A 26 yrs old male with restriction of eye movements in all directions &moderate ptosis but with no diplopia or squint. Diagnosis is
Thyroid ophthaltnopathy
Chronic progressive external ophthalmoplegia
Myasthenia gravis
Multiple cranial nerve palsies
Chronic progressive external ophthalmoplegia Bilateral ptosis without diplopia is seen in chronic progressive external ophthalmoplegia (CPEO). Ptosis & diplopia are presenting symptoms in approx 50% of patients of Myasthenia gravis, & subsequently develop in 96% of patient during the course of the disorder. In thyroid-associated ophthalmopathy, proptosis & lid retraction is found. Pseudoptosis may be observed if contralateral lid retraction is present. Ptosis may occur if levator dehiscence is present b/o inflammation. Diplopia can occur in 5-10% of patients b/o severe muscle swelling . Multiple cranial nerve palsies as in cavernous sinus syndrome & orbital apex syndrome, present with diplopia along with ophthalmoplegia & other symptoms. Chronic progressive external ophthalmoplegia (CPEO): CPEO is the most common feature of mitochondrial myopathy. It occurs in > 50% cases of all mitochondrial myopathies. Typical presentation is B/L ptosis without diplopia in early adulthood Ophthalmoplegia is usually symmetrical & slowly progressive so diplopia is not often a complaint because all eye movements are reduced equally. The progressive ophthalmoplegia is unnoticed till decreased ocular motility limits peripheral vision. Ciliary muscles & iris muscles are often unaffected by CPEO Other variable symptoms are: - Exercise intolerance - Cataract - Hearing loss - Sensory axonal neuropathy - Ataxia - Clinical depression - Hypogonadism - Parkinsonism Diagnosis is made by muscle biopsy. Muscle fibres stained with "Gomori trichrome stain" give rise to dark red staining of muscle fibres k/a "ragged red fibers" This is b/o accumulation of enlarged mitochondria. PCR of blood or muscle tissue can determine a mutation of the mt DNA. There is no definitive treatment for CPEO. Ptosis may be corrected with lid surgery. Experimental treatment with tetracycline & coenzyme Q10 has been used. Also know Kearns - Sayre Syndrome (KSS): Is mutiorgan system, mitochondrial disorder with a triad of - Onset before age 20 - CPEO - Pigmentary retinopathy plus one or more of the following - Cardiac conduction defects - CSF protein > 1.0 gm/1 or - Cerebellar ataxia