In Reply We thank Tai and colleagues for their comments regarding our article.1
They have proposed an alternative interpretation of phenomenology in our patient as clonic perseveration, which has been described as involuntary repetitive movements and can be induced by passively moving a body part or by an external cue.2 Another characteristic feature of this movement disorder is its persistence even after cessation of the external cue. These patients may also have other frontal lobe release signs. The ability to induce the movement is an important point to identify this phenomenology. Fung et al2 reported 4 cases of clonic perseveration following thalamic infarction with (1 case) or without (3 cases) basal ganglia involvement. All patients had distinctive clinical characteristics as they were rhythmic, stereotyped, repetitive, and occurred spontaneously. However, in all cases, movements could be induced by passively moving the patients’ limbs, and they occurred in a setting of aspontaneity such as mutism and grasp reflexes. There was inappropriate repetition of phrases and words in those patients who had preserved speech.
Pandey S, Sarma N. Clonic Perseveration vs Stereotypy Phenomenology—Reply. JAMA Neurol. 2016;73(2):241-242. doi:10.1001/jamaneurol.2015.3926