4.5. Study Strengths and Limitations
aneurysmal SAH, vasospasm, DCI
VASODILATATION, DCI, VASOSPASM, PATHOPHYSIOLOGY
Beyond its noble ambition to serve as proof-of-concept research, our study has several major limitations. First, patients were included from only one institution. Second, the evaluation of DCI included only a radiological criterion, which was based on the imaging definition and not on clinical examination. Third, TNS parameters were chosen empirically based on previous works, and we might have underestimated a “dose-effect” relationship between TENS intensity and its clinical effect in this study, which could have impacted the outcomes. Before claiming TENS inefficacy for preventing vasospasm, studies with electrical dosing should be performed with gradual dosing to ensure the activation of the sought mechanism. Future research could also explore the effects of TENS at the ganglia level. Finally, it would be inappropriate to claim that DCI pathophysiology genesis, including vasodilatation via neuromodulation, would solve the dilemma of vasospasm occurrence since the thrombo-inflammatory co-mechanism also plays a major role, independent of the artery caliber.The strengths of this study lie in the fact that a relatively large series of aneurysmal SAH cases were prospectively collected and that TNS was tested against sham in a double-blind setting. An original and important finding is that 57.1% of the patients presenting with moderate or severe vasospasm 6 days after SAH were asymptomatic. For these patients, the delayed clinical consequences should not be underestimated during the initial phase of monitoring.