Stimulation of the globus pallidus internus in the treatment of Parkinson's disease: Long-term results of a monocentric cohort.

BACKGROUND: Pallidal deep brain stimulation (DBS) has shown to be beneficial in patients with advanced levodopa-responsive Parkinson's disease (PD) in several short-term studies. However, reported long-term outcomes of pallidal DBS for PD are limited and contradictory. METHODS: Eighteen consecutive PD patients were treated with unilateral or bilateral stimulation of the internal part of the globus pallidus (GPi). Assessments were carried out before and six months after neurosurgery, and annually thereafter for up to 16 years (mean follow-up time: 6 years). Primary outcomes included motor signs (Unified PD Rating Scale [UPDRS]-III), activities of daily living (ADL, UPDRS-II), and levodopa-induced motor complications (UPDRS-IV). RESULTS: The results show that GPi stimulation improves levodopa-responsive PD motor signs (UPDRS-III), levodopa-induced motor complications (UPDRS-IV), and ADL (UPDRS-II) in advanced PD. Among motor signs, tremor showed the best response to pallidal stimulation. Levodopa-induced motor complications and tremor showed improvements for more than 10 years after neurosurgery. CONCLUSIONS: The overall findings in our cohort demonstrate that pallidal stimulation is effective in reducing parkinsonian motor signs (UPDRS-III), particularly in the 'off'-medication state. Although the beneficial effects on bradykinesia, rigidity and ADL may be limited to 5-6 years, the follow up results indicate that the improvements of levodopa-induced motor complications (UPDRS-IV) and tremor can be sustained for more than 10 years.

Use of multimodal electrophysiological monitoring to predict outcome after subarachnoid hemorrhage? A prospective series.

AIM: Electrophysiological monitoring (EM) is still controversial in the prediction of outcome after subarachnoid hemorrhage (SAH). The absence of evoked potentials (EP) is a good predictor for unfavorable, whereas the prediction of favorable outcome may be less useful. Aim of this study was to evaluate, if multimodal EM provides significant information about the patients' outcome or if this method might be dispensable. METHODS: Multimodal EP data were recorded sequentially in 51 SAH-patients. The following data were recorded: World Federation of Neurological Surgeons (WFNS-) grade, Fisher grading score, endovascular versus neurosurgical treatment, aneurysm location and clinical outcome according to the Glasgow Outcome Scale (GOS). Multimodal electrophysiological monitoring included median nerve somatosensory evoked potential (M-SSEP), tibial nerve somatosensory evoked potential (T-SSEP), flash-visual evoked potential (f-VEP), brainstem auditory evoked potential (BAEP) and central conduction time (CCT) of M-SSEP. EP data were recorded sequentially; the first and last studies were evaluated. RESULTS: No correlation was found between initial and last M-SSEP, T-SSEP, BAEP and initial f-VEP and the patients' outcome. An 'unfavorable' outcome was in conjunction with an initial delayed CCT (>6 ms, P=0.03) and the final f-VEP correlated well with the patients' outcome (P=0.03). CONCLUSION: In conclusion, neither T-SSEP, f-VEP, BAEP nor CCT can be used as valid predictor for outcome after SAH. The patient's initial clinical grading still provides the only satisfying predictor, independent of the patient's clinical course.

The awakened intraspinal glass shard.

Penetrating spinal injuries from foreign bodies are an exceedingly rare pathological entity. In this report we present an unusual clinical report of an in-driven shard of glass in the cervical spine that remained without symptoms for many years and became symptomatic possibly because of narrowing of the diameter of the vertebral canal.

Comparison of perfusion harmonic imaging and perfusion mr imaging for the assessment of microvascular characteristics in brain tumors.

PURPOSE: The purpose of this study was to evaluate the potential of perfusion harmonic imaging (pHI) for assessing microvascular characteristics of brain tumors and to compare this ultrasound technique to perfusion MRI (pMRI). MATERIALS AND METHODS: Twenty-five patients with brain tumors underwent transtemporal pHI and fourteen of these patients underwent additional pMRI. Time-intensity curves of two different regions of interest (ROIs; (1) enhancing tumor; (2) healthy brain) were calculated off-line, and the following parameters were compared between the two ROIs and the two methodologies: time-to-peak intensity (TTP [sec]), the ratios of the peak intensities (PI ratio), the ratios of the positive slope gradient (PG ratio) and the ratios of the area under the curve (AUC ratio). p < 0.05 was considered statistically significant. RESULTS: Four of 25 patients were excluded due to bone window insufficiency or unfavorable tumor location. Focal abnormal echogenicity was detected in native B-mode in 86 % of the patients. Contrast agent administration led to remarkable echo enhancement in the tumor in all patients with corresponding time-intensity curves. Both pHI and pMRI showed significant differences with respect to the mean PI, PG and AUC (pHI: p < 0.001 / < 0.001 / < 0.001; pMRI: p < 0.05 / < 0.05 / < 0.001) when comparing tumor to healthy brain. The TTP was not significantly different in tumor and brain tissue. Comparison of pHI and pMRI data did not show any significant differences for three of four parameter ratios between both methodologies. CONCLUSION: PHI provides a new technique for assessing microvascular characteristics of brain tumors reflecting their abnormal perfusion. Overall comparison of this methodology to pMRI demonstrated encouraging results. Further studies should address the clinical potential of pHI especially in view of microvascular response to anti-angiogenic treatment.

Transmuscular trocar technique - minimal access spine surgery for far lateral lumbar disc herniations.

OBJECTIVE: Minimal access spine surgery (MASS) is gaining increasing importance in microsurgery of the lumbar spine. From a current prospective series we present data on MASS for far lateral lumbar disc herniations (LLDH) via a transmuscular trocar technique (T(2)). The surgical procedure and operative results are demonstrated in detail. In contrast to conventional percutaneous endoscopic techniques, T(2) allows one to operate in the typical microsurgical fashion combined with the advantages of a minimal endoscopic approach with three-dimensional visualization of the surgical target using the operating microscope. METHODS: Microsurgery was performed through a 1.6-cm skin incision with an 11.5-mm diameter trocar that is obliquely inserted into the paraspinal muscles pointing at the lateral isthmus of the upper vertebral body. Fifteen patients were evaluated after a median follow-up period of 24 months. Overall outcome according to the modified MacNab criteria, effect of surgery on radicular pain and sensory or motor deficits, duration of surgery, complication rate, and duration of hospital stay were evaluated. RESULTS: Good to excellent clinical outcomes were achieved in 14/15 patients. Radicular pain and motor deficits improved in all patients postoperatively, while sensory deficits recovered in 13/15 patients. The cosmetic results were excellent in all patients. No aggravation of symptoms after surgery was observed in any of the patients. CONCLUSIONS: The T(2) technique represents an auspicious alternative to standard open microsurgery for LLDH, which allows achievement of excellent clinical and cosmetic results, preservation of segmental spine stability, and avoidance of excessive soft tissue trauma.

Transcranial ultrasound perfusion imaging: implementation of a low MI and a high frame rate.

PURPOSE: Conventional transcranial ultrasound perfusion imaging (UPI) depends on bolus injection and is limited to triggered imaging. To improve our set-ups, we compared two imaging modalities with two different frame rates (FR) and mechanical indices (MI), intending to approach conditions more similar to real time imaging in order to increase parameter precision. MATERIALS AND METHODS: Fifteen healthy volunteers were investigated twice with UPI after i. v. administration of 1 ml of SonoVue(R): first, with a high MI (1.6) and a low FR (0.67 Hz)) and second, with a low MI (1.0) and a high FR (5 Hz). Apart from visual analysis, time-intensity curves were calculated from three regions of interest (ROI) and peak intensity (PI), time to PI (TP), and area-under-the-curve (AUC) were compared between the two imaging modalities. RESULTS: Visually, only scarce contrast enhancement was observed in 10/15 probands, and penetration depth was markedly lower at the low MI/high FR setting, while the high MI/low FR setting lead to very intense enhancement in 13/15 individuals. Signal-to-noise-ratio was higher at the low MI/high FR setting. TP was not significantly different between the two set-ups (p > 0.05). PI and AUC were significantly lower at the low MI/high FR setting (p

Rare intramedullary hemorrhage of a brainstem hemangioblastoma.

OBJECT: Hemorrhages caused by hemangioblastomas are very rare and mostly located in the subarachnoid space. Intraparenchymal bleedings due to hemangioblastomas are even less frequent, and these hemorrhages are almost exclusively located in the supratentorial brain, cerebellum and spinal cord. We report the first case of a brainstem hemorrhage due to a hemangioblastoma of the medulla oblongata. CASE REPORT: A 47-year-old woman presented with acute onset of headache, anarthria, inability to swallow, left-sided hemiparesis and hemidysesthesia with varying states of vigilance, finally developing acute respiratory failure. Cranial computed tomography (CT) scanning and magnetic resonance imaging (MRI) revealed a small hemangioblastoma of the posterior medulla oblongata causing intraparenchymal hemorrhage and acute occlusive hydrocephalus due to intraventricular hematoma extension. RESULT: After implantation of an external ventricular catheter to treat acute hydrocephalus, the hemangioblastoma as well as its associated hemorrhage could be removed in toto via a microsurgical posterior median suboccipital approach with minimal foramen magnum enlargement. During the follow-up period of six months postoperatively the patient showed good recovery with only slight residual neurological deficits. CONCLUSION: The most common causes of brainstem hemorrhages are arterial hypertension and cavernous hemangiomas. However, hemangioblastomas should not be ignored as a possible differential diagnosis for intraparenchymal brainstem hemorrhage. While the prognosis in hypertensive brainstem bleedings is mostly disastrous and surgery rarely indicated, an operative therapy should be considered in cases of hemorrhages caused by underlying tumors. Especially in the treatment of hemangioblastoma, the surgical management strategy is crucial for a successful result. Therefore, the authors recommend including the search for hemangioblastomas into the diagnostic workup in patients with brainstem hemorrhages.

Endothelin-1 in plasma, cisternal CSF and microdialysate following aneurysmal SAH.

OBJECTIVE: Endothelin-1 (ET-1) is postulated to play an important role in the development of cerebral vasospasm (CVS) following SAH. This study was conducted to investigate the time course of ET-release in three different sources: CSF, plasma and microdialysate. METHODS: In a prospective study ET-1-concentrations were measured in plasma, cisternal CSF and microdialysate in 20 patients with aneurysmal SAH for at least 8 days after hemorrhage. RESULTS: ET-1 concentration in microdialysate was almost four times higher compared to CSF and plasma. (p<0.001) Only in CSF ET-1-release showed a significant increase over time with highest values on day 5 post ictus (p = 0.03). This was parallel to the increase of transcranial Doppler velocities. ET-1 in plasma and microdialysate did not change over time. CONCLUSION: ET-1 may have a different biological function in different biological tissues. Only ET-1 in CSF seemed to be associated with CVS.

Lateral transmuscular or combined interlaminar/paraisthmic approach to lateral lumbar disc herniation? A comparative clinical series of 48 patients.

BACKGROUND: The optimum operative technique for lateral lumbar disc herniations (LLDH) remains unclear, and both interlaminar and extraspinal approaches are used. OBJECTIVE: To compare outcome after LLDH removal either by a lateral transmuscular approach (LTM) or by a combined interlaminar and paraisthmic approach (CIP). METHODS: 28 patients underwent surgery using CIP and 20 using LTM. All patients were operated on by the same neurosurgeon. The clinical presentation of the two groups was comparable. Overall outcome was assessed after a mean follow up period of between 19 and 37 months using the Ebeling classification. In addition, the effect of surgery on radicular pain, low back pain, and sensory and motor deficits was defined. RESULTS: Excellent to good results were achieved in 95% of the LTM group and 57% of the CIP group. The outcome was satisfactory to poor in 5% of the LTM and 43% of the CIP group (p<0.004). The percentage of sensorimotor deficit and of radicular pain improvement was higher in the LTM group. New low back pain was found exclusively in the CIP group (21%). The complication rate was 5% in the LTM group and 11% in the CIP group. CONCLUSIONS: The LTM approach achieves a better overall outcome and improvement in radiculopathy. The complication rate is lower with the transmuscular route and the risk of new low back pain is minimised. These results are likely to be attributable at least in part to the lesser invasiveness of the LTM approach.

Recurrent intracranial sarcoma mimicking chronic subdural haematoma.

Primary sarcomas of the central nervous system and their coincidence with a subdural haematoma are each rare. We describe an unusual case of unsuspected dural spreading of a recurrent spindle cell sarcoma concealed in a chronic subdural haematoma, which occurred months after microsurgical resection and external radiation of a temporal parenchymatous sarcoma.

Microsurgical therapy of symptomatic lumbar juxta facet cysts.

OBJECTIVE: Symptomatic lumbar juxta facet cysts (ganglion and synovial cysts) (JFC) are uncommon lesions of the spine, causing radiculopathy and low back pain. The authors present their experiences with microsurgically treated JFC. This rare pathology is discussed with special focus on therapeutic concepts and long-term outcome. METHOD: The records of 27 patients with symptomatic lumbar JFC were retrospectively reviewed. The clinical data and diagnostic procedures were evaluated. The patient age ranged from 38 to 83 years (mean 61 years). Treatment consisted exclusively of microsurgical excision of the cysts after partial hemilaminectomy. The early surgical results were evaluated 6 weeks after surgery. For assessment of late surgical results (mean follow-up period 70 months), the Finneson and Cooper outcome scale was used. RESULTS: After 6 weeks, the preoperative symptoms were improved in 25 patients (93 %). Long-time follow-up was available in 23 patients. Good (pain improved and able to function well) to excellent (pain free and able to function well) results were still found in 83 % of the patients. With exception of 2 small asymptomatic dural tears and a slight temporary increase of the preoperative paresis, no surgical complications were encountered. One JFC recurred after 4 months and required re-operation with finally good outcome. CONCLUSION: Adequate and definitive treatment in symptomatic JFC consists in microsurgical resection. A partial hemilaminectomy is sufficient for surgical exposure. Excellent long-term outcome can be achieved. Recurrences and surgical complications are rare.

Alpha-B-crystallin expression in tissues derived from different species in different age groups.

alphaB-Crystallin is constitutively expressed in a variety of tissues including the nervous system, the eye, heart and striated muscles and the kidney. The functional significance of the protein in the different cell populations is not yet known. Experimental data indicate that mechanical stress to the cells might play a role but that there is also a close correlation with markers of oxidative activity. Increased expression of alphaB-crystallin is seen in a number of age-related degenerative diseases. Whether aging per se induces expression of the protein has not been investigated yet. In this study tissue samples of the anterior eye segment, optic nerve, heart muscle and thyroid gland from mouse, rat, pig, cow and human donors of different age groups were investigated with immunohistochemical methods. alphaB-Crystallin levels in heart muscle and optic nerve samples from different species and different age groups were investigated using protein immunoblotting (dot blot) and the mRNA levels using semiquantitative PCR methods. The results showed that neither in heart muscle known to show constitutively high amounts of the protein nor in nonlenticular eye tissues with variations in staining intensity of different cell populations or in glandular cells studied for the first time, there were significant age-related staining differences. Dot blot methods as a quantitative evaluation method gave similar results. There were, however, species differences. In the eye these differences could be due to functional differences related to the development of a fovea centralis and an accommodative system in primates. In addition, in all mouse tissues there was less protein expression than in the other species. Differences in the absolute life span might be a factor involved in alphaB-crystallin expression. In summary the findings show that an increase in alphaB-crystallin with age may occur but is not a general phenomenon in tissues constitutively expressing this protein.