Site matters: Central neuropathic pain characteristics and somatosensory findings after brain and spinal cord lesions.

BACKGROUND: It is unknown if different etiologies or lesion topographies influence central neuropathic pain (CNP) clinical manifestation. METHODS: We explored the symptom-somatosensory profile relationships in CNP patients with different types of lesions to the central nervous system to gain insight into CNP mechanisms. We compared the CNP profile through pain descriptors, standardized bedside examination, and quantitative sensory test in two different etiologies with segregated lesion locations: the brain, central poststroke pain (CPSP, n = 39), and the spinal cord central pain due to spinal cord injury (CPSCI, n = 40) in neuromyelitis optica. RESULTS: Results are expressed as median (25th to 75th percentiles). CPSP presented higher evoked and paroxysmal pain scores compared to CPSCI (p < 0.001), and lower cold thermal limen (5.6°C [0.0-12.9]) compared to CPSCI (20.0°C [4.2-22.9]; p = 0.004). CPSCI also had higher mechanical pain thresholds (784.5 mN [255.0-1078.0]) compared to CPSP (235.2 mN [81.4-1078.0], p = 0.006) and higher mechanical detection threshold compared to control areas (2.7 [1.5-6.2] vs. 1.0 [1.0-3.3], p = 0.007). Evoked pain scores negatively correlated with mechanical pain thresholds (r = -0.38, p < 0.001) and wind-up ratio (r = -0.57, p < 0.001). CONCLUSIONS: CNP of different etiologies may present different pain descriptors and somatosensory profiles, which is likely due to injury site differences within the neuroaxis. This information may help better design phenotype mechanism correlations and impact trial designs for the main etiologies of CNP, namely stroke and spinal cord lesions. This study provides evidence that topography may influence pain symptoms and sensory profile. The findings suggest that CNP mechanisms might vary according to pain etiology or lesion topography, impacting future mechanism-based treatment choices.

Contributions of neuroimaging in central poststroke pain: a review.

BACKGROUND: Central neuropathic poststroke pain (CNPSP) affects up to 12% of patients with stroke in general and up to 18% of patients with sensory deficits. This pain syndrome is often incapacitating and refractory to treatment. Brain computed tomography and magnetic resonance imaging (MRI) are widely used methods in the evaluation of CNPSP. OBJECTIVE: The present study aims to review the role of neuroimaging methods in CNPSP. METHODS: We performed a literature review of the main clinical aspects of CNPSP and the contribution of neuroimaging methods to study its pathophysiology, commonly damaged brain sites, and possible differential diagnoses. Lastly, we briefly mention how neuroimaging can contribute to the non-pharmacological CNPSP treatment. Additionally, we used a series of MRI from our institution to illustrate this review. RESULTS: Imaging has been used to explain CNPSP pathogenesis based on spinothalamic pathway damage and connectome dysfunction. Imaging locations associated with CNPSP include the brainstem (mainly the dorsolateral medulla), thalamus (especially the ventral posterolateral/ventral posteromedial nuclei), cortical areas such as the posterior insula and the parietal operculum, and, more recently, the thalamocortical white matter in the posterior limb of the internal capsule. Imaging also brings the prospect of helping search for new targets for non-pharmacological treatments for CNPSP. Other neuropathic pain causes identified by imaging include syringomyelia, multiple sclerosis, and herniated intervertebral disc. CONCLUSION: Imaging is a valuable tool in the complimentary evaluation of CNPSP patients in clinical and research scenarios.

ANTECEDENTES: A dor neuropática central pós-acidente vascular cerebral (DNPAVC) afeta até 12% dos pacientes com AVC em geral e até 18% dos pacientes com déficits sensoriais. Essa síndrome dolorosa costuma ser incapacitante e refratária ao tratamento. A tomografia computadorizada e a ressonância magnética do cérebro são métodos amplamente utilizados na avaliação da DNPAVC. OBJETIVO: Este estudo tem como objetivo revisar o papel dos métodos de neuroimagem na DNPAVC. MéTODOS: Realizamos uma revisão da literatura sobre os principais aspectos clínicos da DNPAVC e a contribuição dos métodos de neuroimagem para estudar a fisiopatologia da DNPAVC, locais cerebrais comumente lesados na DNPAVC e possíveis diagnósticos diferenciais. Por fim, mencionamos brevemente como a neuroimagem pode contribuir no tratamento não farmacológico da DNPAVC. Além disso, utilizamos uma série de imagens de ressonância magnética da nossa instituição para ilustrar esta revisão. RESULTADOS: Os exames de imagem têm sido usados para explicar a patogênese da DNPAVC com base no dano da via espinotalâmica e na disfunção do conectoma. Os locais de imagem associados à DNPAVC incluem o tronco cerebral (principalmente o bulbo dorsolateral), o tálamo (especialmente os núcleos ventral posterolateral/ventral posteromedial), áreas corticais como a ínsula posterior e o opérculo parietal e, mais recentemente, a substância branca tálamo-cortical no membro posterior da cápsula interna. Os exames de imagem também trazem a perspectiva de auxiliar na busca de novos alvos para tratamentos não farmacológicos para DNPAVC. Outras causas de dor neuropática identificadas por exames de imagem incluem siringomielia, esclerose múltipla e hérnia de disco intervertebral. CONCLUSãO: Os exames de imagem são uma ferramenta valiosa na avaliação complementar de pacientes com DNPAVC em cenários clínicos e de pesquisa.

Dissecting central post-stroke pain: a controlled symptom-psychophysical characterization.

Central post-stroke pain affects up to 12% of stroke survivors and is notoriously refractory to treatment. However, stroke patients often suffer from other types of pain of non-neuropathic nature (musculoskeletal, inflammatory, complex regional) and no head-to-head comparison of their respective clinical and somatosensory profiles has been performed so far. We compared 39 patients with definite central neuropathic post-stroke pain with two matched control groups: 32 patients with exclusively non-neuropathic pain developed after stroke and 31 stroke patients not complaining of pain. Patients underwent deep phenotyping via a comprehensive assessment including clinical exam, questionnaires and quantitative sensory testing to dissect central post-stroke pain from chronic pain in general and stroke. While central post-stroke pain was mostly located in the face and limbs, non-neuropathic pain was predominantly axial and located in neck, shoulders and knees (P < 0.05). Neuropathic Pain Symptom Inventory clusters burning (82.1%, n = 32, P < 0.001), tingling (66.7%, n = 26, P < 0.001) and evoked by cold (64.1%, n = 25, P < 0.001) occurred more frequently in central post-stroke pain. Hyperpathia, thermal and mechanical allodynia also occurred more commonly in this group (P < 0.001), which also presented higher levels of deafferentation (P < 0.012) with more asymmetric cold and warm detection thresholds compared with controls. In particular, cold hypoesthesia (considered when the threshold of the affected side was <41% of the contralateral threshold) odds ratio (OR) was 12 (95% CI: 3.8-41.6) for neuropathic pain. Additionally, cold detection threshold/warm detection threshold ratio correlated with the presence of neuropathic pain (ρ = -0.4, P < 0.001). Correlations were found between specific neuropathic pain symptom clusters and quantitative sensory testing: paroxysmal pain with cold (ρ = -0.4; P = 0.008) and heat pain thresholds (ρ = 0.5; P = 0.003), burning pain with mechanical detection (ρ = -0.4; P = 0.015) and mechanical pain thresholds (ρ = -0.4, P < 0.013), evoked pain with mechanical pain threshold (ρ = -0.3; P = 0.047). Logistic regression showed that the combination of cold hypoesthesia on quantitative sensory testing, the Neuropathic Pain Symptom Inventory, and the allodynia intensity on bedside examination explained 77% of the occurrence of neuropathic pain. These findings provide insights into the clinical-psychophysics relationships in central post-stroke pain and may assist more precise distinction of neuropathic from non-neuropathic post-stroke pain in clinical practice and in future trials.

The role of magnetic resonance imaging in Ménière disease: the current state of endolymphatic hydrops evaluation.

Technical advances in magnetic resonance imaging have allowed to accurately detect and grade endolymphatic space distension in Ménière disease; this was only possible in post-mortem histological studies until a few years ago. Magnetic resonance imaging rules out other causes of vertigo and hearing loss, and is able to evaluate the cochlear and vestibular compartments of the endolymphatic space using a dedicated protocol.

Abdominal vascular syndromes: characteristic imaging findings.

Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital-including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)-or compressive-including "nutcracker" syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic.

As síndromes vasculares abdominais englobam doenças raras, com sintomas e causas diversas, mas com achados de imagem característicos. Dividem-se em dois grupos distintos, a depender de sua origem, que pode ser congênita (síndrome de blue rubber bleb nevus, síndrome de Klippel-Trenaunay e telangiectasia hereditária hemorrágica/Rendu-Osler-Weber) ou compressiva (síndrome do "quebra-nozes", síndrome do ligamento arqueado, síndrome de Cockett ou May-Thurner e síndrome da artéria mesentérica superior). Neste artigo, o nosso objetivo é ilustrar achados de imagens determinantes dessas doenças, por meio de estudos adquiridos em nossa instituição, associando uma breve revisão da literatura.

Neuromyelitis optica shorter lesion can cause important pyramidal deficits.

OBJECTIVE: Evaluate the correlation between spinal cord lesion length and pyramidal function system score in a cohort of patients with NMO. METHODOLOGY: Retrospective retrieval of all exams performed in our center from January 2004 to December 2012 for patients with NMO. The exams were evaluated for lesion length, contrast enhancement and T1 hypointensity; these variables were correlated with the functional system score from the EDSS, performed no more than three months from the scan. RESULTS: 41 patients were included. Although patients with lesion extension ≥2 vertebral segments did not present worse pyramidal scores in a direct comparison, the influence of lesion length was not so strong when patients were separated in 3 groups (≥2, ≥3 or ≥4 vertebral segments) and evaluated with a receiving operating characteristics (ROC) curves. Gadolinium enhancement also contributed to more severe pyramidal system scores, but T1 hypointensity did not. CONCLUSION: Although patients with spinal cord lesion extending ≥3 vertebral segments had more pyramidal disability, its difference was not so strong when compared to patients with ≥2 or ≥4 vertebral segments. This suggests that lesion extension might not be the most important factor in favoring a worse prognosis in spinal cord lesions in NMO.

The role of magnetic resonance imaging in Ménière disease: the current state of endolymphatic hydrops evaluation / O papel da ressonância magnética na doença de Ménière: a avaliação da hidropsia endolinfática nos dias atuais

ABSTRACT Technical advances in magnetic resonance imaging have allowed to accurately detect and grade endolymphatic space distension in Ménière disease; this was only possible in post-mortem histological studies until a few years ago. Magnetic resonance imaging rules out other causes of vertigo and hearing loss, and is able to evaluate the cochlear and vestibular compartments of the endolymphatic space using a dedicated protocol.

RESUMO Os avanços técnicos na ressonância magnética têm permitido detectar e classificar com acurácia a distensão do espaço endolinfático na doença de Ménière; isso só era possível nos estudos histológicos post-mortem até poucos anos atrás. Além de afastar outras causas de vertigem e de perda auditiva, a ressonância magnética é capaz de avaliar os compartimentos coclear e vestibular do espaço endolinfático por meio de um protocolo dedicado.

Takayasu's arteritis in children and adolescents: report of three cases.

Takayasu's arteritis (TA) is a systemic vasculitis that affects mainly the aorta and its major branches. Despite being the third most frequent vasculitis in childhood, the occurrence of TA in the pediatric age group is scarce. We report three cases of TA in children, emphasizing signs and symptoms, angiographic alterations and therapeutics.

Abdominal vascular syndromes: characteristic imaging findings / Síndromes vasculares abdominais: achados de imagem característicos

Abstract Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital-including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)-or compressive-including "nutcracker" syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic.

Resumo As síndromes vasculares abdominais englobam doenças raras, com sintomas e causas diversas, mas com achados de imagem característicos. Dividem-se em dois grupos distintos, a depender de sua origem, que pode ser congênita (síndrome de blue rubber bleb nevus, síndrome de Klippel-Trenaunay e telangiectasia hereditária hemorrágica/Rendu-Osler-Weber) ou compressiva (síndrome do "quebra-nozes", síndrome do ligamento arqueado, síndrome de Cockett ou May-Thurner e síndrome da artéria mesentérica superior). Neste artigo, o nosso objetivo é ilustrar achados de imagens determinantes dessas doenças, por meio de estudos adquiridos em nossa instituição, associando uma breve revisão da literatura.

Arterite de Takayasu na infância e na adolescência: relato de três casos / Takayasu's arteritis in children and adolescents: report of three cases

A arterite de Takayasu (AT) é uma vasculite sistêmica que acomete principalmente a aorta e seus ramos. Apesar de ser a terceira vasculite mais frequente na infância, sua ocorrência na faixa etária pediátrica é pouco descrita. Relatamos três casos de AT na faixa etária pediátrica com ênfase nas manifestações clínicas, alterações angiográficas e abordagem terapêutica.

Takayasu's arteritis (TA) is a systemic vasculitis that affects mainly the aorta and its major branches. Despite being the third most frequent vasculitis in childhood, the occurrence of TA in the pediatric age group is scarce. We report three cases of TA in children, emphasizing signs and symptoms, angiographic alterations and therapeutics.