A 42-year-old female executive is referred to the sleep clinic with jaw pain. She complains that after she arrives home at night around 10 pm she frequently drinks 3-4 gin and tonics to help quiet her mind.’ She wakes up the next morning around 3am to read the international stock market news, at which point she states her teeth ache an unbearable amount. A study is performed on the patient and it is noted that she grinds her teeth and mutters during roughly half of her sleep. Which of the following would you expect to see on her EEG and at which stage of sleep would you expect her jaw pain to be caused?

## **Core Concept**
The patient's symptoms suggest a condition known as **bruxism**, which is characterized by grinding or clenching of the teeth during sleep. This condition is often associated with **sleep stage** changes, particularly during the **sleep cycle** that includes both non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Bruxism episodes are more commonly linked to **arousals** during sleep, which can occur in both NREM and REM sleep.

## **Why the Correct Answer is Right**
The correct answer, **D. Low voltage EEG, Stage N2 sleep**, can be inferred from the information provided. The patient's behavior of grinding her teeth and muttering during roughly half of her sleep, along with the specific complaint of jaw pain upon waking, points towards bruxism. Bruxism is most commonly associated with **Stage N2 sleep**, a stage of NREM sleep characterized by **low-voltage EEG** readings, **K-complexes**, and **sleep spindles**. This stage is crucial for **sleep maintenance** and **memory consolidation**. The low-voltage EEG pattern in Stage N2 sleep differentiates it from Stage N1 (higher voltage, more alpha waves) and Stages N3 (very slow delta waves).

## **Why Each Wrong Option is Incorrect**
- **Option A:** High voltage EEG, Stage N3 sleep. **Stage N3 sleep** is characterized by **slow delta waves** on EEG, which is not typical for bruxism episodes. Bruxism events are less commonly associated with this deeper stage of NREM sleep.
- **Option B:** High voltage EEG with alpha waves, Stage N1 sleep. **Stage N1 sleep** features **high-amplitude alpha waves** and is a transitional stage. While arousals can occur here, bruxism events are less typical compared to Stage N2.
- **Option C:** Rapid eye movements, REM sleep. While **REM sleep** is crucial for dreaming and features rapid eye movements, bruxism events are not as exclusively tied to this stage as they are to Stage N2 sleep.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **bruxism** often presents with **jaw pain**, **headaches**, and **tooth wear**. It is associated with **stress**, **anxiety**, and **sleep disorders**. Management includes stress reduction techniques, bite guards, and sometimes medications like **botulinum toxin** injections into the masseter muscles.

## **Correct Answer:** D. Low voltage EEG, Stage N2 sleep.

✓ Correct Answer: D. Sleep spindles, N2