Directional deep brain stimulation in the management of Parkinson's disease: efficacy and constraints-an analytical appraisal.

Deep brain stimulation (DBS) is a widely employed treatment for Parkinson's disease. However, conventional DBS utilizing ring-shaped leads can often result in undesirable side effects by stimulating nearby brain structures, thus limiting its effectiveness. To address this issue, a novel DBS electrode was developed to allow for directional stimulation, avoiding neighboring structures. This literature review aims to analyze the disparities between conventional and directional DBS and discuss the benefits and limitations associated with this innovative electrode design, focusing on the stimulation-induced side effects it can or cannot mitigate. A comprehensive search was conducted in MEDLINE/PubMed, ScienceDirect, and EBSCO databases using the Boolean search criteria: "Deep brain stimulation" AND "Parkinson" AND "Directional." Following the application of inclusion and exclusion criteria, the selected articles were downloaded for full-text reading. Subsequently, the results were organized and analyzed to compose this article. Numerous studies have demonstrated that directional DBS effectively reduces side effects associated with brain stimulation, prevents the stimulation of non-targeted structures, and expands the therapeutic window, among other advantages. However, it has been observed that directional DBS may be more challenging to program and requires higher energy consumption. Furthermore, there is a lack of standardization among different manufacturers of directional DBS electrodes. Various stimulation-induced side effects, including dysarthria, dyskinesia, paresthesias, and symptoms of pyramidal tract activation, have been shown to be mitigated with the use of directional DBS. Moreover, directional electrodes offer a wider therapeutic window and a reduced incidence of undesired effects, requiring the same or lower minimum current for symptom relief compared to conventional DBS. The utilization of directional leads in DBS offers numerous advantages over conventional electrodes without significant drawbacks for patients undergoing directional DBS therapy.

Lacrimal gland pleomorphic adenoma: a narrative review.

We present a literature review of 57 publications describing this pathology, published from the year 2012. In all these studies patients were reported to depict a slow-growing, motionless mass, which is painless at most times. All cases were managed by total excision, except for one report where adjuvant radiotherapy was applied. Among the several therapeutic strategies, the total tumor resection, preserving the tumor pseudocapsule intact, appears to be a consensus in treating the disease efficiently. Furthermore, fine-needle aspiration biopsy, including the assessment of genetic alterations, has proved to be a valuable tool in the diagnosis of challenging cases. Our literature survey also suggests that an incisional biopsy before the surgery may lead to the pseudocapsule disruption, thus considerably increasing the chances of adenoma recurrence, enabling its malignization. At present, genetics studies indicate that the molecular aberrations involved in the adenoma are similar to those represented in the salivary gland tumor pathogenesis. Further, in the recurrent cases, the pathology becomes difficult to treat and multiple surgeries may be required, occasionally, leading to radical surgery treatment.

Lacrimal gland pleomorphic adenoma: a narrative review / Adenoma pleomórfico de glândula lacrimal: uma revisão narrativa

ABSTRACT We present a literature review of 57 publications describing this pathology, published from the year 2012. In all these studies patients were reported to depict a slow-growing, motionless mass, which is painless at most times. All cases were managed by total excision, except for one report where adjuvant radiotherapy was applied. Among the several therapeutic strategies, the total tumor resection, preserving the tumor pseudocapsule intact, appears to be a consensus in treating the disease efficiently. Furthermore, fine-needle aspiration biopsy, including the assessment of genetic alterations, has proved to be a valuable tool in the diagnosis of challenging cases. Our literature survey also suggests that an incisional biopsy before the surgery may lead to the pseudocapsule disruption, thus considerably increasing the chances of adenoma recurrence, enabling its malignization. At present, genetics studies indicate that the molecular aberrations involved in the adenoma are similar to those represented in the salivary gland tumor pathogenesis. Further, in the recurrent cases, the pathology becomes difficult to treat and multiple surgeries may be required, occasionally, leading to radical surgery treatment.

RESUMO Uma revisão narrativa da literatura de 57 publicações que descrevem esta patologia, publicada a partir de 2012. Os pacientes têm uma massa de crescimento lento e imóvel, que na maioria das vezes é indolor. Todos os casos foram tratados por excisão total, com exceção de um relatório de radioterapia adjuvante. Entre as estratégias terapêuticas encontradas, a ressecção total do tumor, preservando a pseudocápsula tumoral intacta, parece ser um consenso. Alternativamente, a biópsia por aspiração de agulha fina incluindo a avaliação de alterações genéticas pode representar uma ferramenta valiosa nos casos diagnósticos desafiadores. Uma biópsia incisional antes da cirurgia não é recomendada, pois a ruptura da pseudocápsula aumenta consideravelmente a recorrência do adenoma, permitindo até mesmo sua malignização. Com relação à genética, estudos atuais indicam que as aberrações moleculares envolvidas no adenoma são semelhantes às da patogênese do tumor da glândula salivar. Para casos de recorrência, a patologia torna-se difícil de tratar e múltiplas cirurgias podem ser necessárias, às vezes levando a um tratamento cirúrgico radical.

Treatment of Hemichoreoathetosis with Arrhythmic Proximal Tremor after Stroke: The Role of Zona Incerta as a Target for Deep Brain Stimulation.

Deep brain stimulation (DBS) of the zona incerta has shown promising results in the reduction of medically refractory movement disorders. However, evidence supporting its efficacy in movement disorders secondary to hemorrhagic stroke or hemichoreoathetosis is limited. We describe a 48-year-old man who developed progressive hemichoreoathetosis with an arrhythmic, proximal tremor in his right arm following a thalamic hemorrhagic stroke. Pharmacological treatment was carried out with no change in the Abnormal Involuntary Movement Scale (AIMS) score after 4 weeks (14). After six sessions of botulinum toxin treatment, a subtle improvement in the AIMS score (13) was registered, but no clinical improvement was noted. The arrhythmic proximal movements were significantly improved after DBS of the zona incerta with a major decrease in the patient's AIMS score (8). The response to DBS occurring after the failure of pharmacological and botulinum toxin treatments suggests that zona incerta DBS may be an alternative for postthalamic hemorrhage movement disorders.

Predictive factors for beneficial application of high-frequency electromagnetics for tumour vaporization and coagulation in neurosurgery.

OBJECTIVE: To identify preoperative and intraoperative factors and conditions that predicts the beneficial application of a high-frequency electromagnetic field (EMF) system for tumor vaporization and coagulation. METHODS: One hundred three subsequent patients with brain tumors were microsurgically treated using the EMF system in addition to the standard neurosurgical instrumentarium. A multivariate analysis was performed regarding the usefulness (ineffective/useful/very helpful/essential) of the new technology for tumor vaporization and coagulation, with respect to tumor histology and location, tissue consistency and texture, patients' age and sex. RESULTS: The EMF system could be used effectively during tumor surgery in 83 cases with an essential contribution to the overall success in 14 cases. In the advanced category of effectiveness (very helpful/essential), there was a significant difference between hard and soft tissue consistency (50 of 66 cases vs. 3 of 37 cases). The coagulation function worked well (very helpful/essential) for surface (73 of 103 cases) and spot (46 of 103 cases) coagulation when vessels with a diameter of less than one millimeter were involved. The light-weight bayonet hand piece and long malleable electrodes made the system especially suited for the resection of deep-seated lesions (34 of 52 cases) compared to superficial tumors (19 of 50 cases). The EMF system was less effective than traditional electrosurgical devices in reducing soft glial tumors. Standard methods where also required for coagulation of larger vessels. CONCLUSION: It is possible to identify factors and conditions that predict a beneficial application of high-frequency electromagnetics for tumor vaporization and coagulation. This allows focusing the use of this technology on selective indications.

Spinal cord stimulation in the treatment of complex regional pain syndrome type 1: Is trial truly required?

OBJECTIVE: Spinal cord stimulation has been proven highly effective in the treatment of Complex Regional Pain Syndrome (CRPS). The definitive implantation of a neurostimulator is usually preceded by a therapeutic test (trial), which has the purpose of identifying whether the patient would respond positively to neuromodulation or not. The present study aims to analyze the surgical results of spinal cord stimulation in type 1 CRPS patients who have not undergone trial. PATIENTS AND METHODS: From January 2011 to August 2017, 160 patients underwent implantation of spinal cord neurostimulator. Out of that total number of surgeries, 33 patients were unequivocally diagnosed with type 1 Complex Regional Pain Syndrome and selected for this study. The efficacy of the surgical procedure concerning pain improvement was analyzed through the application of the Pain Disability Index and the Visual Analog Pain Scale. RESULTS: The mean sample age was 48.08 years. The majority of the study subjects were female (66.66%). In respect to the Pain Disability Index, a 65% improvement in disability was observed subsequently to the neurostimulator implantation; in addition, the means of the scores for preoperative and postoperative periods were, respectively, 55 ±â€¯8.69 (p < 0.0001) and 18.90 ±â€¯11.58 (p < 0.0001). Regarding the Visual Analogue Scale, the mean pain in the preoperative period was 9.43 ±â€¯0.77 (p < 0.0001), while the mean in postoperative period was 2.86 ±â€¯2.08 (p < 0.0001). Thus, an average reduction of 70% of painful symptoms was observed after the surgical procedure. CONCLUSION: Implantation of a spinal cord neurostimulator presented significant improvement in pain and disability of patients with type 1 CRPS in all cases. These results were obtained following the criteria: 1) patients presenting unequivocal diagnosis of type 1 CRPS; 2) submitted to constant current spinal cord neurostimulator implant; 3) underwent intraoperative tests for precise location of the spinal cord electrode implantation. Therefore, it is possible to suggest that a trial may be unnecessary in that subgroup of patients. Further studies would be required to confirm these findings.

Cystic trochlear nerve schwannoma. Case report.

BACKGROUND: Twenty-six cases of pathologically verified schwannomas of the trochlear nerve have been reported in the literature. Five of them had a large cystic component and a smaller solid portion. Complex skull base approaches have been usually applied for their removal. CASE DESCRIPTION: We report on a rare case of cystic trochlear schwannoma in a 52-year-old female patient. The patient presented with double vision, facial palsy, decreased hearing, hemiparesis on the right side, and severe gait instability. Magnetic resonance imaging revealed a 2.5-cm left-sided extra-axial lesion compressing the brain stem at the lower midbrain and upper pontine level. Total resection was performed via a retrosigmoid craniotomy. After the surgery, the neurological deficit diminished considerably. At 28 months follow-up, her only complaint was mild double vision when walking down the stairs and hypesthesia in the right half of her face. CONCLUSIONS: This case represents a rare pontomesencephalic lesion removed successfully via the simple retrosigmoid route.

Combined transconjunctival-eyebrow approach providing minimally invasive access to all orbital quadrants. Technical note.

Surgical approaches to treat orbital disease should provide a good exposure of intraorbital anatomical structures, allow their functional preservation, and provide good cosmetic results. The authors describe a minimally invasive, combined transconjunctival-eyebrow approach to all orbital quadrants in a step-wise manner. The indications, advantages, and limitations of the technique are highlighted. A transconjunctival approach via the postseptal area is described. It allows exposure of the medial, inferior, and lateral parts of the orbit. Depending on the orbital space to be exposed, a lateral or a medial eyebrow incision is then made. The eyebrow and the conjunctival incisions are connected by subperiosteal dissection. This combined access provides exposure to all intraconal muscles and to the superior, medial, lateral, and inferior portions of the optic nerve. The combined transconjunctival-eyebrow approach provides an excellent orbital exposure, with minimal damage to the circumjacent structures. It requires less operative time than other approaches and yields good cosmetic results. Intracranial or intrafacial tumor extension and tumors located purely in the orbital apex are limitations for the use of this technique.

Using an end-to-side interposed sural nerve graft for facial nerve reinforcement after vestibular schwannoma resection. Technical note.

Increasing rates of facial and cochlear nerve preservation after vestibular schwannoma surgery have been achieved in the last 30 years. However, the management of a partially or completely damaged facial nerve remains an important issue. In such a case, several immediate or delayed repair techniques have been used. On the basis of recent studies of successful end-to-side neurorrhaphy, the authors applied this technique in a patient with an anatomically preserved but partially injured facial nerve during vestibular schwannoma surgery. The authors interposed a sural nerve graft to reinforce the facial nerve whose partial anatomical continuity had been preserved. On follow-up examinations 18 months after surgery, satisfactory cosmetic results for facial nerve function were observed. The end-to-side interposed nerve graft appears to be a reasonable alternative in cases of partial facial nerve injury, and might be a future therapeutic option for other cranial nerve injuries.

The impact of hypotension due to the trigeminocardiac reflex on auditory function in vestibular schwannoma surgery.

OBJECT: Surgical manipulation of the fifth cranial nerve during its intra- or extracranial course may lead to bradycardia or even asystole as well as arterial hypotension, a phenomenon described as the trigeminocardiac reflex (TCR). The authors studied the impact of this reflex on postoperative auditory function in patients undergoing vestibular schwannoma (VS) surgery. METHODS: One hundred patients scheduled for VS surgery were studied prospectively for parameters influencing the postoperative auditory function. The evaluation included sex, age, pre- and postoperative auditory function, preoperative mean arterial blood pressure, preoperative medical diseases or medication (for example, antiarrhythmia drugs), tumor size and localization, and the intraoperative occurrence of the TCR. The TCR, which occurred in 11% of the patients, influenced the postoperative hearing function in the patients with Hannover Class T3 and T4 VSs. With an overall hearing preservation of 47%, 11.1% of the patients in the TCR group and 51.4% of those in the non-TCR group experienced preserved hearing function postoperatively. In cases involving larger tumors (Hannover Class T3 and T4), an intraoperative TCR was associated with a significantly worse postoperative hearing function during VS surgery (p = 0.005). CONCLUSIONS: The hypotension following TCR is a negative prognostic factor for hearing preservation in patients undergoing VS surgery. Patients' knowledge of this can be increased pre- and postoperatively. Further study of this phenomenon will advance the understanding of the underlying mechanisms and may help to improve hearing preservation by controlling the occurrence of the TCR.

Hemodynamic evaluation during balloon test occlusion of the sigmoid sinus: clinical and technical considerations.

Test occlusion of a patent dural sinus requires careful hemodynamic evaluation. We performed balloon test occlusion of the sigmoid sinus in a patient with an advanced-stage temporal bone malignancy that affected the dominant sigmoid sinus. Before and during the test occlusion, intrasinus pressure was monitored upstream from the balloon via the inner lumen of a double-lumen angioplasty balloon microcatheter. On the basis of the hemodynamic findings, permanent balloon occlusion was carried out without complications.

Peroneal nerve compression resulting from fibular head osteophyte-like lesions.

BACKGROUND: The anatomical relationship of the fibular head with the fibular nerve is a critical point in regard to injuries of peripheral nerves in the lower extremities. In this location, the peroneal nerve may be injured due to several mechanisms, and osteophyte-like lesions can be considered as a differential diagnosis. METHODS: The suitable literature concerning this association is reviewed and a case is presented. A 15-year-old adolescent boy presented with right peroneal nerve palsy on admission. The radiological examinations (computed tomography and magnetic resonance imaging) demonstrated an osteophytic lesion in the head of the right fibula. The patient underwent surgical decompression of the nerve and resection of the lesion. Postoperatively, there was a complete recovery of the deficits. CONCLUSIONS: The association of osteophyte-like bone changes and peroneal nerve palsy is rare. The differential diagnoses of these lesions include cartilaginous exostoses and osteochondromas, which may be related to hereditary multiple exostoses syndrome. The timing of the treatment plays an important role in the neurological recovery.

Epidermoid cysts of the cavernous sinus.

BACKGROUND: Epidermoid cysts involving the cavernous sinus are rare lesions. They can be divided into 3 different categories: extracavernous, interdural, and true intracavernous. METHODS: This classification of cavernous epidermoid cysts is correlated with the extent of tumor resection and the clinical outcome in reported cases here and elsewhere. RESULTS: Patients with cysts invading or compressing the cavernous sinus present with an excellent functional recovery after surgery independent of the extent of tumor resection. In cases of interdural cysts, there is often an adherence of the tumor capsule to the third and fourth cranial nerves. Therefore, in this group, subtotal resection is a safe strategy to prevent surgical morbidity. However, this policy may lead to a higher incidence of tumor recurrence in these cases. In true intracavernous lesions, a higher rate of total removal is possible despite the increased occurrence of internal carotid artery encasement and cranial nerve displacement. CONCLUSION: Postoperative outcome with preservation of neural and vascular structures in cavernous epidermoid cysts is more likely related to surgical strategy than to tumor localization. Independent of the different tumor origins in these cases, a subtotal resection is usually sufficient to achieve postoperative improvement of the symptoms without additional morbidity.

Evolution of vestibular schwannoma surgery: the long journey to current success.

The extraordinary improvement of patient outcome after surgical treatment for vestibular schwannomas is relatively recent and has occurred mainly over the last 30 years. The introduction of microsurgical techniques has resulted in increasing degrees of precise anatomical and functional preservation of the facial and cochlear nerves. An expanded microsurgical technique accompanied by continuous electrophysiological monitoring has resulted in marked changes in the primary goals for this surgery. Whereas in the past the primary goal of vestibular schwannoma management was to preserve the patient's life, the objective in vestibular schwannoma treatment today is to preserve neurological function. Long-term follow-up examinations show negligible recurrence rates, indicating that the aim of preservation of nerve function does not limit the completeness of tumor removal with modern neurosurgical techniques. Despite these advances in preserving the anatomical integrity of, for example, the cochlear nerve, losses of function and even deafness may occur postoperatively in some cases. Current biological and technical research in experimental and clinical settings addresses these problems. In this article, the authors report in detail the developments achieved in vestibular schwannoma surgery and the great clinicians to whom these results can be credited.

Ventral extradural spinal meningeal cyst causing cord compression: neurosurgical treatment.

Spinal extradural meningeal cysts are typically formed by a thin fibrotic membranous capsule, macroscopically similar that of an arachnoid membrane, filled by cerebro spinal fluid and related to a nerve root or to the posterior midline. Ventral location is extremely rare and when it occurs they usually cause spinal cord herniation through the ventral dural gap. A 61 year-old man who began with a two years long history of insidious tetraparesis, spasticity and hyperreflexia in lower extremities, and flaccid atrophy of upper limbs, without sensory manifestations, is presented. Investigation through magnetic resonance imaging demonstrated an extensive spinal ventral extradural cystic collection from C6 to T11. The lesion was approached through a laminectomy and a cyst-peritoneal shunt was introduced. The cyst reduced in size significantly and the patient is asymptomatic over a 48 months follow-up. This is the first reported case of a spontaneous ventral extradural spinal meningeal cyst causing cord compression. Cyst-peritoneal shunt was effective in the treatment of the case and it should be considered in cases in which complete resection of the cyst is made more difficult or risky by the need of more aggressive surgical maneuvers.

Raeder's syndrome after embolization of a giant intracavernous carotid artery aneurysm: pathophysiological considerations.

We present the case of a 47 years old woman submitted to an endovascular trapping of a left cavernous internal carotid artery aneurysm, in which the distal balloon was inflated, as usually done, within the cavernous segment of the internal carotid artery, different from the proximal one which was inflated inside the carotid canal due to technical problems. Consequently, a clinical picture of Raeder's paratrigeminal neuralgia took place. This is the first case report in the literature with theses characteristics. A review of the anatomic pathways and further considerations about the possible pathophysiological mechanisms involved are presented.

Primary pituitary abscess: case report.

Pituitary abscesses are potentially life-threatening lesions if not appropriately diagnosed and treated. The authors have operated on more than five hundred cases of pituitary tumors and only one represented a case of pituitary abscess. A 35-year-old woman was investigated for chronic frontal headache. CT scan showed a cystic sellar lesion with ring enhancement after contrast injection leading to an initial diagnosis of pituitary adenoma. She underwent a sublabial transsphenoidal approach to the pituitary gland. After dural opening, purulent material was obtained and no tumor or other associated lesion was detected. There was no evidence of current or previous septicemic illness, meningitis, cavernous sinus thrombosis or sinus infection. Cultures were negative. She was put on antibiotics and discharged after 4 weeks. Nowadays, 10 years after treatment, she is doing well, with no anterior pituitary hormone deficit. MRI shows a partially empty sella without residual lesion and the pituitary stalck is in the midline. The early diagnosis and adequate treatment of this life-threatening lesion may result in excellent prognosis.

[Prognostic factors in the treatment of the intradural extramedullary tumors: a study of 44 cases]. / Fatores prognósticos no tratamento dos tumores intradurais extramedulares: estudo de 44 casos.

Between 1993 and 1999, 44 patients submitted to resection of an expansible intradural extramedullary lesion who filled protocol requirements of appropriate follow up were studied. Patients were constituted by 43.2% female and 56.8% male. The mean age was 32.9 years old. Lesion most common location was at the thoracic spine, with 45.5% of the cases, followed by the lumbar level with 18.2%. Tumor extension varied from 1 to 7 vertebral segments, with an average of 2.5 levels. Schwannoma, with 65,9% of the cases, was the most frequent lesion, followed by meningioma with 20.5%. There were 2 cases of neurofibroma and 1 case of paraganglioma, neuroenteric cyst, metastasis and malignant schwannoma. The evolution was of improvement in 56.8%, stability in 31.8% and of worsening in 11.4%. There was no mortality related to the surgical procedure. All cases of worsening had total resection and they had lesions located in the thoracic segment. Total resection is the ideal modality of surgical treatment. However, at the thoracic level, where the peculiarities of spine irrigation prevail, surgical morbidade may be higher (p=0.014).

Posterior fossa gangliocytoma with facial nerve invasion: case report.

A 5 year-old boy with a cerebellar gangliocytoma with a peripheral right facial paresis and ataxia is presented. His MRI showed a heterogenous, diffuse lesion, isointense on T1 and hyperintense on T2-weigthed sequences, involving the right cerebellar hemisphere with direct extension into the right facial nerve. The present case is the first description of a gangliocytoma with direct facial nerve invasion, as demonstrated for the facial nerve paresis and supported by MRI and surgical inspection.