Clinical Significance of Isolated Third Cranial Nerve Palsy in Traumatic Brain Injury: A Detailed Description of Four Different Mechanisms of Injury through the Analysis of Our Case Series and Review of the Literature

Neuroradiological Correlates of Abnormal Pupillary Light Reflex Findings Among Patients in the Neuroscience Intensive Care Unit

ABSTRACT

BACKGROUND: Changes in pupil reactivity secondary to cerebral mass effect are traditionally linked to compression of the oculomotor nerve by the uncus or by horizontal midbrain displacement. The neurological pupil index (NPi) is a metric to assess the pupillary light reflex. This study explores the relationship of midline shift, cisternal, and sulcal effacement or ventricular compression in patients with a new finding of abnormal pupillary light reflex. METHODS: This retrospective study identified adult patients with serial pupillometer readings between 2018 and 2023 who had a baseline head computed tomography (CT) scan, subsequent new-onset NPi worsening from normal to abnormal, and a repeat CT scan within 2 hours of the NPi changes. Those with NPi worsening were compared with those with no NPi change. RESULTS: Among 77 patients (27 with NPi worsening, 50 without), those with NPi worsening exhibited a higher incidence of midline shift on the repeat CT. Regression models revealed a significant correlation between midline shift change and abnormal NPi ( r = 0.2260, P < .001). However, NPi worsening was not linked to changes in ventricular compression, nor sulcal or cisternal effacement. CONCLUSION: Midline shift, rather than cisternal or sulcal effacement, is associated with abnormal NPi values.

Microvascular Decompression for Oculomotor Nerve Palsy Due to Nonaneurysmal Neurovaslur Conflict: 5 Cases Report and Literature Review

BACKGROUND

Oculomotor nerve palsy (ONP) is frequently caused by aneurysm compression and diabetes mellitus. However, nonaneurysmal compression (nAVC) of the oculomotor nerve is a condition rarely reported in the literature. Cases treated with microvascular decompression (MVD) for nAVC-induced ONP (nAVC-ONP) are exceptionally rare.

METHODS

Between October 2022 and October 2023, we performed MVD surgery on 5 patients diagnosed with nAVC-ONP. The clinical symptoms, imaging characteristics, and intraoperative findings of these patients were reviewed and analyzed using a self-developed evaluation scale (S-T Evaluation Scale) to guide diagnosis and corresponding treatment plans.

RESULTS

All patients underwent MVDs and demonstrated favorable recovery and a good prognosis. No postoperative complications occurred in any of the patients. The superior cerebellar artery and posterior cerebral artery were common offending vessels in these cases.

CONCLUSIONS

Neurovascular conflict has been proposed as another possible cause of ONP in a limited number of cases. Based on our findings, MVD is a potentially effective solution for patients experiencing oculomotor nerve palsy resulting from nonaneurysmal neurovascular conflicts. It holds great promise for significantly alleviating symptoms and improving overall quality of life.

Pupil Unleashed: Unraveling the Enigma of an Unusual Traumatic Head Injury: A Case Report

Introduction

Isolated oculomotor nerve palsy after mild traumatic brain injury is unusual and prognostically significant due to unclear mechanisms and recovery challenges. We present a case of isolated oculomotor nerve palsy following minor head trauma, shedding light on this unusual occurrence.

Case Report

A 24-year-old male experienced severe vision loss and right-sided oculomotor nerve palsy after a motor vehicle collision. Initial imaging showed a hemorrhagic focus in the left posterior fossa and a contusion in the corpus callosum, yet no direct cause for the nerve palsy was found. Partial recovery was observed after 12 months.

Conclusion

This case underscores the importance of maintaining a heightened suspicion for occult intracranial findings, especially when the initial non-contrast computed tomography was inconclusive. Timely clinical assessment and appropriate radiological investigations by emergency physicians are crucial for improving the prognosis.

Outcome of patients with traumatic cranial nerve palsy admitted to a university hospital in Nepal

BACKGROUND

Cranial nerve palsy (CNP) is a common complication of traumatic brain injury (TBI). Despite a high incidence of TBI in Nepal (382 per 100,000), literature on the specific management and outcome of CNP is lacking. This study aimed to examine the outcomes of TBI patients involving single versus multiple CNP.

METHODS

A retrospective chart review of 170 consecutive TBI patients admitted to the tertiary neurosurgical center in Nepal between April 2020 and April 2022 was conducted. Demographic, clinical, and etiological characteristics; imaging findings; and management strategies were recorded, compared, and analyzed using descriptive statistics. The Glasgow Outcome Scale Extended (GOSE) was used to measure the outcomes in two groups of patients (single and multiple CNP) at 3 months.

RESULTS

Out of 250 eligible patients, 80 were excluded and CNP was noted in 29 (17.1%) of the remaining 170. The median age was 34.9 years, and falls (60.6%) were the most common cause of trauma. TBI severity was categorized based on GCS: mild (82.4%), moderate (15.9%), and severe (1.8%). Cranial nerve involvement was seen in 29 (17.05%) patients: single cranial nerve involvement in 26 (89.65%) and multiple nerve involvement in 3 (10.34%). The most common isolated cranial nerve involved was the oculomotor nerve (37.9%). CT findings revealed a maximum of skull fractures with no significant association between CNP and CT findings.

CONCLUSIONS

CNP is a common consequence of TBI with the most common etiology being falls followed by RTA. Single CNP was more common than multiple CNP with no significant difference in the outcome in the 3-month GOSE score. Further research is needed to determine the burden of traumatic CNP and establish specific management guidelines for different types of CNP.

Characteristics of ocular injuries associated with mortality in patients admitted with major trauma

BACKGROUND

Few ocular trauma studies have addressed mortality outcomes. We sought to determine characteristics of mortality-related ocular trauma admissions and compared them with non-fatal injuries.

METHODS

A retrospective study was conducted using de-identified data of patients admitted with major trauma from the National Trauma Data Bank (2008-2014). Patients with ocular injury were identified using ICD- 9CM codes. Demographics, intention and mechanism, types of ocular and head injuries, and injury severity were documented. Mortality was determined using post-admission disposition. Statistical analysis using student t-test, chi-square, and odds ratios (OR) calculations were performed with STATA-17 software. Significance was set at P < 0.05.

RESULTS

Of 316,485 patients admitted with ocular trauma, 12,233 (3.86%) were mortality related. Expired patients were older than survivors: mean (SD) of 50.1(25.5) vs. 41.5(22.8) years. White (OR = 1.32; P < 0.001), ≥ 65years old (OR = 2.25; P < 0.001), and male (OR = 1.05; P = 0.029) patients were most likely to expire than their counterparts. Common mechanisms of injury in survivors were falls (25.3%), motor vehicle traffic-occupant, MVTO (21.8%) and struck by/against (18.1%) and for fatal injuries, falls (29.7%), MVTO (21.9%) and firearms (11.5%). Traumatic brain injury (TBI) was documented in 88.2% of mortality-related admissions. Very severe injury severity scores (ISS > 24) (OR = 19.19; P < 0.001) and severe Glasgow Coma Score (GCS < 8) (OR = 19.22; P < 0.001) were most associated with mortality than survival. Firearms were most associated with very severe ISS (OR = 3.73; P < 0.001), severe GCS (OR = 4.68; P < 0.001) and mortality (OR = 5.21; P < 0.001) than other mechanisms. Patients with cut/pierce injuries had the greatest odds of survival (OR = 13.48; P < 0.001). Optic nerve/visual pathways injuries (3.1%) had the highest association with very severe ISS (OR = 2.51; P < 0.001), severe GCS (OR = 3.64; P < 0.001) and mortality (OR = 2.58; P < 0.001) than other ocular injuries. Black patients with very severe ISS (OR = 32.14; P < 0.001) and severe GCS (OR = 31.89; P < 0.001) were more likely to expire than other race/ethnicities with similar injury severity.

CONCLUSIONS

Mortality-related admissions were older, male, and mostly of White race than ocular trauma admissions of survivors. Firearms were the deadliest mechanism. TBI was commonly associated and patients with optic nerve/pathway injuries, very severe ISS and severe GCS had higher mortality rates. Characteristics and demographic variations identified in this study may be useful in developing focused measures aimed at preventing trauma-related deaths.

Traumatic cavernous sinus syndrome - A peculiar presentation of multiple cranial nerve neuropathies following a minor head injury: Case report and literature review

BACKGROUND

In patients with traumatic head injuries, the percentage of cranial nerve injuries (CNI) range from4.3 to 17.6% in which majority are isolated CNI[1-5].In present literature, moderate to severe types of head injuries are often studied which may result in a lack of representation and description of CNI associated with minor head injuries (MHI). Alongside this peculiar case of a traumatic cavernous sinus syndrome (CSS) that is non-thrombotic and non-fistulous in nature, this paper aims to analyse traumatic CNI in non-severe head injuries and the surrounding literature.

CASE REPORT

A 65-year-old man who had sustained a minor head injury was found to have CNI of III, IV and VI.Brain imaging showed scattered traumatic subarachnoid haemorrhage and a non-displaced right zygomatic arch fracture. Despite the short course of high dose dexamethasone, he showed only partial recovery of his CNI after one year.

CONCLUSION

We present a case of traumatic CSS likely secondary to tractional injury from a MHI. Injury to the extraocular nerves wasfound to be one of the more commonly observed combination of CNI from the literature review conducted. In patients with MHI, multiple CNI is less common. Hence, consideration should be given to work upfor secondary causes such as tumours. There is presently no known clear identifiable pattern of CNI associated with MHI. CT brain findings of skull base fractures and early onset of cranial nerve palsies are generally associated with worse outcomes. More remains to be studied about tractional CNI in non-severe head injuries.

Traumatic oculomotor nerve palsy treated with transnasal endoscopic decompression through the optic strut

Objective

To present a surgical treatment regimen of transnasal endoscopic decompression through the optic strut for traumatic oculomotor nerve palsy based on the anatomical study of the superior orbital fissure and the oculomotor nerve fissure segment.

Methods

The bone structure of the oculomotor nerve fissure segment and the important bone anatomical landmarks of the lateral wall of the sphenoidal sinus were identified on a dried skull and a cadaveric head, respectively, using a nasal endoscope, and a surgical plan was determined. Decompression was conducted on the orbital apex, the superior orbital fissure, the optic canal and the optic strut of the two patients in sequence, after which the degree and range of decompression were identified by three-dimensional (3D) computed tomography (CT).

Results

The oculomotor nerve had a close correlation with the lateral surface of the optic strut. The transnasal endoscope was employed to identify the lateral optic-carotid recess (LOCR), as well as the positions of the optic nerve, internal carotid artery (ICA), and superior orbital fissure, collectively called the "optic strut triangle". The surgical plans for decompression of the orbital apex, superior orbital fissure, optic canal, and optic strut and the necessity of optic strut drilling were determined, and the surgical procedures for safe drilling of the optic strut were elaborated. After surgery, the two patients had significantly improved symptoms, without complications. In addition, their postoperative CT showed that the medial margin of the superior orbital fissure was fully decompressed.

Conclusion

The optic strut triangle is a crucial anatomical landmark in the decompression of the oculomotor nerve, and optic strut drilling is necessary for such decompression. For patients with traumatic oculomotor nerve palsy and fractures of the medial wall of the superior orbital fissure on CT, the oculomotor nerve fissure segment can be decompressed in an effective, complete and safe manner as per the surgical plan of decompressing the orbital apex, superior orbital fissure, optic canal and optic strut in turn under a transnasal endoscope, conducive to the recovery of neurological function of patients.

Traumatic brain injury: Mechanisms, manifestations, and visual sequelae

Traumatic brain injury (TBI) results when external physical forces impact the head with sufficient intensity to cause damage to the brain. TBI can be mild, moderate, or severe and may have long-term consequences including visual difficulties, cognitive deficits, headache, pain, sleep disturbances, and post-traumatic epilepsy. Disruption of the normal functioning of the brain leads to a cascade of effects with molecular and anatomical changes, persistent neuronal hyperexcitation, neuroinflammation, and neuronal loss. Destructive processes that occur at the cellular and molecular level lead to inflammation, oxidative stress, calcium dysregulation, and apoptosis. Vascular damage, ischemia and loss of blood brain barrier integrity contribute to destruction of brain tissue. This review focuses on the cellular damage incited during TBI and the frequently life-altering lasting effects of this destruction on vision, cognition, balance, and sleep. The wide range of visual complaints associated with TBI are addressed and repair processes where there is potential for intervention and neuronal preservation are highlighted.

Oculomotor nerve palsy presumably caused by cisternal drain during microsurgical clipping

Background:

Oculomotor nerve palsy can be caused by diverse etiologies, but no report has yet documented its association with a cisternal drain.

Case Description:

A 35-year-old woman presented with severe headache. The patient did not exhibit oculomotor nerve palsy at presentation. Cranial computed tomography (CT) revealed diffuse subarachnoid hemorrhage. The patient underwent open microsurgical clipping of a ruptured middle cerebral artery aneurysm. During surgery, a cisternal drain was placed in the basal cistern at the medial aspect of the clinoidal portion of the internal carotid artery. The patient presented with the left oculomotor nerve palsy immediately after surgery. CT revealed displacement of the cisternal drain to the lateral aspect of the anterior clinoid process. The patient’s mydriasis and sluggish light reaction recovered after 7 days, while extraocular movements persisted for 50 days. The constructive interference steady-state sequence detected the left oculomotor nerve coursing adjacent to the clinoidal internal carotid artery.

Conclusion:

Oculomotor nerve palsy can be caused by collision with a thin silastic tube placed during surgery for aneurysmal subarachnoid hemorrhage. Withdrawal of the drain as early as possible is recommended when drain-associated oculomotor nerve palsy is suspected.