Table 4

Sensitivity and negative predictive value of intraoperative monitoring

	Type of surgery	No of cases	Sensitivity	Negative predictive value	Comment
BA, basilar artery; BAEP, brain stem auditory evoked potentials; IOM, intraoperative monitoring; MCA, middle cerebral artery; SEP, somatosensory evoked potentials; TEA, thrombendarterectomy.
Bejjani, 1998¹⁵	Skull base	224	58%	90%	Recommend IOM
Dawson, 1991¹⁶	Spinal deformity	33 000	72%	99.9%	Multicentre survey
Fisher, 1995¹⁷	Carotid TEA	3028	76%	99.7%	Meta-analysis
Forbes, 1991¹⁰	Spinal deformity	1168	100%	100%	Temporary changes included, one patient with delayed onset of deficit
Friedman, 1987¹⁸	Intracranial aneurysm	50	63%	90%	IOM not reliable in BA aneurysms
Friedman, 1991¹⁹	MCA aneurysms	53	80%	97%	Recommend IOM
Guerit, 1997²	Carotid TEA	205	92%	99%	One false negative
Haupt, 1992²⁰	Carotid TEA	994	88%	99%	Complete SEP loss considered only
Henderson, 1994¹¹	Spinal surgery	308	100%	100%	IOM may replace wake-up test
Linstedt, 1998¹²	Carotid TEA	146	20%	97%	Patients with preoperative neurological deficits
Little, 1987¹³	BA aneurysms	16	30%	70%	SEP and BAEP
Manninen, 1998²¹	Spinal surgery	309	70%	99%	Radicular lesions included
May, 1996²²	Cervical spine	191	90%	99%	Technical failure considered
Mizoi, 1993²³	Intracranial aneurysms	97	50%	95%	Temporary vessel clipping
Noonan, 2002¹⁴	Spinal deformity	134	100%	100%	Inconsistent findings in temporary changes
Nuwer, 1995 (9)	Spinal deformity	51 263	82%	99.9%	Multicentre survey, sensitivity increases to 92% if cases with intervention included
Schramm, 1990⁶	Intracranial aneurysms	113	81%	98%	IOM less reliable in BA aneurysms
Wiedemayer, 2002⁷	Intracranial and spinal surgery	423	81%	95%	Sensitivity increases to 85% if cases with intervention included