Eeg And Sleep Physiology Ppt [better] Direct

Seizures often have a strong circadian preference. Some forms of epilepsy, such as Sleep-Related Hypermotor Epilepsy (SHE) or Benign Rolandic Epilepsy, present almost exclusively during NREM sleep. Interictal epileptiform discharges (spikes and sharp waves) are easier to detect on a sleep EEG because the desynchronizing effect of wakefulness is absent. Parasomnias

(large, singular spikes). These markers are vital for memory consolidation and protecting sleep from external noise. NREM Stage 3 (N3): Slow Wave Sleep (SWS) or Deep Sleep. The EEG is dominated by high-amplitude Delta waves

The EEG shows a decrease in frequency and amplitude, characterized by . Alpha waves disappear. Stage 2 (N2) - Deeper Sleep: Characterized by specific, unique phenomena on the EEG:

An electroencephalogram (EEG) measures and records the electrical activity of populations of neurons in the brain. It utilizes electrodes placed on the scalp to detect postsynaptic potentials. In sleep medicine, the EEG is the most critical component of a Polysomnography (PSG) study—the gold standard diagnostic test for sleep disorders. The Role of EEG in Sleep Analysis

Alpha waves are most prominent in the occipital region when the eyes are closed and relaxed. They are immediately blocked (or "desynchronized") by eye-opening or mental concentration—a phenomenon known as the Alpha Block . eeg and sleep physiology ppt

: Specific frequencies act as biological markers for distinct states of consciousness.

: Sleep Spindles (11–16 Hz bursts) and K-complexes .

13–30 Hz low-amplitude, high-frequency waves during active mental concentration or when eyes are open. Stage N1 (Light NREM Sleep)

Short list explaining sleep fragmentation, micro-arousals, and sleep apnea impacts. Seizures often have a strong circadian preference

REM (Rapid Eye Movement) Sleep Content:

The longer you stay awake, the more adenosine builds up, increasing the "need" for sleep.

shows low-frequency, high-amplitude waves (spindles/delta).

REM sleep accounts for 20% to 25% of sleep time, occurring predominantly in the latter half of the night. This is the stage most closely associated with vivid, narrative dreaming. Parasomnias (large, singular spikes)

Orexin (hypocretin) neurons in the lateral hypothalamus stabilize this switch. A deficiency in orexin destabilizes the boundaries between wake and sleep, causing the sleep disorder known as Narcolepsy.

Stage R is the most fascinating stage for neurophysiologists.

Marked by an increase in high-frequency power (gamma and beta activity) during NREM sleep, showing cortical hyperarousal.