The authors’ observations
In consultation with neurology, the leading differential diagnoses include tardive dyskinesia, chorea gravidarum, and Huntington’s disease. See the Table1,2 for the differential diagnosis of chorea.
Ms. A reports taking quetiapine for 3 years, which suggests possible tardive dyskinesia. Although second-generation antipsychotics have a lower incidence of movement disorders than first-generation antipsychotics, the risk still exists. Withdrawal dyskinesias can occur after suddenly stopping or tapering antipsychotics and appear as extrapyramidal symptoms, including choreoathetosis similar to what Ms. A experienced.3,4 This type of dyskinesia is thought to be secondary to chronic dopamine antagonism leading to increased postsynaptic receptors and dopamine hypersensitivity.5 Because Ms. A discontinued quetiapine early in her pregnancy, withdrawal dyskinesias are less likely.
Because Ms. A presented with a movement disorder while pregnant, the neurology service considers chorea gravidarum, the term given to chorea occurring during pregnancy. This syndrome is thought to be caused by the effects of pregnancy on the basal ganglia.6 Historically, chorea gravidarum was associated with rheumatic fever (RF); however, with the decline in prevalence of RF, most choreiform movements that appear during pregnancy typically are caused by other diseases, such as systemic lupus erythematosus or Huntington’s disease. Approximately one-half of chorea gravidarum cases are idiopathic, with RF and antiphospholipid syndrome accounting for the remainder.7 Huntington’s disease during pregnancy is rare because it tends to present in women beyond childbearing age.
Based on Ms. A’s symptoms and previous MRI findings, we ask her if she has a known family history of Huntington’s disease. She denies this, but says she has not seen her father since she was very young and is uncertain of his medical history.
Table
Differential diagnosis for chorea
| Genetic | Huntington’s disease, benign hereditary chorea, neuroacanthocytosis, dentatorubral-pallidoluysian atrophy, Wilson’s disease, spinocerebellar ataxia, Friedreich’s ataxia |
| Rheumatic disorders | Sydenham’s chorea, chorea gravidarum |
| Drug-induced/toxicity | Neuroleptic drugs, steroids, anticonvulsants, antiparkinson agents, stimulants (amphetamines, cocaine), lithium, dopamine agonists |
| Systemic disorders | Systemic lupus erythematosus, thyrotoxicosis, polycythemia vera, hyperglycemia, AIDS, paraneoplastic syndrome |
| Vascular/trauma | Cerebral hemorrhage, vasculitis, stroke, antiphospholipid antibody syndrome |
| AIDS: acquired immune deficiency syndrome Source: References 1,2 | |
TREATMENT: Restart medication
Ms. A’s laboratory results show a slightly low hemoglobin of 10.5 g/dL and hematocrit of 32.8%. Her mean corpuscular volume is slightly decreased at 77 fL. Her urinalysis is negative, and blood glucose and thyroid-stimulating hormone are within normal limits. Rapid plasma regain, anti-nuclear antibody, and human immunodeficiency virus (HIV) are negative. Based on hospital records, we learn that during the previous admission a year ago a serum ceruloplasmin and serum copper were drawn and were normal.
We contact Ms. A’s outpatient psychiatrist for collateral information. The psychiatrist says he first evaluated Ms. A 3 years ago after a friend brought her in because of strange behavior, including talking to herself, making odd facial gestures, and laughing inappropriately. Although Ms. A denies past psychiatric hospitalizations, her psychiatrist states that she was hospitalized for 1 week after the suicide attempt 4 years ago and prescribed lorazepam and sertraline during that admission. He speculates that the suicide attempt may have been related to 5 of her children being taken from her by the Department of Family and Child Services after police raided her home to search for drugs. Custody was awarded to their respective fathers, causing Ms. A to “snap,” according to her friend.
Since then, neither Ms. A nor her psychiatrist have reported any further psychotic symptoms. Her psychiatrist confirms that Ms. A’s abnormal movements were present before her first appointment with him. He says that he referred Ms. A to a local hospital for a neurology work-up, but she did not schedule an appointment.
When we follow up with Ms. A 2 days after delivery, she continues to deny depressive symptoms, although her affect remains blunted. She says she is looking forward to going home with the baby, whom she plans to bottle feed. Her choreiform movements appear unchanged. She also continues to experience lip smacking. Although Ms. A recognizes that she has some movements, she minimizes them and says they do not bother her. She continues to demonstrate latency in her verbal responses to questions. Based on the collateral history and positive response with quetiapine, we recommend that Ms. A be restarted on quetiapine, 200 mg/d.
The authors’ observations
Ms. A’s choreiform movements started before her psychotic symptoms and subsequent usage of neuroleptic medication, which makes tardive dyskinesia less likely. Laboratory studies rule out systemic lupus erythematosus, HIV, and Wilson’s disease as the cause of her abnormal movements.