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Published on: May 9, 2013
Changes in cerebral hemodynamic and cognitive parameters after external carotid-internal carotid bypass surgery in
Yanhong Dong1, Hock Luen Teoh, Bernard P L Chan
1Department of Pharmacology, National University Health System, Singapore.
Insights
External carotid-internal carotid (EC-IC) bypass surgery improved cerebral hemodynamics and cognitive functions like verbal memory and executive function in patients with severe steno-occlusive disease. This pilot study highlights potential benefits for carefully selected individuals.
Area of Science:
- Neurosurgery
- Vascular Neurology
- Cognitive Neuroscience
Background:
- The impact of external carotid-internal carotid (EC-IC) bypass surgery on cognition in patients with severe internal carotid artery (ICA) or middle cerebral artery (MCA) steno-occlusive disease remains unclear.
- This pilot study investigates the effects of EC-IC bypass on cerebral hemodynamics and cognitive function in these patients.
Purpose of the Study:
- To evaluate the changes in cerebral hemodynamic reserve and cognitive performance following EC-IC bypass surgery.
- To assess the efficacy of EC-IC bypass in patients with severe steno-occlusive disease and impaired cerebral vasodilatory reserve.
Main Methods:
- Patients with severe steno-occlusive disease and impaired cerebral vasodilatory reserve (CVR) underwent EC-IC bypass surgery.
- Cerebral hemodynamic reserve was assessed using transcranial Doppler (TCD) breath holding index (BHI) and acetazolamide-challenged HMPAO-Single Photon Emission Tomographic (SPECT) imaging.
- Cognitive performance was evaluated using a formal neuropsychological battery before and 3-6 months after surgery.
Main Results:
- Nine patients and nine matched controls were included.
- Surgery patients demonstrated significant improvements in CVR as measured by TCD-BHI and SPECT (p<0.001).
- EC-IC bypass patients showed significant improvements in verbal memory (p=0.037) and executive function (p=0.043), with a trend toward improved visual memory (p=0.052) compared to controls.
Conclusions:
- EC-IC bypass surgery can enhance cerebral hemodynamics in carefully selected patients.
- The procedure may lead to significant improvements in verbal memory and executive functions.
- This study suggests EC-IC bypass is a viable option for improving cognitive outcomes in specific patient populations.
Background:
The direct impact of external carotid-internal carotid (EC-IC) bypass surgery on cognition of patients with severe steno-occlusive disease of internal carotid (ICA) or middle cerebral artery (MCA) is unknown. In this pilot study, we evaluated changes in cerebral hemodynamic and cognition in these patients.
Methods:
Patients with severe steno-occlusive disease and impaired cerebral vasodilatory reserve (CVR) with transcranial Doppler (TCD) breath holding index (BHI) and acetazolamide-challenged HMPAO-Single Photon Emission Tomographic (SPECT) imaging were offered EC-IC bypass surgery. CVR and cognitive performance using a formal neuropsychological battery were evaluated before and 3-6 months after surgery.
Results:
Nine patients and 9 matched controls were recruited. Significant CVR improvement from TCD-BHI [median 0 (Inter-quartile range IQR 0.45) to 1.10 (IQR 0.73), p<0.001] and SPECT (p<0.001) was observed in surgery patients. EC-IC bypass patients had significant improvement in verbal memory (p=0.037) and executive function (p=0.043) and a trend of improvement in visual memory (p=0.052) compared to controls.
Conclusion:
EC-IC bypass surgery in carefully selected patients could improve cerebral hemodynamics and verbal memory and executive function.
