EVALUATION Cognitive deficits
Because of her acute condition and resistance to the evaluation, a modified screening neuropsychological battery is used. During the evaluation Ms. S is guarded and demonstrates paucity of speech; her responses are odd at times or contain word-substitution errors. Hand stiffness, tremor, and imprecision are noted during writing and drawing. Results of testing indicate average-range premorbid intellectual ability, with impairments in memory and information processing speed and a mild weakness in phonemic verbal fluency. Ms. S endorses statements reflecting paranoia and hostility on a self-report measure of emotional and personality functioning, consistent with her behavioral presentation. However, her responses on other subscales, including depression and psychotic symptoms, are within normal limits. Her cognitive deficits would be unusual if she had a psychiatric illness alone and are likely associated with her positive neuroimaging findings that suggest a demyelinating process. Overall, the results of the evaluation support a MS diagnosis.
The authors’ observations
Psychosis is found at a higher rate among MS patients (2% to 3%) than the general population (0.5% to 1%).9 Although rare, psychosis often can cloud the diagnosis of MS. Psychiatric symptoms that can occur in MS include:
- hallucinations and delusions (>50%)
- irritability and agitation (20%)
- grandiosity (15%)
- confusion, blunted affect, flight of ideas, depression, reduced self-care, and pressured speech (10%).11
A review of 10 studies found that depression was the most prevalent symptom in MS, and that schizophrenia occurred in up to 7% of MS patients.12 There are currently 3 theories about the relationship between psychosis and MS:
- MS and psychosis are thought to share the same pathophysiological process.
- Psychotic symptoms arise from regional demyelination simultaneously with MS.
- Psychosis is caused by medical treatment of MS.9
Other causes of psychiatric symptoms in MS include:
- depression associated with brain atrophy and lesions
- depression and anxiety as a result of chronic illness
- depression resulting from inflammatory changes
- corticosteroid treatment causing depression, mania, or psychosis.12
The link between psychosis and MS is still poorly understood and further investigation is needed.
How would you treat Ms. S?
a) haloperidol
b) risperidone
c) corticosteroids
d) selective serotonin reuptake inhibitors
Treating psychiatric symptoms in the context of MS
The literature, mainly case reports, suggests several treatment modalities for psychosis with MS. Clozapine has been shown to be beneficial in several case reports, and risperidone9 and ziprasidone13 also have been effective. Other studies recommended low-dose chlorpromazine.9
For MS patients with cognitive impairment, one study showed that interferon beta-1b (IFN-1b) treatment resulted in significant improvement in concentration, attention, visual learning, and recall after 1 year compared with control patients.9 However, there are also case reports of IFN-1b and glucocorticoid-induced psychosis in patients, which resolved after discontinuing treatment.9
Psychotic symptoms have been shown to resolve after corticosteroid treatment of MS.14 In another case report, mania and delusions subsided 3 days after IV methylprednisolone, whereas risperidone had no effect on psychotic features. However, it was unclear whether risperidone was discontinued when methylprednisolone was administered, therefore the specific effect of methylprednisolone is difficult to discern.15 Finally, in a case of a patient who has chronic MS for 16 years and presented with acute onset paranoid psychosis, symptoms resolved with aripiprazole, 10 to 20 mg/d.16 Because of the limited utility of case reports, there is a need for further research in medical management of psychiatric symptoms in MS.