Hippocampus Mandatory Synthesis

The hippocampus is a paired brain structure, which resembles a seahorse and is located in the ventromedial part of the temporal lobes. The granular cell layer of the hippocampus contains mitotically active neural stem cells (NSCs). The hippocampus forms new memories and is also associated with learning and emotions. Since the brain is symmetrical, the hippocampus is found in both hemispheres of the brain. When both sides of the hippocampus are damaged, the ability to create new memories can be delayed. The theory of the hippocampus supporting memory function was first discovered more than fifty years ago, in the case study of Henry Gustav Molaiso (H.M.). He endured a bilateral medial temporal lobectomy for the relief of epilepsy. Immediately

WBRT is an effective and treatment of choice in patients with both identifiable brain metastases and prophylaxis for microscopic disease. WBRT has been reported to improve symptoms of brain metastases in 64-83%of patients, although some of the improvement is also a result of corticosteroids. [8,9,10] Even with this symptom improvement, recurrence is common, and control of brain metastases may only be achieved in half of the patients. Patients with tumors that are more radiosensitive to the effects of radiation such as lung and breast cancer cells have a better outcome than those with radioresistant tumors such as melanoma and renal cancers. Many patients receive WBRT in combination with another therapy such as surgery, radiosurgery, and chemotherapy. For WBRT, standard dose-fractionation in the US is 3000 cGy in 10 treatments. [8,10] Opinions against WBRT usually focus around the risks and toxicities, particularly neurocognitive decline. Studies verify that when cognitive function is properly tested before WBRT, 89% of patients had significant damage.

The clinical trial involved 113 enrolled adult patients with brain metastasis, which 100 individuals were analyzed. The patients received what’s called hippocampal avoidance whole-brain radiotherapy. The radiation dose to the whole brain was 30 Gy in 10 fractions, yet the dose to the entire hippocampus did not exceed 10 Gy, with a maximum dose of 17 Gy (17-19). Participants were given cognitive and memory delayed recall tests using the Hopkins Verbal Learning Test before treatment and then two, four, and six months after the radiotherapy. Four months after the radiation treatment, the 42 participants who were tested showed a 7 percent decline in delayed recall. This decline is significantly less than the 30 percent drop in delayed recall usually experienced by patients undergoing whole brain radiation therapy without sparring the hippocampus. At six months, the decline was only an additional 2