Multiple Sclerosis Signs and Symptoms - Tremor and Ataxia

Tremor and Ataxia

Tremor is an unintentional, somewhat rhythmic, muscle movement involving to-and-fro movements (oscillations) of one or more parts of the body. It is the most common of all involuntary movements and can affect the hands, arms, head, face, vocal cords, trunk, and legs. Ataxia is an unsteady and clumsy motion of the limbs or torso due to a failure of the gross coordination of muscle movements. People with ataxia experience a failure of muscle control in their arms and legs, resulting in a lack of balance and coordination or a disturbance of gait.

Tremor and ataxia are frequent in MS and present in 25 to 60% of patients. They can be very disabling and embarrassing, and are difficult to manage. The origin of tremor in MS is difficult to identify but it can be due to a mixture of different factors such as damage to the cerebellar connections, weakness, spasticity, etc.

Many medications have been proposed to treat tremor; however their efficacy is very limited. Medications that have been reported to provide some relief are isoniazid, carbamazepine, propranolol and gluthetimide but published evidence of effectiveness is limited. Physical therapy is not indicated as a treatment for tremor or ataxia although the use of orthese devices can help. An example is the use of wrist bandages with weights, which can be useful to increase the inertia of movement and therefore reduce tremor. Daily use objects are also adapted so they are easier to grab and use.

If all these measures fail patients are candidates for thalamus surgery. This kind of surgery can be both a thalamotomy or the implantation of a thalamic stimulator. Complications are frequent (30% in thalamotomy and 10% in deep brain stimulation) and include a worsening of ataxia, dysarthria and hemiparesis. Thalamotomy is a more efficacious surgical treatment for intractable MS tremor though the higher incidence of persistent neurological deficits in patients receiving lesional surgery supports the use of deep brain stimulation as the preferred surgical strategy.