Reduction in cerebral blood flow volume in infants complicated with hypoxic ischemic encephalopathy resulting in cerebral palsy

Does abnormal Doppler on cranial ultrasound predict disability in infants with hypoxic-ischaemic encephalopathy? A systematic review

AIM

To evaluate whether abnormal resistive index or cerebral blood flow velocity (CBFV) on cranial ultrasound predicts disability (≥1 year) in infants with hypoxic-ischaemic encephalopathy (HIE).

METHOD

This was a systematic review and meta-analysis of studies comparing developmental outcomes of infants with HIE with normal versus abnormal resistive index or CBFV.

RESULTS

Twenty-six studies were included (pre-therapeutic hypothermia era, 20; therapeutic hypothermia era, six). Data from 15 studies (pre-therapeutic hypothermia, 10; therapeutic hypothermia, five) were available for meta-analysis. Pooled sensitivity and specificity, summary area under the receiver operating characteristic curve, and diagnostic odds ratio of resistive index or CBFV for predicting 'death or severe disability' were as follows. Pre-therapeutic hypothermia era: 0.83 (95% confidence interval [CI] 0.45-0.97) and 0.92 (95% CI 0.74-0.98), 0.94 (95% CI 0.92-0.96), 54 (95% CI 7-391). Therapeutic hypothermia era (measurements before therapeutic hypothermia): 0.62 (95% CI 0.41-0.80) and 0.96 (95% CI 0.88-0.99), 0.93 (95% CI 0.89-0.94), 23 (95% CI 6-91). Therapeutic hypothermia era (measurements during/after therapeutic hypothermia): 0.51 (95% CI 0.24-0.78) and 0.83 (95% CI 0.73-0.90), 0.81 (95% CI 0.78-0.85), 5 (95% CI 2-13). Overall Grading of Recommendations Assessment, Development and Evaluation (GRADE) rating of evidence was 'low' or 'very low'.

INTERPRETATION

Low-level evidence suggests that abnormal resistive index or CBFV can predict death or disability with high sensitivity and specificity in infants with HIE who are not cooled. The specificity of these tests was high when performed before starting cooling in infants who received therapeutic hypothermia.

WHAT THIS PAPER ADDS

Cerebral doppler ultrasound may be useful in predicting death or disability in infants with hypoxic-ischaemic encephalopathy who are not cooled. Cerebral doppler ultrasound may also be useful in infants who are cooled, if done before starting cooling. Cerebral doppler ultrasound may not be useful when performed during or after completing cooling.

Molecular and Therapeutic Aspects of Hyperbaric Oxygen Therapy in Neurological Conditions

In hyperbaric oxygen therapy (HBOT), the subject is placed in a chamber containing 100% oxygen gas at a pressure of more than one atmosphere absolute. This treatment is used to hasten tissue recovery and improve its physiological aspects, by providing an increased supply of oxygen to the damaged tissue. In this review, we discuss the consequences of hypoxia, as well as the molecular and physiological processes that occur in subjects exposed to HBOT. We discuss the efficacy of HBOT in treating neurological conditions and neurodevelopmental disorders in both humans and animal models. We summarize by discussing the challenges in this field, and explore future directions that will allow the scientific community to better understand the molecular aspects and applications of HBOT for a wide variety of neurological conditions.

Combined prediction of miR-210 and miR-374a for severity and prognosis of hypoxic-ischemic encephalopathy

BACKGROUND AND AIM

Hypoxic-ischemic encephalopathy (HIE) is a disorder featured by hypoxic and ischemic damages during the perinatal period and its high mortality (i.e., 15%-20%) could be partly attributed to late diagnosis. Therefore, miR-210 and miR-374a were investigated to find if they could improve the diagnostic values of S100B protein and neuron-specific enolase (NSE) for HIE.

METHODS

Altogether 167 HIE newborns and 82 healthy newborns were recruited, and their blood were sampled for determining the levels of biomarkers. Specifically, S100B protein and NSE levels were detected based on the enzyme-linked immunosorbent assay (ELISA) kit, while the expressions of miR-210 and miR-374a were quantified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Moreover, the receiver operating characteristic (ROC) curves were established to assess the diagnostic values of the above biomarkers for HIE. Finally, the correlation analysis between miR-210/miR-374 and Neonatal Behavioral Neurological Assessment (NBNA) scoring or Gesell intellectual development were also conducted.

RESULTS

The levels of miR-210, miR-374a, S100B protein, and NSE were significantly distinct between HIE patients and healthy newborns (p < .05). Besides, miR-210 (r_s = .573), miR-374a (r_s = .651), NSE level (r_s = -.622), and S100B level (r_s = -.55) were all, respectively, correlated with NBNA scoring with statistical significance (p < .05). Furthermore, it was revealed that the combined diagnosis of miR-210, miR-374a, S100B protein, and NSE could obtain the highest accuracy regarding pairs of mild HIE versus moderate HIE (AUC = 0.898), moderate HIE versus severe HIE (AUC = 0.922), mild HIE versus severe HIE (AUC = 0.996), and HIE versus control (AUC = 0.960). More than that, the four molecules were also remarkably associated with Gesell intellectual development (p < .05).

CONCLUSION

MiR-210 and miR-374a could help to elevate the diagnostic value and prognostic prediction of S100B protein and NSE for HIE.

Impaired cerebral autoregulation and brain injury in newborns with hypoxic-ischemic encephalopathy treated with hypothermia

Impaired cerebral autoregulation may contribute to secondary injury in newborns with hypoxic-ischemic encephalopathy (HIE). Continuous, noninvasive assessment of cerebral pressure autoregulation can be achieved with bedside near-infrared spectroscopy (NIRS) and systemic mean arterial blood pressure (MAP) monitoring. This study aimed to evaluate whether impaired cerebral autoregulation measured by NIRS-MAP monitoring during therapeutic hypothermia and rewarming relates to outcome in 36 newborns with HIE. Spectral coherence analysis between NIRS and MAP was used to quantify changes in the duration [pressure passivity index (PPI)] and magnitude (gain) of cerebral autoregulatory impairment. Higher PPI in both cerebral hemispheres and gain in the right hemisphere were associated with neonatal adverse outcomes [death or detectable brain injury by magnetic resonance imaging (MRI), P < 0.001]. NIRS-MAP monitoring of cerebral autoregulation can provide an ongoing physiological biomarker that may help direct care in perinatal brain injury.

Relationship of neonatal cerebral blood flow velocity asymmetry with early motor, cognitive and language development in term infants

The objective of this study was to examine the relationships of Doppler cerebral blood flow velocity (CBFV) asymmetry measures with developmental outcomes in term infants. Doppler CBFV parameters (peak systolic velocity [PSV] and mean velocity [MV]) of the bilateral middle cerebral arteries of 52 healthy term infants were prospectively examined on postnatal days 1-5, and then their motor, cognitive and language development was evaluated with the Bayley Scales of Infant and Toddler Development, Third Edition, at 6, 12, 18 and 24 months of age. The left CBFV asymmetry measure (PSV or MV) was calculated by subtracting the right-side value from the left-side value. Left CBFV asymmetry measures were significantly positively related to motor scores at 6 (r = 0.3-0.32, p < 0.05) and 12 (r = 0.35, p < 0.05) months of age, but were not related to cognitive or language outcome. Thus, the leftward hemodynamic status of the middle cerebral arteries, as measured by cranial Doppler ultrasound in the neonatal period, predicts early motor outcome in term infants.

Changes in cerebral and visceral blood flow velocities in asphyxiated term neonates with hypoxic-ischemic encephalopathy

OBJECTIVE

The purpose of this study was to evaluate changes in the Doppler blood flow velocity (BFV) in the cerebral and visceral arteries in asphyxiated term neonates.

METHODS

The BFV was measured in 47 asphyxiated and 37 healthy term neonates in the anterior cerebral artery, middle cerebral artery, basilar artery, internal carotid artery, celiac artery (CA), superior mesenteric artery (SMA), and renal artery (RA) up to the age of 60 to 149 days.

RESULTS

At the age of 12 to 120 hours after asphyxia, the mean BFV had increased, and the resistive index (RI) had decreased (P < .05) in all cerebral arteries in neonates with severe hypoxic-ischemic encephalopathy (HIE) compared with the control group. In neonates with severe HIE, the mean BFV in the RA had significantly decreased at the age of 3 to 240 hours, and the RI had increased at the age of 24 to 240 hours, normalizing by the age of 21 to 59 days compared with the control group (P < .05). In the SMA, a decreased mean BFV was found in neonates with severe HIE compared with those with mild to moderate HIE only at the age of 24 to 36 hours. In neonates with mild to moderate HIE, the mean BFV had increased in the SMA and CA compared with the control group at the age of 2 to 11.9 hours.

CONCLUSIONS

A severe alteration of the cerebral and visceral BFV takes place during the first days after asphyxia in neonates with different severities of HIE.

Low cerebral blood flow velocity and head circumference in infants with severe hypoxic ischemic encephalopathy and poor outcome

AIMS

To evaluate long-term changes in cerebral blood flow velocity (CBFV) and head circumference in asphyxiated infants.

METHODS

CBFV was measured in 83 asphyxiated and 115 healthy term infants in anterior and middle cerebral, basilar and internal carotid artery (ICA) up to the age of 60-149 days. The psychomotor development and head circumference was followed for 18 months. RESULTS. Mean CBFV was increased (p < 0.05) during the first days after asphyxia in infants with severe hypoxic-ischemic encephalopathy (HIE) (n = 25) compared to control group or infants with mild to moderate HIE (n = 58) with maximum values found at the age of 36-71.9 h: in ICA (mean [95% CI]) 31.2 (25.5-36.6) cm/s in severe HIE infants compared to 13.0 (12.2-13.9) cm/s in controls. Decreased (p < 0.0001) mean CBFV developed in severe HIE infants by the age of 21-59 days: in ICA 14.1 (11.5-16.8) cm/s compared to 22.9 (21.4-24.4) cm/s in controls. Infants with severe HIE had similar mean height but lower head circumferences compared to controls (p < 0.05) at the age of 21-59 days.

CONCLUSION

The high mean CBFV found in infants with severe HIE during the first days after asphyxia is temporary and low CBFV and head circumference develops by the age of 21-59 days.