47-year-old female with neck problems underwent Blink Reflex tests and EMG of the neck, and was diagnosed with cervical dystonia. Medical treatments available for cervical dystonia include anticholinergic therapy, Baclofen, or deep brain stimulation, but the mainstay of therapy remains botulinum toxin injections, which are considered the superior treatment for symptom control with less side effects in comparison to oral medications.
47 year old female with neck problems since 2004. She underwent tests including a Blink Reflex and EMG of the neck. Her EMG showed co-contraction of agonist and antagonist muscles compatible with a diagnosis of cervical dystonia.
There is no report of symptoms or her physical examination. In most cases, movement disorders are diagnosed based on physical examination findings with the remainder of the neurological examination being normal. Patients with atypical signs or other neurological findings on examination should be considered for structural causes in the brain or spinal cord. Secondary causes of dytonia also occur, but are also accompanied by other neurological signs and symptoms such as swallowing problems, speech problems, cognitive loss and walking problems. These require further investigation with laboratory testing and possible neuroimaging.
Adult onset dystonia tends to occur in the face and neck. Cervical dystonia tends to be the more frequent form and is thought to be sporadic rather than familial. The estimated incidence is 9/100,000. Dystonia may spread to an adjacent body part such as from the neck to face or arm. It does not tend to spread to the entire body in adult onset forms. 10-20% of patients with cervical dystonia will have temporary remission of symptoms, but typically with reoccurrence within 5 years. The typical onset is 40-60 years of age and is more common in females. Symptoms may worsen within the first 3-5 years, but this is highly variable.
A number of treatments are available for cervical dystonia. Medical treatments include anticholinergic therapy (trihexyphenidyl, benztropine). These medications should be started at the lowest dosage possible and slowly increased. Response rates in double-blind trials range from 65-71%. These medications have side effects including dry mouth, constipation, blurry vision and forgetfulness. Baclofen is another agent that has been studied in dystonia. It should again be started at low dosage and slowly increased to a total of 120 mg a day. Experience in cervical dystonia is primarily with clinical use. Reports of baclofen show a response up to 47%. Side effects include sleepiness, dizziness, and nausea. Another option for medical therapy includes tetrabenazine at dosages of 12.5-100mg daily. This is again open label experience with a reported 63% response rate. Side effects include sleepiness, restlessness, depression and slowness of movement.
The mainstay of therapy remains botulinum toxin injections. Trials comparing oral medications to botulinum toxin show botulinum toxin to the superior treatment for symptom control with less side effects. Two toxins botulinum toxin type A and type B are available for use. A comparative trial shows that they have similar effects for control of symptoms. Patients are normally treated initially with small amounts of botulinun toxin type A or B to help prevent side effects. The toxin is injected every three to six months and can be increased slowly over time to improve effectiveness. Only a small percentage of patients are botulinum toxin unresponsive and typically if an initial injection is ineffective, the dosage needs to increased or muscle location changed. Some individuals can develop resistance to botulinum toxin over time with repeated injections.
In these cases, we would convert then to the other type of toxin. Side effects of botulinum toxin include weakness, flu like syndrome, dry mouth and bruising.
In patients that have failed medical therapy and botulinum toxin therapy, surgical therapy can be a last resort. Deep brain stimulation is in clinical trials for effectiveness for focal forms of dystonia.