Injury of the corticoreticular pathway in subarachnoid haemorrhage after rupture of a cerebral artery aneurysm.

OBJECTIVE: Several studies have reported on injury of the corticoreticular pathway in patients with stroke and traumatic brain injury. However, little is known about injury of the corticoreticular pathway in patients with subarachnoid haemorrhage. The aim of the current study was to investigate corticoreticular pathway injury in patients with subarachnoid haemorrhage.

DESIGN: Comparative study.

SUBJECTS: Among 137 patients with subarachnoid haemorrhage, 17 patients with motor weakness who showed intact integrity of the corticospinal tract were recruited.

METHODS: Motricity Index was used for measurement of motor function. The fractional anisotropy value, apparent diffusion coefficient value, fibre volume, and integrity of the corticoreticular pathway were used for the diffusion tensor imaging parameters.

RESULTS: Twelve (70.6%) of 17 patients and 18 (52.9%) of 34 hemispheres showed a discontinuation of the corticoreticular pathway at the midbrain level. The contralateral shoulder, hip, and lower extremity of the discontinued corticoreticular pathway showed lower motor functions, in comparison with those of the contralateral side of the intact corticoreticular pathway (p < 0.05). By contrast, the Motricity Index for distal joint, upper and total Motricity Index were not different irrespective of the state of the corticoreticular pathway (p > 0.05).

CONCLUSION: Corticoreticular pathway injury is common in patients with motor weakness after subarachnoid haemorrhage, and it appears to be related to weakness in the contralateral shoulder, hip and lower extremity.