Executive Disorders and Stroke

Executive disorders occur at a high frequency in stroke, yet their true frequency remains uncertain due to varying methods of defining and evaluating them. Now, a new study has taken a systematic approach to the process by comparing the diagnostic accuracy of shortened vs. full battery tests for the cognitive and behavioral aspects of executive disorders in stroke.¹

The study was published online in PLOS One.

“This comprehensive neuropsychological assessment of a large patient population provided unique data on the characteristics of executive function disorders. Our results hint at ways to improve the standardized assessment of post-stroke cognitive impairments,” wrote first author Martine Roussel, PhD, of the University Hospital of Amiens (France), and colleagues.

In the study, researchers sought to evaluate behavioral and cognitive factors of executive functioning, while accounting for impairment in function. They used a standardized battery of tests and diagnostic criteria defined and validated by the Groupe de Reflexion pour l’Evaluation des Fonctions Exécutives (GREFEX) study.² Then they interpreted their results using a validated framework taken from 780 normal controls in the GREFEX database. They compared the diagnostic accuracy of the harmonization standards protocol (HSP) (a shorter cognitive inventory) to the full GREFEX cognitive battery. They also compared a shortened diagnostic battery for behavioral disorders to the full GREFEX battery of tests.

 The study included 237 patients: 57 with infarcts, 54 with cerebral hemorrhage, 80 with subarachnoid hemorrhage (SAH), and 46 with cerebral venous thrombosis (CVT). Patients were aged 50-90 and came from 11 neurology and rehabilitation centers participating in the GREFEX study.

Key results in 156 patients who had full cognitive and behavioral data:

• Dysexecutive syndrome: 55.7% (n=88)

♦ Combined behavioral and cognitive syndromes: 45.5% (n=40)

♦ Behavioral disorder alone: 33% (n=29)

♦ Cognitive syndrome alone: 21.6% (n=19)

• Dysexecutive syndrome typified by:

♦ Cognitive domain: Impairments of initiation and generation

♦ Behavioral domain: Hypoactivity with disinterest and anticipation loss, and hyperactivity

• Cognitive impairment more frequent in hemorrhage (P=0.014)

• Behavioral disorders more frequent in infarct and hemorrhage (P=0.004)

• Sensitivity of the shortened inventory for the diagnosis of behavioral disorders not significantly different from the full GREFEX battery (P=0.9)

• Sensitivity of the HSP significantly lower than the full GREFEX cognitive battery for SAH and CVT (P=0.01) but not for cerebral infarct or hemorrhage (P=0.4)

• Behavioral and cognitive factors both linked to poor outcome

The authors suggested that clinical assessment of executive functions in stroke should include a validated battery of behavioral and cognitive tests. The HSP may be used for initial evaluation of executive function in patients with infarct and cerebral hemorrhage, they wrote. But patients may still need a full battery of executive tests when they have a normal initial assessment and at least one of the following: cognitive complaints, poor functional outcome otherwise not explained, or high risk of cognitive impairment and stroke due to CVT or a ruptured aneurysm.

“The finding that a third of stroke patients have a pure behavioral disorder is especially relevant… since it indicates that failure to use a specific inventory would entail the omission of a large proportion of impaired patients,” the authors emhpasized, “Both behavioral and cognitive summary scores are independently associated with a poor functional outcome emphasizing the need to assess both behavioral and cognitive executive functions.”

Take-home Points

• A French study found over half of patients have dysexectuvie syndrome after stroke.

• A shortened version of tests used to diagnose behavioral disorders was not significantly different from the full GREFEX battery.

• A shortened version of tests used to diagnose cognitive disorders (the HSP) had lower sensitivity than the full GREFEX cognitive battery for SAH and CVT, but not for infarct or hemorrhage.

• Behavioral and cognitive factors were both linked to poor outcome.

• The clinical assessment of executive functions in stroke should include a validated battery of behavioral and cognitive tests; the HSP may be used for initial evaluation, but some patients may still need a full battery of tests.

References:

1. Roussel M, et al. The Behavioral and Cognitive Executive Disorders of Stroke: The GREFEX Study. PLoS One. 2016 Jan 29;11(1):e0147602.

2. Godefroy O, et al. Dysexecutive syndrome: diagnostic criteria and validation study. Ann Neurol. 2010; 68: 855-864.