Hyperbaric Oxygen Therapy Associated with Ventricular-Subcutaneous Shunt Promotes Neuroprotection in Young Hydrocephalic Rats.

Hydrocephalus is characterized by the accumulation of CSF within the cerebral ventricles and the subarachnoid space. Ventricular volume can progressively increase and generate serious damage to the nervous system, with cerebral hypoxia/ischemia as one of the most important factors involved. Hyperbaric oxygen therapy (HBOT) improves oxygen supply to tissues, which can reduce the progression of lesions secondary to ventricular enlargement. We evaluated whether HBOT associated with CSF diversion can promote neuroprotective effects to structures damaged by ventriculomegaly and understand its role. Seven-day-old male Wistar Hannover rats submitted to hydrocephalus by intracisternal injection of 15% kaolin were used. The animals were divided into six groups, with ten animals in each: control, control associated with hyperbaric therapy, hydrocephalic without treatment, hydrocephalic treated with hyperbaric oxygen therapy, hydrocephalic treated with CSF deviation, and hydrocephalic treated with hyperbaric oxygen therapy associated with CSF deviation. To assess the response to treatment, behavioral tests were performed such as modified Morris water maze and object recognition, evaluation by transcranial ultrasonography, histology by Hematoxylin-Eosin and Luxol Fast Blue, immunohistochemistry for GFAP, Ki-67, Caspase-3, COX-2, NeuN and SOD1, and biochemical ELISA assay for GFAP and MBP. The results show that the association of treatments exerts neuroprotective effects such as neurobehavioral improvement, preservation of periventricular structures, antioxidant effect, and reduction of damage resulting from ischemia and the neuroinflammatory process. We conclude that HBOT has the potential to be used as an adjuvant treatment to CSF deviation surgery in experimental hydrocephalus.

Transcranial ultrasonography as a reliable instrument for the measurement of the cerebral ventricles in rats with experimental hydrocephalus: a pilot study.

PURPOSES: Demonstrate that transcranial ultrasonography (TUS) scanning is viable and useful as a diagnostic method in experimental hydrocephalus, as well as to compare measurements of cerebral and ventricular width obtained from TUS scans of hydrocephalic rats with post-mortem anatomical specimens, aiming for the development of accurate criteria to establish ventricular enlargement and progression of hydrocephalus subsequently. METHODS: Thirty-five male Wistar rats were used. Following hydrocephalus induction, they underwent a transcranial ultrasound scan to measure cerebral and ventricular dimensions, in the fourth and 21 post-induction days. By the end of the experiments, measurements obtained from TUS scans were compared with actual values as seen in the post-mortem specimens of each animal. RESULTS: Ventricular dilation could be clearly visualized in hydrocephalic animals. We performed intraclass correlation coefficient and linear regression analyses that have demonstrated a precise correlation between measurements of TUS scans and post-mortem specimens; we have found a similarity of 0,95 for the cerebral diameter and 0,97 for ventricular width. CONCLUSIONS: Transcranial ultrasonography is a useful and reliable diagnostic tool for experimental hydrocephalus; also, it can be used to assess the progression of ventriculomegaly in animal models of hydrocephalus.

Hyperbaric oxygen therapy reduces astrogliosis and helps to recovery brain damage in hydrocephalic young rats.

PURPOSE: We investigated the possible beneficial effects that hyperbaric oxygen therapy could offer in different brain structures affected by ventriculomegaly in pup rats submitted to experimental hydrocephalus. METHODS: Seven-day-old Wistar rats were submitted to hydrocephalus by intracisternal injection of 10% kaolin into the cisterna magna. The animals were divided into four groups: control (n = 5); control with HBOT (3ATA/2 h/day) (n = 5); untreated hydrocephalic (n = 10); hydrocephalic treated with HBOT (3ATA/2 h/day) (n = 10). The treatment with HBOT was performed daily for 14 days post-induction of hydrocephalus. To evaluate the response to treatment, behavioral tests (open field, Morris water maze, and activity monitor) were performed. After 14 days, the animals were euthanized, and the brain was removed for histological (hematoxylin-eosin and solochrome-cyanine) and immunohistochemical (GFAP and Ki-67) studies. RESULTS: The hyperbaric treatment, although not causing changes in ventricular enlargement, resulted in a significant improvement in the behavioral performance (p = 0.0001), with greater agility and exploration of the environment, preservation of spatial memory, and greater learning capacity (p = 0.0001). Through the immunohistochemical study, the astrocytic activity (glial fibrillary acidic protein) in the corpus callosum (p = 0.0001) and in the germinative matrix (p = 0.0033) was significantly reduced as compared to that in the H group. CONCLUSION: The results suggest that hyperbaric treatment bettered the behavioral performance and offered benefits to the structures affected by the ventricular increase helping to recover the brain damages. In this way, the HBOT it can be considered an adjuvant therapy for the treatment of hydrocephalus.