Psychomotor Side Effects of Carbamazepine in an Elderly Patient With Bipolar Disorder and Cognitive Impairment

Abstract

AbstractIntroductionThe management of elderly bipolar patients can become very complex due to higher prevalence of medical comorbidities and sensitivity to treatment-related adverse effects. One of the antiepileptic drugs used for their treatment, carbamazepine, has had a number of cognitive and psychomotor effects linked to it: deterioration in measures of information processing speed, and attention and faster motor skills after discontinuation, among others. The literature concerning them is quite sparse.MethodologyWe report the case of a 75-year-old woman with bipolar disorder and unspecified cognitive impairment who was brought to the emergency department by her family due to global functional decline dating 3 weeks back.ResultsThe patient had been diagnosed and in treatment with bipolar disorder for 40 years. About 2 months before the current episode, because of the presence of tremor and family reports of marked functional decline (from being independent for daily life activities to being bound to a wheelchair and with worsening cognitive symptoms), the psychiatrist opted for a gradual switch from valproate to carbamazepine. During our interview, her husband pointed to the complete dose of 100 mg of carbamazepine 3 weeks ago as the onset of her current symptoms. The patient demonstrated clear psychomotor inhibition, with an absence of spontaneous movement and sporadic, almost monosyllabic, responses to only the simplest questions. Although aware that she was in a hospital, she could not recall its name and was completely disoriented in regards to time. Barely capable of emoting with her facial muscles, she denied feeling depressed and only acknowledged a stomachache. After spending the night in observation, and the suspension of carbamazepine, the patient experienced an improvement of her cognitive functions: although still not fully oriented in space and time, she could now speak in sentences and answer most of our questions. Even though she still maintained not being depressed, when pressed about any weird sensations she admitted to the feeling of being dead inside. The decision was made to transfer her to the psychogeriatric hospitalization unit.DiscussionThe initial assessment of the patient was complicated due to a variety of factors. Beyond the physical comorbidities, the psychomotor inhibition impeded a thorough examination of her emotional state. Only the suppression of her evening dose of carbamazepine allowed for the diagnosis of Cotard-like major depressive symptoms. Even though the cognitive impairment was apparent before, the state of the patient was markedly improved with just the removal of carbamazepine and was confirmed by her family to be a lot closer to her base state of more than a month ago.ConclusionThe use of anticonvulsant therapy in elderly bipolar patients with cognitive impairment can have important side effects. Further evidence of the prevalence and specific nature and frequency of its side effects is needed.FundingNo Funding