Surveys indicate that clinicians are frequently ill equipped to treat cancer pain. Pain is often poorly assessed, and many caregivers lack sufficient knowledge to optimize treatment. Effective management requires an understanding of pain pathophysiology, the ability to identify and evaluate pain syndromes, and familiarity with proven therapeutic strategies. Opioid pharmacotherapy is the mainstay of treatment. Practical aspects of opioid therapy include selection of both drug and route, dose titration, and management of side effects. Specific strategies for the management of patients who are unable to attain an acceptable balance between pain relief and side effects include both noninvasive interventions (such as adjuvant analgesics, psychological therapies, and physiatric techniques) and invasive interventions (such as the use of intraspinal opioids, neural blockade, and neuroablative therapies). Sedation is an option at the end of life for the treatment of pain that is refractory to other interventions. These approaches can provide adequate relief to the vast majority of patients, most of whom will respond to systemic pharmacotherapy alone. Patients with refractory pain should have access to specialists in pain management or palliative medicine.

The management of cancer pain

✓ To minimize the sensory loss associated with intradural posterior rhizotomy for medically refractory occipital neuralgia, partial sectioning of the upper cervical posterior rootlets was performed in 11 patients. The ventrolateral aspect of each posterior rootlet from C-1 to the upper portion of C-3 was divided at the root entry zone. In three patients with bilateral neuralgia, the procedure was performed on both sides, for a total of 14 partial rhizotomy procedures in the 11 patients. This resulted in satisfactory preservation of scalp sensation in all cases. Pain within the territory of the greater occipital nerve was consistently reduced or abolished by this procedure. The overall degree of pain relief was rated good or excellent after 10 of the 14 procedures. The other four procedures alleviated pain in the territory of the greater occipital nerve, but the results were marred by persistent periorbital or temporal pain. Two patients subsequently underwent complete C1–3 posterior rhizotomy without furt...

Treatment of occipital neuralgia by partial posterior rhizotomy at C1–3

Since 1972, micro-DREZ-tomy has been performed in 367 patients: with cancer pain in 81, neurogenic pain in 139, hyperspasticity in 135, and hyperactive neurogenic bladder in 12. MDT consists of an incision and bipolar coagulations performed ventro-laterally in the Dorsal Root Entry Zone (DREZ) at the entrance of the rootlets into the dorso-lateral sulcus. The lesion is directed at 45 degrees ventro-medially, and 2-3 mm deep according to the pre-operative neurological status and the desired effects. MDT 1 degree interrupts the small (nociceptive) fibres regrouped laterally and the large (myotatic) afferents which runs centrally, whilst sparing part of the large medial (lemniscal) fibres. 2 degrees destroys the (excitatory) medial part of the Lissauer's tract, 3 degrees and the cells of the dorsalmost layers of the dorsal horn, which can be the site of hyperactivity, as we were able to record in patients with deafferentation pain. Best indications are: 1) well localized cancer pain, such as Pan-coast syndrome; 2) neuropathic pain due to: brachial plexus injuries, cauda equina and/or spinal cord lesions especially for pain corresponding to segmental lesions, peripheral nerve injuries-amputation-herpes zoster-(especially when the predominant component of pain is of the paroxysmal type and/or corresponds to provoked hyperalgesia/allodynia); 3) excess of spasticity and 4) neurogenic hyperactive bladder.

Microsurgical DREZotomy (MDT) for pain, spasticity, and hyperactive bladder: a 20-year experience.

One, if not the only effective way of treating pain due to preganglionic avulsion of the brachial plexus is the Dorsal Root Entry Zone (DREZ) lesion procedure. In 1985 the author began to use ultrasound as a lesion-maker for operations in the DREZ. Since then, 127 (3 patients were operated on twice) DREZ-Operations have been carried out on 124 patients suffering from chronic pain due to brachial plexus avulsion. Different technical lesioning modalities were employed: ultrasonic discontinuous DREZ lesions in 20 cases and a new modality: ultrasonic DREZ-sulcomyelotomy in 107 cases. Analysis of the results after ultrasonic DREZ-operations revealed that ultrasonic DREZ-sulcomyelotomy was the most effective technical modality. Immediately after operation good pain relief was obtained in 103 (96%) out of the 107 patients operated on with the ultrasonic DREZ-sulcomyelotomy method, and in 15 (75%) out of the 20 patients with ultrasonic discontinuous DREZ-lesions. The total follow-up study (47.5 months on average) revealed 87% good results overall.

Ultrasonic DREZ-operations for treatment of pain due to brachial plexus avulsion

PURPOSE To characterize the MR findings of glioblastoma multiforme in the posterior fossa. METHODS MR studies of nine patients with surgically proved posterior fossa glioblastoma multiforme were retrospectively evaluated. MR characteristics studied included tumor location, signal intensity, enhancement pattern, and presence of intratumoral hemorrhage, as well as presence of secondary hydrocephalus or metastatic spread. RESULTS The tumors were located in the median portion of the cerebellum or brain stem in eight cases. Six extended into the fourth ventricle. Hydrocephalus was seen in four cases. Six cases demonstrated decreased T1- and increased T2-weighted signal intensities. Three cases demonstrated mixed signal intensities suggesting intratumoral hemorrhage. All of the eight patients who received contrast showed moderate to marked heterogeneous ringlike enhancement suggesting intratumoral necrosis. Multicentric/multifocal lesions or extraaxial metastases were identified in three of the nine cases, and there was extracranial extension into the cervical region in one case. CONCLUSION Glioblastoma multiforme is a rare tumor in the posterior fossa. Differentiating it from metastatic tumor or malignant astrocytoma was difficult. However, combination of heterogeneous and ringlike enhancement, midline location, poorly defined margin, tumoral hemorrhage, concomitant multicentric/multifocal lesions, and extraaxial or extracranial metastasis may be clues for the prospective diagnosis of glioblastoma multiforme.

http://www.ajnr.org/content/ajnr/16/3/583.full.pdf

G. Fischer

Papers

Posterior Spinal Rhizotomy and Selective Posterior Rhizidiotomy

Brain stem tumors