Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: Jaime López x
  • Refine by Access: all x
Clear All Modify Search
Restricted access

Scheherazade Le, Viet Nguyen, Leslie Lee, S. Charles Cho, Carmen Malvestio, Eric Jones, Robert Dodd, Gary Steinberg, and Jaime López

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.

Restricted access

Alvaro Arjona Sánchez, Carlos Diaz Iglesias, Cesar Díaz López, David Martínez Cecilia, Jaime Alonso Gómez, Jose Gómez Barbadillo, and Sebastian Rufian Peña

✓ A rectothecal fistula secondary to anterior sacral meningocele is an extremely rare disease. To the authors' knowledge, only 2 cases have been reported in the English-language literature. It can cause symptoms by compressing adjacent structures, causing urinary difficulties and constipation. The authors report an unusual case of a patient in whom this condition was diagnosed as an incidental finding. The patient had a sacral myelomeningocele with secondary meningitis to a rectothecal fistula. The authors will briefly review the diagnosis, the various treatments, and the surgical approach to treat this infrequent entity.

Full access

Santiago T. Lubillo, Dácil M. Parrilla, José Blanco, Jesús Morera, Jaime Dominguez, Felipe Belmonte, Patricia López, Ismael Molina, Candelaria Ruiz, Francisco J. Clemente, and Daniel A. Godoy

OBJECTIVE

In severe traumatic brain injury (TBI), the effects of decompressive craniectomy (DC) on brain tissue oxygen pressure (PbtO2) and outcome are unclear. The authors aimed to investigate whether changes in PbtO2 after DC could be used as an independent prognostic factor.

METHODS

The authors conducted a retrospective, observational study at 2 university hospital ICUs. The study included 42 patients who were admitted with isolated moderate or severe TBI and underwent intracranial pressure (ICP) and PbtO2 monitoring before and after DC. The indication for DC was an ICP higher than 25 mm Hg refractory to first-tier medical treatment. Patients who underwent primary DC for mass lesion evacuation were excluded. However, patients were included who had undergone previous surgery as long as it was not a craniectomy. ICP/PbtO2 monitoring probes were located in an apparently normal area of the most damaged hemisphere based on cranial CT scanning findings. PbtO2 values were routinely recorded hourly before and after DC, but for comparisons the authors used the first PbtO2 value on ICU admission and the number of hours with PbtO2 < 15 mm Hg before DC, as well as the mean PbtO2 every 6 hours during 24 hours pre- and post-DC. The end point of the study was the 6-month Glasgow Outcome Scale; a score of 4 or 5 was considered a favorable outcome, whereas a score of 1–3 was considered an unfavorable outcome.

RESULTS

Of the 42 patients included, 26 underwent unilateral DC and 16 bilateral DC. The median Glasgow Coma Scale score at the scene of the accident or at the initial hospital before the patient was transferred to one of the 2 ICUs was 7 (interquartile range [IQR] 4–14). The median time from admission to DC was 49 hours (IQR 7–301 hours). Before DC, the median ICP and PbtO2 at 6 hours were 35 mm Hg (IQR 28–51 mm Hg) and 11.4 mm Hg (IQR 3–26 mm Hg), respectively. In patients with favorable outcome, PbtO2 at ICU admission was higher and the percentage of time that pre-DC PbtO2 was < 15 mm Hg was lower (19 ± 4.5 mm Hg and 18.25% ± 21.9%, respectively; n = 28) than in those with unfavorable outcome (12.8 ± 5.2 mm Hg [p < 0.001] and 59.58% ± 38.8% [p < 0.001], respectively; n = 14). There were no significant differences in outcomes according to the mean PbtO2 values only during the last 12 hours before DC, the hours of refractory intracranial hypertension, the timing of DC from admission, or the presence/absence of previous surgery. In contrast, there were significant differences in PbtO2 values during the 12- to 24-hour period before DC. In most patients, PbtO2 increased during the 24 hours after DC but these changes were more pronounced in patients with favorable outcome than in those with unfavorable outcome (28.6 ± 8.5 mm Hg vs 17.2 ± 5.9 mm Hg, p < 0.0001; respectively). The areas under the curve for the mean PbtO2 values at 12 and 24 hours after DC were 0.878 (95% CI 0.75–1, p < 0.0001) and 0.865 (95% CI 0.73–1, p < 0.0001), respectively.

CONCLUSIONS

The authors’ findings suggest that changes in PbtO2 before and after DC, measured with probes in healthy-appearing areas of the most damaged hemisphere, have independent prognostic value for the 6-month outcome in TBI patients.

Restricted access

Oral Presentations

2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010