Which of the following EEG patterns is characteristic of West syndrome?

Hypsarrythmia is the characteristic EEG pattern associated with West syndrome. This pattern is defined by irregularly distributed high-voltage slow waves and multifocal spikes, typically observed during the sleeping and waking states of affected infants. It reflects a disorganized electrical activity in the brain that is a hallmark feature of this condition, which is also known as infantile spasms.

In West syndrome, which often presents within the first year of life, the presence of hypsarrythmia can be crucial for diagnosis and elucidates the underlying neurological disturbances. Recognizing this pattern on an EEG is vital as it helps clinicians differentiate West syndrome from other epileptic conditions, guiding appropriate management and treatment strategies.

Understanding why this pattern is defined as hypsarrythmia rather than the other options is essential, as generalized spike and waves, status epilepticus, and hypersynchrony can relate to various other types of seizure disorders and do not reflect the unique disorganization seen in West syndrome.