Inobvious Stroke: A Cause of Delirium and Dementia

Abstract

Six hundred and sixty-one patients with stroke, confirmed by CT scan or at autopsy, were reviewed in order to evaluate the frequency of presentation with altered mental state. Nineteen patients (3%) had presented with delirium, an organic delusional state, the acute onset of dementia, or mania, mimicking psychiatric illness. All had focal cerebrovascular lesions which were usually, but not invariably, right sided. None had a previous history of cognitive impairment, psychiatric disease, drug abuse, or alcohol excess. Neurological signs were absent or mild and transient, and therefore easily missed. Post-mortem examinations in four patients showed localised cerebral infarctions with no evidence of multiple lesions, Alzheimer's disease, or metabolic encephalopathies. The possible causative factors are discussed and the evidence of asymmetrical cerebral representation of emotion, and for a relationship with epilepsy, is reviewed.

Delirium in acute stroke: screening tools, incidence rates and predictors: a systematic review

“…The designs employed in the studies included in this review were prospective studies (n=11), retrospective studies (n=3) case controls (n=3), one cross sectional study, one pilot study of treatment intervention and one study which was described as "observational" (see table 2). A total of 12 studies reported applying established diagnostic criteria when assessing patients for delirium: Six (30%) studies applied DSM IV[2, [23][24][25][26][27], three (15%) studies applied DSM III-R [28][29][30], two studies applied DSM IV-R [31,32], and one (5%) study applied DSM III [33]. Three studies referred to "clinical assessment" but did not detail any diagnostic guidelines [34][35][36], and one study referred to the diagnosis of "disorientation" using a simple 3 point scale [37].…”

“…There was no attempt in any of the studies to assess the suitability of using a generic delirium screening tool in acute stroke. A number of studies considered the challenge of using the above tools in acute stroke, as ten studies reported excluding patients with reduced consciousness [23,27,29,30,32,33,[36][37][38][39] and four studies excluded patients with aphasia [24,26,29,36]. Caeiro et al reported scoring zero in certain items of the DRS if patients had "language difficulties" [23,31,32], however, this term is somewhat vague.…”

“…The most frequently cited risk factors for developing delirium in the acute stage of stroke were: older age[2, 23,26,27,29,30,32]; specific symptoms resultant from the stroke (aphasia, neglect or dysphagia) [23,26,27,31,32,38]; impaired vision [25][26][27]38], either as a result of the stroke or pre-morbid visual disturbance, elevated cortisol levels [28,29,37] and drugs with anticholinergic effect [30,31]. Eight studies (n=209 with delirium) reported the association between lesion location and development of delirium: three studies found an association between right sided lesions [33,36,44] and two for left sided lesions [30,34]. One study associated lesions of the posterior cerebral artery (PCA) with the development of delirium [35] while another reported a longer duration of delirium in patients with right hemisphere lesions, but the finding were not statistically significant [24].…”

“…Three of the studies included in this review predate the development of validated delirium diagnostic or screening tools [33,36,44], one of which was a retrospective case note review and shall be discussed separately below [33]:…”

“…Four of the studies included in this review conducted retrospective reviews of patient case notes to establish the incidence of delirium after stroke [33][34][35]44], while these methods are valid, the rigour of diagnostic procedures is impossible to critique as the reporting of these is lacking, perhaps understandably as the researchers did not conduct the delirium assessments.…”