When evaluating intracranial tumors, emphasis is placed on conditions that may be indicative of neurological diseases.
Clinical neurological examination
The examination will be able to give some indication of where in the nervous system the disease is localized. Mental status, cranial nerve examination, examination of the head, neck, spinal column, motility, balance and coordination, sensibility, reflexes, standing position and gait are reviewed systematically.
The clinical neurological examination generally also includes a general medical examination, which can provide additional, valuable information in the work-up.
MRI is the most important diagnostic aid in detecting a brain tumor. Due to limited MRI availability, the primary examination is often a cerebral CT. However, the CT examination has clear limitations when it comes to the presentation of tumors in the cerebellum/brain stem, and non contrast-enhancing tumors can be easily overlooked.
Cerebral angiography is only rarely indicated. It may be appropriate, for example, for suspicion of angiomatous tumors or for differential diagnostics in relation to vessel malformation. Often, however, the CT-angiography or MRI-angiography will provide a satisfactory clarification of the vascular conditions.
Functional MRI (fMRI) is an important supplement to the preoperative work-up, especially for tumors in close proximity to the speech area and motor cerebral cortex.
EEG and testing of speech lateralization (WADA test) are included in the routine evaluation of tumors when they are operated according to epilepsy protocol for medically intractable epilepsy.
Examination of blood and cerebrospinal fluid.
For the majority of intracranial tumors, examinations of blood and cerebrospinal fluid have little or no diagnostic importance. In addition, spinal puncture carries a risk of tentorial herniation at elevated intracranial pressures. However, the detection of hormones in peripheral blood is of considerable importance for pituitary gland tumors.
Measurement of tumor markers in peripheral blood and spinal fluid can be useful in the event of medullablastomas (neuron-specific enolase (NSE)), germinal cell tumors (human chorion gonadotropin (b-hCG) and alpha-fetoprotein (AFP)) and in case of suspected brain metastases from testicular cancer (b-hCG and AFP).
Cytological examination of spinal fluid can be useful on rare occasions, since findings which confirm the presence of malignant cells can be decisive for the choice of radiation dosage and radiation volume for germinomas or medullablastomas/PNET.
There are three types of biopsy:
- Neuronavigation-guided open