Neural activity in trigeminal neuralgia patients with sensory and motor stimulations: A pilot functional MRI study.

OBJECTIVE: Trigeminal neuralgia (TN) is a neuropathic pain syndrome that typically exhibits paroxysmal pain. However, the true mechanism of pain processing is unclear. We aim to evaluate the neural activity changes, before and after radiofrequency rhizotomy, in TN patients using functional MRI (fMRI) with sensory and motor stimulations. METHODS: Six patients with classical TN participated in the study. Each patient underwent two boxcar paradigms of fMRI tasks: air-sensation and jaw-clenching around 1-3 weeks before and after the surgical intervention. McGill Pain Questionnaire (MPQ) was used to evaluate the pain intensity prior to fMRI study. RESULTS: Before rhizotomy, the jaw-clenching stimulation yielded reduced brain activation in primary motor (M1) and primary (SI) and secondary somatosensory (SII) cortices. Following intervention, activation in those regions returned to near normal levels observed in healthy subjects. For air-sensation stimulation, several pain and pain modulation regions such as right thalamus, right putamen, insula, and brainstem, were activated before the intervention, but subsided after the intervention. This correlated well with the change of MPQ scores (p < 0.01). CONCLUSIONS: In our study, we observed significant pain reduction accompanied by increased motor activities after rhizotomy in patients with TN. We hypothesize that the reduced motor activities identified in fMRI may be reversed after the treatment with radiofrequency rhizotomy. More research is warranted.

Evaluation of factors associated with interhospital transfers to pediatric and adult tertiary level of care: A study of acute neurological disease cases.

INTRODUCTION: Patient referrals to tertiary level of care neurological services are often potentially avoidable and result in inferior clinical outcomes. To decrease transfer burden, stakeholders should acquire a comprehensive perception of specialty referral process dynamics. We identified associations between patient sociodemographic data, disease category and hospital characteristics and avoidable transfers, and differentiated factors underscoring informed decision making as essential care management aspects. MATERIALS AND METHODS: We completed a retrospective observational study. The inclusion criteria were pediatric and adult patients with neurological diagnosis referred to our tertiary care hospital. The primary outcome was potentially avoidable transfers, which included patients discharged after 24 hours from admission without requiring neurosurgery, neuro-intervention, or specialized diagnostic methodologies and consult in non-neurologic specialties during their hospital stay. Variables included demographics, disease category, health insurance and referring hospital characteristics. RESULTS: Patient referrals resulted in 1615 potentially avoidable transfers. A direct correlation between increasing referral trends and unwarranted transfers was observed for dementia, spondylosis and trauma conversely, migraine, neuro-ophthalmic disease and seizure disorders showed an increase in unwarranted transfers with decreasing referral trends. The age group over 90 years (OR, 3.71), seizure disorders (OR, 4.16), migraine (OR, 12.50) and neuro-ophthalmic disease (OR, 25.31) significantly associated with higher probability of avoidable transfers. Disparities between pediatric and adult transfer cases were identified for discrete diagnoses. Hospital teaching status but not hospital size showed significant associations with potentially avoidable transfers. CONCLUSIONS: Neurological dysfunctions with overlapping clinical symptomatology in ageing patients have higher probability of unwarranted transfers. In pediatric patients, disease categories with complex symptomatology requiring sophisticated workup show greater likelihood of unwarranted transfers. Future transfer avoidance recommendations include implementation of measures that assist astute disorder assessment at the referring hospital such as specialized diagnostic modalities and teleconsultation. Additional moderators include after-hours specialty expertise provision and advanced directives education.

Cauda equina syndrome (CES) from lumbar disc herniations.

STUDY DESIGN: A retrospective review was performed to determine the outcomes of patients with cauda equina syndrome (CES) from a herniated lumbar disc at our institutions. OBJECTIVE: CES from lumbar herniated discs is considered the only absolute indication for surgery. It is considered a neurosurgical emergency with the outcome related to how quickly it is diagnosed and treated. The results of recovery of bladder function are felt by many authors to be related to early diagnosis and surgical intervention. Most authors recommend a wide decompressive laminectomy when surgery is performed. We reviewed our cases to determine if they conformed to these assumptions. SUMMARY OF BACKGROUND DATA: Although many articles regarding the outcome of CES from herniated lumbar discs suggest that early surgery is superior to surgery that is delayed, others have demonstrated no correlation between time-to-surgery and chances for recovery of neurologic and bladder function. METHODS: A retrospective review of all patients with lumbar herniated discs and CES from the years 1985 to 2004 was carried out. There were 31 patients, 28 of whom had bladder incontinence or retention requiring catheterization. Six patients were operated within 24 hours, 8 between 24 and 48 hours, and 17 after 48 hours (range: 60 h to 2 wk). Average follow-up was 5 years. RESULTS: Twenty-seven of these patients regained continence not requiring catheterization. There was no correlation between the time-to-surgery and recovery of bladder function. There was also no correlation between the time-to-surgery and recovery of motor and sensory function. The majority of patients underwent unilateral hemilaminotomy or bilateral hemilaminotomies; decompressive laminectomy was reserved for patients with underlying spinal stenosis or posteriorly herniated fragments. All of the patients were relieved of their radicular pain. CONCLUSIONS: In our series of patients with CES and bladder incontinence or retention, over 90% regained continence. Recovery of function was not related to the time to surgical intervention. The majority of the patients were adequately treated without the need for a complete laminectomy.

Proton MR Spectroscopy in Patients with Structural MRI-Negative Temporal Lobe Epilepsy.

BACKGROUND AND PURPOSE: With conventional magnetic resonance imaging (MRI), 20-30% of patients with temporal lobe epilepsy (TLE) have negative pathological MRI findings. Further investigations of the role of magnetic resonance spectroscopy (MRS) in the pre-surgical evaluation of patients with MRI-negative TLE are important to avoid intracranial EEG recording and to better understand the mechanism of the epileptogenic process. This study aimed to compare the measurements of N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) in the hippocampi of MRI-negative TLE patients and normal subjects. METHODS: Twenty patients with MRI-negative TLE and 10 age-matched healthy control subjects underwent MRI and MRS. The concentrations of NAA, Cr, and Cho and the ratios of NAA/Cr and NAA/(Cr+Cho) were measured. Seven of these 20 patients also underwent surgical treatment for TLE. Their pathological results and surgical outcomes were evaluated. RESULTS: In the hippocampi ipsilateral to the seizure side, the NAA/Cr and NAA/(Cr+Cho) ratios were significantly decreased compared with the ratios of the hippocampi contralateral to the seizure side and the normal control hippocampi. There was no significant difference between the hippocampi contralateral to the seizure side and the normal control hippocampi. The pathological results from the patients who underwent temporal lobe resection indicated mild to moderate gliosis and minimal loss of neurons. Five patients were seizure-free during the follow-up period of 9- 47 months (mean 27.7 months). CONCLUSIONS: In MRI-negative TLE, significant reductions in the NAA/Cr and NAA/(Cr+Cho) ratios ipsilateral to the seizure side may help lateralize and localize the epileptogenic zone.

Intracranial hemorrhage following blunt injury to a shunt valve.

CASE REPORT: The authors report a case of a child who sustained blunt injury to a shunt valve during a basketball game, which resulted in an intracranial hemorrhage. CONCLUSION: This occurrence, although rare, reinforces the recommendation for protective headgear when patients with shunts engage in activities that may result in direct impact to the head.