Skip to main content

Positive Occipital Sharp Transients of Sleep compared to Interictal Epileptiform Discharges

Positive Occipital Sharp Transients of Sleep (POSTS) and interictal epileptiform discharges (IEDs) are both EEG patterns, but they have distinct characteristics, clinical implications, and contexts. 

Positive Occipital Sharp Transients of Sleep (POSTS)

1.      Definition:

§  POSTS are sharp waveforms that occur predominantly during sleep, particularly in non-rapid eye movement (NREM) sleep.

2.     Waveform Characteristics:

§  They typically exhibit a triangular shape and can be monophasic or diphasic. The first phase usually has a higher amplitude than the second phase.

3.     Location:

§  Recorded primarily from the occipital leads (O1 and O2) of the EEG, with a positive field at the occiput. Phase reversals are often observed at these electrodes.

4.    Duration and Frequency:

§  Each transient lasts approximately 80 to 200 milliseconds and can occur in trains, typically lasting about 1 to 2 seconds.

5.     Clinical Significance:

§  Generally considered a normal variant in healthy individuals, especially in children and adolescents. They are not associated with any pathological conditions and are common in the EEGs of healthy adults.

6.    Age-Related Variability:

§  More prevalent in younger populations and tend to decrease with age. Rarely observed in individuals over 70 years old.

Interictal Epileptiform Discharges (IEDs)

7.     Definition:

§  IEDs are abnormal EEG patterns that occur between seizures in individuals with epilepsy. They represent a transient abnormality in the brain's electrical activity.

8.    Waveform Characteristics:

§  IEDs can vary in morphology but are often characterized by sharp waves or spikes. They typically have a more asymmetric shape compared to POSTS and may show a sharper contour.

9.    Location:

§  IEDs can occur in various regions of the brain, depending on the type of epilepsy. They are not limited to the occipital region and can be localized to specific areas associated with seizure activity.

10.                        Duration and Frequency:

§  IEDs are usually brief, lasting less than 100 milliseconds, and can occur sporadically or in bursts. They do not typically occur in trains like POSTS.

11.  Clinical Significance:

§  The presence of IEDs is indicative of an underlying epileptic condition and may correlate with seizure activity. They are considered abnormal findings and can help in diagnosing epilepsy.

12. Age-Related Variability:

§  IEDs can occur in individuals of any age with epilepsy, but their presence and frequency may vary based on the type of epilepsy and the individual's age.

Summary

In summary, while both Positive Occipital Sharp Transients of Sleep and interictal epileptiform discharges are observed in EEG recordings, they differ significantly in their characteristics, clinical implications, and contexts. POSTS are generally benign and associated with normal sleep activity, while IEDs are abnormal findings indicative of epilepsy and potential seizure activity. The identification of POSTS suggests normal sleep function, whereas the presence of IEDs raises concerns about underlying neurological conditions.

 

Comments

Popular posts from this blog

Bipolar Montage

A bipolar montage in EEG refers to a specific configuration of electrode pairings used to record electrical activity from the brain. Here is an overview of a bipolar montage: 1.       Definition : o    In a bipolar montage, each channel is generated by two adjacent electrodes on the scalp. o     The electrical potential difference between these paired electrodes is recorded as the signal for that channel. 2.      Electrode Pairings : o     Electrodes are paired in a bipolar montage to capture the difference in electrical potential between specific scalp locations. o   The pairing of electrodes allows for the recording of localized electrical activity between the two points. 3.      Intersecting Chains : o    In a bipolar montage, intersecting chains of electrode pairs are commonly used to capture activity from different regions of the brain. o     For ex...

Dorsolateral Prefrontal Cortex (DLPFC)

The Dorsolateral Prefrontal Cortex (DLPFC) is a region of the brain located in the frontal lobe, specifically in the lateral and upper parts of the prefrontal cortex. Here is an overview of the DLPFC and its functions: 1.       Anatomy : o    Location : The DLPFC is situated in the frontal lobes of the brain, bilaterally on the sides of the forehead. It is part of the prefrontal cortex, which plays a crucial role in higher cognitive functions and executive control. o    Connections : The DLPFC is extensively connected to other brain regions, including the parietal cortex, temporal cortex, limbic system, and subcortical structures. These connections enable the DLPFC to integrate information from various brain regions and regulate cognitive processes. 2.      Functions : o    Executive Functions : The DLPFC is involved in executive functions such as working memory, cognitive flexibility, planning, decision-making, ...

Cell Death and Synaptic Pruning

Cell death and synaptic pruning are essential processes during brain development that sculpt neural circuits, refine connectivity, and optimize brain function. Here is an overview of cell death and synaptic pruning in the context of brain development: 1.      Cell Death : o     Definition : Cell death, also known as apoptosis, is a natural process of programmed cell elimination that occurs during various stages of brain development to remove excess or unnecessary neurons. o     Purpose : Cell death plays a crucial role in shaping the final structure of the brain by eliminating surplus neurons that do not establish appropriate connections or serve functional roles in neural circuits. o     Timing : Cell death occurs at different developmental stages, with peak periods of apoptosis coinciding with specific phases of neuronal migration, differentiation, and synaptogenesis. 2.      Synaptic Pruning : o ...

How can EEG findings help in diagnosing neurological disorders?

EEG findings play a crucial role in diagnosing various neurological disorders by providing valuable information about the brain's electrical activity. Here are some ways EEG findings can aid in the diagnosis of neurological disorders: 1. Epilepsy Diagnosis : EEG is considered the gold standard for diagnosing epilepsy. It can detect abnormal electrical discharges in the brain that are characteristic of seizures. The presence of interictal epileptiform discharges (IEDs) on EEG can support the diagnosis of epilepsy. Additionally, EEG can help classify seizure types, localize seizure onset zones, guide treatment decisions, and assess response to therapy. 2. Status Epilepticus (SE) Detection : EEG is essential in diagnosing status epilepticus, especially nonconvulsive SE, where clinical signs may be subtle or absent. Continuous EEG monitoring can detect ongoing seizure activity in patients with altered mental status, helping differentiate nonconvulsive SE from other conditions. 3. Encep...

Parent Child Relationship in brain development

Parent-child relationships play a fundamental role in shaping brain development, emotional regulation, social behavior, and cognitive functions. Here is an overview of how parent-child relationships influence brain development: 1.      Early Interactions : o     Variations in the quality of early parent-infant interactions can have profound and lasting effects on brain development, emotional well-being, and social competence. o     Positive interactions characterized by warmth, responsiveness, and emotional attunement promote secure attachment, stress regulation, and neural connectivity in brain regions involved in social cognition and emotional processing. 2.      Maternal Care : o     Maternal care, including maternal licking, grooming, and nursing behaviors, has been shown to modulate neurobiological systems, stress responses, and gene expression patterns in the developing brain. o    ...