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Visual Dysfunction Although optic neuritis, the most common visual symptom, usually is transient and associated with good recovery, some patients have persisting and occasionally progressive deficits and may benefit from referral to a low vision clinic. Involuntary eye movement disorders, such as nystagmus and oscillopsia, also cause distressing visual disturbance. These symptoms may be helped by the use of prisms, and there is anecdotal evidence to suggest the use of a number of medications including baclofen, gabapentin, and isoniazid. A small study has evaluated the role of the glutamate agonist memantine in pendular nystagmus, and all 11 patients treated with this agent showed a positive response.
Vertigo Dizziness or vertigo may occur as part of a brain stem relapse and may be accompanied by nystagmus and ataxia, resulting in a profound reduction in mobility and safety. Prochlorperazine may be helpful in acute vertigo, while physiotherapy, including Cawthorne-Cooksey exercises, together with cinnarazine, may be helpful when symptoms are chronic.
Swallowing, Speech, and Respiratory Dysfunction Dysphagia is not uncommon in MS, and suggestive symptoms have been reported in up to 43 percent of the MS population. These symptoms included coughing when eating, choking, anxiety about swallowing, and change in swallowing function. Such symptoms are often overlooked until the patient has a severe choking episode. Mild dysphagia usually is easily managed with assessment and advice from a speech therapist. There is a risk of aspiration pneumonia in more severe cases, and investigation may include videofluoroscopy. Percutaneous gastrostomy may be required if swallowing is unsafe or intake is inadequate. Speech disturbance in MS usually is due to dysarthria, although dysphasia does occasionally occur, usually in patients with severe cognitive deficits. Again, assessment and management by a speech therapist is helpful, and a communication aid may be useful in very severe dysarthria. Respiratory insufficiency may occur in advanced MS but also may complicate acute brain stem episodes. Respiratory muscle weakness, including diaphragmatic weakness, is the most common cause. Respiratory support may be required in an acute event, while in more chronic situations the patient may be taught to incorporate the diaphragm when talking.
Temperature Sensitivity Many patients report a worsening of symptoms associated with an increase in temperature or exercise, particularly in relation to visual function (Uthoff’s phenomenon). Practical advice about air-conditioning systems may be helpful, and the use of a cooling suit might be considered if the symptoms are very severe. The drug 4-aminopyridine has been reported to be particularly beneficial in patients with temperature sensitivity.
Psychiatric and Psychological Dysfunction Psychiatric morbidity is increased in MS, with over 50 percent of patients being symptomatic at some stage. Irritability, poor concentration, depressed mood, and anxiety are the most common symptoms. The depressive symptoms often are not severe, and only a minority of patients require medication. The treatment of depression is similar to that for people who do not have MS, and there are few randomized controlled trials of antidepressants in MS. A study of desipramine showed moderate efficacy, but the dose was limited by anticholinergic side effects. Psychological disturbances are not uncommon in MS, and many patients have difficulty coping from the time of initial diagnosis, which may be compounded by the subsequent development of disability. Different methods for treating psychological difficulties have been described, but few have been evaluated. The role of psychotherapy in MS has been described, and the role of group psychotherapy has been evaluated in a small group of patients with MS. Some benefit was seen in relation to “locus of control,” but no effect was seen in anxiety or self-esteem.
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