Weakness of extraocular muscle may be seen in all of the following conditions except :
A i.e. Polymyositis Ocular muscles are spared even in advanced, untreated cases of inflammatory myopathies (polymyositis, dermatomyositis & inclusion body myositis) Q. If these muscles are affected, the diagnosis of inflammatory myopathy should be questioned. (H-2540) Inflammatory Myopathies Characteristic Dermatomyositis Polymyositis Inclusion body myositis Age Adulthood and childhood > 18 years > 50 years Male: Female = 3:1 Sex Female > Male Familial association Absent Absent Present in some cases Associated conditions Drugs - D-penicillamine - D-penicillamine Absent - Contaminated tryptophan - Zidovudine Connective tissue disease Present e.g. scleroderma & mixed connective tissue disease (overlap Present e.g. SLE, RA, sjogren, systemic sclerosis & mixed Present e.g. SLE, RA, sjogren, systemic sclerosis syndrome) connective tissue disease & mixed connective tissue disease Systemic autoimmune disease Infrequent Frequent e.g. chron's ds, vasculitis, sarcoidosis, 10 biliary cirrhosis etc. Infrequent Malignancy Present, in upto 15% cases Absent Absent Viruses Unproven Present e.g. HIV & HTLV-1 Present e.g.HIV & HTLV-1 Parasites & bacteria Absent Present Absent Clinical features * Rash - Accompany or more often precede muscle weaknessQ - Consists of a blue purple discolouration on the upper eyelids with edema (heliotrope rash) Q, a flat red rash on the face & upper trunk, & erythema of knuckles with raised violaceous scaly eruption (Gottron rashQ). The erythematous rash on neck & anterior chest (V sign) or back & shoulder (Shawl sign) can also occur. * It is a diagnosis of exclusion. It is subacute myopathy affecting adults & rarely children who do not have - rash Q, involvement of extraocular & facial muscles Q, family h/o neuromuscular disease, h/o exposure to myotoxic drugs or toxins, endocrinopathy, neurogenic disease, muscular dystrophy, biochemical muscle disorder (deficiency of enzyme) or IBM as excluded by muscle biopsy analysis. - May worsen after sun exposure & may be pruritic * The cuticles may be irregular thickened & distoed and the fingers (lateral & palmar areas) may become rough & cracked with irregular diy horizontal lines, resembling mechanic's hands. Muscle weakness - Progressive & often - Progressive & often - Progress very slowly over symmetrical muscle weakness, which progress subacutely, over a period of weeks or month symmetrical muscle weakness, which progress sub acutely, over a period of weeks or years simulating a late life muscular dystrophy or - Increasing difficulty with month slowly progressive motor everyday tasks requiring the - Increasing difficulty with neuron disease use of proximal muscles Q such everyday tasks requiring the - Fine motor movements as getting up from a chair, climbing steps or combing hair etc. use of proximal muscles Q such as getting up from a chair, climbing steps or combing hair (distal muscles) are involved early _ Mild fascial weakness is - Fine motor movements that depend on the strength of distal etc. - Fine motor movements that common muscles, such as buttoning a depend on the strength of - Falling is common shi, sewing, knitting or distal muscles, such as because of early writing are affected only late in course buttoning a shi, sewing, knitting or writing are affected involvement of quadriceps muscle with buckling of - Fascial muscle are unaffected only late in course knees. - Myalagia & muscle tenderness may occur in some patients of - Fascial muscle are unaffected DM with connective tissue disease
Polymyositis
Myasthenia-gravis
Eaten-lambe-myasthenic syndrome
Thyrotoxicosis