Letters to the Editor
Quetiapine in the Management of Psychosis Secondary to Huntington’s Disease: A Case Report
Dear Editor:
Psychiatric disorders are common in patients with Huntington’s disease (HD) and include mood disorders, anxiety, sexual dysfunction, and psychosis (1–3). Although up to 23% of patients with HD have psychotic symptoms (3), the literature regarding management of psychosis secondary to HD is limited to case reports or series. Agents reported to be effective in the management of HD psychosis include clozapine (4), risperidone (5), and olanzapine (6,7). Recent reports indicate that olanzapine (7) and quetiapine (8) may also improve the motor symptoms of HD.
However, to our knowledge, no reports exist describing the efficacy of quetiapine in managing psychotic symptoms associated with HD. We describe the first report of quetiapine in the management of psychosis caused by HD.
Mr A, aged 43 years, has a history of HD and psychosis and was admitted to hospital for management of a psychotic episode. Prior to admission, the patient’s community treatment team observed that he was not eating, was unable to care for himself, and was experiencing paranoid delusions. He was diagnosed with HD 16 years prior, and his family history was positive for HD. Past treatment of his psychosis included chlorpromazine, haloperidol, lithium, olanzapine, and benzodiazepines. We began treatment with olanzapine, titrating to 20 mg daily.
Olanzapine blood levels were 91 nmol/L at 15 mg daily. Unfortunately, Mr A experienced side effects while taking olanzapine, and his psychosis was poorly controlled. It was decided to discontinue olanzapine, and quetiapine was titrated up to 300 mg daily, while the dosage of olanzapine was tapered over the course of 1 week. We evaluated baseline psychiatric symptomatology, using the Positive and Negative Syndrome Scale (PANSS), on the first day of quetiapine-only therapy and at 8 weeks of quetiapine-only therapy. We evaluated extrapyramidal symptoms (EPS) initially and at 8 weeks, using the Extrapyramidal Symptom Rating Scale (ESRS) (9).
Initially, the total PANSS score was 68, with subsection scores of 19, 12, and 37 on the positive, negative, and general psychopathology subscales, respectively, at a quetiapine dosage of 300 mg daily. At the start of our study period, the ESRS score was 6. At 8 weeks, the total PANSS score was 53, with subsection scores of 12, 12, and 29 on the positive, negative, and general psychopathology scales, at a quetiapine dosage of 500 mg daily. At 8 weeks, the ESRS score was 12. Serum quetiapine levels at the end of our study were 384 nmol/L. Despite the increase in EPS, Mr A felt subjectively better during quetiapine therapy, compared with olanzapine therapy. Quetiapine appears to be effective in treating the positive symptoms of HD psychosis, with little effect on negative symptomatology. The potential worsening of EPS during quetiapine therapy in HD patients warrants caution in its use, and we suggest careful monitoring for EPS to minimize the impact of these side effects while treating psychotic symptoms. Further large-scale studies are required to evaluate the efficacy of quetiapine in the management of psychosis in HD.
References
1. Leroi I, Michalon M. Treatment of the psychiatric manifestations of Huntington’s disease: a review of the literature. Can J Psychiatry 1998;43:933–40.
2. Naarding P, Kremer HPH, Zitman FG. Huntington’s disease: a review of the literature on prevalence and treatment of neuropsychiatric phenomena. Eur Psychiatry 2001;16:439–45.
3. Shiwach R. Psychopathology in Huntington’s disease patients. Acta Psychiatr Scand 1994;90:241–6.
4. Sajatovic M, Verbanac P, Ramirez LF, Meltzer HY. Clozapine treatment of psychiatric symptoms resistant to neuroleptic treatment in patients with Huntington’s chorea. Neurology 1991;41:156.
5. Madhusoodanan S, Brenner R. Use of risperidone in psychosis associated with Huntington’s disease. Am J Ger Psychiatry 1998;6:347–9.
6. Paleacu D, Anca M, Giladi N. Olanzapine in Huntington’s disease. Acta Neurol Scand 2002;105:441–4.
7. Bonelli RM, Mahnert FA, Niederweiser G. Olanzapine for Huntington’s disease: an open label study. Clin Neuropharmacol 2002;25:263–5.
8. Bonelli RM, Niederwieser G. Quetiapine in Huntington’s disease: a first case report. J Neurol 2002;249:1114–5.
9. Chouinard G, Ross-Chouinard A, Annable L, Jones BD. Extrapyramidal rating scale. Can J Neurol Sci 1980;7:233.
Dallas P Seitz, MD, BSc
Richard C Millson, MD, FRCPC
Kingston, Ontario
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