Summary about Disease
Kinesigenic dyskinesia (KD) is a rare movement disorder characterized by brief episodes of involuntary movements (dyskinesias) triggered by sudden, voluntary movements. These movements are typically quick, jerky, and dance-like (chorea) or sustained and twisting (dystonia). The episodes are generally short-lived, lasting seconds to minutes. KD can be inherited (familial) or acquired due to other medical conditions.
Symptoms
The primary symptom is brief, involuntary movements (dyskinesias) triggered by sudden voluntary movements. Other specific manifestations include:
Type of Movements: Chorea (jerky, irregular movements) or dystonia (sustained muscle contractions causing twisting and repetitive movements), or a combination of both.
Body Parts Affected: Often affects the limbs (arms and legs), but can also involve the face, trunk, and neck.
Duration: Episodes usually last less than a minute, often only seconds.
Frequency: Varies greatly from person to person, from multiple times a day to very rare occurrences.
Triggering Movements: Sudden starts, changes in direction, standing up, speaking, swallowing, chewing, or other voluntary actions.
Awareness: Individuals are fully conscious and aware during episodes.
Absence of Neurological Problems: Typically, there are no other neurological deficits between attacks.
Causes
KD can be either familial or acquired:
Familial (Paroxysmal Kinesigenic Dyskinesia - PKD): This is usually inherited in an autosomal dominant pattern, most commonly caused by mutations in the PRRT2 gene. *PRRT2* encodes a protein involved in neurotransmitter release at synapses.
Acquired: Can be associated with various conditions, including:
Multiple Sclerosis (MS)
Stroke
Traumatic brain injury
Cerebral Palsy
Encephalitis
Certain medications (rare)
Metabolic disorders (rare)
Idiopathic: In some cases, the cause remains unknown.
Medicine Used
The primary medications used to manage KD are:
Anticonvulsants:
Carbamazepine: Often the first-line treatment and highly effective in many cases.
Oxcarbazepine: A derivative of carbamazepine with a potentially improved side effect profile.
Phenytoin: Another anticonvulsant that may be used.
Other Anticonvulsants: Other anticonvulsants may be used depending on the individual and how they respond to the first-line treatments.
Other Medications:
Benzodiazepines (e.g., Clonazepam): May be used as adjunctive therapy.
Levetiracetam: sometimes used for those that do not respond well to carbamazepine
Is Communicable
Kinesigenic dyskinesia is not communicable. It is a neurological disorder caused by genetic factors or acquired brain injury/disease, not by an infectious agent.
Precautions
Adherence to Medication: Take prescribed medications exactly as directed by your physician.
Avoidance of Triggers: Identify and, if possible, avoid activities or movements that reliably trigger episodes. This may involve modifying movements or using assistive devices.
Safety Measures: If episodes are severe or frequent, take precautions to prevent injury during attacks (e.g., avoid driving or operating heavy machinery, pad sharp corners).
Medical Alert: Consider wearing a medical alert bracelet or carrying identification indicating the diagnosis and emergency contact information.
Fall Prevention: If the dyskinesia leads to falls, implement fall prevention strategies at home.
Education and Support: Educate family members, caregivers, and close friends about the condition, its symptoms, and how to assist during an episode.
How long does an outbreak last?
Kinesigenic dyskinesia is not an "outbreak" like an infectious disease. Instead, it consists of individual episodes. Each episode typically lasts only seconds to a minute. The frequency and severity of these episodes can vary greatly between individuals and can be influenced by medication, stress, and other factors.
How is it diagnosed?
Diagnosis typically involves:
Clinical Evaluation: A detailed medical history, including family history, and a neurological examination by a physician experienced in movement disorders. The physician will assess the characteristics of the involuntary movements, triggers, and duration.
Observation: Observing the movements in person is the best way to help the physician make an accurate diagnosis.
Exclusion of Other Conditions: Ruling out other movement disorders that could cause similar symptoms (e.g., other types of dyskinesias, epilepsy).
Genetic Testing: In cases of suspected familial KD, genetic testing for mutations in the PRRT2 gene is helpful to confirm the diagnosis.
Neuroimaging: MRI or CT scans of the brain are usually performed to rule out structural abnormalities or other underlying causes, particularly in acquired cases.
Electroencephalogram (EEG): To rule out epileptic seizures as the cause of the movements.
Timeline of Symptoms
Onset: Can occur at any age, but often begins in childhood or adolescence.
Prodrome: Some individuals may experience a brief warning sensation (e.g., tingling, stiffness) before an episode, but often episodes occur without warning.
Trigger: Sudden voluntary movement initiates the involuntary movements.
Episode: Dyskinesias occur, lasting seconds to minutes.
Resolution: Symptoms resolve spontaneously, leaving the individual neurologically normal until the next episode.
Long-Term: The frequency and severity of episodes can fluctuate over time, and may be influenced by factors such as medication adherence, stress, and overall health.
Important Considerations
Accurate Diagnosis: Crucial to differentiate KD from other movement disorders.
Medication Management: Finding the right medication and dosage can significantly reduce the frequency and severity of episodes. Regular follow-up with a neurologist is essential.
Quality of Life: KD can significantly impact daily life, affecting activities, work, and social interactions. Support groups and counseling can be helpful.
Genetic Counseling: For individuals with familial KD, genetic counseling is recommended to discuss inheritance patterns and the risk of passing the condition on to future generations.
Comorbidities: Consider associated conditions, such as anxiety or depression, and provide appropriate management.
Emergency Preparedness: Ensure that family members and caregivers are educated about how to respond to an episode. Have a plan in place for managing severe or prolonged attacks.