EEG of a teenager with early morning involuntary movements of hands in his sleep noticed by parents. Immunization is complete. What does it indicate?
**Core Concept**
The question describes a clinical scenario involving a teenager with early morning involuntary movements of hands during sleep, which is a classic symptom of a specific neurodevelopmental disorder. This condition is characterized by abnormal electrical activity in the brain, which can be detected on an electroencephalogram (EEG).
**Why the Correct Answer is Right**
The correct answer is related to a condition where the individual has a specific genetic mutation affecting the GABAergic neurotransmission. This results in an abnormal EEG pattern, known as a "hypnagogic hypersynchrony" or "hypnic jerk," which is often associated with this condition. The condition is a result of a mutation in the gene encoding the enzyme responsible for GABA synthesis, leading to an imbalance in the inhibitory neurotransmitter GABA. This imbalance causes the abnormal brain activity and the characteristic early morning involuntary movements.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not directly related to the described clinical scenario. While sleep disorders can cause a range of symptoms, the specific combination of early morning involuntary movements and abnormal EEG findings points to a different diagnosis.
**Option B:** This option is incorrect because it refers to a different condition altogether, which is characterized by seizures and is not typically associated with early morning involuntary movements.
**Option C:** This option is incorrect because it is not the correct diagnosis for the described condition. While it shares some similar symptoms, the underlying pathophysiology and EEG findings are different.
**Clinical Pearl / High-Yield Fact**
This condition is often associated with a specific genetic mutation and can be diagnosed based on a combination of clinical features, EEG findings, and genetic testing. It is essential to consider this diagnosis in teenagers presenting with early morning involuntary movements, especially if they have a family history of similar symptoms.
**Correct Answer:** C.