Athletes with neurologic disease.

Neurologic disease does not discriminate, even among athletes. Common neurologic diseases among athletes include multiple sclerosis, seizures, headaches, and sleep disorders. Although concrete guidelines for sport participation among athletes with neurologic diseases do not exist, evidence-based and consensus statements can aid healthcare providers in determining whether and to what extent such athletes should participate in sports. Moreover, sport participation is important, since multiple studies indicate that exercise improves disease-specific symptoms, manifestations, and overall quality of life. Although some risk is involved for athletes with neurologic disease, risk is mitigated with proper supervision and neurologic oversight, disease-specific accommodations, and counseling of the athletic staff and the athletes. Neurologic oversight entails an initial comprehensive neurologic assessment by a neurologist followed by regular follow-up. Preparation for environmental conditions encountered by athletes with neurologic disease will further improve safety during their participation in sport. With sound recommendations, neurologic oversight, and proper supervision, most athletes with neurologic disease can participate in athletics. The health benefits that they will gain from participation in athletics outweigh the risks.

Interdisciplinary treatment of post-concussion and post-traumatic headaches.

INTRODUCTION: Chronic headaches following concussion are debilitating and difficult to treat. Commonly employed initial therapeutic modalities include pharmacologic, physical, and psychological interventions. Despite these efforts, a subset of patients with chronic pain remains. Peripheral nerve surgery has never before been reported as an effective treatment for the management of post-concussion headaches. In this study, we report on our early outcomes following peripheral nerve surgery for this novel indication. METHODS: A retrospective review of 28 consecutive patients with post-concussion headaches who underwent occipital nerve surgery was performed. Preoperative and postoperative headache pain was evaluated on visual analog scale (VAS) in 24 patients with at least 6 months follow-up. RESULTS: The average VAS headache pain reduced from 6.4 preoperatively, to 1.4 (P < 0.0001). Twenty-one patients (88%) had a successful outcome of at least a 50% reduction in their VAS following peripheral nerve surgery. Additionally, twelve patients (50%) were pain free at time of final follow-up. There were no surgical complications. CONCLUSIONS: Early results indicate peripheral nerve surgery is a safe and effective new therapy for post-concussion headaches in the properly selected patients, whose chronic pain persists despite initial treatments by a neurologist, specialized in headache management. Future studies should focus on larger patient populations, and examine the long-term durability of outcome. In the meantime, an interdisciplinary approach involving neurologists and a peripheral nerve surgeon is suggested for the care of patients with refractory chronic post-concussion occipital neuralgia and other post-traumatic chronic headaches.

Managing patients with neurologic disorders who participate in sports activities.

PURPOSE OF REVIEW: Patients with neurologic conditions have been discouraged from participating in organized sports because of theoretical detrimental effects of these activities to their underlying conditions. The purpose of this article is to review known risks associated with three specific clinical conditions most commonly encountered in a sports neurology clinic (epilepsy, migraines, and multiple sclerosis and to add to the neurologist's toolkit suggested interventions regarding management of athletes with these disorders. RECENT FINDINGS: Increased participation in sports and athletics has positive benefits for patients with neurologic conditions and can be safely integrated into the lives of these patients with proper supervision from their treating neurologists. SUMMARY: Patients with neurologic conditions can and should be encouraged to participate in organized sports as a method of maintaining their overall fitness, improving their overall level of function, and reaping the physical and psychological benefits that athletic competition has to offer.

Sports neurology topics in neurologic practice: A survey of AAN members.

We sought to assess neurologists' interest in sports neurology and learn about their experience in treating sports-related neurologic conditions. A survey was sent to a random sample of American Academy of Neurology members. A majority of members (77%) see at least some patients with sports-related neurologic issues. Concussion is the most common sports-related condition neurologists treat. More than half of survey participants (63%) did not receive any formal or informal training in sports neurology. At least two-thirds of respondents think it is very important to address the following issues: developing evidence-based return-to-play guidelines, identifying risk factors for long-term cognitive-behavioral sequelae, and developing objective diagnostic criteria for concussion. Our findings provide an up-to-date view of the subspecialty of sports neurology and identify areas for future research.

Advanced neuroimaging of mild traumatic brain injury.

This article focuses on advancements in neuroimaging techniques, compares the advantages of each of the modalities in the evaluation of mild traumatic brain injury, and discusses their contribution to our understanding of the pathophysiology as it relates to prognosis. Advanced neuroimaging techniques discussed include anatomic/structural imaging techniques, such as diffusion tensor imaging and susceptibility-weighted imaging, and functional imaging techniques, such as functional magnetic resonance imaging, perfusion-weighted imaging, magnetic resonance spectroscopy, and positron emission tomography.

Transcranial Doppler investigation of hemodynamic alterations associated with blunt cervical vascular injuries in trauma patients.

OBJECTIVES: Blunt cervical vascular injuries, often missed with current screening methods, have substantial morbidity and mortality, and there is a need for improved screening. Elucidation of cerebral hemodynamic alterations may facilitate serial bedside monitoring and improved management. Thus, the objective of this study was to define cerebral flow alterations associated with single blunt cervical vascular injuries using transcranial Doppler sonography and subsequent Doppler waveform analyses in a trauma population. METHODS: In this prospective pilot study, patients with suspected blunt cervical vascular injuries had diagnoses by computed tomographic angiography and were examined using transcranial Doppler sonography to define cerebral hemodynamics. Multiple vessel injuries were excluded for this analysis, as the focus was to identify hemodynamic alterations from isolated injuries. The inverse damping factor characterized altered extracranial flow patterns; middle cerebral artery flow velocities, the pulsatility index, and their asymmetries characterized altered intracranial flow patterns. RESULTS: Twenty-three trauma patients were evaluated: 4 with single internal carotid artery injuries, 5 with single vertebral artery injuries, and 14 without blunt cervical vascular injuries. All internal carotid artery injuries showed a reduced inverse damping factor in the internal carotid artery and dampened ipsilateral mean flow and peak systolic velocities in the middle cerebral artery. Vertebral artery injuries produced asymmetry of a similar magnitude in the middle cerebral artery mean flow velocity with end-diastolic velocity alterations. CONCLUSIONS: These data indicate that extracranial and intracranial hemodynamic alterations occur with internal carotid artery and vertebral artery blunt cervical vascular injuries and can be quantified in the acute injury phase by transcranial Doppler indices. Further study is required to elucidate cerebral flow changes resulting from a single blunt cervical vascular injury, which may guide future management to preserve cerebral perfusion after trauma.

Transcranial Doppler velocities in a large, healthy population.

BACKGROUND: Transcranial Doppler (TCD) ultrasonography has been extensively used in the evaluation and management of patients with cerebrovascular disease since the clinical application was first described in 1982 by Aaslid and colleagues TCD is a painless, safe, and noninvasive diagnostic technique that measures blood flow velocity in various cerebral arteries. Numerous commercially available TCD devices are currently approved for use worldwide, and TCD is recognized to have an established clinical value for a variety of clinical indications and settings. Although many studies have reported normal values, there have been few recently, and none to include a large cohort of healthy subjects across age, race, and gender. As more objective, automated processes are being developed to assist with the performance and interpretation of TCD studies, and with the potential to easily compare results against a reference population, it is important to define stable normal values and variances across age, race, and gender, with clear understanding of variability of the measurements, as well as the yield from various anatomic segments. METHODS: To define normal TCD values in a healthy population, we enrolled 364 healthy subjects, ages 18-80 years, to have a complete, nonimaging TCD examination. Subjects with known or suspected cerebrovascular disorders, systemic disorders with cerebrovascular effects, as well as those with known hypertension, diabetes, stroke, coronary artery disease, or myocardial infarction, were excluded. Self-reported ethnicity, handedness, BP, and BMI were recorded. A complete TCD examination was performed by a single experienced sonographer, using a single gate nonimaging TCD device, and a standardized protocol to interrogate up to 23 arterial segments. Individual Doppler spectra were saved for each segment, with velocity and pulsatility index (PI) values calculated using the instrument's automated waveform tracking function. Descriptive analysis was done to determine the mean velocities and PI, and all data were analyzed for changes by decade of age, sex race, handedness, BMI, and BP. RESULTS: Among the key intracranial segments, mean blood flow velocities (MBFV) were highest in the MCA and lowest in the PCA across all ages, sexes, and ethnic groups. There was no difference in the MBFVs between left and right side segments of the Circle of Willis, with the exception of the distal M1 (P = .022) and the C1 (P < .0001), both slightly higher on the left. MBFV were higher among women than men in all segments except for the OA. MBFV decreased with advancing age in both men and women, but this was specific to Caucasian subjects. There were lower velocities in the OA for non-Caucasians. The PI was lower in the left VA (P < .0001), and for most segments was lower in women than men. The PI increased with age in all segments for women, but only in some segments for men, and this finding was also specific to Caucasian subjects. The yield of usable data ranged from 99.7% for the VA and BA, to 88.2% for C2. CONCLUSION: Our study provides normal, reference TCD values for a large cohort of healthy subjects across a wide range of age, sex, and race groups. We observed decreased MBFV and increased PI with aging, and higher MBFV in women. There were few differences in MBFV related to side or ethnicity, but the MFBV and PI changes with age were specific to Caucasians. We provide means and standard deviations of MBFVs across various demographic groups in key intracranial arteries. Such normal TCD values across age, gender, and ethnic groups in healthy subjects represent a useful reference tool for detecting individuals with TCD values outside normal limits and at increased vascular risk. TCD studies in large multiethnic populations are still required to determine differences in brain hemodynamics across various ethnic groups.

Cerebrovascular dynamics and vascular endothelial growth factor in acute mountain sickness.

OBJECTIVE: To determine if serum vascular endothelial growth factor (VEGF) and ultrasonic monitoring of vascular dynamics with dynamic vascular analysis at sea level and high altitude correlate with acute mountain sickness symptoms. METHODS: Nine volunteers participated in a staged ascent from sea level to 4300 m undergoing complete transcranial Doppler studies with dynamic vascular analysis. Serum VEGF levels, Lake Louise scores, Spielberger-1 scores, Subjective Exercise Experiences Scale positive scores, and Symptom Checklist-90 surveys were collected after 24 hours at each altitude. RESULTS: Symptom scores, index of pulsatility, and dynamic flow index differentiated the subjects into 2 distinct groups. Symptomatic subjects had increased VEGF levels at sea level but decreased levels at 4300 m. The dynamic flow index increased in symptomatic subjects at 4300 m compared with the asymptomatic subjects. The mean flow velocity increased in both groups and could not be used to differentiate the subjects. CONCLUSIONS: Altered vascular physiology is associated with acute mountain sickness. Increased vascular permeability increases vascular capacitance, with an increase in dynamic flow index to meet these demands. Altered vascular dynamics were associated with high-altitude cerebral edema in 1 subject. Dynamic vascular analysis demonstrated altered vascular pathophysiology associated with acute mountain sickness. Changes in VEGF were meaningful when interpreted with the dynamic vascular analysis findings. These physiological findings may help explain the vascular changes associated with hypocarbic hypoxemia at altitude.

Differentiating vascular pathophysiological states by objective analysis of flow dynamics.

BACKGROUND AND PURPOSE: There is an unmet need to classify cerebrovascular conditions physiologically and to assess cerebrovascular system performance. The authors hypothesized that by simultaneously considering the dynamic parameters of flow velocity, acceleration, and pulsatility index (PI) (impedance) in individual Doppler spectrum waveforms, they could develop an objective method to elucidate the pathophysiology of vascular conditions and classify cerebrovascular disorders. This method, dynamic vascular analysis (DVA), is described. METHODS: First, a theoretical model was developed to determine how any vascular segment and the ensemble of intracranial vascular segments could be defined according to its dynamic physiological characteristics. Next, the DVA method was applied to 847 anonymous serial complete clinical transcranial Doppler (TCD) studies of patients without regard for their diagnosis to ascertain actual reference ranges and the normality of the distribution curves for each dimension of the 3-parameter nomogram. The authors applied DVA to 2 clinical cases to see if they could track the changes in vascular performance of 2 known progressive diseases. RESULTS: The theoretical analysis identified 295,245 possible vascular states for the ensemble of vascular segments in the cerebral circulation. When applied to clinical TCD data, DVA revealed continuous, normally distributed data for the velocity, PI, and logarithm of the acceleration. CONCLUSIONS: DVA is proposed as a method for monitoring the physiological state of each cerebral artery segment individually and in ensemble. DVA evaluates the relationship among acceleration (force or pressure), velocity, and PI and provides an objective means to evaluate intracranial vascular segments using the paradigm of the well-described pressure-perfusion autoregulation relationship. DVA may be used to study cerebrovascular pathophysiology and to classify, evaluate, and monitor cerebrovascular disorders or systemic disorders with cerebrovascular effects.