Globus pallidus internus activity during simultaneous bilateral microelectrode recordings in status dystonicus.

Limited data are available regarding the electrophysiology of status dystonicus (SD). We report simultaneous microelectrode recordings (MERs) from the globus pallidus internus (GPi) of a patient with SD who was treated with bilateral deep brain stimulation (DBS). Mean neuronal discharge rate was of 30.1 ± 10.9 Hz and 38.5 Hz ± 11.1 Hz for the right and left GPi, respectively. On the right side, neuronal electrical activity was completely abolished at the target point, whereas the mean burst index values showed a predominance of bursting and irregular activity along trajectories on both sides. Our data are in line with previous findings of pallidal irregular hypoactivity as a potential electrophysiological marker of dystonia and thus SD, but further electrophysiological studies are needed to confirm our results.

Shifting from constant-voltage to constant-current in Parkinson's disease patients with chronic stimulation.

The study aimed to evaluate safety and efficacy of shifting stimulation settings from constant-voltage (CV) to constant-current (CC) programming in patients with Parkinson's disease (PD) and chronic subthalamic nucleus deep brain stimulation (STN DBS). Twenty PD patients with chronic STN DBS set in CV programming were shifted to CC and followed for 3 months; the other stimulation settings and the medication regimen remained unchanged. Side effects, motor, non-motor, executive functions, and impedance were assessed at baseline and during follow-up. No adverse events were observed at time of shifting or during CC stimulation. Motor and non-motor measures remained unchanged at follow-up despite impedance decreased. Compared to baseline, inhibition processes improved at follow-up. The shifting strategy was well tolerated and the clinical outcome was maintained with no need to adjust stimulation settings or medications notwithstanding a decrease of impedance. Improvement of inhibition processes is a finding which needed further investigation.

Hydrocephalus: an underrated long-term complication of microvascular decompression for trigeminal neuralgia. A single institute experience.

BACKGROUND: Hydrocephalus is a common complication of posterior fossa surgery, but its real incidence after microvascular decompression (MVD) for idiopathic trigeminal neuralgia (TN) still remains unclear. The aim of this study was to focus on the potential association between MVD and hydrocephalus as a surgery-related complication. METHODS: All patients who underwent MVD procedure for idiopathic TN at our institute between 2009 and 2014 were reviewed to search for early or late postoperative hydrocephalus. RESULTS: There were 259 consecutive patients affected by idiopathic TN who underwent MVD procedure at our institution between 2009 and 2014 (113 men, 146 women; mean age 59 years, range 30-87 years; mean follow-up 40.92 months, range 8-48 months). Nine patients (3.47 %) developed communicating hydrocephalus after hospital discharge and underwent standard ventriculo-peritoneal shunt. No cases of acute hydrocephalus were noticed. CONCLUSIONS: Our study suggests that late communicating hydrocephalus may be an underrated potential long-term complication of MVD surgery.

Peripheral nerve field stimulation for chronic neuropathic pain: a single institution experience.

BACKGROUND: Peripheral nerve field stimulation (PNFS) is a novel neurosurgical procedure consisting of implantation of subcutaneous leads in specific painful areas in different types of painful, drug-resistant syndromes. The objective of this study was to evaluate the efficacy of PNFS in several patients affected by different chronic neuropathic pain syndromes, along with its risks, limits and possible correlation between the results achieved and the patients' main symptoms. METHODS: Twenty-two patients affected by different types of chronic neuropathic pain were submitted to PNFS at the Department of Neurosurgery of the Istituto Neurologico "C. Besta" in Milan between July 2009 and July 2013. The visual analog scale (VAS) and variations in the use of analgesic drugs, along with complications, were considered to assess results. RESULTS: In 59 % of our patients, an average pain reduction of 5.50 points on the visual analog scale was observed (average pre-implant score 8.86 and average post-implant score 3.36). These patients reduced their analgesic drug use after PNFS. We observed no early or long-term complications after our last follow-up evaluation. CONCLUSIONS: PNFS can be considered an effective and safe option to treat carefully selected, drug-resistant and chronic neuropathic pain patients; the reversibility of the procedure and its lack, at least in our hands, of long-term complications may contribute to wider use of this procedure.

Pallidal stimulation for acquired dystonia due to cerebral palsy: beyond 5 years.

BACKGROUND AND PURPOSE: There is increasing evidence that deep brain stimulation (DBS) of the globus pallidus internus (GPi) is effective in patients with idiopathic or inherited generalized dystonia. There is comparatively less experience about the effects of GPi DBS on acquired dystonia, particularly dystonia due to cerebral palsy (DCP). Clinical and demographic outcome predictors for DBS in dystonia syndromes are also poorly defined. Our aim was to examine the efficacy and safety of GPi DBS for the treatment of generalized DCP. METHODS: Fifteen patients with DCP up to 6.2 years after DBS surgery were studied. Only mild limb spasticity or mild static brain magnetic resonance imaging abnormalities were acceptable for inclusion. Dystonia severity and disability were assessed by the Burke-Fahn-Marsden dystonia rating scale (BFMDRS), and health-related quality of life was assessed by the Short Form General Health Survey (SF-36) scale. The amount of energy delivered was calculated, and adverse events and side effects were collected. RESULTS: At last follow-up, BFMDRS motor score improved on average by 49.5%, and the disability score improved by 30%. Health-related quality of life improved in most patients. Age at implant, age at onset and disease duration did not correlate to outcome, whilst higher pre-operative dystonia severity and occurrence of spasticity were associated with poorer outcome. The patients received a stable amount of energy after the first 2 years post-implant and throughout all the observation period. There were few serious adverse events or side effects. CONCLUSIONS: The outcome was encouraging in the majority of DCP patients, with a stable outlook and a good safety profile.

Impulse control behaviours in patients with Parkinson's disease after subthalamic deep brain stimulation: de novo cases and 3-year follow-up.

OBJECTIVE: To document the occurrence of impulse control behaviours (ICBs) in patients with Parkinson's disease after 3 years of continuous deep brain stimulation (DBS) of the subthalamic nucleus (STN). METHODS: Detailed neurological and ICB assessments were performed before STN DBS and up to 3 years after implant. RESULTS: 13 out of 56 patients (23.2%) had ICBs at baseline; they took higher doses of dopamine agonists (DAA). Three years after implant 11 had fully remitted with a 60.8% reduction of DAA medication; the remaining two, who had a similar medication reduction, had only compulsive eating, having recovered from hypersexuality. Six of the 43 patients without ICBs at baseline (14%) developed transient de novo ICBs after implant; none of them had ICBs at the 3-year observation. CONCLUSIONS: ICBs were abolished in patients 3 years after STN DBS and DAA dosages were lowered. New ICBs may occur after implant and are transient in most cases. Compulsive eating may be specifically related to STN stimulation.

Adult medulloblastoma: multiagent chemotherapy with cisplatinum and etoposide: a single institutional experience.

In 1991, a prospective phase II trial was initiated to evaluate the efficacy of treatment for adults with medulloblastoma (MB). After surgery, patients were staged with a neuroradiologic examination of the brain and neuroaxis and by cerebrospinal fluid cytology. All patients received three cycles of upfront cisplatinum (cisplatinum) and etoposide (VP16) chemotherapy followed by cranio-spinal radiation therapy. The current article reports on the long-term results from that trial. After a median follow-up of 14.9 years, among a total of 28 adults with MB, the overall progression-free survival and overall survival (OS) rates at 5 years were 57.6 and 80%, respectively. The median OS for the whole group of patients was 11.3 years. The observed toxicity was mainly hematological, with leukopenia and thrombocytopenia (16% of grades 3 and 4). In summary, in our small series of patients, the role of combination administration of CDDP + VP16 started before the initiation of radiotherapy in reducing recurrences, particularly distant recurrences, remains unclear. To know whether adding chemotherapy to craniospinal radiation in adult therapy increases relapse-free and overall survival, we must await the results of a larger randomized controlled clinical trial.

Treatment of alterations in CSF dynamics.

Alterations of the intracranial pressure (ICP) may be present in several conditions. The aim of this brief review is to focus on two relatively rare conditions characterized by alterations in cerebro-spinal fluid dynamics--Spontaneous Intracranial hypotension (SIH) and Idiopathic Intracranial hypertension (IIH)--in which headache is one of the key symptoms. The most relevant clinical features, the expected MRI findings, and the therapeutic options regarding both conditions are discussed.

A modified visual analogue scale for the assessment of chronic pain.

The present common evaluation of pain is scored through the use of visual analogue scale (VAS) to assess the intensity of pain and, sometimes, an additional table in which the frequency of pain attacks during the day is reported. We propose a modified 2D-VAS to assess both the intensity and the frequency (expressed by the percentage of the time in which pain is experienced during the day). Thus with only one scale and graphic representation, we can have a clear picture of the patient's condition before and during any treatment to relieve his pain.

Application of intraoperative indocyanine green angiography for CNS tumors: results on the first 100 cases.

PURPOSE: To investigate the application of indocyanine green (ICG) videoangiography during microsurgery for central nervous system (CNS) tumors. METHODS: One hundred patients with CNS tumors who underwent microsurgical resection from December 2006 to December 2008 were retrospectively analyzed. The diagnosis was high grade glioma in 54 cases, low grade in 17 cases, meningioma in 14 cases, metastasis in 12 cases and hemangioblastoma in 3 cases. Overall, ICG was injected intraoperatively 194 times. The standard dose of 25mg of dye was injected intravenously and intravascular fluorescence from within the blood vessels was imaged through an ad hoc microscope with dedicated software (Pentero, Carl Zeiss Co., Oberkochen, Germany). Pre-resection and post-resection arterial, capillary and venous ICG videoangiographic phases were intraoperatively observed and recorded. RESULTS: ICG videangiography allowed for a good evaluation of blood flow in the tumoral and peritumoral exposed vessels in all cases. No side effects due to ICG were observed. CONCLUSIONS: ICG video-angiography is a significant method for monitoring blood flow in the exposed vessels during microsurgical removal of CNS tumors. Pre-resection videoangiography provides useful information on the tumoral circulation and the pathology-induced alteration in surrounding brain circulation. Post-resection examination allows for an immediate check of patency of those vessels that are closely related to the tumor mass and that the surgeon does not want to damage.

Expression of vascular endothelial growth factor receptor-1/-2 and nitric oxide in unruptured intracranial aneurysms.

The biological mechanisms associated with the development and rupture of intracranial aneurysms are not fully understood. To clarify the role of VEGF and the related receptors in the pathophysiology of aneurysm, immunostaining for VEGF, VEGFR1 and VEGFR2 was performed on specimens from six unruptured aneurysms and on two specimens of normal arteries wall as a control. The results were correlated with NO concentration of CSF collected during surgery from 8 patients affected by unruptured aneurysms and in 11 control patients. The immunohistochemical data showed a different pattern of VEGF/VEGFR1/VEGFR2 in aneurysms when compared with control. The results of this preliminary study suggest an imbalance of VEGF, VEGFR1 and VEGFR2, and the interaction of VEGF and NO in the pathophysiology of unruptured aneurysms. Our data support the hypothesis of aneurysm formation associated with a loss of expression of VEGFR1, moderate expression of VEGFR2 and high concentration of nitrate.

Intraoperative microrecordings in the posterior hypothalamus of anaesthetized humans with aggressive behaviour.

Two patients with uncontrollable aggressive behaviour underwent the placement of stimulating leads in the posterior hypothalamus (pHyp). One patient had also multifocal refractory epilepsy. Microrecordings were obtained in both patients during surgery under general anaesthesia. Firing rate, interspike intervals and oscillatory discharge patterns were analysed in 14 neurons. A mean discharge rate of 19 Hz, and oscillatory activity at 7-8 Hz were recorded in the first patient with aggressiveness and epilepsy. In the second patient the mean firing rate was 10 Hz, with evidence of both tonic and random firing patterns. Previous studies in patients with cluster headache showed that a discharge rate around 20 Hz and lack of a specific rhythmic pattern were the most consistent characteristics of neuronal discharge in this area. Our present findings therefore would suggest that the pattern of discharge of neurons in the pHyp should be evaluated with reference to the presence of concurrent pathology.

A computational model to compare different investment scenarios for mini-stereotactic frame approach to deep brain stimulation surgery.

UNLABELLED: Deep brain stimulation (DBS) alleviates symptoms of many neurological disorders by applying electrical impulses to the brain by means of implanted electrodes, generally put in place using a conventional stereotactic frame. A new image guided disposable mini-stereotactic system has been designed to help shorten and simplify DBS procedures when compared to standard stereotaxy. A small number of studies have been conducted which demonstrate localization accuracies of the system similar to those achievable by the conventional frame. However no data are available to date on the economic impact of this new frame. AIM: The aim of this paper was to develop a computational model to evaluate the investment required to introduce the image guided mini-stereotactic technology for stereotactic DBS neurosurgery. METHODS: A standard DBS patient care pathway was developed and related costs were analyzed. A differential analysis was conducted to capture the impact of introducing the image guided system on the procedure workflow. The analysis was carried out in five Italian neurosurgical centers. RESULTS: A computational model was developed to estimate upfront investments and surgery costs leading to a definition of the best financial option to introduce the new frame. Investments may vary from Euro 1.900 (purchasing of Image Guided [IG] mini-stereotactic frame only) to Euro 158.000.000. Moreover the model demonstrates how the introduction of the IG mini-stereotactic frame doesn't substantially affect the DBS procedure costs.

Hypothalamic stimulation for trigeminal neuralgia in multiple sclerosis patients: efficacy on the paroxysmal ophthalmic pain.

Trigeminal neuralgia is a disorder characterized by paroxysmal pain arising in one or more trigeminal branches; it is commonly reported in multiple sclerosis. In multiple sclerosis patients the ophthalmic branch may be frequently involved and the risks carried by neurosurgical ablative procedures are higher including major adverse effects such as corneal reflex impairment and keratitis. The objective of this works is to assess the role of posterior hypothalamus neuromodulation in the treatment of trigeminal neuralgia in multiple sclerosis patients. Five multiple sclerosis patients suffering from refractory recurrent trigeminal neuralgia involving all three trigeminal branches underwent deep brain stimulation of the posterior hypothalamus. The rationale of this intervention emerges from our earlier success in treating pain patients suffering from trigeminal autonomic cephalalgias. After follow-up periods that ranged from 1 to 4 years after treatment, the paroxysmal pain arising from the first trigeminal branch was controlled, whereas the recurrence of pain in the second and third trigeminal branches necessitated repeated thermorhizotomies to control in pain in two patients after 2 years of follow-up. In conclusion, deep brain stimulation may be considered as an adjunctive procedure for treating refractory paroxysmal pain within the first trigeminal division so as to avoid the complication of corneal reflex impairment that is known to follow ablative procedures.

Clinical features and outcomes in spontaneous intracranial hypotension: a survey of 90 consecutive patients.

Spontaneous intracranial hypotension (SIH) is a rare disabling condition whose main clinical manifestation is orthostatic headache. We analysed clinical characteristics in relation to time to resolution in 90 consecutive patients diagnosed with SIH at our centre between 1993 and 2006. After excluding 7 patients lost to follow-up, the remaining 83 cases were divided into four groups: Group A (53 cases) with progressively worsening orthostatic headache; Group B (3 cases) with severe acute-onset orthostatic headache; Group C (9 cases) with fluctuating non-continuous headache, of mild severity, that, in 33% of cases, did not worsen on standing; Group D (18 cases), 5 with a previous history of headache, 14 with orthostatic headache, and 10 with altered neurological examination. Complete symptoms and neuroradiological resolution occurred during follow-up in Groups A, B and D, but was longer in Group D probably in relation to more severe clinical picture with altered neurological examination. However, after a mean of 52 months (range 24-108), none of the nine Group C patients had MRI indicating complete resolution. The main characteristic of Group C related to incomplete resolution was delayed diagnosis. These preliminary findings suggest that early diagnosis of SIH correlates with better outcome, further suggesting that patients with a new headache that may worsen on standing or sitting should undergo MRI with contrast to expedite a possible SIH diagnosis, even if the pain is relatively mild.

Costs of hypothalamic stimulation in chronic drug-resistant cluster headache: preliminary data.

In about 20% of chronic cluster headache (CH) cases, drugs may become ineffective. Under these circumstances, steroids and triptans are frequently employed leading to fearful side effects in one and high costs in the other. The direct costs of drug-resistant chronic CH are mainly due to frequent medical consultations and frequent use of expensive drugs. In recent years, hypothalamic stimulation has been employed to treat drug-resistant chronic CH patients suffering multiple daily attacks and long-term results from different centres show a 60% overall benefit. Nine years since the introduction of this technique, we attempt a preliminary analysis of the direct costs of hypothalamic stimulation based on patients treated at our centre. We estimated the following direct costs as follows: cost of neurosurgery plus cost of equipment (electrode, connection and impulse generator = 25,000 euro), cost of hospital admissions in long-term follow-up (2,000 euro per admission), cost of single sumatriptan injection (25 euro). Number of daily sumatriptan injections in the year before and for each year after hypothalamic implantation was obtained from headache diaries. To estimate the saving due to the reduction in sumatriptan consumption following hypothalamic stimulation, we calculated the following for each year of follow-up after surgery: number of sumatriptan injections in the year before surgery minus number of sumatriptan injections in each year, updated to December 2008. In our 19 implanted patients, the costs of neurosurgery plus cost of equipment were 475,000 euro; the costs of hospital admissions during follow up were 250,000 euro. Reduction in sumatriptan consumption resulted in a total saving of 3,573,125 euro. Hence, in our 19 patients, the sumatriptan saving (3,573,125 euro) minus the direct costs due to operation and follow up hospitalisations (475,000 + 250,000) euro is equal to 2,848,125 euro. These preliminary results indicate that hypothalamic stimulation is associated with marked reduction of direct costs in the management of complete drug-resistant chronic CH.

Cluster headache and TACs: rationale for central and peripheral neuromodulation.

Cluster headache, the most severe of primary headache conditions for functional and social impairment it provokes, has been recently the object of a great amount of clinical, physiopathological, surgical and functional neuroradiological studies aimed to uncover the real mechanisms which underlie its disabling manifestations. Refinement of methodological and systematic features of multidisciplinary researches in this field has been allowing for more and more precise delineations of the role of both peripheral and central nervous system's contribution in pathophysiology of the disease. Aim of this manuscript is the report of the present knowledge in the role of the different surgical options in the treatment of drug-resistant cluster headache and Short-lasting Unilateral neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT), which take into account their different hypothesized pathological mechanisms and which comprise central nervous system's approach (Deep Brain Stimulation [DBS] and peripheral approach, namely Occipital Nerve Stimulation (ONS) and Vagal Nerve Stimulation (VNS).

Application of IHS criteria to headache attributed to spontaneous intracranial hypotension in a large population.

We applied the recent International Headache Society (IHS) criteria for headache related to spontaneous intracranial hypotension (SIH) to 90 consecutive patients with a final diagnosis of SIH confirmed by cerebral magnetic resonance imaging with contrast. Orthostatic headache (developing within 2 h of standing or sitting up) was present in 67 patients (75%) but appeared within 15 min after standing or sitting-as required by point A of the criteria-in only 53 (59%). Forty-four (49%) patients did not satisfy point A, including 22 (24%) with non-orthostatic headache and 14 (16%) with headache developing >or= 15 min after standing or sitting up; 80 (89%) did not satisfy point D. Only three (3%) patients had headache fully satisfying the IHS criteria. These findings indicate that the current IHS criteria do not capture most patients with SIH-associated headache. Excluding the requirement for response to epidural blood patch (criterion D) and considering headaches appearing within 2 h of sitting or standing up would capture more patients.

Use of self-closing U-clips for dural repair in mini-invasive surgery for herniated disc.

OBJECT: The feasibility of a new technique of dural repair (self-closing U-clips) in mini-invasive surgery for herniated disk is demonstrated in this case report. MATERIALS AND METHODS: A 44-year-old male patient underwent lumbar microdiscectomy at out Institute, with subsequent dural leak as surgical complication; the dural leak re-appeared even after a second intervention in which we used muscle and dural graft and fibrin glue to repair the leak. We then decided to employ self-closing nitinol- U-clip to achieve primary dural closure. RESULTS: After the intervention the patient no more presented signs or symptoms due to the unintended durotomy, and the postoperative course was uneventful. CONCLUSION: Self-closing nitinol U-clips (Medtronic, Inc., Minneapolis) can be used for closing a dural tear through a mini-invasive approach that could make a conventional microsuturing technique very difficult.

Results by motor cortex stimulation in treatment of focal dystonia, Parkinson's disease and post-ictal spasticity. The experience of the Italian Study Group of the Italian Neurosurgical Society.

Extradural motor cortex stimulation has been employed in cases of Parkinson's disease (PD), fixed dystonia (FD) and spastic hemiparesis (SH) following cerebral stroke. Symptoms of PD are improved by EMCS: results were evaluated on the basis of the UPDRS and statistically analysed. In PD EMCS is less efficacious than bilateral subthalamic nucleus (STN) stimulation, but it may be safely employed in patients not eligible for deep brain stimulation (DBS). The most rewarding effect is the improvement, in severely affected patients, of posture and gait. FD, unresponsive to bilateral pallidal stimulation, has been relieved by EDMS. In SH reduction of spasticiy by EMCS allows improvement of the motor function.