Page 92 - JSOM Fall 2025

measurements before and within 5 minutes after the lumbar strong evidence base exists for its use in screening and moni-
puncture. Their results showed significant reduction in ONSD, toring patients with TBI. This case is the first instance to our
leading them to conclude that “ONSD decreases immediately knowledge of a patient’s ONSD decreasing in real time during
following a reduction in CSF pressure, thereby confirming that and after administration of 3% hypertonic saline. Our case re-
ONSD reacts to ICP in real time.” 7 port suggests the need for further study to assess the suitability
of ONSD measurement as a modality for assessing treatment
Likewise, Bender et al. conducted a prospective, observational efficacy of 3% hypertonic saline boluses in the context of TBI,
study over a 15-month period of 35 patients experiencing both blunt and penetrating, and adds further support for the
acute, non-traumatic, intracranial hemorrhage. Of note, as use of serial ONSD measurements during prolonged field care
12
was the case with our patient, 11 of their patients had one to optimize patient management.
ONSD at least 5% greater than the others, as compared with
no such difference in any of the healthy volunteers in the con- Author Contributions
trol group. In addition, their findings “demonstrate[d] that in MA and TS obtained and labeled the ultrasound images. MA
some ICH patients[,] ONSD values change significantly during was a major contributor to the conception, design, research,
the acute stage, and whether they rise or fall, . . . those pa- analysis, writing, and editing of this case report. CM contrib-
tients are more likely to have worse functional outcomes when uted to the research, writing, and editing of this case report.
compared to ICH patients with stable acute-phase ONSD CA contributed to the editing of this case report. DB was a
values.” They also showed a significant decrease in ONSD major contributor to the concept and the editing of this case
12
in two patients following external ventricular drain (EVD) report. All authors read and approved the final manuscript.
placement, positing that, “[t]his could be one more proof that
ONSD reacts to ICP changes in real-time.” 12 Disclaimer
The views expressed in this case report are those of the authors
The literature does contain findings that depart from these and do not reflect the official policy or position of the Depart-
conclusions, 19,22,23 though aspects of the design and execution ment of the Army, Department of Defense, or U.S. Government.
of the studies limit their utility, and the results are not general-
izable to the case at hand. One study’s population was pediat- Disclosures
ric. In another the description of the patients was unclear, but The authors have nothing to disclose.
22
they may have experienced “episodes of prolonged intracra-
nial hypertension” that were hypothesized to have “impaired” Funding
the “elastic properties of the ONS.” And the remaining study No funding was received for this work.
23
used a porcine model of elevated ICP that did not respond to
3% hypertonic saline the way human brains experiencing ele- References
vated ICP do. None of the studies entailed ONSD measure- 1. Military Health System. DOD numbers for traumatic brain injury
19
ment in the immediate aftermath of penetrating head trauma. worldwide. Health.mil. Accessed May 27, 2025. https://www.
health.mil/Reference-Center/Reports/2025/08/21/2024-DOD-
In our case, consistent with the findings of Thotakura et al., Worldwide-Numbers-for-TBI
Duyan and Vural, Chen et al., and Bender et al., the down- 2. DuBose JJ, Barmparas G, Inaba K, et al. Isolated severe traumatic
brain injuries sustained during combat operations: demographics,
ward trend of the patient’s ONSD measurements over a pe- mortality outcomes, and lessons to be learned from contrasts to
riod of less than 20 minutes suggests that the patient initially civilian counterparts. J Trauma. 2011;70(1):11–18. doi:10.1097/
experienced elevated ICP secondary to the penetrating head TA.0b013e318207c563
trauma, and that the patient responded positively and immedi- 3. Van Wyck D, Loos P, Friedline N, et al. “Clinical Practice Guide-
ately to the bolus of 3% hypertonic saline with declining ICP. lines for Traumatic Brain Injury Management in Prolonged Field
This demonstration suggests that ONSD measurement has the Care.” Joint Trauma System. Published December 06, 2017.
Accessed May 27, 2025. https://jts.health.mil/assets/docs/cpgs/
potential to serve both as a screening and monitoring function Traumatic_Brain_Injury_PFC_06_Dec_2017_ID63.pdf
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of treatment efficacy. Larger, prospective studies to test the ac- Rubiano AM; noninvasive ICP monitoring international con-
curacy and reliability of ONSD measurement as an assessment sensus group. Using optic nerve sheath diameter for intracranial
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review. Neurocrit Care. 2024;40(3):1193–1212. doi:10.1007/
s12028-023-01884-1
Our case report has limitations. We performed the ONSD 5. Sekhon MS, Griesdale DE, Robba C, et al. Optic nerve sheath
measurements in the midst of a critical resuscitation, and the diameter on computed tomography is correlated with simultane-
constraints of the situation allowed for imaging in one plane ously measured intracranial pressure in patients with severe trau-
only. The speed necessitated by the environment did not allow matic brain injury. Intensive Care Med. 2014;40(9):1267–1274.
for correction of minor errors in the measurement, and the pa- doi:10.1007/s00134-014-3392-7
tient’s lack of ability to cooperate with the study led to some of 6. Soldatos T, Karakitsos D, Chatzimichail K, Papathanasiou M,
the images being slightly off axis. Moreover, no confirmation Gouliamos A, Karabinis A. Optic nerve sonography in the diag-
nostic evaluation of adult brain injury. Crit Care. 2008;12(3):R67.
of elevated ICP via lumbar puncture or CT scan, much less doi:10.1186/cc6897
via EVD or other intracranial catheter, was performed prior 7. Chen LM, Wang LJ, Hu Y, Jiang XH, Wang YZ, Xing YQ. Ultra s-
to transfer. onic measurement of optic nerve sheath diameter: a non- invasive
surrogate approach for dynamic, real-time evaluation of intra-
cranial pressure. Br J Ophthalmol. 2019;103(4):437–441. doi:10.
Conclusion 1136/bjophthalmol-2018-312934
8. Duyan M, Vural N. The association between hyponatremia and
Measurement of ONSD is already included within the clini- optic nerve sheath diameter: a prospective study. Cureus. 2023;15
cal guidelines for managing TBI in prolonged field care, and a (1):e34084. doi:10.7759/cureus.34084

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