Paroxysmal kinesigenic choreoathetosis
| Paroxysmal kinesigenic choreoathetosis | |
|---|---|
| Autosomal dominant - en.svg | |
| Paroxysmal kinesigenic choreoathetosis is inherited in an autosomal dominant manner | |
| Synonyms | Familial PKD, Paroxysmal kinesigenic dyskinesia
|
| Specialty | Neurology, Genetics |
| Symptoms | Sudden, brief episodes of chorea, athetosis, or dystonia triggered by voluntary movement |
| Complications | Impaired mobility during attacks, anxiety related to attacks |
| Usual onset | Childhood or adolescence |
| Duration | Chronic, lifelong condition |
| Types | Primary (familial) or secondary to other disorders |
| Causes | Mutations in the PRRT2 gene (most commonly) |
| Risk factors | Family history of similar movement disorders |
| Diagnosis | Clinical evaluation, family history, genetic testing |
| Differential diagnosis | Epilepsy, other paroxysmal dyskinesias, tic disorders |
| Prevention | Avoiding movement triggers may reduce episodes |
| Treatment | Anticonvulsants such as carbamazepine or oxcarbazepine |
| Medication | Carbamazepine, oxcarbazepine, phenytoin |
| Prognosis | Good with appropriate medication; episodes often decrease with age |
| Frequency | Rare |
| Deaths | Not typically life-threatening |
Paroxysmal kinesigenic choreoathetosis (PKC), also known as paroxysmal kinesigenic dyskinesia (PKD), is a rare neurological disorder characterized by sudden, involuntary movements triggered by voluntary movement. These episodes are typically brief, lasting seconds to minutes, and can include chorea, athetosis, or dystonia.
Presentation[edit]
PKC is marked by episodes of abnormal movements that are often precipitated by sudden voluntary movements, such as standing up or beginning to walk. The episodes can vary in frequency and severity, and they typically last less than a minute. Patients may experience multiple episodes per day. The movements can include:
- Chorea: Rapid, irregular, and unpredictable movements.
- Athetosis: Slow, writhing movements, particularly of the hands and feet.
- Dystonia: Sustained muscle contractions causing twisting and repetitive movements or abnormal postures.
Pathophysiology[edit]
The exact cause of PKC is not fully understood, but it is believed to involve dysfunction in the basal ganglia, a group of nuclei in the brain associated with movement control. Genetic factors play a significant role, with several cases linked to mutations in the PRRT2 gene. This gene is involved in synaptic function and neuronal communication.
Diagnosis[edit]
Diagnosis of PKC is primarily clinical, based on the characteristic presentation of the disorder. A detailed patient history and neurological examination are essential. Magnetic resonance imaging (MRI) and other neuroimaging techniques are typically normal but may be used to rule out other conditions. Genetic testing can confirm mutations in the PRRT2 gene, supporting the diagnosis.
Management[edit]
Management of PKC involves both pharmacological and non-pharmacological approaches. The primary treatment is the use of anticonvulsants, such as carbamazepine or phenytoin, which can significantly reduce the frequency and severity of episodes. Lifestyle modifications, including avoiding known triggers, can also be beneficial.
Prognosis[edit]
The prognosis for individuals with PKC is generally favorable, especially with appropriate treatment. Many patients experience a significant reduction in symptoms with medication. The disorder does not typically progress, and life expectancy is normal.
