Final answer:
Neurosurgeons use diagnostic tools like EEG and CT scans in combination with a full medical history and physical exam to determine brain tumor location and operability. In some scenarios, entire hemispheres may be removed to treat conditions like severe epilepsy, reflecting the brain's functional redundancy and ability to adapt, especially in children.
Step-by-step explanation:
Neurosurgeons utilize a variety of diagnostic tools and techniques to determine precisely which parts of the brain are affected by a tumor and whether they can be safely removed through surgery. Prior to surgery, a full medical history and physical exam are conducted to determine potential neurological deficits. Tools such as electroencephalography (EEG) and computerized tomography (CT) scans play a crucial role in identifying the exact location and extent of brain tumors.
EEG, for example, measures electrical activity in the brain and is particularly useful in the case of patients who have experienced seizures. It can pinpoint the brain regions involved in the seizure. CT scans, which are specialized X-rays, allow neurologists and neurosurgeons to view the internal structures of the brain, revealing the presence of tumors or hemorrhages, and guiding surgical planning.
In some cases, when tumors are in areas that are less critical for function or are well delineated, they can be completely removed. When tumors are located in more sensitive areas, neurosurgeons must carefully balance the removal of as much tumor tissue as possible against the risk of damaging crucial brain functions. As such, some tumors may be deemed inoperable and treated with other modalities like radiation or chemotherapy.
Unique cases such as severe epilepsy may require surgeries like cutting the corpus callosum, which gives insight into the lateralized brain functions. However, due to the brain's redundancy and especially in younger patients, sometimes an entire hemisphere can be removed with surprisingly few deficits.
Thorough diagnostic imaging and testing, combined with a detailed understanding of brain function and individual patient history, enable neurosurgeons to make informed decisions about tumor removal, aiming to maximize patient outcomes while minimizing risks.