[Development of epidural spinal cord stimulation. Fortieth anniversary of the first implantation in Germany]. / Entwicklung der epiduralen Rückenmarkstimulation. 40 Jahre seit der Erstimplantation in Deutschland.

Spinal cord stimulation is nowadays an established therapy for various neuropathic and vasculopathic pain syndromes after more conservative measures have failed. However, 40 years ago, only 5 years after the first worldwide implantation in the US, this therapy was promoted in Germany. In 1972, the first devices were implanted in the Departments of Neurosurgery at the Universities Hannover and Freiburg. These pioneering efforts and the establishment of the therapy are intimately associated with three names: Jörg-Ulrich Krainick, Uwe Thoden, and Wolfhard Winkelmüller. Nowadays about 1700 spinal cord stimulation systems are implanted annually in Germany. The development of spinal cord stimulation from the beginnings up to now taking into special consideration the early years in Germany are presented.

[The epifacial electric stimulation of the occipital nerve in cases of therapy-resistant neuralgia of the occipital nerve]. / Die epifasziale Elektrostimulation des N. occipitalis bei therapierefraktärer Okzipitalisneuralgie.

BACKGROUND: The term "neuralgia of the occipital nerve" in clinical work includes different kinds of pain in the occipital region. Correctly, this diagnosis should be reserved for such pain syndromes which, corresponding to the definition of neuralgia, are due to damage of the cervical roots C1-C3 or of the major occipital nerve arising from those roots. We introduce an operative method to treat chronic therapy-resistant headaches in the area of the major and minor occipital nerve. The courses of three of the first patients operated in our hospital are described. METHODS: An electrode with four poles is positioned epifacially in the area of the affected nerve in local anaesthesia. In cooperation with the patient the correct position of the electrode and the right poling have to be found. Afterwards, the electrode is externalized after subcutaneous tunneling. For several weeks, the patients stimulate while being at home. If they report about a satisfactory reduction of pain, a subcutaneous receiver for use with an external stimulator is implanted. RESULTS: Most of the patients who received an electrode had a satisfying reduction of pain of 50-100% during the testing period so that the receiver was implanted. We had no success in two patients whose occipital nerves were destroyed by previous operations so that the system was explanted. CONCLUSIONS: The epifacial stimulation of the occipital nerve is an effective method to treat neuralgia of this nerve. Patients with destruction of the nerve have to be excluded, because in their cases the stimulation does not work.

Intrathecal opioid therapy for pain: efficacy and outcomes.

Although opioid therapy has been accepted for the treatment of patients with cancer pain, its use for nonmalignant pain is still regarded as controversial due to concerns about the development of tolerance and psychological dependence. However, recent studies indicate that there is a low incidence of addiction in patients who do not have a history of addictive disorders, and opioid use is increasing for long-term treatment in patients with nonmalignant pain. This paper reviews the results from recent studies that evaluated the efficacy of intrathecal opioid delivery using a number of outcome measures. These studies demonstrate that intrathecal opioid delivery produces short-term relief of specific symptoms and improves long-term outcomes such as patient functioning (measured by increases in activities of daily living [ADLs] and capacity to work), mood, treatment satisfaction, and quality of life, as well as decreases in oral opioid use. Furthermore, these studies showed there was no development of tolerance or addiction in patients who received long-term intrathecal opioid delivery.

Intrathecal therapy for cancer and nonmalignant pain: patient selection and patient management.

Intrathecal drug delivery improves pain relief, reduces suffering, and enhances quality of life in the small proportion of patients who do not respond well to oral analgesics, including oral morphine. Although morphine is the "gold standard," and the only drug approved for intrathecal pain therapy in the United States, off-label use of alternative agents appears promising, particularly in patients with neuropathic pain. Careful patient selection and management are significant determinants of successful treatment outcomes. Patient selection criteria for cancer and nonmalignant pain are similar; however, a more comprehensive psychological and social assessment is required for patients with nonmalignant pain. In addition, all patients (those with cancer or nonmalignant pain) must exhibit a positive response to an epidural or intrathecal screening test. A multidisciplinary team approach, involving psychologists, nurses, physical therapists, social workers, and spiritual leaders should be used to manage patients. Current practices for patient selection and management, screening tests, and dosing guidelines for intrathecal drug delivery systems are discussed.

Clinical realities and economic considerations: efficacy of intrathecal pain therapy.

Studies of analgesia in cancer patients have revealed that intrathecal administration of opioids can deliver potent analgesia with fewer systemic side effects than equivalent doses of systemic opioids. In addition, several trials have examined the safety and efficacy of this modality in patients with pain of nonmalignant origin. In one survey of 35 physicians involving 429 patients treated with intrathecal therapy, physician reports of global pain relief scores were excellent in 52.4% of patients, good in 42.9%, and poor in 4.8%. In another study of 120 patients, the mean pain intensity score had fallen from 93.6 to 30.5 six months after initiation of therapy. In both studies, patients reported significant improvement in activities of daily living, quality of life measures, and satisfaction with the therapy. Constipation, urinary retention, nausea, vomiting, and pruritus are typical early adverse effects of intrathecal morphine and are readily managed symptomatically. Other potential adverse effects include amenorrhea, loss of libido, edema, respiratory depression, and technical issues with the intrathecal system.

Long-term effects of continuous intrathecal opioid treatment in chronic pain of nonmalignant etiology.

In the present retrospective investigation, the long-term effects of continuous intrathecal opioid therapy via implantable infusion pump systems were examined in 120 patients with chronic, nonmalignant pain syndromes. The follow-up period was 6 months to 5.7 years (mean 3.4 years +/- 1.3 standard error of the mean). Deafferentation pain and neuropathic pain showed the best long-term results, with 68% and 62% pain reduction (visual analog scale), respectively. The mean morphine dosage initially administered was 2.7 mg/day (range 0.3-12 mg/day); after an average of 3.4 years, it was 4.7 mg/day (range 0.3-12 mg/day). In a long-term observation of 28 patients who received intrathecal morphine for longer than 4 years. 18 patients (64.3%) had a constant dosage history and 10 patients (35.7%) showed an increase in morphine dosage to more than 6 mg/day 1 year after dosage determination. In seven cases, a tolerance developed: in four patients the tolerance was controlled by means of "drug holidays"; but in three patients it was necessary to remove the pump systems. Explantation of the pump system occurred in 22 additional cases for other reasons. Throughout the follow-up period, 74.2% of the patients profited from the intrathecal opiate therapy: the average pain reduction after 6 months was 67.4% and, as of the last follow-up examination, it was 58.1%. Ninety-two percent of the patients were satisfied with the therapy and 81% reported an improvement in their quality of life. The authors' 6-year experience with administration of intrathecal opioid medications for nonmalignant pain should encourage the use of this method in carefully selected patients.

[Results of microsurgical decompression in trigeminal neuralgia.]. / Ergebnisse der mikrochirurgischen vaskulären Dekompression bei der Trigeminusneuralgie.

INTRODUCTION: From 1 August 1983 to 6 June 1992, 284 patients underwent decompression of the trigeminal root in the rear part of the skull as treatment for tic douloureux. According to preoperative diagnosis and intraoperative inspection, a space-occupying process was the cause of the typical neuralgia in 13 cases (4 meningiomas, 3 epidermoid tumours, 3 acoustic neuromas and 2 trigeminal neuromas). In 271 cases (95.4%) microsurgical vascular decompression according to Jannetta was carried out. METHODS: The majority of patients were between 45 and 75 years of age. The follow-up period ranged from 10 months to 9.3 years (average 59.45 months). The results of the long-term investigations are based on standardized questionnaires completed by 202 patients. Of the total of 271 patients operated upon by Jannetta's technique, 261 (96.3%) were free of pain immediately after the operation. The main causes of failure were misdiagnosis (myoarthropathy, cluster headache) and incorrect indications (encephalomyelitis disseminata, trigeminal neuropathy following peripheral lesion). In 3 cases vascular displacement and complete decompression of the trigeminal root were impossible because the basilaris was exceptionally long. RESULTS: In the long term, 87.6% of the patients operated on remained free of pain or improved sufficiently to require no further carbamazepine medication. Relapses developed in 7.4% of cases, and except for operative revision and rhizolysis of the trigeminal root in a case of relapsed trigeminal neuralgia, thermo-controlled high-frequency lesion of the gasserian ganglion was carried out in a second operation. The complications of the Jannetta operation were hypoacusis and anacusis (4%), hyposmia (1%), dizziness (3.5%) and chronic subdural haematoma (1 case). Neither postoperative bacterial meningitis nor any lethality was recorded. In 94.5% of cases the patients expressed positive opinions of the operation and its results, while 4% regretted having the operation and 1.5% were undecided. The question as to whether the operation had significantly improved the quality of life was answered in the affirmative by 88.4% of the patients. DISCUSSION: In summary, the long-term results confirm that microsurgical vascular decompression can be offered as the method of choice for treatment of trigeminal neuralgia in younger patients, and in older patients when cardiopulmonary risk factors and cerebrovascular processes can be eliminated. Alternative methods are high-frequency lesionsing of the gasserian ganglion according to Sweet and chemorhizolysis of the gasserian ganglion, but these must be restricted exclusively to the treatment of typical trigeminal neuralgia with tic douloureux. Persistent neuropathic pain caused by atraumatic or drug-induced lesion to the trigeminal nerve cannot be positively influenced either by surgical decompression or by destructive operations on the gasserian ganglion.

[Primary intracerebral non-Hodgkin's lymphoma--a clinicopathologic study]. / Primäre intracerebrale Non-Hodgkin-Lymphome--eine klinikopathologische Studie.

Primary cerebral lymphomas (PCL) were diagnosed with increasing frequency also in our retrospective study of 44 patients. Clinically these tumors presented with signs of a rapidly growing brain neoplasm. The analysis of CCT data showed that the tumors were of varying density before and showed mostly (60%) homogeneous enhancement after contrast medium application. MR imaging was more sensitive, but could not aid in distinguishing PCL from other brain tumors. The lesions lay mainly (82%) in the supratentorial space and involved the frontal lobe in 42% of cases. Only 16% were located in the periventricular region including corpus callosum and basal ganglia. 20% of cases showed multiple lesions. Suspected diagnoses were therefore mainly meningeoma, glioma and metastases. Morphological diagnosis was easily possible with the aid of immunohistological methods: there were 41 B-cell lymphomas (93%), two T-cell lymphomas and one large cell anaplastic lymphoma of the non-B non-T phenotype. An unequivocal correlation between morphology and radiological picture existed in the way that tumors with a dense cellular infiltrate appeared mainly as hyperdense lesions with homogeneous contrast enhancement. The clinical course was characterized by CNS-relapses frequently with multiple cerebral lesions and a spinal recurrence in one case. 7% of cases showed evidence of extracerebral disease in a bone marrow biopsy specimen or at autopsy. The average survival of the patients was 15 months, one year survival was 36%, two year survival 12% and 5% of patients lived for more than 5 years.

[Spinal neurostimulation for the treatment of chronic pain: changes in indications and patient selection after 19 years' experience.]. / Spinale Neurostimulation : Rückblick und aktueller Stand nach 19 Jahren Erfahrung.

After the initial clinical reports of Shealy 1967 dorsal column stimulation (DCS) was first introduced in Germany by Krainick (Freiburg) and Winkelmüller (Hannover) in 1972. At first, the success rate in unselected patients was unsatisfactory. The results improved with careful patient selection and better technical equipment allowing preliminary testing procedures before definitive implantation. The authors' own results in 335 patients treated by intermittent spinal cord stimulation (SCS) with implanted devices between 1972 and 1989 show that long-term beneficial effects can be obtained in pain of neurogenic origin rather than in nociceptor pain. Guidelines for the use of SCS were proposed by the German Society of Neurosurgery in 1990. The best indications and target group are cases with radicular low-back pain after failed back surgery, stump and phantom pain, pain states following partial lesions of brachial/lumbar plexus and peripheral nerves, sympathetic dystrophy and rest pain in peripheral vascular disease (PVD). Possible indications for SCS are pain after incomplete lesions of spinal cord or cauda equina, postherpetic neuralgia, sclerodermia and PVD. Failures must be expected in pain states related to progressive malignant disease and complete deafferentation after spinal lesions or root avulsion.

[Continuous administration of opiates with implantable drug delivery systems in patients with intractable non-malignant pain.]. / Intrathekale Opiattherapie bei chronischen Schmerzsyndromen benigner Atiologie über implantierbare Medikamentenpumpen.

The use of implantable systems for intrathecal administration of opioids in chronic pain of non-malignant origin is a controversial subject. Opioid therapy is reserved mainly for pain patients with malignant disease and reduced life-expectancy. The main reasons for this restricted range of indications of chronic subarachnoid administration of opioids are fear of addiction and the build-up of tolerance. During July 1988 and April 1990 we treated 60 patients suffering from pain of non-malignant origin with continuous opioid infusion by implanted pumps. Wishing to find whether opiates can relieve deafferentation pain, we subdivided the different pain syndromes into three groups according to their pathophysiology: nociceptive, neurogenic/neuropathic, and deafferentation pain. After a follow-up period of 11.5+/-7.1 months 47 patients were evaluated. Pain intensity according to the visual analogue scale was reduced in a mean of 79.4% of the patients. Activity level and mood scores as pain-associated parameters were both significantly increased after therapy. Analysis of the McGill Pain Questionnaire reveals that the improved quality of life is attributable to a reduction of affective pain perception more than to sensory discrimination. The best results in terms of pain reduction (82.5%) were obtained in the group of patients with deafferentation pain. This is in contrast to reports in the literature. It seems that neuropathic and deafferentation pain syndroms are susceptible to intrathecal opioids. The initial daily average dose of morphine was 2.6 mg/day, increasing to 6.1 mg/day after 25 months without the development of major tachyphylaxis. the administration of intrathecal opioids by means of implantable systems is justified in carefully selected patients with chronic non-malignant pain. This method should be applied in preference to destructive neurosurgical treatments.

[Classification of trigeminal neuralgia and its effect on the results of surgical treatment]. / Die Klassifikation der Trigeminusneuralgie und ihr Einfluss auf die Ergebnisse der operativen Behandlung.

The trigeminal neuralgia has to be differentiated from the trigeminal neuropathy in respect of pain character and etiology. The neuralgia is characterized by paroxysmal pain evoked by trigger stimuli. The most frequent cause of this type of pain is a parapontine vascular compression of the trigeminal root without neurological deficits. The symptoms of neuropathy are some sensory loss associated with continuous pain resulting from peripheral damage of the trigeminal nerve. This distinction alleviates the indication for specific operative procedures and is more precise than the subdivision in typical and atypical neuralgia. The results of neurovascular decompression and thermorhizotomy can be much improved if neuropathic pain syndromes are excluded from operation. Out of 180 patients suffering from trigeminal neuralgia 94% were pain-free after neurovascular decompression and 96% of 144 patients following thermorhizotomy. For the treatment of continuous neuropathic pain augmentative electrostimulation of the Gasserian Ganglion via implanted electrodes is recommended.

[Treatment of deafferentation pain by high-frequency intervention on the dorsal root entry zone]. / Behandlung des Deafferentierungsschmerzes durch Hochfrequenzläsion der Hinterwurzeleintrittszone.

From August 1980 to May 1981, high-frequency lesions of the dorsal root entry zone of the spinal cord were performed on 35 patients with chronic deafferentiation pains. Among them were 15 patients with traumatic transverse cord lesions, 5 with non-traumatic transverse lesions and 7 with cervical root tears or traumatic brachial plexus lesions, 6 with stump or phantom pain after amputation, and 1 each with sciatic paralysis or spinal arachnopathy. Treatment results were best in complete transverse lesions, cervical root avulsion and brachial plexus lesion, less so for stump or phantom pain of the lower extremities. It failed in patients with sciatic-nerve lesion and arachnopathy. Thus best results are to be expected if the method is limited to genuine deafferentiation pain.

Phantom phenomena (phantom arm) following cervical root avulsion. Effect of dorsal root entry zone thermocoagulation.

We report on nine male patients with cervical root avulsions and brachial plexus injuries following traffic accidents. These non-amputees (mean age 33.7 years) had a phantom arm beside the paralysed arm. Cervical root avulsions were demonstrated either by myelography or surgically. Mostly the roots C5-Th1 were affected. Eight of the nine patients had Horner's syndrome on the side of the root avulsion. The phantom arm appeared immediately after the accident, except in one patient who was symptom-free for 2 weeks. In two cases the phantom arm disappeared spontaneously. Four patients underwent a DREZ lesion. After surgery the phantom arm disappeared, and three of the patients became painfree, while one patient experienced pain relief of 20% to 50%. Reviewing the literature it is assumed that phantom limb following injury to the brachial plexus indicates cervical root avulsion. In such cases Horner's syndrome is a good indication for lower cervical root avulsion (C8-Th2).

[On the biological behaviour of the rare malignant plexus papilloma in childhood: long-term observations in two operated cases]. / Zum biologischen Verhalten des seltenen malignen Plexuspapilloms im Kindesalter: Langzeitbeobachtungen in zwei operierten Fällen.

Only a few verified cases of malignant papilloma of the choroid plexus have been described in the literature. The biological nature and prognosis of those tumours are not well known. Two cases of our own material are presented in whom large tumours of the lateral ventricles have been removed. One patient was 9 months and the other seven years old at the time of operation. The clinical follow-up period was seven years. Computer-tomography controls did not reveal any sign of recurrence. The published cases are reviewed until 1981. Their clinical aspects, the histological features and the nature of these rare tumours are discussed.

[The influence of permanent cerebellar stimulation on senso-motor disorders in cerebral palsy (author's transl)]. / Uber die Beeinflussung von Bewegungsstörungen bei der infantilen Cerebralparese durch chronische Kleinhirnstimulation.

Based on Cooper's good results implantation of a bilateral cerebellar stimulator was performed in 2 children with cerebral palsy. The patients suffered from marked hypertonia of all limbs and involuntary movements. The follow-up study of 8 months revealed a decrease of spasticity and a progressive improvement of fine motor control. Our preliminary results justify the clinical application of cerebellar stimulation for functional treatment of sensory-motor disorders.

Ventral midbrain stimulation, blood pressure responses and their relation to the dopaminergic nigro-striatal pathways.

In 40 cats systematic, electrical stimulation of ventral midbrain structures was performed. In the lightly anaesthetised animals, fixed in a stereotaxic frame, ECoG and arterial blood pressure were registrated. As a result stimulation-induced phasic blood pressure increases have been found within a distinct area including substantia nigra and ventral tegmentum. From the same region nonspecific responses in the ECoG (spindling, recruiting and desynchronisation by low and middle frequent stimulation) could be obtained. The blood pressure responses were enhanced after hemisection at the level of the posterior hypothalamus ipsilateral to the stimulation side. Drugs (Haloperidol, alpha-methyltyrosin and 6-hydroxydopamine), affecting the dopamine metabolism in different ways, abolished the stimulation-induced blood pressure responses. In agreement with previous findings it is concluded that motor and autonomic activation, elicited in ventral midbrain structures are mediated by catecholaminergic transmission.