Intraoperative monitoring of motor evoked potentials: a review of 116 cases.

We reviewed the results of motor evoked potential (MEP) and somatosensory evoked potential (SEP) monitoring during 116 operations on the spine or spinal cord. We monitored MEPs by electrically stimulating the spinal cord and recording compound muscle action potentials from lower extremity muscles and monitored SEPs by stimulating posterior tibial or peroneal nerves and recording both cortical and subcortical evoked potentials. We maintained anesthesia with an N2O/O2/opioid technique supplemented with a halogenated inhalational agent and maintained partial neuromuscular blockade using a vecuronium infusion. Both MEPs and SEPs could be recorded in 99 cases (85%). Neither MEPs nor SEPs were recorded in eight patients, all of whom had preexisting severe myelopathies. Only SEPs could be recorded in two patients, and only MEPs were obtained in seven cases. Deterioration of evoked potentials occurred during nine operations (8%). In eight cases, both SEPs and MEPs deteriorated; in one case, only MEPs deteriorated. In four cases, the changes in the monitored signals led to major alterations in the surgery. We believe that optimal monitoring during spinal surgery requires recording both SEPs and MEPs. This provides independent verification of spinal cord integrity using two parallel but independent systems, and also allows detection of the occasional insults that selectively affect either motor or sensory systems.

Complications of intravenous immune globulin treatment in neurologic disease.

Intravenous immune globulin (IVIg) is advocated as a safe treatment for immune-mediated neurologic disease. We reviewed the medical records of 88 patients who were given IVIg for a neurologic illness. Major complications in four patients (4.5%) included congestive heart failure in a patient with polymyositis, hypotension after a recent myocardial infarction, deep venous thrombosis in a bed-bound patient, and acute renal failure with diabetic nephropathy. Other adverse effects included vasomotor symptoms 26, headache 23, rash 5, leukopenia 4, fever 3, neutropenia 1, proteinuria (1.9 g/day) 1, viral syndrome 1, dyspnea 1, and pruritus 1. Fifty-two patients (59%) had some adverse effect of IVIg infusion, most commonly vasomotor symptoms, headaches, fever, or shortness of breath in 40 (45%), which improved with reduced infusion rate or symptomatic medications. Five (6%) had asymptomatic laboratory abnormalities and seven (8%) had other minor adverse effects. Adverse effects led to discontinuation of therapy in 16% and permanent termination of therapy in 10% of patients. There was no mortality or long-term morbidity. Although adverse effects were frequent, serious complications were rare except in patients with heart disease, renal insufficiency, and bed-bound state.

Localization of a gene for partial epilepsy to chromosome 10q.

There is strong evidence for a genetic contribution to epilepsy, but it is commonly assumed that this genetic contribution is limited to 'generalized' epilepsies, and that most forms of 'partial' epilepsy are nongenetic. In a linkage analysis of a single family containing 11 affected individuals, we obtained strong evidence for localization of a gene for partial epilepsy. This susceptibility gene maps to chromosome 10q, with a maximum two-point lod score for D10S192 of 3.99 at theta = 0.0. All affected individuals share a single haplotype for seven tightly linked contiguous markers; the maximum lod score for this haplotype is 4.83 at theta = 0.0. Key recombinants place the susceptibility locus within a 10 centimorgan interval.