The concept of "Four Walls, Two Poles" in the lesions of the thalamus and ganglion regions: case report and literature review.

BACKGROUND: There are few articles about the surgical techniques of thalamic glioma and the lesions in the basal ganglia area. According to three existing cases and the literature review (Twelve articles were summarized which mainly described the surgical techniques), we discuss the surgical characteristics of lesions of the thalamus and basal ganglia area and summarize the relevant surgical skills. CASE PRESENTATION: Of the three cases, two were thalamic gliomas and one was brain abscess in basal ganglia. According to the three-dimensional concept of the "Four Walls, Two Poles", lesions of the thalamus and basal ganglia were surgically removed, and the operative effect was analysed by relevant surgical techniques. Surgical resection of the lesions of the thalamus and basal ganglia area according to the three-dimensional concept of the "Four Walls, Two Poles" has achieved good surgical results. Relevant surgical techniques, such as the use of retractors, the use of aspirators, the choice of surgical approaches, and the haemostasis strategy, also played an important role in the operation process. CONCLUSIONS: In the presented three cases the three-dimensional concept of the "Four Walls, Two Poles" allowed for safe surgical resection of lesions of the thalamus and basal ganglia.

Neurologic Clinical Manifestations of Fahr Syndrome and Hypoparathyroidism.

A 41-year-old female with a history of chronic hypoparathyroidism with Fahr syndrome presented with complaints of weakness and muscle spasticity. Brain imaging demonstrated diffuse intracranial calcifications. In addition, cervical spine imaging revealed extensive calcification along the anterior and posterior cervical vertebral bodies causing multilevel stenosis and cord compression. The patient underwent a multilevel posterior cervical decompression and fusion. Postoperatively, the patient had noted improvement in her upper and lower extremity strength and spasticity. This illustrative case demonstrates rare clinical and radiographic neurologic sequelae of long-standing hypoparathyroidism.

Impact of isolated basal ganglia infarction at pretreatment DWI on outcomes after endovascular thrombectomy in acute anterior circulation stroke.

PURPOSE: Acute infarction confined to the basal ganglia (BG) is occasionally observed on baseline imaging before endovascular thrombectomy. This study aimed to investigate the impact of isolated BG infarction revealed on pretreatment DWI in a large cohort of patients with acute anterior circulation stroke who underwent thrombectomy. METHODS: We retrospectively analyzed clinical and DWI data from 328 patients who underwent thrombectomy for emergent occlusions of the intracranial internal carotid artery or the middle cerebral artery. Characteristics and treatment outcomes were compared between patients with isolated BG infarction and those with non-isolated BG infarction. Binary logistic regression analyses were performed to identify independent predictors of good outcome (90-day mRS 0-2). RESULTS: Isolated BG infarction was found in 57 patients (17.4%). Patients with isolated BG infarction had a higher incidence of underlying severe intracranial atherosclerotic stenosis (21.1% vs. 10.7%, P = 0.032) than those with non-isolated BG infarction. Successful reperfusion occurred more frequently in patients with isolated BG infarction than those with non-isolated BG infarction (93% vs. 79%, odds ratio 3.529, 95% confidence interval 1.226-10.161, P = 0.014). On multivariate logistic regression analysis, independent predictors of good outcome were age, DWI-ASPECTS, and admission NIHSS score. There was no significant difference in the rate of good outcome between the two groups (54.4% vs. 42.8%, P = 0.110). CONCLUSION: Isolated BG infarction on pretreatment DWI may predict successful reperfusion after endovascular thrombectomy in patients with acute anterior circulation stroke. In addition, our study suggested a novel finding that isolated BG infarction was more frequently associated with underlying severe ICAS than non-isolated BG infarction.

Transtubular excisional biopsy as a rescue for a non-diagnostic stereotactic needle biopsy-case report and literature review.

Stereotactic needle biopsy, a standard of care for acquiring deep-seated pathology, has limitations and risks in some situations. We present an uncommon case with basal ganglia dematiaceous mycetoma. Due to the firm consistency of the lesion, the initial stereotactic needle biopsy failed to provide a diagnosis. In a second operation, transtubular excisional biopsy was successfully performed to remove the entire mycetoma. We reviewed recent case series of transtubular approaches to deep-seated brain lesions and suggest this method could be a rescue for a non-diagnostic stereotactic needle biopsy and even may be the approach of choice in some cases.

[Chronic intracerebral hemorrhage in the basal ganglia: Report of two cases and prevalence].

Two patients presented with chronic intracerebral hemorrhage (CIH) in the basal ganglia. A 48-year-old man (Case 1) was admitted to our hospital because of hypertensive right putaminal hemorrhage. On day 14, his hematoma surrounding the edema had grown without re-bleeding as seen on head CT, which was then removed endoscopically on day 28. Biopsied specimen of the hematoma capsule showed granulomatous tissue with vascularity. A 54-year-old man (Case 2) was admitted to our hospital because of bilateral intracerebral hemorrhage in the basal ganglia of the right putamen and left thalamus. On head CT, both hematomas were found to be enlarged without change in his symptoms on the 11th day after onset. His symptoms and signs subsided with medical treatment for 4 weeks. Cerebral angiography showed no abnormality of cerebral vessels. The patient had intracerebral hemorrhage in the basal ganglia or cerebral lobes 5 times in the past 10 years. Although no arterial or venous abnormality was detected by cerebral angiography and MRI/MRA, the abnormality of vessels including capillaries was strongly suggested. CIH should be considered a possibility when the symptom or hematoma does not improve even 2 weeks after the onset. The prevalence of CIH in our hospital was 0.08% of total intracerebral hemorrhages and 0.15% of hemorrhages in the basal ganglia.

Extensive basal ganglia edema caused by a traumatic carotid-cavernous fistula: a rare presentation related to a basal vein of Rosenthal anatomical variation.

The authors report a very rare presentation of traumatic carotid-cavernous fistula (CCF) with extensive edema of the basal ganglia and brainstem because of an anatomical variation of the basal vein of Rosenthal (BVR). A 45-year-old woman was admitted to the authors' institution for left hemiparesis, dysarthria, and a comatose state caused by right orbital trauma from a thin metal rod. Brain MRI showed a right CCF and vasogenic edema of the right side of the brainstem, right temporal lobe, and basal ganglia. Digital subtraction angiography confirmed a high-flow direct CCF and revealed a hypoplastic second segment of the BVR responsible for the hypertension in inferior striate veins and venous congestion. Endovascular treatment was performed on an emergency basis. One month after treatment, the patient's symptoms and MRI signal abnormalities almost totally disappeared. Basal ganglia and brainstem venous congestion may occur in traumatic CCF in cases of a hypoplastic or agenetic second segment of the BVR and may provoke emergency treatment.

Rare co-occurrence of dural arteriovenous fistula and arteriovenous malformation with bilateral subcortical and basal ganglia calcification.

The present study describes the imaging findings in a patient with dural arteriovenous fistula (AVR) and arteriovenous malformation (AVM) with bilateral subcortical and basal ganglia calcification. A 29 year old male patient presented with chief complaint of recent onset of generalized tonic clonic seizures and mild disorientation. The imaging studies on MCT demonstrated diffuse, symmetric calcification in the bilateral basal ganglia and subcortical white matter. MR imaging and angiography revealed AVM in parietooccipital region with supply predominantly from left posterior cerebral and middle cerebral arteries. Multiple dural feeders from meningeal branches of occipital and superficial temporal branches of bilateral external carotid and right internal carotid arteries. Calcification is proposed to be due to chronic reflux into the parenchymal veins or vascular steal phenomenon. This rare co-occurrence of subcortical calcification in a patient with a dural AVF and AVM is being reported.

Preoperative localization of intracranial lesions with MRI using marking pills.

OBJECTIVE: To describe a simple technique for preoperative surface localization of intracranial lesions. METHODS: 11 pills in total, including Alfarol (alfacalcidol) capsules, were affixed to a phantom with adhesive tape and a MRI scan was performed. The visibility of the pills and any spatial errors in determining their locations were evaluated. Between June 2006 and April 2009, we employed Alfarol capsules as a skin marker in MRI in clinical surgical cases. RESULTS: Alfarol capsules, whose actual size is 5.6 mm in diameter, were identified as a hyperintense spot at a size of 4.2, 4.2, and 4.5mm in diameter in T1-weighted, T2-weighted, and FLAIR (fluid attenuated inversion recovery) sequence images, respectively. The size discrepancies were within 1.4 mm. The average spatial errors were 0.7, 0.6, and 0.7 mm in T1-weighted, T2-weighted, and FLAIR sequence images, respectively. Other pills were not identified in the MRI scans. During this 35-month period, 8 patients underwent preoperative MRI-guided localization at our institution. There were 5 men and 3 women in whom 8 biopsies were performed. In all cases, the result of the biopsy was positive and useful for the treatment that followed. No perioperative complications were encountered. CONCLUSION: Alfarol capsule can be used as an external skin marker. Our simple and inexpensive method is a useful addition to preoperative evaluation of superficial intracranial lesions.

Use of a minimally invasive tubular retraction system for deep-seated tumors in pediatric patients.

OBJECT: Microsurgical removal is the preferred treatment for most deep-seated, intraaxial tumors in the pediatric population. The feasibility of surgery as an option has improved with advances in surgical technology and technique. Tubular retractors disperse retraction forces over a greater surface area than do conventional retractors, which can lower the risk of ischemic complications. The authors describe their experience utilizing a new tubular retractor system specifically designed for cranial applications in conjunction with frameless neuronavigation. METHODS: The Vycor ViewSite retractor was used in 4 pediatric patients (ages 15 months and 9, 10, and 16 years) with deep-seated intraaxial tumors. The lesions included a papillary tumor of the pineal region, a low-grade astrocytoma in the occipital lobe, a dysembryoplastic neuroepithelial tumor arising from the basal ganglia, and an intraventricular low-grade glioma. The extent of white matter damage along the surgical trajectory (based on T2 or FLAIR and diffusion restriction/apparent diffusion coefficient signals) and the extent of resection were assessed on postoperative imaging. RESULTS: Satisfactory resection or biopsy was achieved in all patients. A comparison of pre- and postoperative MR imaging studies revealed evidence of white matter damage along the surgical trajectory in 1 patient. None of the patients demonstrated new neurological deficits postoperatively. CONCLUSIONS: Obtaining surgical access to deep-seated, intraaxial tumors is challenging. In this small series of pediatric patients, the combination of the ViewSite tubular retractor and frameless neuronavigation facilitated the surgical approach. The combination of these technologies adds to the armamentarium to safely approach tumors in deep locations.

Stereotactic radiosurgery for deep-seated cavernous malformations: a move toward more active, early intervention. Clinical article.

OBJECT: The role of radiosurgery in the treatment of cavernous malformations (CMs) remains controversial. It is frequently recommended only for inoperable lesions that have bled at least twice. Rehemorrhage can carry a substantial risk of morbidity, however. The authors reviewed their practice of treating deep-seated inoperable CMs to assess the complication rate of radiosurgery, the impact that radiosurgery might have on rebleeding, and whether a more active, earlier intervention is justified in managing this condition. METHODS: The authors performed a retrospective analysis of 113 patients with 79 brainstem and 39 thalamic/basal ganglia CMs treated with Gamma Knife surgery. Lesions were stratified into 2 groups: those that might be lower risk with no more than 1 symptomatic bleed before radiosurgical treatment and those deemed high risk with multiple symptomatic hemorrhages before treatment. RESULTS: Forty-one CMs had multiple symptomatic hemorrhages before radiosurgery with a first-ever bleed rate of 2.9% per lesion per year, a rebleed rate of 30.5% per lesion per year, and a median time of 1.5 years between the first and second bleeds. In this group the rebleed rate decreased to 15% for the first 2 years after radiosurgery and declined further to 2.4% thereafter. Pretreatment multiple bleeds led to persistent deficits in 72% of the patients. Seventy-seven CMs had no more than 1 symptomatic bleed before radiosurgery, making for a lifetime bleed rate of 2.2% per lesion per year. The short period between the presenting bleed and treatment (median 1 year) makes the natural history in this group uncertain. The rate of hemorrhage in the first 2 years after treatment was 5.1%, and 1.3% thereafter. Pretreatment hemorrhages resulted in permanent deficits in 43% of the patients in this group, a rate significantly lower than in the multiple-bleeds group (p < 0.001). Posttreatment hemorrhages led to persistent deficits in only 7.3% of the patients. Permanent adverse radiation effects were rare (7.3%) and minor in both groups. CONCLUSIONS: Stereotactic radiosurgery is a safe management strategy for CMs in eloquent sites with the marked advantage of reducing rebleed risks in patients with repeated pretreatment hemorrhages. The benefit in treating CMs with a single bleed is less clear. Note, however, that repeated hemorrhage carries a significant risk of increased morbidity far in excess of any radiosurgery-related morbidity, and the authors assert that this finding justifies the early active management of deep-seated CMs.

Haemorrhagic presentation of low-grade glioma in adults.

Intracranial bleeding is rare in patients with low-grade gliomas, above all in adult population. We reviewed the literature of such cases and reported another case of a haemorrhagic low-grade glioma in a 54-year-old woman presenting with a left hemiparesis. Computer tomography (CT) images showed a right basal ganglia haemorrhage with no mass effect. Vascular malformations were ruled out by angiography. Eighteen fluoro-fluoro deossiglucosio (18F-FDG) positron emission tomography (PET/CT) showed a large hypometabolic area corresponding to the lesion. We waited for patient's improvement. Late magnetic resonance images revealed a low-grade glioma at the bleeding site. Tumour was removed and histopathologic examination revealed a WHO grade II mixed glioma. The authors emphasize that this evidence has to be kept in mind since it has important therapeutic implications.

[Hyperperfusion syndrome following carotid revascularization--a subject for the family doctor]. / Zerebrales Hyperperfusionssyndrom nach Karotisrevaskularisation--ein Thema für den Hausarzt.

Hyperperfusion following revascularization of ischemic organs is a well-known phenomenon. It is usually self-limiting and may corroborate success. In the brain, however, hyperperfusion may cause catastrophic consequences. Symptoms range from seizures and neurological deficits to intracerebral haemorrhage. It should be taken into consideration that symptoms may occur between days and even several weeks after revascularization. Therefore in times of "fast-track-rehabilitation" it is the family doctor who sees the patient's complication first. He should be familiar with the hyperperfusion syndrome. Most important are the questions, to what extent the patient at "high-risk" can be identified preoperatively, whether the development of hyperperfusion syndrome can be predicted in the postoperative period and furthermore, how the magnitude of syndrome can be influenced. By analyzing two impressive cases, critical and striking findings are isolated and discussed with the comprehensive literature. It can be seen that nearly all the findings which are known as "high-risk-factors" are inconsistently presented in the literature. Their predictive value seems to be extremely questionable. Consensus, however, consists in that the extent of the symptoms may be limited by intensive blood pressure control, even if the patient's pressure is "normal".

[Functional models of movement disorders of basal ganglia origin and effects of functional neurosurgery].

The rate model regarding the development of movement disorders of basal ganglia origin suggests that hyperkinetic and hypokinetic disorders occur as a result of changes in the firing rates in the GPi and SNr, which in turn suppress thalamocortical output. Dopamine depletion in Parkinson's disease increases basal ganglia output, then decreases thalamocortical output, leading to bradykinesia. This model, however, cannot explain a lack of deterioration of parkinsonian signs following thalamic coagulation surgery. Instead of the rate model, the beta oscillation hypothesis has been proposed, explaining that synchronized oscillation in the beta frequency in the basal ganglia disturbs initiation of voluntary movement. We observed that effective high-frequency STN stimulation in parkinsonian monkeys was associated with increase in the firing rate and the pattern shift from irregular burst firing to regular high-frequency firing in the projecting sites. High-frequency neural activation by deep brain stimulation is supposed to cancel lower frequency oscillation including beta oscillation, leading to improvement of bradykinesia. Our observation supports the significance of the neural activity pattern, rather than the tonic activity level, in the development of movement disorders. The rate model cannot explain the improvement of ballismus and chorea by pallidotomy because pallidotomy increases the disinhibition of the thalamocortical projection, which should increase the movements. We observed repetitive bursts or pauses of neuronal firing of the globus pallidus synchronized to ballistic movements in patients with hemiballism or chorea, suggesting that phasic neuronal driving in the basal ganglia is important as their pathophysiology.

Circuits and circuit disorders of the basal ganglia.

Views of the anatomy and function of the basal ganglia and their role in motor and nonmotor disorders have undergone major revisions during the past decades. The basal ganglia are now appreciated as components of parallel, reentrant cortico-subcortical circuits, which originate from individual cortical areas, traverse the basal ganglia and thalamus, and terminate in their respective areas of origin in the frontal lobe. Further research and clinical experience have resulted in new insights and perspectives on the details of the circuitry and on the role of these structures in Parkinson disease and other basal ganglia disorders. On the basis of anatomical and physiological studies and the striking success of focused surgical interventions, it seems appropriate to view these varied clinical disorders as circuit disorders, resulting from pathologic disturbances in neuronal activity throughout specific cortico-subcortical loops.

A giant intradiploic epidermoid cyst with perforation of the dura and brain parenchymal involvement.

A patient with a long-standing intradiploic epidermoid cyst with perforation of the dura and brain parenchymal involvement is reported. A 69-year-old man, who had previously presented with a subcutaneous mass on the left frontoparietal scalp, developed a sudden grand mal seizure. Magnetic resonance imaging showed a well-defined mass in the frontoparietal scalp with destruction of the skull. Penetration of the dura allowed for communication with the intracranial structures. Surgical resection and cranioplasty were performed. There were no well-defined margins in the deep portion and the mass was subtotally removed. Histological examination showed that the cystic structure was lined by squamous epithelium containing laminated keratin material. The pathologic findings were consistent with the diagnosis of an epidermoid cyst.

[Functional models of movement disorders of basal ganglia origin and effects of functional neurosurgery].

The rate model regarding the development of movement disorders of basal ganglia origin suggests that hyperkinetic and hypokinetic disorders occur as a result of changes in the firing rates in the GPi and SNr, which in turn suppress thalamocortical output. Dopamine depletion in Parkinson's disease increases basal ganglia output, then decreases thalamocortical output, leading to bradykinesia. This model, however, cannot explain a lack of deterioration of parkinsonian signs following thalamic coagulation surgery. Instead of the rate model, the beta oscillation hypothesis has been proposed, explaining that synchronized oscillation in the beta frequency in the basal ganglia disturbs initiation of voluntary movement. We observed that effective high-frequency STN stimulation in parkinsonian monkeys was associated with increase in the firing rate and the pattern shift from irregular burst firing to regular high-frequency firing in the projecting sites. High-frequency neural activation by deep brain stimulation is supposed to cancel lower frequency oscillation including beta oscillation, leading to improvement of bradykinesia. Our observation supports the significance of the neural activity pattern, rather than the tonic activity level, in the development of movement disorders. The rate model cannot explain the improvement of ballismus and chorea by pallidotomy because pallidotomy increases the disinhibition of the thalamocortical projection, which should increase the movements. We observed repetitive bursts or pauses of neuronal firing of the globus pallidus synchronized to ballistic movements in patients with hemiballism or chorea, suggesting that phasic neuronal driving in the basal ganglia is important as their pathophysiology.

Evolution of basal ganglia surgery for movement disorders.

In 1942, it was thought that basal ganglia surgery would cause permanent unconsciousness and significant impairment of motor control. By 1947, when human stereotactic surgery was introduced, the first target was the globus pallidus in a patient with chorea. What happened during those 5 years to set the stage for stereotactic surgery? During the last half of the 19th century, it was first noted that motor disorders were often accompanied by atrophy of various parts of the basal ganglia, and when histopathology became part of necropsy, that relationship between movement disorders and the basal ganglia was strengthened. The impairment of fine motor control was noted in experiments that involved lesioning the basal ganglia, which led to the conclusion that disease of the basal ganglia might cause motor impairment. Finally, in 1939, Russel Meyers took the bold move of surgically resecting the head of the caudate nucleus at craniotomy in a patient with Parkinson's disease, demonstrating that Dandy was wrong in the view that the basal ganglia were the center of consciousness, and that symptoms and motor control might be improved by caudate lesions without motor impairment. He reported his first patient in a meeting in 1940, which was published in 1942, and was encouraged to investigate basal ganglia surgery further. Although results were encouraging, the mortality rate was prohibitive. Since the introduction of pallidoansotomy in 1947, basal ganglia surgery has become both safe and effective and has been expanded and refined.