation

VII – symmetrical facial movements

IX – normal soft palate

X – no hoarseness/dysphonia, normal cough

XI – symmetrical shoulder lift

XII – tongue midline

Brachial plexus:

normal radial, ulnar, median function of hand

musculocutaneous – normal forearm flexion

axillary  – normal arm abduction

 

Summary:

In penetrating neck trauma, evaluate the airway and esophagus, in addition to the vascular and neurologic functions.