Ocular changes in traumatic brain injury: A review

Paediatric traumatic brain injury and attention-deficit/hyperactivity disorder medication in Finland: a nationwide register-based cohort study

BACKGROUND

The association between paediatric traumatic brain injury (pTBI) and post-traumatic attention-deficit/hyperactivity disorder (ADHD) medication usage remains understudied subject.

OBJECTIVE

We aimed to evaluate the association between pTBI and subsequent ADHD medication.

METHODS

A nationwide retrospective cohort study in Finland from 1998 to 2018 included 66 594 patients with pTBI and 61 412 references with distal extremity fractures. ADHD medication data were obtained from the Finnish Social Insurance Institution. The primary outcome was post-traumatic pediatric ADHD medication. A 1-year washout period was applied, and follow-up started 1 year post-pTBI.

FINDINGS

Kaplan-Meier analyses showed higher ADHD medication usage in patients with pTBI, especially post-operatively. Both sex groups exhibited elevated rates compared with the reference group. Over 10 years, cumulative incidence rates were 3.89% (pTBI) vs 1.90% (reference). HR for pTBI was 1.89 (95% CI 1.70 to 2.10) after 4 years and 6.31 (95% CI 2.80 to 14.20) for the operative group after the initial follow-up year. After 10 years, cumulative incidence in females increased to 2.14% (pTBI) vs 1.07% (reference), and in males, to 5.02% (pTBI) vs 2.35% (reference). HR for pTBI was 2.01 (95% CI 1.72 to 2.35) in females and 2.23 (95% CI 2.04 to 2.45) in males over 1-20 years.

CONCLUSIONS

A substantial association between pTBI and post-traumatic ADHD medication was evidenced over a 20-year follow-up period.

CLINICAL IMPLICATIONS

These results stress the need for preventive measures for pTBI and highlight the potential impact of long-term post-traumatic monitoring and psychoeducation.

The Variety of Mechanosensitive Ion Channels in Retinal Neurons

Alterations in intraocular and external pressure critically involve the pathogenesis of glaucoma, traumatic retinal injury (TRI), and other retinal disorders, and retinal neurons have been reported to express multiple mechanical-sensitive channels (MSCs) in recent decades. However, the role of MSCs in visual functions and pressure-related retinal conditions has been unclear. This review will focus on the variety and functional significance of the MSCs permeable to K+, Na+, and Ca2+, primarily including the big potassium channel (BK); the two-pore domain potassium channels TRAAK and TREK; Piezo; the epithelial sodium channel (ENaC); and the transient receptor potential channels vanilloid TRPV1, TRPV2, and TRPV4 in retinal photoreceptors, bipolar cells, horizontal cells, amacrine cells, and ganglion cells. Most MSCs do not directly mediate visual signals in vertebrate retinas. On the other hand, some studies have shown that MSCs can open in physiological conditions and regulate the activities of retinal neurons. While these data reasonably predict the crossing of visual and mechanical signals, how retinal light pathways deal with endogenous and exogenous mechanical stimulation is uncertain.

Association between pediatric traumatic brain injury and epilepsy at later ages in Finland: A nationwide register-based cohort study

OBJECTIVE

This study was undertaken to examine how pediatric traumatic brain injury (pTBI) correlates with incidence of epilepsy at later ages in Finland.

METHODS

This nationwide retrospective register-based cohort study extended from 1998 to 2018. The study group consisted of 71 969 pediatric (<18 years old) patients hospitalized with TBI and a control group consisting of 64 856 pediatric patients with distal extremity fracture. Epilepsy diagnoses were gathered from the Finnish Social Insurance Institution. Kaplan-Meier and multivariable Cox regression models were conducted to analyze the probability of epilepsy with 95% confidence intervals (CIs).

RESULTS

Cumulative incidence rates (CIRs) for the first 2 years were .5% in the pTBI group and .1% in the control group. The corresponding rates after 15 years of follow-up were 1.5% in the pTBI group and .7% in the control group. Due to proportional hazard violations, the study population was split to the first 2 years and in subgroup analysis 4 years. During the first 2 years of surveillance, the hazard ratio (HR) for the pTBI group was 4.38 (95% CI = 3.39-5.66). However, between years 2 and 20, the HR for the pTBI group was 2.02 (95% CI = 1.71-2.38). A total of 337 patients (.47%) underwent neurosurgery, and 36 (10.7%) patients subsequently developed epilepsy. The CIR for the first year after TBI was 4.5% (95% CI = 2.3-6.7) in operatively managed patients and .3% (95% CI = .3-.4) in nonoperatively managed patients. Corresponding figures after 15 years were 12.0% (95% CI = 8.2-15.8) and 1.5% (95% CI = 1.4-1.6). During the first 4 years of surveillance, the HR for the operative pTBI group was 14.37 (95% CI = 9.29-20.80) and 3.67 (95% CI = 1.63-8.22) between years 4 and 20.

SIGNIFICANCE

pTBI exposes patients to a higher risk for posttraumatic epilepsy for many years after initial trauma. Children who undergo operative management for TBI have a high risk for epilepsy, and this risk was highest during the first 4 years after injury.

Window into the mind: Advanced handheld spectroscopic eye-safe technology for point-of-care neurodiagnostic

Traumatic brain injury (TBI), a major cause of morbidity and mortality worldwide, is hard to diagnose at the point of care with patients often exhibiting no clinical symptoms. There is an urgent need for rapid point-of-care diagnostics to enable timely intervention. We have developed a technology for rapid acquisition of molecular fingerprints of TBI biochemistry to safely measure proxies for cerebral injury through the eye, providing a path toward noninvasive point-of-care neurodiagnostics using simultaneous Raman spectroscopy and fundus imaging of the neuroretina. Detection of endogenous neuromarkers in porcine eyes' posterior revealed enhancement of high-wave number bands, clearly distinguishing TBI and healthy cohorts, classified via artificial neural network algorithm for automated data interpretation. Clinically, translating into reduced specialist support, this markedly improves the speed of diagnosis. Designed as a hand-held cost-effective technology, it can allow clinicians to rapidly assess TBI at the point of care and identify long-term changes in brain biochemistry in acute or chronic neurodiseases.

Modifications in Macular Perfusion and Neuronal Loss After Acute Traumatic Brain Injury

Purpose

Traumatic brain injury (TBI) causes structural damage and functional impairment in the visual system, often with retinal ganglion cell (RGC) degeneration occurring without visual symptoms. RGC degeneration is associated with reduced retinal blood-flow, however, it is not known whether reductions in perfusion precede or are secondary to neurodegeneration.

Methods

We conducted a prospective observational single-center case series. Patients were included if they were admitted to the hospital after acute TBI and underwent ophthalmic clinical examination, including optical coherence tomography (OCT) and OCT angiography (OCTA) acutely and at follow-up. Ganglion cell layer thickness (GCL) thickness, vascular density in the superficial vascular plexus (SVP), and intermediate capillary plexus (ICP) were quantified.

Results

Twenty-one patients aged 20 to 65 years (mean = 38 years) including 16 men and 5 women were examined less than 14 days after moderate to severe TBI, and again after 2 to 6 months. Macular structure and perfusion were normal at baseline in all patients. Visual function was abnormal at baseline in three patients and subsequent neurodegeneration and loss of perfusion corresponded to baseline visual function abnormalities. Nine patients (43%) had reduced macular GCL thickness at follow up. Perfusion in the SVP strongly associated with local GCL thickness. The strongest association of the SVP metrics was the sum of vessel density (P < 0.0001).

Conclusions

In cases of reduced visual function after TBI, macular perfusion remained normal until reductions in GCL thickness occurred, indicating that perfusion changes were secondary to local GCL loss.

Montreal Brain Injury Vision Screening Test for General Practitioners

Visual disturbances are amongst the most commonly reported symptoms after a traumatic brain injury (TBI) despite vision testing being uncommon at initial clinical evaluation. TBI patients consistently present a wide range of visual complaints, including photophobia, double vision, blurred vision, and loss of vision which can detrimentally affect reading abilities, postural balance, and mobility. In most cases, especially in rural areas, visual disturbances of TBI would have to be diagnosed and assessed by primary care physicians, who lack the specialized training of optometry. Given that TBI patients have a restricted set of visual concerns, an opportunity exists to develop a screening protocol for specialized evaluation by optometrists—one that a primary care physician could comfortably carry out and do so in a short time. Here, we designed a quick screening protocol that assesses the presence of core visual symptoms present post-TBI. The MOBIVIS (Montreal Brain Injury Vision Screening) protocol takes on average 5 min to perform and is composed of only “high-yield” tests that could be performed in the context of a primary care practice and questions most likely to reveal symptoms needing further vision care management. The composition of our proposed protocol and questionnaire are explained and discussed in light of existing protocols. Its potential impact and ability to shape a better collaboration and an integrative approach in the management of mild TBI (mTBI) patients is also discussed.

Disrupted functional network connectivity predicts cognitive impairment after acute mild traumatic brain injury

Aims

This study aimed to detect alterations of brain functional connectivity (FC) in acute mild traumatic brain injury (mTBI) and to estimate the extent to which these FC differences predicted the characteristics of posttraumatic cognitive impairment.

Methods

Resting‐state fMRI data were acquired from acute mTBI patients (n = 50) and healthy controls (HCs) (n = 43). Resting‐state networks (RSNs) were established based on independent component analysis (ICA), and functional network connectivity (FNC) analysis was performed. Subsequently, we analyzed the correlations between FNC abnormalities and cognitive impairment outcomes.

Results

Altered FC within the salience network (SN), sensorimotor network (SMN), default mode network (DMN), executive control network (ECN), visual network (VN), and cerebellum network (CN) was found in the mTBI group relative to the HC group. Moreover, different patterns of altered network interactions were found between the mTBI patients and HCs, including the SN‐CN, VN‐SMN, and ECN‐DMN connections. Correlations between functional disconnection and cognitive impairment measurements in acute mTBI patients were also found.

Conclusion

This study indicated that widespread FNC impairment and altered integration existed in mTBI patients at acute stage, suggesting that FNC disruption as a biomarker may be applied for the early diagnosis and prediction of cognitive impairment in mTBI.