What percentage of patients with schizophrenia and stroke develop dementia?

From the Guidelines

Up to 60% of stroke survivors, including those with schizophrenia, may develop post-stroke cognitive impairment, which increases the risk of dementia, although the exact percentage of patients with schizophrenia and stroke who develop dementia is not directly stated in the provided evidence. The risk of developing dementia after stroke is increased, even in those with transient cognitive impairment, as stated in the American Heart Association/American Stroke Association statement 1. Key factors to consider include:

• The severity of the stroke
• The presence of recurrent strokes
• The age of the patient
• The presence of other vascular risk factors The mechanism of dementia in stroke patients involves direct damage to brain tissue, disruption of neural networks, and vascular changes that compromise blood flow 1. In patients with schizophrenia, cognitive decline often begins early in the disease and progresses gradually, with about one-third of patients showing significant cognitive impairment, although the provided evidence does not specifically address the percentage of patients with schizophrenia and stroke who develop dementia 1. It is essential to note that early intervention with appropriate management of vascular risk factors for stroke patients and antipsychotics for schizophrenia may help reduce the progression to dementia. Main points to consider:
• Post-stroke cognitive impairment ranges in severity from mild to severe and occurs in up to 60% of stroke survivors in the first year after stroke 1
• Up to 20% of individuals with mild post-stroke cognitive impairment recover fully, with the highest rate of recovery seen shortly after stroke 1
• The risk of developing future dementia is increased after stroke, even in those with transient cognitive impairment 1

From the Research

Association between Schizophrenia, Stroke, and Dementia

• There is no direct evidence in the provided studies to determine the percentage of patients with schizophrenia and stroke who develop dementia.
• However, studies have shown that patients with schizophrenia have a higher risk of developing cardiovascular disease, including stroke, due to factors such as hypertension, diabetes, and dyslipidemia 2.
• Additionally, research has found that antihypertensive drugs may have a preventive effect on cognitive decline and dementia, particularly in patients with hypertension 3.
• Atherosclerosis has been associated with an increased risk of post-stroke dementia, and post-stroke statin use has been linked to a decreased risk of cognitive impairment 4.
• The relationship between Alzheimer's disease and vascular cognitive impairment is unclear, but there is evidence that stroke risk factors, such as hypertension and diabetes, are independently associated with an increased risk of Alzheimer's disease and vascular cognitive impairment 5.

Risk Factors for Dementia in Schizophrenia Patients

• Metabolic disorders, such as diabetes, hyperlipidemia, and hypertension, are highly prevalent in populations with schizophrenia, exceeding 50% in some studies 2.
• Non-treatment rates for these disorders are high, ranging from 30.2% for diabetes to 88.0% for dyslipidemia 2.
• Nonwhite women may be especially vulnerable to undertreatment of dyslipidemia and diabetes compared to nonwhite men 2.

Limitations of Current Research

• The provided studies do not directly address the question of the percentage of patients with schizophrenia and stroke who develop dementia.
• Further research is needed to confirm the findings of the studies and to investigate the relationship between schizophrenia, stroke, and dementia 4, 3.