Current Applications of MRI-Guided Laser Interstitial Thermal Therapy in the Treatment of Brain Neoplasms and Epilepsy: A Radiologic and Neurosurgical Overview.

Minimally invasive stereotactic tumor ablation is a viable option for the treatment of benign and malignant intracranial lesions. Although surgical excision constitutes first-line therapy for various brain pathologies, it can cause irreversible neurologic deficits. Additionally, many patients who may benefit from surgery do not qualify as surgical candidates due to multiple comorbidities. Recent advancements in laser interstitial thermal therapy, namely the ability to monitor ablation in real-time under MR imaging, have improved the safety and efficacy of the procedure. MRI-guided laser interstitial thermal therapy is currently used as a minimally invasive treatment for brain metastases, radiation necrosis, glioma, and epilepsy. This article will discuss the principles, suggested indications, complications, and imaging characteristics of MRI-guided laser interstitial thermal therapy as they pertain to the treatment of brain pathology.

Objective monitoring of tremor and bradykinesia during DBS surgery for Parkinson disease.

OBJECTIVE: High-frequency subthalamic nucleus deep brain stimulation (STN-DBS) is an established treatment for patients with advanced Parkinson disease (PD). To date, intraoperative monitoring of parkinsonian symptoms, such as tremor and bradykinesia, is largely based on subjective strategies. We conducted a pilot study to evaluate short-term intraoperative outcomes of unilateral macrostimulation of the STN-DBS in PD patients using a neuromotor symptom registration device (CATSYS 2000 System). METHODS: We studied 12 consecutive PD patients who received staged unilateral STN-DBS implants and 10 male control subjects free of neurologic deficits using a simple portable system with two sensors: a tremor pen and a touch recording plate. Results revealed excellent test-retest reliability for postural tremor in control subjects. PD patients were evaluated preoperatively during "off" state and intraoperatively for rest, postural tremor intensity, and frequency of finger tapping. Comparisons between premacrostimulation and postmacrostimulation were made using analysis of variance for repeated measures. RESULTS: Electronic rest tremor registration revealed a mean improvement of x 12.5 in tremor intensity measurements in the stimulated/contralateral side (p = 0.002). An overall x 3.8 improvement was registered on the nonstimulated/ipsilateral side. Significant improvements after STN-DBS were also recorded for postural tremor and frequency of finger tapping. CONCLUSION: Using a noninvasive, simple, and sensitive electronic recording method of intraoperative motor symptom registration, we were able to supplement short-term clinical observation by objectively quantifying the characteristics of tremor and finger tapping in response to subthalamic nucleus deep brain macrostimulation.

Detrimental effects of systemic hyperthermia on locomotor function and histopathological outcome after traumatic spinal cord injury in the rat.

OBJECTIVE: Posttraumatic hyperthermia has been demonstrated to worsen neurological outcome in models of brain injury. The purpose of this study was to examine the effects of systemic hyperthermia on locomotor and morphological outcome measures after traumatic spinal cord injury (SCI) in the rat. METHODS: After a T10 laminectomy, spinal cord contusions were produced from a height of 12.5 mm onto exposed cords (NYU Impactor; New York University Neurosurgery Laboratory, New York, NY) in adult rats that were divided into three groups. Group 1 (n = 9) underwent whole body hyperthermia (rectal temperature, 39.5 degrees C) 30 minutes postinjury for 4 hours, Group 2 (n = 8) underwent normothermia (rectal temperature, 37 degrees C) 30 minutes postinjury for 4 hours, and Group 3 (n = 10) underwent traumatic SCI with no postinjury thermal treatment. Twice-weekly assessments of locomotor function were made during a 6-week survival period using the Basso-Beattie-Breshnahan locomotor rating scale. Forty-four days after injury, animals were perfused, and their spinal cords serially sectioned. Sections were stained with hematoxylin, eosin, and Luxol fast blue for histopathological analysis. The percentage of tissue damage was quantitatively determined by using computer-aided image analysis. RESULTS: The results showed that 4 hours of postinjury hyperthermia significantly worsened locomotor outcome (final Basso-Beattie-Breshnahan scores were 9.7 +/- 0.3 [Group 1] versus 10.8 +/- 0.4 [Group 2] versus 11.3 +/- 0.3 [Group 3]) and led to an increase in the percentage of tissue damage (32.9 + 3.2% [Group 1] versus 22.3 +/- 2.8% [Group 3]). CONCLUSION: These data suggest that complications of SCI (e.g., fever, infection) leading to an elevation of systemic temperature may add to the severity of secondary injury associated with traumatic SCI and significantly affect neurological outcome.

Adrenocortical carcinoma with cerebral metastasis in a child: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Adrenocortical carcinoma (ACC) is rare in the pediatric population, and brain metastasis seldom occurs. CLINICAL PRESENTATION: The authors report a case of metastatic ACC to the brain in a 9-year-old patient who had an adrenal cortex neoplasm removed at 4 years of age, and was free of symptoms for 5 years. Two weeks before admission she complained of blurred vision in both eyes. INTERVENTION: Examination revealed bilateral papilledema, and a Magnetic Resonance Imaging (MRI) of the brain revealed a mass in the left lateral ventricle with extensive vasogenic edema and hydrocephalus. The tumor was removed, and histopathologic examination demonstrated metastatic ACC. CONCLUSION: Although ACC is a rare neoplasm it must be considered in the differential diagnosis of cerebral lesions in patients with a history of this tumor. Periodic long-term brain imaging is suggested as part of the follow up in patients with adrenocortical neoplasms.

Unique clinical presentation of pediatric shunt malfunction.

INTRODUCTION: A cerebrospinal fluid (CSF) shunt is the primary treatment for most etiologies of hydrocephalus in the pediatric population. Malfunction of the shunt may present with unique symptoms and signs. This retrospective review investigates the presenting signs and symptoms of pediatric patients with shunt malfunction. Clinical MATERIAL AND METHOD: One-hundred-and-thirty CSF diversion procedures were performed at two affiliated pediatric hospitals over a 2-year period. Seventy consecutive cases of CSF shunt revision were reviewed. These 70 operations were performed on 65 patients. Their medical records and radiographic studies were reviewed, and supplemented with a telephone interview to obtain a minimum of 3 months follow-up. RESULTS: The 65 patients' age ranged from 3 months to 16 years. The original etiology of the hydrocephalus was Chiari II malformation in 17, idiopathic in 15 and intraventricular hemorrhage in 10, neoplasm in 8 patients and meningitis in 5 patients. The most frequent presenting symptoms were headache (39 admissions), nausea/vomiting (28) and drowsiness (21). Seven Chiari patients (41%) presented with neck pain, 2 (12%) presented with lower cranial nerve palsy, and 2 (12%) presented with symptomatic syrinx, complaints not reported by non-Chiari patients (p < 0.01, chi2 analysis). Four myelodysplastic patients presented with a new-onset or recurrent seizure episode, which was significantly more frequent than in nonmyelodysplastic patients (p < 0.05, chi2 analysis). On examination, increased head circumference was noted in 17 patients. Parinaud's syndrome was noted more prominently in patients with a history of intracranial neoplasm (4 of 8 cases) than in patients with nonneoplastic diseases (2 of 62 cases; p < 0.05, chi2 analysis). Other interesting presenting signs were pseudocyst (2), syringomyelia (2), hemiparesis (2) and Parkinson-like rigidity (2). CONCLUSION: Pediatric shunt malfunction generally presents with headache, nausea/vomiting, altered mental status, increased head circumference and bulging fontanelle. Other less frequent but unique presenting signs and symptoms, such as neck pain, syringomyelia and lower cranial nerve palsy in the myelodysplastic population, and Parinaud's syndrome in patients with a history of intracranial neoplasm are frequently associated with shunt malfunction and should prompt a radiographic workup.

Induction of Eph B3 after spinal cord injury.

Spinal cord injury (SCI) in adult rats initiates a cascade of events producing a nonpermissive environment for axonal regeneration. This nonfavorable environment could be due to the expression of repulsive factors. The Eph receptor protein tyrosine kinases and their respective ligands (ephrins) are families of molecules that play a major role in axonal pathfinding and target recognition during central nervous system (CNS) development. Their mechanism of action is mediated by repellent forces between receptor and ligand. The possible role that these molecules play after CNS trauma is unknown. We hypothesized that an increase in the expression of Eph proteins and/or ephrins may be one of the molecular cues that restrict axonal regeneration after SCI. Rats received a contusive SCI at T10 and in situ hybridization studies 7 days posttrauma demonstrated: (i) a marked up-regulation of Eph B3 mRNA in cells located in the white matter at the lesion epicenter, but not rostral or caudal to the injury site, and (ii) an increase in Eph B3 mRNA in neurons in the ventral horn and intermediate zone of the gray matter, rostral and caudal to the lesion. Immunohistochemical analyses localizing Eph B3 protein were consistent with the mRNA results. Colocalization studies performed in injured animals demonstrated increased Eph B3 expression in white matter astrocytes and motor neurons of the gray matter. These results suggest that Eph B3 may contribute to the unfavorable environment for axonal regeneration after SCI.