What is described as rhythmic oscillations of the head with axial involvement of the trunk?

The term that describes rhythmic oscillations of the head with axial involvement of the trunk is titubation. This phenomenon typically presents as a tremor-like movement, primarily involving the head but can also include the upper body and trunk. Titubation often occurs in conditions affecting balance and coordination, such as cerebellar dysfunction.

This rhythmic movement is not just a simple head nod but involves a certain degree of axial rotation or swaying of the trunk, which distinguishes it from other movement disorders. For instance, asthenia refers to a lack of strength or energy rather than specific oscillatory movements. Dysdiadokinesia relates to difficulty performing rapid alternating movements and does not capture the specific rhythmic oscillation described. Dystonia is characterized by abnormal muscle tone and involuntary movements, but again, it does not specifically refer to the rhythmic head and trunk movements that define titubation. Thus, titubation is the most accurate choice for this description.