[Neurosurgery in old age. II: CNS tumors--cerebrospinal-vascular diseases--pain surgery--conclusions]

Abstract

The relative percentage of patients who are admitted to our clinic with benign tumours often susceptible to therapy has increased from 23% (1974) to 55% (1989). In patients over 60 years old, these are above all cranial tumours (most frequently meningiomas), whereas metastases predominate at the spinal cord. 8% of the cranial meningiomas show an apoplectiform course (mostly steal effects). On the other hand, very large cranial meningiomas causing few symptoms are particularly frequent in elderly patients (larger reserve space, reduced tendency to edema). The use of minimally damaging surgical approaches, palliative operations and possibly a cautious radicality adapted to location and extent are especially important for tumour surgery in elderly patients, especially for tumours with a low tendency to proliferate. Our own experience in vascular pathology concern arteriovenous aneurysms and the diagnosis/therapy of spontaneous intracerebral hemorrhage and space-occupying malacia in the region of the cerebrum and the cerebellum. Epidural hematomas and the spinal dural arteriovenous fistulae which often become manifest at an advanced age owing to increasing medullary venous stasis are of particular therapeutic importance in elderly patients. Depending on the situation, direct surgical elimination or treatment by selective embolization may be considered. Typical trigeminal neuralgia is especially frequent in patients over 60 years in neurosurgical treatment of very severe therapy-resistant pain. Whereas the microvascular decompression of the trigeminal roots near the pons (compression by arterial loops) is most important in younger patients, we use the minimally invasive, relatively simple percutaneous thermo-rhizotomy in the Gasserian ganglion with selective functional elimination of the thinner pain fibers in elderly patients. Ablative measures are otherwise possible, above all in nociceptive pain, whereas the stimulation of the lemniscal system is of primary significance in deafferentation pain (e.g. causalgia). Spinal stimulation in inoperable peripheral arterial occlusive disease (leg, pelvis) to improve the microcirculation is of special importance: The prospect of success is greater than 80% in Fontain stage III. We do not apply subarachnoid spinal morphine administration only in malignancies, in contrast to intraventricular morphine administration (right anterior horn). For elderly patients with very severe inoperable lumbar stenosis (mostly spondylarthritis), the dosage-controlled continuous low-dose subarachnoid administration of morphine via a subcutaneously implanted programmable pump with a reservoir is suitable in some cases. These examples show that neurosurgery may be appropriate even in elderly patients. Today, more differentiated and at the same time minimally invasive diagnostic and surgical methods are available.