Cervical Dystonia

1. Cervical Dystonia Meagan Smith

2. movement disorder characterized by motor manifestations, primarily involuntary muscle contractions causing twisting movements and abnormal postures • Persistent co-contraction of agonists and antagonists • Pain is the primary cause of disability in patients with CD and occurs in 2/3 to ¾ of patients • Stress or self-consciousness and walking/fatigue/carrying objects increased symptoms in >70% patients • Also referred to as spasmodic torticollis • non-motor component including abnormalities in sensory and perceptual functions, as well as neuropsychiatric, cognitive and sleep domains • widespread abnormalities detected in non-motor brain regions in functional imaging studies of patients with dystonia

3. Onset of symptoms occurresmainly between 40-60 yo • Female > male • Primary CD – idiopathic cause with no history of a secondary cause for their symptoms • Often gradual onset of symptoms • Secondary CD may have abnormal birth or developmental history, exposure to drugs known to cause dystonia (tardivedystonia), neurological illness,or recent trauma • Often more acute onset, marked limitation of ROM, absence of sensory tricks and lack of improvement after sleep • Recommended if patient is < 40 yo to test for Wilson disease as this often has dystonia associated with it • Tardivedystonia can be induced by long-term neuroleptic medication, antiemetic agents or even some antivertiginous agents

6. Non-motor features Sensory abnormalities Neuropsychiatric abnormalities Temporal discrimination Spatial discrimination Vibration Risk for Anxiety Risk for Depression

7. Neuropsychiatric abnormalities • With regard to depressive disorders, these appear to be frequent in cervical dystonia • The severity of depression in patients with dystonia is usually not correlated with the severity of dystonia, suggesting a primary rather than a secondary abnormality. • some proportion of depression in patients with dystonia may be secondary to motor symptoms and pain as improvement in mood does occur with successful treatment of dystonia • In contrast to depression, anxiety disorders do not seem to represent a primary non-motor feature of dystonia

8. mild sensory symptoms such as discomfort in the neck months before cervical dystonia develops • Overt sensory signs in a patient with dystonia would indicate diagnoses other than primary dystonia; for example, some heredodegenerative forms of dystonia that cause sensory neuropathy, an incidental second disorder causing the sensory disturbance or secondary mechanical complications from abnormal postures, e.g. nerve root entrapment and carpal tunnel syndrome • Pain–pressure thresholds have been found to be two times lower in patients with dystonia

9. Gesteantagoniste • The 'sensory trick' indicates an involvement of sensory afferent input in dystonia and can be observed in up to 70% of patients with cervical dystonia and in lower percentages in other forms of focal dystonia • the sensory trick modifies EMG recruitment, sometimes even before the hand makes contact with the face • Holding the chin or touching the face

11. Cognition • attention deficit in patients with cervical dystonia that improves after botulinum toxin treatment, suggesting that this might be a secondary phenomenon related to the distracting effects of dystonic spasms • evidence of little or no alteration of cognitive functions in primary dystonia, and evidence to suggest that the attention deficit and subtle cognitive alterations in some studies may well be related to the distracting effects of abnormal movements and pain.

12. Sleep • sleep impairment may be a feature of primary dystonia that is independent of the severity of the motor features of the disorder. It is, however, correlated with depression and therefore it is not clear at present if there is a primary sleep abnormality in dystonia

13. Quality of Life • Patients with cervical dystonia seem to be more severely impaired by pain and depression • The impact of non-motor symptoms on quality of life indicates the importance of taking non-motor symptoms into account for clinical assessment and treatment when developing and evaluating new treatments for primary dystonia.

14. Treatment • reports of induction or worsening of dystonia with selective serotonin re-uptake inhibitors and dopamine receptor antagonist • Medications in low doses such as benzodiazepines, baclofen, or anticholinergic agents are useful in the early stages of CD • Intrathecalbaclofen at a high cervical level has also been used to treat hypertonicity • Botulinum toxin treatment provides moderate to marked effect on the quality of life • (BoNT/A) = treatment of choice • Provides graded, reversible denervation of the NMJ by preventing release of Ach from presynaptic axons of the motor end plate • Average duration of benefit is 12-16 wks • bilateral pallidal deep brain stimulation and selective peripheral denervation is used when a patient has not responded to pharmacological or other interventions • Clinical sx should be stable for at least 1 year before surgery is considered • DBS to the basal ganglia, thalamus, Gpi and subthalamic nucleus has been noted

15. Botox injections based on presentation Torticollis – C/L SCM and ipsilateral trapezium and splenius Laterocollis – Splenius, trapezium and ipsilateral SCM Anterocollis– B/L SCM Retrocollis – Trapezium and B/L paraspinalis

16. Recognition of the importance of non-motor symptoms in the clinical picture of primary dystonia may lead the way towards novel targets to improve the movement disorder. • The recognition of the sensory components of dystonia has led some to investigate if manipulating sensory input could be a way to correct primary or secondary abnormalities in sensory representations and improve motor symptoms

18. Questions?????

19. References • Cervical Dystonia; Camargo et al, ArqNeuropsiquiatr 2008; 66(1)15-21. • Cervical Dystonia: Disease Profile and Clinical Management; Beth E Crowner. Phys Ther. 2007; 87:1511-1526. • The Non-motor Syndrome of Primary Dystonia Clinical and Pathophysiological Implications Maria Stamelou; Mark J. Edwards; Mark Hallett; Kailash P. Bhatia Brain. 2012;135(6):1668-1681. • The Sensory and Motor Representation of Synchronized Oscillations in the GlobusPallidus in Patients with Primary Dystonia; Xuguang Liu et al. Brain (2008), 131, 1562-1573.