What is Chorea Gravidarum?
Chorea gravidarum is a rare condition where the patient develops chorea during her pregnancy. Chorea gravidarum is a complication of pregnancy and it is related with eclampsia. This condition is characterized by abrupt, abnormal, involuntary movements that are non-rhythmic, brief and sporadic movements of any limb. These movements are commonly associated with non-patterned grimacing of the face. Chorea gravidarum is not a pathologically or etiologically distinct fatal condition, but is a broad term used when a woman experiences chorea from any cause during her pregnancy. Chorea gravidarum is linked with history of Sydenham's chorea and is commonly seen in young women of about 20 to 22 years. Rheumatic fever is thought to be a major cause of chorea gravidarum. There has been decrease in the incidence of chorea gravidarum because of decrease in the cases of Rheumatic fever.
Cause & Pathophysiology of Chorea Gravidarum
Many pathogenetic processes for chorea gravidarum have been put forward; however, none of these have been proven. Majority of the patients had a previous history of either chorea or rheumatic fever. Amongst the patients presenting with chorea without any apparent carditis, around 20% of these patients tend to develop rheumatic heart disease after some years. About half of the patients suffering from chorea that is induced from use of oral contraceptives have a previous history of chorea, about which 40% of these have rheumatic origin. This goes to suggest that hormones, progesterone and estrogen, can lead to sensitization of the dopamine receptors and lead to chorea in patients who are prone to this complication from preexisting pathology in the basal ganglion.
Autopsy on the patients with chorea gravidarum has revealed pathological changes such as perivascular degeneration in the caudate nucleus. Rheumatic brain disease shows pathology of nonspecific arteritis with perivascular lymphocytic infiltration, endothelial swelling and petechial hemorrhages. There is absence of Aschoff bodies. These changes are more apparent in the corpus striatum. There is severe neuronal loss in the putamen and caudate nucleus and these pathologic changes have been observed in chorea gravidarum; however, those patients also suffered from cardiac disease. It is thought that as the inflammation abates, the chorea also resolves with degenerative changes still remaining in the small arterioles.
There is also thought to be a possible relationship between moyamoya disease and chorea gravidarum. The movements of chorea are thought to occur as a result of ischemia or increased dopaminergic sensitivity, which is facilitated by the increase in the female hormones during pregnancy.
Signs & Symptoms of Chorea Gravidarum
Symptoms of Chorea Gravidarum are experienced by the patient in her second or third trimester, especially if the patient also has changes in her mental status such as confusion and agitation. Such mothers or patients are more prone to develop seizures, rhabdomyolysis, hemiplegia, hyperthermia and coma. The symptoms of chorea gravidarum usually subside in the mid to late second trimester. There is an elevation in the Anti-streptolysin O antibodies, which may continue to remain elevated throughout the pregnancy. Patients often also have valvular heart disease; however, the patients usually respond well to medical intervention, supportive therapy and reassurance.
Diagnosis of Chorea Gravidarum
Medical history and physical examination of the patient is carried out. Various investigations are carried out to confirm the diagnosis of chorea gravidarum. Imaging studies are also important for diagnosis. The different tests and investigations done for confirmation of diagnosis of chorea gravidarum include:
- MRI scan of the brain.
- Anti-Streptolysin O (ASO) test.
- Toxicology screening.
- Blood cultures.
- Complete blood count.
- Peripheral RBC smear for acanthocytes.
- Sedimentation rate.
- Antinuclear antibody test.
- Coagulation times (PT and APTT).
- Anticardiolipin antibody test.
- Lupus anticoagulant test.
- Liver function test.
- Electrolyte panel.
- Slit lamp examination.
Treatment of Chorea Gravidarum
Treatment for chorea gravidarum is chosen taking into consideration the teratogenic risks to the fetus, which is weighed against the benefit to the mother. Haloperidol is thought to give the most effective relief from the symptoms of chorea gravidarum. Pimozide is also a neuroleptic drug carrying lesser adverse effects than haloperidol. Phenothiazines can also be prescribed for nausea and vomiting. Other treatment approaches for chorea gravidarum consist of steroids and sedation. Chlorpromazine can also be prescribed alone or with diazepam. Other medicines which can be used in chorea gravidarum include risperidone, valproic acid, phenobarbital and chloral hydrate. All these medicines are prescribed in severe and debilitating cases of chorea gravidarum.
It is possible to manage chorea gravidarum without medicines. Conservative treatment for chorea gravidarum consists of rest for the patient, proper diet and peace or seclusion. Patients who have mild chorea gravidarum usually are not aware of the involuntary movements of chorea. In any case, the abnormal involuntary choreic movements cause more distress to the observers than the patient.
It should be born in mind that Chorea Gravidarum is not an indication for premature interruption of pregnancy or abortion whatsoever.