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We review the present status of surgery for Parkinson's disease. Surgical options for Parkinson's disease are rapidly spanding. The main objectives of surgical techniques are to restore the dopaminergic deficit in the striatum (transplantation) and to normalize the neuronal activity of the subthalamic-pallidal circuit (pallidotomy and deep brain stimulation). Whereas cell transplantation is still considered an experimental procedure, ablative procedures and deep brain stimulation are widely used. Both types of surgical procedures are supported by strong scientific data. However, much work remains to be done in order to understand several aspects not clearly elucidated at present. The results and current indications for pallidotomy and deep brain stimulation are analyzed.

Background: There is a renewed interest in pallidotomy as a treatment for complicated Parkinson's disease (PD)., Aim: To present the clinical results as well as the analysis of prognostic factors obtained in 28 patients with PD and motor complications submitted to pallidotomy and followed by one year (n = 28) and 2 years (n = 12)., Results: The total motor score (Unified Parkinson's Disease Rating Scale [UPDRS]) in the off state improved by 33 and 23% at one and two years, respectively (p < 0.01). All the cardinal signs of the disease were significantly improved (p < 0.01): tremor (92%), rigidity (67%), bradykinesia (46%) and axial symptoms (21%). A slight tendency to worsening in axial symptoms was observed. Dyskinesias disappeared in all but one patient. The Schawb & England Scale in off was improved by 21%. No improvement in the non-operated side was observed. The subgroup of patients with an improvement of less than 30% in the UPDRS was older than the one with larger clinical benefit. The observed tendency to worsening in the total motor score was related mainly to the progression of the symptoms in the non-operated side. Complications were mild and transient., Conclusions: Pallidotomy is a relatively safe and effective therapeutic option for complicated PD patients. An adequate selection of patients is necessary, since efficacy is partial and limited to one hemibody.

The authors reviews genetic fingerprinting practice and cases in Germany following the adoption of the new specific regulatory measures in the StPO, and looks at German case law on the subject. Also examined are the way in which the issue of human rights and some doubts which have arisen among authors and the courts have been resolved. The positive aspects of the new regulations are underlined and the author concludes with some proposals for application of these, lege ferenda, in Spain.

A large number of surgical procedures involving the globus pallidus and ansa lenticularis were performed from 1939 to the late 1950s for alleviation of rigidity and tremor, two of the main symptoms of Parkinson's disease. Several groups reported beneficial effects using a wide array of techniques and targets within the pallidum and its projections. Over time, pallidal targets lying in the ventral and posterior portions of the internal pallidum were considered to be the most effective. Based on anatomic studies, surgical misadventures, and empirical observations, there was an abrupt shift regarding the favored target to treat parkinsonian tremor to the thalamus, and most neurosurgeons abandoned pallidotomy in the 1960s. With the advent of L-dopa and the realization of its striking clinical benefits in the mid 1960s, within 5 to 10 years, virtually all surgery for Parkinson's disease ceased. We are now witnessing a rediscovery of pallidotomy as patients with Parkinson's disease are experiencing the shortcomings of medical therapy. In this article, we examine the evolution of pallidotomy and discuss the reasons for the renewed interest in this procedure.

Stereotactic surgery for Parkinson's disease (PD) has regained interest due to the recently described hyperactivity of the subthalamic-pallidal pathway. Many patients suffering from complications associated with the chronic use of levodopa may benefit from surgical treatments. There are different surgical targets and techniques (ablative and deep brain stimulation). The choice of one particular target and technique relies on the clinical symptoms of the patient. The risk/benefit ratio of surgery is related to the careful selection of patients and the technical accuracy. Intraoperative microrecording is considered the best method to avoid side effects and partial results. A series of patient's selection and follow-up assessment criteria are proposed.

At present, there are three major surgical approaches to Parkinson's disease (PD): (1) Ablative surgery (i.e. pallidotomy, thalamotomy); (2) deep brain stimulation (DBS) of the thalamus, internal globus pallidus (GPi) and subthalamic nucleus (STN); and (3) grafting fetal mesencephalic cells into the striatum. As a result of increasing understanding of the pathophysiology of the basal ganglia and the demonstration of surgical alleviation of experimental parkinsonism, surgery has regained a paramount importance in the management of PD. The aim of pallidotomy and DBS is to reduce the excessive inhibitory output from the GPi and substantia nigra reticulata (SNr). Pallidotomy and DBS of the STN or GPi aim to reverse the pathophysiological consequences of dopamine deficiency in PD, and should be considered entirely symptomatic treatments. The ideal candidates for pallidotomy are young patients in good general health in whom dyskinesias are the main reasons for disability. Patients with severe bilateral problems uncontrollable with present pharmacological tools are candidates for DBS. As yet, there are no formal data to help decide how to choose between GPi and STN stimulation. In our practice, patients are allocated to GPi stimulation when 'on' dyskinesias are extremely severe. In most other instances, we prefer to perform STN stimulation. At present there is almost no reason to decide for the thalamic stimulation since tremor is equally arrested by STN stimulation, which in addition improves all other features of PD. Equally the only indication for thalamotomy would be a patient with long-standing tremor as the main clinical manifestation, which can not be controlled with drugs. The proportion of patients in whom the thalamus will be the preferable target for either DBS or thalamotomy is small (less than 5%). Grafting aims to repair the nigrostriatal pathway and restore dopaminergic function in the striatum. In the future implants containing not only dopaminergic cells but also growth factors and a variety of other substances could become a method to not only functionally compensate the biochemical abnormalities of PD but also to arrest its progression. This technique is limited to a few centres around the world owing to the technical, logistical and ethical problems of obtaining and handling embryonic cells. At present, grafting of dopaminergic cells is perhaps best suited for patients with young-onset PD (less than 45 years old) who are at high risk of developing complications within a short time of beginning pharmacological treatment and in whom the idea of making lesions or implanting electrodes into the brain for decades seems less appealing. Consideration of surgery in any given patient should be weighed against the risks (about 1% mortality and 2-6% of severe morbidity-hemiplegia, cognitive deficit, speech problems, etc.) associated with these techniques. The development of better imaging methods and the growing expertise of multidisciplinary teams will undoubtedly make surgery for PD safer and more effective in the future.

The effects of nigrostriatal denervation and L-dopa therapy on GABAergic neurons were analysed in patients with Parkinson's disease and in monkeys rendered parkinsonian by MPTP intoxication. The expression of the messenger RNA coding for the 67 kDa isoform of glutamic acid decarboxylase (GAD67 mRNA), studied by quantitative in situ hybridization, was used as an index of the GABAergic activity of the striatal neurons. A significant increase in GAD67 mRNA expression, generalized to all GABAergic neurons, was observed in MPTP-treated monkeys compared to control monkeys in the putamen and caudate nucleus (+44 and +67% respectively), but not in the ventral striatum. L-Dopa therapy significantly reduced GAD67 mRNA expression in the putamen and caudate nucleus to levels similar to those found in control monkeys. However, the return to normal of GAD67 mRNA expression was not homogeneous across all neurons since it was followed by an increase of labelling in one subpopulation of GABAergic neurons and a decrease in another. These data suggest that in MPTP-treated monkeys the degeneration of nigrostriatal dopaminergic neurons results in a generalized increase in GABAergic activity in all the GABAergic neurons of the striatum, which is partially reversed by L-dopa therapy. As the expression of GAD67 mRNA is less intense in the ventral than in the dorsal striatum, this increase in striatal GABAergic activity may be related to the severity of nigrostriatal denervation. In parkinsonian patients who had been chronically treated with L-dopa, GAD67 mRNA expression was significantly decreased in all GABAergic neurons, in the caudate nucleus (by 44%), putamen (by 43.5%) and ventral striatum (by 26%). The opposite variation of GAD67 mRNA in patients with Parkinson's disease, compared with MPTP-treated monkeys, might be explained by the combination of chronic nigrostriatal denervation and long-term L-dopa therapy.

Hyperactivity of the subthalamic nucleus (STN) is major characteristic of parkinsonism secondary to substantia nigra lesions. Interruption of the STN-internal pallidum (GPi) pathway is a new stereotactic target for Parkinson's disease. We have studied the antiparkinsonian efficacy of STN lesions in MPTP-treated monkeys. Four rhesus monkeys were made parkinsonian by MPTP (i.v. 0.15 +/- 1 mg/kg) administration over 3 months. Unilateral subthalamotomy (kainic acid) was performed by a standard stereotactic method. Severity was rated from 0 (normal) to V by fine manual motor tests. Three monkeys (severity state III/IV) showed marked improvement in spontaneous activity, facial expression and manual dexterity bilaterally but significantly greater in the limb contralateral to the lesion. Mild hemichorea was present in 2 and hemiballism in one. L-Dopa treatment (50 mg b.i.d.) enhanced the hemidyskinesias moderately. The therapeutic effect has persisted for over 8 months postsurgery. Monkey No.4 (severity stage V) showed chorea in the lower limb contralateral to the lesion but no improvement and died a few days later. Subthalamotomy improves parkinsonism in moderately severe parkinsonian monkeys. Dyskinesia might be a persistent complication.

Hyperactivity in the subthalamic nucleus (STN) projections to the globus pallidus medialis (GPM) has been established as a crucial feature of parkinsonism in animal models of Parkinson's disease (PD). Recent experiments blocking the STN glutamatergic output to GPM or lesioning the STN support this concept by showing a dramatic reversal of parkinsonism. We review the role of stereotaxic surgery in the past and the possible future application of subthalamotomy for PD.

Spinal epidural abscesses (SEA) are an infrequent disease which should be suspected in patients with spinal and/or radicular pain, neurologic deficits and fever. We present 3 patients with SEA (two lumbar and one dorsal) who recovered following exclusively antibiotic treatment. The complete disappearance of the abscess was proven by magnetic resonance. Patients with SEA and discrete, stable deficits and with known germs, are susceptible to medical and not surgical treatment.

In rats with a lesion of the dopaminergic nigrostriatal pathway induced by 6-hydroxydopamine (6-OHDA), the histologic and functional viability of the striatal implant of fetal mesencephalic substantia nigra has been demonstrated. In the same model, the implant of adrenal medulla is also effective but less lasting. In monkeys with parkinsonism induced by MPTP there are suggestions of effectiveness of the fetal mesencephalic implant and also of other tissues such as placenta and sympathetic ganglion or sural nerve. Now the possibility of a better functional recovery by acting on the neuronal growth factors is being evaluated. In patients with Parkinson's disease, the accumulated experience indicates that 32% are improved with adrenal medulla implant, but the best candidates are those who also benefit from the available drug therapy without the risks of surgery. The implant of fetal tissue has been carried out in about 90 patients, with very variable results. In the most thoroughly investigated patients the improvement has been moderate. The future research points to the identification of the factors that control and regulate striatal reinnervation and the use of genetically determined cells. That would permit a more precise reposition of the biochemical deficiency in Parkinson's disease, without the ethical and practical problems derived from the use of fetal tissue.

The authors evaluate subarachnoid hemorrhage (SAH) in the autonomous community of Navarra during 3 years. Ninety-five patients were evaluated (mean age (MA) 51.47 years). They were divided in groups depending on angiographic findings. Thirty-four had an intracranial aneurysm (MA 5%.23 years) with a female preponderance (66.7% vs 33.3%). Eight patients had an arteriovenous malformation (AVM) (MA 33.7 years); in 35 patients the angiographic study was negative (MA 44 years) and in 18 angiography was not carried out (MA 66.66 years). Computed tomography was positive in 40% of patients and there was a correlation between the amount of blood in the cisterns and poor outcome of patients after 6 months. In the discussion, the authors emphasize the high incidence of SAH without angiographic findings.

The authors describe a case of a giant intradiploic epidermoid cyst of the occipital bone with an intracranial extension in the posterior fossa and no signs of neurological involvement. The lesion started as a painless lump under the scalp. Roentgenographic and computed tomographic findings led to a correct diagnosis, and the complete removal of the cyst was accomplished, despite its large size. The total removal of these cysts is associated with a good prognosis.

Subarachnoid hemorrhage (SAH) from a ruptured intracranial aneurysm represents a major health issue. The natural history, rebleeding, fibrinolytic therapy and vasospasm are reviewed in this article. Current evaluation of the existing data suggests that early aneurysm surgery and aggressive postoperative volume expansion therapy constitute the best presently approach to patients with ruptured intracranial aneurysms.