Abstract Committee Review

This abstract addresses a topic of clear clinical interest and merit, namely the evaluation and refinement of diagnostic criteria for cervical dystonia. However, major revisions are required before it can be considered suitable for acceptance. The results and conclusions focus almost exclusively on electromyography (EMG), while the syndrome itself is primarily defined by abnormal posture and/or movement. EMG can indeed provide valuable information on muscle activation patterns, but it is not sufficient to distinguish physiologic activity required for stabilization and head control from dystonic contraction, and the abstract does not describe how such differentiation would be achieved.

Furthermore, recent developments in the field—particularly AI-based image analysis methods for the detection and operationalization of abnormal posture and movement—are highly relevant to the stated purpose of revisiting diagnostic criteria. These approaches are absent from the review, leaving the abstract incomplete and overly narrow in scope.

In its current form, the abstract risks overstating the diagnostic utility of EMG while underrepresenting the essential clinical features and modern advances that define the syndrome. Substantial changes are therefore needed to broaden the review, incorporate posture/movement-based criteria, and contextualize EMG appropriately as a complementary rather than primary diagnostic tool.

My responses are listed below:

• The results and conclusions focus almost exclusively on electromyography (EMG), while the syndrome itself is primarily defined by abnormal posture and/or movement. EMG can indeed provide valuable information on muscle activation patterns, but it is not sufficient to distinguish physiologic activity required for stabilization and head control from dystonic contraction, and the abstract does not describe how such differentiation would be achieved.

Agree with postural muscle activation.  I our clinic we do our utmost to position the patient in a position that minimizes such activity.  Added: “For EMG assessment it is important to have the patient in a position that minimizes postural muscle activity.”  With the patient supine the gravity effect can to some extent be mitigated, but supine position can also cause some muscle relaxation. The object of the abstract is to focus on milder forms of CD where head position is nearly normal.

• Furthermore, recent developments in the field—particularly AI-based image analysis methods for the detection and operationalization of abnormal posture and movement—are highly relevant to the stated purpose of revisiting diagnostic criteria. These approaches are absent from the review, leaving the abstract incomplete and overly narrow in scope.

The abstract has been significantly improved by adding AI developments.
I much appreciate the suggestion by the reviewer.

• In its current form, the abstract risks overstating the diagnostic utility of EMG while underrepresenting the essential clinical features and modern advances that define the syndrome. Substantial changes are therefore needed to broaden the review, incorporate posture/movement-based criteria, and contextualize EMG appropriately as a complementary rather than primary diagnostic tool.

While “abnormal” posture is a challenge, the proposed new definition includes reduced range of motion. Again, the abstract is focused on milder forms of CD where head position is nearly normal.
EMG is used for guided chemodenervation but not for diagnosis, which would be more appropriate than using manifestations of muscle over activity such as subjective assessment of posture and movement.
One article stated: Probably a live examination would provide better outcome than video examination”. 

Defazio G, Belvisi D, Comella C, Hallett M, Jinnah HA, Cimino P, Latorre A, Mascia MM, Rocchi L, Gigante AF, Ercoli T, Berardelli A. Validation of a guideline to reduce variability in diagnosing cervical dystonia. J Neurol. 2023 May;270(5):2606-2612. doi: 10.1007/s00415-023-11585-6. Epub 2023 Feb 15. PMID: 36790546; PMCID: PMC10129917.

Many thanks,

Ib Odderson, MD, PhD

This abstract addresses a topic of clear clinical interest and merit, namely the evaluation and refinement of diagnostic criteria for cervical dystonia. However, major revisions are required before it can be considered suitable for acceptance. The results and conclusions focus almost exclusively on electromyography (EMG), while the syndrome itself is primarily defined by abnormal posture and/or movement. EMG can indeed provide valuable information on muscle activation patterns, but it is not sufficient to distinguish physiologic activity required for stabilization and head control from dystonic contraction, and the abstract does not describe how such differentiation would be achieved.

Furthermore, recent developments in the field—particularly AI-based image analysis methods for the detection and operationalization of abnormal posture and movement—are highly relevant to the stated purpose of revisiting diagnostic criteria. These approaches are absent from the review, leaving the abstract incomplete and overly narrow in scope.

In its current form, the abstract risks overstating the diagnostic utility of EMG while underrepresenting the essential clinical features and modern advances that define the syndrome. Substantial changes are therefore needed to broaden the review, incorporate posture/movement-based criteria, and contextualize EMG appropriately as a complementary rather than primary diagnostic tool.