Direct brainstem somatosensory evoked potentials for cavernous malformations

View More View Less
  • 1 Department of Neurology, Division of Neurophysiology & Intraoperative Neuromonitoring (IONM), Stanford University School of Medicine; and
  • | 2 Department of Neurosurgery, Stanford University School of Medicine, Stanford, California
Restricted access

Purchase Now

USD  $45.00

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $515.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $612.00
Print or Print + Online

OBJECTIVE

Brainstem cavernous malformations (CMs) often require resection due to their aggressive natural history causing hemorrhage and progressive neurological deficits. The authors report a novel intraoperative neuromonitoring technique of direct brainstem somatosensory evoked potentials (SSEPs) for functional mapping intended to help guide surgery and subsequently prevent and minimize postoperative sensory deficits.

METHODS

Between 2013 and 2019 at the Stanford University Hospital, intraoperative direct brainstem stimulation of primary somatosensory pathways was attempted in 11 patients with CMs. Stimulation identified nucleus fasciculus, nucleus cuneatus, medial lemniscus, or safe corridors for incisions. SSEPs were recorded from standard scalp subdermal electrodes. Stimulation intensities required to evoke potentials ranged from 0.3 to 3.0 mA or V.

RESULTS

There were a total of 1 midbrain, 6 pontine, and 4 medullary CMs—all with surrounding hemorrhage. In 7/11 cases, brainstem SSEPs were recorded and reproducible. In cases 1 and 11, peripheral median nerve and posterior tibial nerve stimulations did not produce reliable SSEPs but direct brainstem stimulation did. In 4/11 cases, stimulation around the areas of hemosiderin did not evoke reliable SSEPs. The direct brainstem SSEP technique allowed the surgeon to find safe corridors to incise the brainstem and resect the lesions.

CONCLUSIONS

Direct stimulation of brainstem sensory structures with successful recording of scalp SSEPs is feasible at low stimulation intensities. This innovative technique can help the neurosurgeon clarify distorted anatomy, identify safer incision sites from which to evacuate clots and CMs, and may help reduce postoperative neurological deficits. The technique needs further refinement, but could potentially be useful to map other brainstem lesions.

ABBREVIATIONS

BAEP = brainstem auditory evoked potential; CM = cavernous malformation; CN = cranial nerve; IONM = intraoperative neuromonitoring; LE = lower extremity; SSEP = somatosensory evoked potential; UE = upper extremity.

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $515.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $612.00
  • 1

    Steinberg GK, Chang SD, Gewirtz RJ, López JR. Microsurgical resection of brainstem, thalamic, and basal ganglia angiographically occult vascular malformations. Neurosurgery. 2000;46(2):260271.

    • Search Google Scholar
    • Export Citation
  • 2

    Pandey P, Westbroek EM, Gooderham PA, Steinberg GK. Cavernous malformation of brainstem, thalamus, and basal ganglia: a series of 176 patients. Neurosurgery. 2013;72(4):573589.

    • Search Google Scholar
    • Export Citation
  • 3

    López JR. Mapping the brainstem: floor of the fourth ventricle. In: Nuwer MC, ed. Intraoperative Monitoring of Neural Function: Handbook of Clinical Neurophysiology.Elsevier;2008:350362.

    • Search Google Scholar
    • Export Citation
  • 4

    Duckworth EAM. Modern management of brainstem cavernous malformations. Neurol Clin. 2010;28(4):887898.

  • 5

    Jameson LC, Sloan TB. Neurophysiologic monitoring in neurosurgery. Anesthesiol Clin. 2012;30(2):311331.

  • 6

    Deletis V, Fernández-Conejero I. Intraoperative monitoring and mapping of the functional integrity of the brainstem. J Clin Neurol. 2016;12(3):262273.

    • Search Google Scholar
    • Export Citation
  • 7

    Sinclair J, Kelly ME, Steinberg GK. Surgical management of posterior fossa arteriovenous malformations. Neurosurgery. 2006;58(4)(suppl 2):ONS-189-ONS201.

    • Search Google Scholar
    • Export Citation
  • 8

    Walcott BP, Choudhri O, Lawton MT. Brainstem cavernous malformations: natural history versus surgical management. J Clin Neurosci. 2016;32:164165.

    • Search Google Scholar
    • Export Citation
  • 9

    López JR. The use of evoked potentials in intraoperative neurophysiologic monitoring. Phys Med Rehabil Clin N Am. 2004;15(1):6384.

  • 10

    Karakis I. Brainstem mapping. J Clin Neurophysiol. 2013;30(6):597603.

  • 11

    Chang SD, López JR, Steinberg GK. Intraoperative electrical stimulation for identification of cranial nerve nuclei. Muscle Nerve. 1999;22(11):15381543.

    • Search Google Scholar
    • Export Citation
  • 12

    Hashimoto I. Somatosensory evoked potentials from the human brain-stem: origins of short latency potentials. Electroencephalogr Clin Neurophysiol. 1984;57(3):221227.

    • Search Google Scholar
    • Export Citation
  • 13

    Urasaki E, Uematsu S, Lesser RP. Short latency somatosensory evoked potentials recorded around the human upper brain-stem. Electroencephalogr Clin Neurophysiol. 1993;88(2):92104.

    • Search Google Scholar
    • Export Citation
  • 14

    Eisner W, Schmid UD, Reulen HJ, Oeckler R, Olteanu-Nerbe V, Gall C, Kothbauer K. The mapping and continuous monitoring of the intrinsic motor nuclei during brain stem surgery. Neurosurgery. 1995;37(2):255265.

    • Search Google Scholar
    • Export Citation
  • 15

    Sala F, Krzan MJ, Deletis V. Intraoperative neurophysiological monitoring in pediatric neurosurgery: why, when, how? Childs Nerv Syst. 2002;18(6-7):264287.

    • Search Google Scholar
    • Export Citation
  • 16

    Gonzalez AA, Shilian P, Hsieh P. Spinal cord mapping. J Clin Neurophysiol. 2013;30(6):604612.

Metrics

All Time Past Year Past 30 Days
Abstract Views 376 376 376
Full Text Views 36 36 36
PDF Downloads 48 48 48
EPUB Downloads 0 0 0