Preoperative visualization of the greater occipital nerve with magnetic resonance imaging in candidates for occipital nerve decompression for headaches.

Occipital nerve decompression is effective in reducing headache symptoms in select patients with migraine and occipital neuralgia. Eligibility for surgery relies on subjective symptoms and responses to nerve blocks and Onabotulinum toxin A (Botox) injections. No validated objective method exists for detecting occipital headache pathologies. The purpose of the study is to explore the potential of high-resolution Magnetic Resolution Imaging (MRI) in identifying greater occipital nerve (GON) pathologies in chronic headache patients. The MRI protocol included three sequences targeting fat-suppressed fluid-sensitive T2-weighted signals. Visualization of the GON involved generating 2-D image slices with sequential rotation to track the nerve course. Twelve patients underwent pre-surgical MRI assessment. MRI identified four main pathologies that were validated against intra-operative examination: GON entanglement by the occipital artery, increased nerve thickness and hyperintensity suggesting inflammation compared to the non-symptomatic contralateral side, early GON branching with rejoining at a distal point, and a connection between the GON and the lesser occipital nerve. MRI possesses the ability to visualize the GON and identify suspected trigger points associated with headache symptoms. This case series highlights MRI's potential to provide objective evidence of nerve pathology. Further research is warranted to establish MRI as a gold standard for diagnosing extracranial contributors in headaches.

Can Diffusion Tensor Imaging Apparent Diffusion Coefficient Diagnose Carpal Tunnel Syndrome? A Systematic Review and Meta-Analysis.

Magnetic resonance diffusion tensor imaging (DTI) can detect microstructural changes in peripheral nerves. Studies have reported that the median nerve apparent diffusion coefficient (ADC), a quantification of water molecule diffusion direction, is sensitive in diagnosing carpal tunnel syndrome (CTS). Five databases were searched for studies using ADC to investigate CTS. Apparent diffusion coefficient (measured in mm2/s) were pooled in random-effects meta-analyses. Twenty-two studies met criteria yielding 592 patients with CTS and 414 controls. Median nerve ADC were measured at the level of the distal radioulnar joint (CTS ADC: 1.11, 95% CI: 1.07-1.15, I2 = 54%; control ADC: 1.04, 95% CI: 1.01-1.07, I2 = 57%), pisiform (CTS ADC: 1.39, 95% CI: 1.37-1.42, I2 = 0%; control ADC: 1.27, 95% CI: 1.23-1.31, I2 = 59%), hamate (CTS ADC: 1.40, 95% CI: 1.36-1.43, I2 = 58%; control ADC: 1.27, 95% CI: 1.25-1.28, I2 = 47%), and as an combination of several measurements (CTS ADC: 1.40, 95% CI: 1.37-1.47, I2 = 100%; control ADC: 1.39, 95% CI: 1.24-1.53, I2 = 100%). Median nerve ADC is decreased in individuals with CTS compared to controls at the levels of the hamate and pisiform. ADC cut-offs to diagnose CTS should be established according to these anatomic levels and can be improved through additional studies that include use of a wrist coil.

Amantadine as a Potential Treatment for Marchiafava-Bignami Disease: Case Reports and a Possible Mechanism.

Introduction: Several reports have described the use of amantadine for managing symptoms in Marchiafava-Bignami disease (MBD); however, amantadine's role for the treatment of MBD symptoms is unclear. Here, we describe 2 patients with MBD who were treated with amantadine and hypothesize a potential mechanism responsible for clinical benefit. Case 1. A 38-year-old woman with excessive wine drinking presented with agitation, impaired speech, and a minimally conscious state. MRI revealed lesions in the splenium and genu. After being diagnosed with MBD, she was treated with intravenous thiamine, multivitamins, and 100 mg of amantadine twice a day for 2 weeks. She recovered to near baseline after 3 weeks. Case 2. A 54-year-old woman with years of heavy alcohol use presented with sudden bradyphrenia, acalculia, disinhibited behavior, weakness, and urinary incontinence. MRI revealed a large anterior callosal lesion. Two years after initial recovery from MBD, she noted that consuming "energy drinks" resulted in a transient, near-complete resolution of her residual behavioral, fatigue, and language symptoms. 100 mg of amantadine twice a day was trialled. After noted improvement, a further escalation to 200 mgs 3 times a day resulted in significant improvement in language and behavioral symptoms. Conclusion: Amantadine in addition to vitamins may be beneficial in the treatment of MBD. It is possible that the dopaminergic effect of amantadine leads to improved recovery and function in dopamine-mediated pathways, including mesocortical and mesolimbic pathways during initial recovery, as well as improved speech, behavior, and fatigue in the following months. The role of amantadine in the treatment of MBD warrants further study.

Outcomes of transcutaneous nerve stimulation for migraine headaches: a systematic review and meta-analysis.

BACKGROUND: Implanted and transcutaneous nerve stimulators have shown promise as novel non-pharmacologic treatment for episodic and chronic migraines. The purpose of this study was to summarize the reported efficacy of transcutaneous single nerve stimulators in management of migraine frequency and severity. METHODS: A systematic review of five databases identified studies treating migraines with transcutaneous stimulation of a single nerve. Random effects model meta-analyses were conducted to establish the effect of preventive transcutaneous nerve stimulation on headache days per month and 0-10 numeric rating scale pain severity of headaches for both individuals with episodic and chronic migraines. RESULTS: Fourteen studies, which treated 995 patients, met inclusion criteria, including 7 randomized controlled trials and 7 uncontrolled clinical trials. Transcutaneous nerve stimulators reduced headache frequency in episodic migraines (2.81 fewer headache days per month, 95% CI 2.18-3.43, I2 = 21%) and chronic migraines (2.97 fewer headache days per month, 95% CI 1.66-4.28, I2 = 0%). Transcutaneous nerve stimulators reduced headache severity in episodic headaches (2.23 fewer pain scale points, 95% CI 1.64-2.81, I2 = 88%). CONCLUSIONS: Preventive use of transcutaneous nerve stimulators provided clinically significant reductions in headache frequency in individuals with chronic or episodic migraines. Individuals with episodic migraines also experienced a reduction in headache pain severity following preventive transcutaneous nerve stimulation.

First Bite Syndrome Relief With Trigeminal Nerve Branch Block and Ablation: A Case Report.

First bite syndrome (FBS) is intense facial pain at the first bite of each meal. Currently, no guidelines exist for treating FBS, although botulinum toxin injection has shown benefit. We describe a case of right-sided FBS and painful trigeminal neuropathy, in which FBS resolved for 2 weeks using maxillary and mandibular nerve block and radiofrequency nerve thermal ablation (RFA). Our treatment may have disrupted somatic sensory input from the parotid carried by the auriculotemporal nerve or lesioned the otic ganglion resulting in decreased parasympathetic hyperactivation. Further studies are warranted to evaluate the use of this procedure for FBS.

Multiple myeloma presenting as an intramedullary spinal cord tumor: a case report and review of the literature.

BACKGROUND: Extramedullary disease in multiple myeloma often portends a worse diagnosis. In approximately 1% of cases, multiple myeloma may metastasize to the central nervous system as either leptomeningeal involvement or an intracranial, intraparenchymal lesion. Spinal cord metastases, however, are exceedingly rare. We present a case of spinal cord multiple myeloma as well as a literature review of reported cases. CASE PRESENTATION: A 66-year-old African American man with multiple myeloma presented with acute midthoracic pain and lower extremity paresis and paresthesia. Magnetic resonance imaging of the spine revealed two contrast-enhancing intramedullary enhancing lesions in the T1-T2 and T6-T7 cord. Resection with biopsy yielded a diagnosis of metastatic multiple myeloma. CONCLUSION: To date, only six cases of extramedullary disease to the spinal cord in patients with multiple myeloma have been reported, including our patient's case. In all cases, neurologic deficit was observed at presentation, and magnetic resonance imaging of the spine revealed an intramedullary, homogeneously enhancing lesion. Current evidence suggests worse prognosis in patients with extramedullary disease to the central nervous system, and treatment paradigms remain debatable.

Cryptogenic Intracranial Hemorrhagic Strokes Associated with Hypervitaminosis E and Acutely Elevated α-Tocopherol Levels.

OBJECTIVES: Up to 41% of intracerebral hemorrhages (ICH) are considered cryptogenic despite a thorough investigation to determine etiology. Certain over-the-counter supplements may increase proclivity to bleeding, and we hypothesize that specifically vitamin E may have an association with ICH and acutely elevated serum levels of α-tocopherol. Our aim is to report 3 cases of recently admitted patients with hypervitaminosis E and otherwise cryptogenic ICH. METHODS: At our institution between January and December 2018, 179 patients were admitted with ICH with 73 imputed to be "cryptogenic" (without clear etiology as per Structural vascular lesions, Medication, Amyloid angiopathy, Systemic disease, Hypertension, or Undetermined and Hypertension, Amyloid angiopathy, Tumor, Oral anticoagulants, vascular Malformation, Infrequent causes, and Cryptogenic criteria). Of these, we found 3 (4.1%) clearly admitted to consistent use of vitamin E supplementation for which α-tocopherol levels were checked. We describe the clinical presentation and course of these patients and their etiologic and diagnostic evaluations including neuroimaging and α-tocopherol laboratory data. RESULTS: All patients in this series were consistently consuming higher than recommended doses of vitamin E and developed acute ICH. The first 2 patients both had subcortical (thalamic) intraparenchymal hemorrhages while the third had an intraventricular hemorrhage. Serum α-tocopherol levels in patient A, B, and C were elevated at 30.8, 46.7, and 23.3 mg/L, respectively (normal range 5.7-19.9 mg/L) with a mean of 33.6 mg/L. No clear alternate etiologies to their ICH could be conclusively determined despite thorough workups. CONCLUSIONS: In patients with cryptogenic ICH, clinicians should consider hypervitaminosis E and check serum α-tocopherol level during admission. Reviewing the patient's pharmacologic history, including over-the-counter supplements such as vitamin E, may help identify its association, and its avoidance in the future may mitigate risk. With its known vitamin K antagonism, hypo-prothrombinemic effect, cytochrome p-450 interaction, and antiplatelet activity, vitamin E may not be as benign as presumed. Its consumption in nonrecommended doses may increase ICH risk, which may be underestimated and under-reported.

Cervical Spinal Cord Stimulator Lead Migration and Transection Adjacent to the Foramen Magnum: A Case Report.

BACKGROUND: Spinal cord stimulation (SCS) is a relatively safe therapy for the treatment of pain but has the potential for several complications, including lead migration and breakage. While instances of lead breakage and electrode shearing have been described, there are no reported cases of stimulator lead transection and migration to the foramen magnum. AIMS: We describe the case of a 53-year-old woman who reported that her cervical spinal cord stimulator was no longer functioning after a traumatic fall. CASE: Fluoroscopy of the neck revealed that one of the MRI conditional leads had migrated cephalad, and the distal aspect appeared to be transected. This was confirmed by computerized tomography, which showed a transected portion of the lead in the epidural space, just inferior to the posterior aspect of the foramen magnum. An SCS device revision was performed to replace the lead, but the distal transected tip was left in place in the epidural space adjacent to the foramen magnum to avoid complications of retrieval. DISCUSSION/CONCLUSION: Given the location of the transected portion of the lead, we recommended avoiding MRI imaging. In addition, we advised the patient that a repeat x-ray may be necessary if she has increased neck pain or any other concerning symptoms. In this report, we discuss the known complications with SCS, as well as management of a retained lead fragment.

Hand asymmetries of tactile attention in younger and older adults.

Background/Objectives: The allocation of attention can alter the perception of magnitude. When performing line bisections, young adults deviate leftward (pseudoneglect), a bias thought to be induced by right hemisphere dominance for allocating spatial attention. However, when performing body bisections young adults deviate rightward, suggesting left hemisphere dominance for allocating body-centered attention. With aging, there is a reduction of pseudoneglect thought to result from either an age-related decrease in right hemispheric functions (right hemi-aging) or from hemispheric asymmetry reduction in older adults (HAROLD). The goal of this study was to learn if there are tactile body-centered perceptual-attentional right-left asymmetries in that change with aging. Methods: The participants were younger and older healthy adults. Semmes-Weinstein Monofilaments were used to test for differences in the perceived magnitude of pressure differences between a reference stimulus and test stimuli applied to the right and left palmar thenar eminence. Results: Young adults perceived the magnitude of difference in the lightest pressure stimuli applied to the right hand as being greater than the older adults. Young adults perceived the magnitude of difference between the lightest pressure and reference applied to the right hand to be greater than the left hand, but older adults perceived a lighter stimulus greater on the left compared to the right. Conclusions: Whereas the right hemisphere appears to be dominant in mediating spatial attention, the left hemisphere may play a dominant role in the allocation of body-centered attention. Like the aging-related reduction of the visual perception of the magnitude (length) of the left side of a line, this tactile reduction in magnitude (pressure) perception in older adults suggests that with aging, there is a reduction of left-hemispheric mediated allocation of tactile attention, and this result is not fully consistent with either the HAROLD or hemi-aging models.

Left hemispatial neglect with a splenial lesion.

With injury of the anterior two-thirds of the corpus callosum, each hemisphere's attentional bias to contralateral hemispace becomes manifest with each hand deviating ipsilaterally during line bisection tasks. Patients with infarctions in the right posterior cerebral artery distribution with occipital and splenial damage can also exhibit spatial neglect. The goal of this report is to learn the role of the splenium of the corpus callosum in mediating visuospatial attention. A right-handed woman with Marchiafava-Bignami disease and damage to the splenium of her corpus callosum without evidence of a mesial frontal, parietal, or occipital injury was assessed for spatial neglect with line bisections. When bisecting lines in her left hemispace with her right hand, she deviated to the right, but revealed no major deviations when the line was place in the midline, in right hemispace, or when bisecting lines with her left hand. This patient provides evidence that damage to the splenium can induce a special form of asymmetrical spatial neglect. This asymmetry might be related to the disconnected right hemisphere's ability to allocate attention to both right and left hemispaces with the disconnected left hemisphere's ability to allocate attention to the right but not left hemispace.

Right hemispatial ipsilesional neglect with chronic right hemisphere strokes.

BACKGROUND: Patients who present with spatial neglect after stroke often perform normally on tests for neglect after a few weeks. Whereas tests for neglect are often performed directly in front of a patient, in their actual environments many important stimuli may be present within their left or right hemispace. The presence and severity of neglect often depends on the hemisphere injured. It is possible, in chronic stroke, for spatial judgments to be influenced by an interaction of stroke laterality and the spatial location of stimuli. The objective of this study was to learn if unilateral hemispheric chronic strokes contribute to a spatial bias with laterally presented stimuli. METHOD: There were 70 participants, 62 with unilateral chronic strokes (>6 months post onset) including 35 with left hemisphere damage (LHD), 27 with right hemisphere damage (RHD), and 8 demographically similar people without history of stroke. Participants were asked to bisect 300 lines presented with distractors on the left, right, or both sides of the line, or no distractor, on a touch-screen monitor in right, center or left hemispace. RESULTS: There was a significant interaction between the side of the hemispheric lesion and the side of the body where these lines were presented. Specifically, in right space, patients with RHD deviated leftward in comparison to the other groups. Furthermore, there was an interaction between group and distractor induced bias. All three groups approached the left distractor, and the patients with LHD also approached the right distractor. CONCLUSIONS: Although spatial neglect is more severe in contralesional than ipsilesional hemispace in the period immediately following a stroke, over time patients with RHD may develop ipsilesional neglect that is more severe in ipsilesional than contralesional space. The mechanism underlying this bias is not known and may be related to attempted compensation or the development of a contralateral attentional/intentional grasp.

Allocentric But Not Egocentric Pseudoneglect of Peripersonal Space.

BACKGROUND AND OBJECTIVE: Healthy adults often deviate leftward on line bisection tasks (allocentric pseudoneglect) but rightward on body part bisection tasks (egocentric pseudoneglect). People visually estimate distance in peripersonal space by comparing the distance to the length of a body part such as an arm's length (an egocentric reference) or using standard units of distance such as inches (an allocentric reference). Our objective was to learn whether people have pseudoneglect when estimating distances in peripersonal space using egocentric versus allocentric reference frames. METHODS: Twelve healthy participants standing either next to or 5 feet away from a wall were asked to move away from or toward the wall such that their shoulder would be what they judged to be an arm's length or a distance of 1, 2, or 3 feet from the wall. RESULTS: The participants estimated their arm's length more accurately than the standard units of distance (possibly related to learning and practice). Participants were more precise when estimating the length of their left than their right arm. When estimating standard units of distance, participants underestimated the distances on their left side more than on their right. CONCLUSIONS: Our results support the postulate that left pseudoneglect is an allocentric phenomenon related to a hemispheric asymmetry in computing allocentric distances. The participants underestimated 2 and 3 feet, but overestimated 1 foot. This dichotomy may relate to using focused versus distributed attention. The brain mechanisms leading to these asymmetries remain to be determined.

Abnormal tactile pressure perception in Parkinson's disease.

BACKGROUND/OBJECTIVE: Some of the behavioral disorders associated with Parkinson's disease (PD), such as the reduced magnitude of actions (hypometria) may be related to an impairment in cognitive disengagement. A reduced ability to disengage attention from previous sensory stimuli will alter perception with a reduced range of estimated stimulus magnitudes (contraction to the mean). To test this disengagement hypothesis, participants with PD were tested to learn whether they had abnormal sensory perception with overestimation of the relative magnitude of weaker tactile stimuli and underestimation of the relative magnitude of stronger tactile stimuli in relation to a reference stimulus. DESIGN/METHOD: The participants were 12 people with PD and 12 healthy adults. Test stimuli were applied to the palm using Semmes-Weinstein monofilaments (SWM) of 6 magnitudes, 3 greater and 3 less than a standard stimulus. In each trial, after being stimulated with the reference (standard) stimulus, a test monofilament was applied, and the participant was asked to provide a numerical estimate of the magnitude of the second stimulus relative to the standard. RESULTS: Compared to the control group, participants with PD overestimated the magnitudes of the tactile stimuli below the standard stimulus and underestimated the magnitudes of stimuli above the standard stimulus. CONCLUSIONS: These results demonstrate that people with PD likely have a reduced ability to estimate the relative magnitudes of tactile sensory stimuli. Whereas deafferentation would alter perception in one direction, the impairment of these participants with PD may result from a disorder of disengagement, and disorders of disengagement are often due to frontal-executive dysfunction.

Critical appraisal of rotigotine transdermal system in management of Parkinson's disease and restless legs syndrome - patient considerations.

Rotigotine (RTG) is a dopamine agonist that is used as mono and adjunct therapy to treat Parkinson's disease, and as therapy for moderate-to-severe restless legs syndrome. RTG is the only dopamine agonist currently available as a 24-hour/day transdermal system, providing once-a-day dosing. As a transdermal patch, RTG bypasses the gastrointestinal tract, making it a treatment option for patients with dysphagia. The use of RTG also avoids the need to schedule administration of medication around meals. This review provides a critical appraisal of RTG as treatment of Parkinson's disease and RLS.

Global attentional neglect of segmented lines in Parkinson's disease.

Global attention requires disengagement from focal elements of stimuli. Since people with Parkinson's disease (PD) may reveal impaired disengagement, this study attempted to learn if people with PD may be impaired at allocating global attention. Healthy adults and people with PD attempted to bisect lines of uniform thickness and lines composed of two segments of unequal thickness and length. When the longer line segment was to the right of the shorter segment, the group with PD demonstrated an increased deviation toward the longer segment, supporting the postulate that people with PD have an impaired ability to disengage focal attention and engage global spatial attention.

Hypometric allocentric and egocentric distance estimates in Parkinson disease.

OBJECTIVE AND BACKGROUND: Persons with Parkinson disease (PD) show hypometric movements and make hypometric estimates of imagined actions. These deficits may be related to misestimates of the length of body parts. Our objective was to learn whether patients with PD are impaired in their estimations of their arm's length and standard units of distance. METHODS: We tested 20 patients with PD, all on therapeutic doses of dopaminergic medications, and 13 healthy controls. In half of the trials, the participants stood so that either their right or left shoulder was adjacent to a wall; in the other half, their right or left shoulder was 5 feet from the wall. In the egocentric testing condition, they were asked to move their body toward or away from the wall to what they considered was an arm's length from the wall. In the allocentric testing condition, they were to move toward or away from the wall so that their proximal shoulder was a standard unit distance of 1, 2, or 3 feet from the wall. RESULTS: The patients with PD made much greater hypometric (too close to the wall) errors. Since at 5 feet from the wall they had to move farther to underestimate distances, their errors cannot be explained by hypometric movements. The results did not differ significantly by egocentric or allocentric estimation, side of shoulder proximity, or side of PD onset. CONCLUSIONS: Our findings support the idea that the egocentric and allocentric hypometria associated with PD is a perceptual rather than motor disorder.