Differentiating psychosis versus fluent aphasia

Following a stroke, a patient may present with varying degrees of neurological impairment, depending on the area of the brain which is damaged. Specifically, damage to the left cortical hemisphere may result in aphasia. The characteristic speech in a patient with an aphasia caused by a stroke can be similar to the speech in some patients with schizophrenia or other psychotic disorders. In a new patient without a reliable history who presents with suspected aphasia, it is important to include psychotic disorders as part of the differential diagnosis. Failure to differentiate psychotic disorders from aphasia could result in either a lack of treatment that would improve the patient's thought process, thought content, or language, or in a delayed treatment for a stroke, respectively. While a number of psychotic disorders exist and must be differentiated from one another in accordance with DSM-IV guidelines, speech abnormalities in patients with schizophrenia are well described in the literature. For this reason, schizophrenia is the psychotic disorder of focus in this paper. This case report illustrates a clinical situation where a patient required both a psychiatric and neurological consultation in order to determine the etiology of his language disorder. The purpose of this paper is to emphasize the need to consider both psychiatric disorders and aphasia in patients with unknown histories who present with language abnormalities, and to help the clinician critically examine the patient's speech so that, in conjunction with other clinical data, the correct diagnosis can be made and appropriate treatment initiated.