Practical of Neuro

MYASTHENIA GRAVIS EYE SIGNS (EYELID FATIGABILITY,Cogan's LID TWITCH SIGN,CURTAIN SIGN,PEEK SIGN EYE SIGNS IN MYASTHENIA GRAVIS: • Weakness usually involves one or more ocular muscles without overt pupillary abnormality. • Weakness is typically variable, fluctuating and fatigable. • Ptosis that shifts from one eye to the other is virtually pathognomonic of MG. • With limited ocular excursion, saccades are superfast, producing ocular “quiver.” • After downgaze, upgaze produces lid overshoot (“lid twitch”). • Pseudo-internuclear ophthalmoplegia—limited adduction, with nystagmoid jerks in abducting eye. • In asymmetric ptosis, covering the eye that has lid ptosis may relieve contraction of the opposite frontalis. • Passively lifting a ptotic lid may cause the opposite lid to fall—“enhanced ptosis” • Edrophonium may improve only some of several weak ocular muscles; others may actually become weaker. • Edrophonium may relieve asymmetric ptosis and produce retraction of the opposite lid from frontalis contraction. • The opposite lid may droop further as the more involved lid improves after edrophonium. • Cold applied to the eye may improve lid ptosis—“Ice pack test” Most MG patients have weakness of ocular muscles.Asymmetrical weakness of several muscles in both eyes is typical, the medial rectus being more frequently and usually more severely involved. The pattern of weakness is not localizable to lesions of one or more nerves, and the pupillary responses are normal. Ptosis is usually asymmetrical and varies during sustained activity. To compensate for ptosis, chronic contraction of the frontalis muscle produces a worried or surprised look. Unilateral frontalis Contraction is a clue that the lid elevators are weak on that side. When mild, ocular weakness may not be obvious on routine examination and appear only uponprovocative testing (i.e., sustained upward gaze). Eyelid closure is usually weak, even when strength is normal in all other facial muscles, and may be the only residual weakness in otherwise complete remission. This is usually asymptomatic unless it is severe enough to allow soap or water in the eyes during bathing. With moderate weakness of these muscles, the eyelashes are not “buried” during forced eye closure. Fatigue in these muscles may result in slight involuntary opening of the eyes as the patient tries to keep the eyes closed, the so-called peek sign.

Quick Discussion SeriesMyotonic dystrophy1.Delayed relaxation of handgrip2.Percussion myotoniaTHE WHITE ARMYTo make studies more interesting and enjoyable, w...