Table 1
Clinical Features of Four Patients with “Closing the Loop” Phenomenon
| Patient no. | Age at Onset | Age at Evaluation | Other Dystonia | Severity of CD | Response to Btx | Sensory Tricks | Imagined Geste | Examiner's Touch | “Closing the Loop” |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 42 | 47 | WC | Marked | Poor | Chin, head | – | – | + |
| 2 | 61 | 68 | – | Moderate | Good | Chin, head | + | – | + |
| 3 | 56 | 59 | – | Moderate | Good | Chin, head | + | – | + |
| 4 | 22 | 27 | – | Mild | Good | Chin, head | – | – | + |
[ii] Clinical features of four patients are presented: other dystonia refers to the presence of dystonia in other body regions. The examiner rated severity of dystonia as mild, moderate, or marked, and response to Btx injection was similarly rated as poor, partial, or good. Sensory tricks of touching the chin or back of the head benefitted all patients, and two patients experienced benefit from imagining themselves touching their chin. No patients benefitted from the examiner touching their chin at the same location, but all benefitted when the patient put the examiner's hand on the same location (“closing the loop”).
Video 1.
Clinical Examination Findings in Patients 1 and 2.
Patient 1 demonstrated a significant rightward turning torticollis, with prominent improvement with sensory tricks of either touching the right cheek or leaning the back of the head against a wall. Improvement occurred about a half-second before each trick was applied. When the examiner applied gentle pressure to the back of the head or to the side of the face, no benefit was seen. When the patient placed the examiner's fingers on the side of her chin, sensory trick benefit occurred. The second patient illustrates a jerky, leftward turning torticollis with mild right tilt. Prominent sensory trick benefit from touching the chin was not replicated by passive touch of the examiner, but “closing the loop” produced benefit.