Cognitive functioning after subarachnoid haemorrhage of unknown origin.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Subarachnoid hemorrhage (SAH) is a serious neurological condition.
• Identifying the source of bleeding is crucial for treatment and prognosis.
• Unruptured cerebral aneurysms are a common cause of SAH, but in some cases, the source remains unknown (SAH-NUD).

Purpose of the Study:

• To investigate the cognitive functioning of patients with SAH-NUD.
• To compare the cognitive performance of SAH-NUD patients with normal individuals and patients with aneurysmal SAH (SAH-AN).
• To determine if SAH-NUD is associated with specific cognitive deficits.

Main Methods:

• Neuropsychological examination of 20 SAH-NUD patients assessing memory, spatial organization, visuoconstruction, reasoning, perceptual speed, and concept formation.
• Comparison of SAH-NUD patient performance with normal reference values.
• Comparison of SAH-NUD patient performance with SAH-AN patients.

Main Results:

• SAH-NUD patients exhibited significant reductions in verbal learning, retention, abstract thinking, and concept formation, suggesting frontotemporal involvement.
• No significant differences in mean cognitive test scores were found between SAH-NUD and SAH-AN patients.
• When patient groups were combined, a higher number of significant cognitive deviations from normality were observed, mainly due to more impaired SAH-AN patients.

Conclusions:

• Subarachnoid hemorrhage of unknown etiology (SAH-NUD) can lead to significant cognitive impairments, particularly in executive functions and memory.
• The cognitive sequelae of SAH-NUD are comparable to those of aneurysmal SAH (SAH-AN).
• The presence of blood in the subarachnoid space, regardless of the source, may negatively impact higher brain functions.