Cognitive function and regional cerebral blood flow in partial seizures

Area of Science:

• Neuroscience
• Neurology
• Cognitive Psychology

Background:

• Partial seizures are associated with cognitive impairments, often attributed to medication side effects or brain damage.
• However, neuropsychological deficits persist even in the absence of these factors, indicating other underlying causes.
• Cerebral blood flow (CBF) and metabolism studies suggest focal physiological deficits in structurally normal brain regions.

Purpose of the Study:

• To investigate the relationship between regional cerebral blood flow (rCBF) and neuropsychological (NP) deficits in patients with partial seizures.
• To determine if physiological deficits correlate with cognitive impairments in structurally normal brain areas.

Main Methods:

• Evaluated 50 patients with partial seizures using single-photon emission computed tomography (SPECT) for rCBF assessment and the Halstead-Reitan Battery for NP testing.
• Visually identified rCBF deficits were compared with the locations of NP deficits.
• Quantified rCBF in hypoperfused areas and analyzed NP variables for discrimination.

Main Results:

• A significant correlation was found between the location of visually identified rCBF deficits and NP deficits.
• Quantified rCBF was significantly lower in visually identified hypoperfused areas compared to normal areas.
• Quantified NP variables effectively discriminated between patients with and without visual rCBF deficits in frontal and temporal regions.

Conclusions:

• Regional cerebral blood flow deficits in structurally normal brain areas are significantly correlated with neuropsychological impairments in patients with partial seizures.
• These findings suggest that physiological alterations in cerebral blood flow contribute to cognitive dysfunction in partial epilepsy.
• SPECT and NP assessments can identify and differentiate patients with these underlying physiological changes.