What term describes the stiffening of the muscles?

The term that describes the stiffening of the muscles is "tonic." In the context of seizure types, tonic activity refers to the sustained contraction of muscles, which can result in a posture of stiffness or rigidity. This can be observed in certain types of seizures, particularly tonic-clonic seizures, where the tonic phase is characterized by this muscle stiffening. Understanding the distinction between tonic and other types of seizure movements is important in the field of electroencephalography and clinical neurology, as it helps in classifying seizure types and determining appropriate treatment options.