Final answer:
The electroencephalographic pattern that most often characterizes infantile spasms is hypsarrhythmia, which is an abnormal pattern of brain wave activity characterized by chaotic, high-amplitude spikes and slow waves.
Step-by-step explanation:
The electroencephalographic (EEG) pattern that most often characterizes infantile spasms is option B) Hypsarrhythmia. Hypsarrhythmia is an abnormal and chaotic EEG pattern often seen in infants with West Syndrome, a rare epileptic encephalopathy. Infantile spasms are a type of seizure disorder typically observed in the first year of life. Hypsarrhythmia is characterized by a disorganized and high-amplitude EEG with multifocal spikes and sharp waves. This chaotic pattern reflects abnormal brain activity and is considered a hallmark feature of West Syndrome. Recognizing hypsarrhythmia on EEG is crucial for diagnosing and managing infantile spasms effectively, as it helps guide appropriate treatment strategies for this challenging neurological condition.