clinical features
Last reviewed 10/2022
The clinical features of myasthenia gravis are:
- external ocular muscles - affected in over 90% of cases, and are the muscles first affected in 65% of cases; diplopia or ptosis, often asymmetrical, are typical; ocular myasthenia describes myasthenia confined to the eyes.
- limb weakness - characteristically, increased by exercise, i.e. easily fatigued; shoulder girdle is commonly affected - patient may complain of difficulty in raising their arms above their head, or of brushing their hair; arm flexion is often more strong than extension; tone is normal and reflexes are often brisk; lower limbs are rarely affected; muscle wasting may occur in chronic disease.
- bulbar - loss of facial expression - patient appears unable to smile and may seem to snarl; inability to whistle; dysarthria - often, slurring speech; difficulty in chewing and swallowing; weakness of the neck muscles may force the patient to sit with their jaw propped by a hand
- respiratory - shortness of breath; may be exacerbated by lying down.