The brain consists of four lobes: the frontal, temporal, occipital and parietal. Imagining a line on the top of the head from ear to ear, the portion of the brain at the top of the skull just to the rear of the line is the parietal lobe. In addition to providing reasoning and memory capabilities, the parietal lobe receives and interprets sensory information. It helps other regions of the brain plan responses to environmental stimuli. Tumors situated in the parietal lobe seriously affect its function, according to the Massachusetts Hospital in association with Harvard Medical School.
Glioma tumors are the most common type of primary tumor. They arise from the supportive cells of the brain, namely, astrocytes and oligodendrocytes. Astrocytomas, a type of glioma, are the most common type of childhood and adult brain tumors, according to the University at Alabama at Birmingham Medical School. Gliomas are graded one to four, four being the most severe and malignant tumor type. Cedars-Sinai hospital says that gliobastomas are the highest grade--grade 4--astrocytoma tumors. If present within the parietal lobe, tumors cause speech disturbances, especially if the tumor is in the left hemisphere; agraphia, or loss of the ability to write; and agnosia, or the loss of the ability to recognize objects, people, shapes, sounds or smells. Seizures occur and acalculia develops, which is the inability to add and subtract, according to Massachusetts Hospital in association with Harvard Medical School and Johns Hopkins Hospital.
This type of tumor originates from another region of the body before it spreads into the bloodstream and enters the central nervous system. Colon, lung and breast cancers are the most common metastasizing cancers, as well as skin cancer. It is common for several metastatic tumors to develop in the brain; therefore, it is aggressively treated with surgery, radiation or chemotherapy. Metastatic tumors typically recur following treatment, according to the University at Alabama at Birmingham Medical School.
Primitive Neuroectodermal Tumors
Primitive neuroectodermal tumors affect children and young adults. They develop from the primitive brain cells left over from early nervous system development. Typically malignant, this type of tumor rapidly grows and spreads throughout the brain and spinal cord. Since these tumors are aggressive, physicians recommend surgery to attempt to remove as much of the tumor as possible, followed with radiation and chemotherapy, according to Cedars-Sinai.