OCP Related Chorea

05 November 2004

Rare complication of OCP compared to stroke & migraine

Risk Factors

1.Previous chorea (rheumatic fever, chorea gravidarum)

2.Henoch Schonlein purpura

3.Cyanotic congenital heart disease

Clinical

Average age 22

Starts 1-3 mths after commencement of OCP (average 9 weeks)

82% show a subacute pattern of evolution

77% asymmetrical

Associated with both high & low dose estrogen preparations

Signs resolve within 1 week to 5 months (average 5 weeks)

Chorea does not always occur with subsequent pregnancy

Progestogen (noresthisterone) only OCP has been used without consequence

Pathophysiology

Chronic dopaminergic sensitivity after Sydenham’s chorea:

            41% cases of OCP induced chorea (enhanced central dopaminergic sensitivity)

            10% cases of dilantin induced chorea

            35% cases of chorea gravidarum

            Increase incidence in hyperthyroid chorea (T4 sensitises central dopamine

receptors)

            Indirect dopamine agonists (amphetamines) induce chorea

            Low dose Levo dopa can induce chorea

Differential Diagnosis

Rheumatic fever, SLE / antiphospholipid syndrome, Wilson’s disease, polycythemia, hyperthyroidism, hypocalcemia, CO poisoning, familial benign chorea, Huntington’s disease, neuroacanthocytosis, porphyria, dilantin toxicity, Henoch Schonlein purpura, chorea gravidarum.