- [Pain management in children with erythromelalgia: case report]. [Journal Article]
- RBRev Bras Anestesiol 2018 Feb 02
- Erythromelalgia is a neuropathic pain syndrome due to an autosomal dominant gene, characterized by erythema, increased skin temperature and burning pain in hands and feet, whose treatment is often un...
Erythromelalgia is a neuropathic pain syndrome due to an autosomal dominant gene, characterized by erythema, increased skin temperature and burning pain in hands and feet, whose treatment is often unsatisfactory. In this paper, we report a case of a 9 years old female patient whose first episode of burning pain, erythema and edema of the hands, without triggering factors, had instant relief after immersion in cold water. She presented with systemic arterial hypertension and had seizures. The patient was treated with gabapentin (150mg.8h-1) and amitriptyline (12.5mg) orally, intravenous lidocaine infusion (120mg), without relieving pain complaints. Due to the lack of response to the proposed treatment, it was decided to gradually reduce these medications and to introduce carbamazepine (200mg) orally and, after 4 days of treatment, there was complete relief of the manifestations.
- Translational Model Systems for Complex Sodium Channel Pathophysiology in Pain. [Journal Article]
- HEHandb Exp Pharmacol 2018 Jan 28
- Chronic pain patients are often left with insufficient treatment as the pathophysiology especially of neuropathic pain remains enigmatic. Recently, genetic variations in the genes of the voltage-gate...
Chronic pain patients are often left with insufficient treatment as the pathophysiology especially of neuropathic pain remains enigmatic. Recently, genetic variations in the genes of the voltage-gated sodium channels (Navs) were linked to inherited neuropathic pain syndromes, opening a research pathway to foster our understanding of the pathophysiology of neuropathic pain. More than 10 years ago, the rare, inherited pain syndrome erythromelalgia was linked to mutations in the subtype Nav1.7, and since then a plethora of mutations and genetic variations in this and other Nav genes were identified. Often the biophysical changes induced by the genetic alteration offer a straightforward explanation for the clinical symptoms, but mutations in some channels, especially Nav1.9, paint a more complex picture. Although efforts were undertaken to significantly advance our knowledge, translation from heterologous or animal model systems to humans remains a challenge. Here we present recent advances in translation using stem cell-derived human sensory neurons and their potential application for identification of better, effective, and more precise treatment for the individual pain patient.
- Erythromelalgia. [Journal Article]
- VASAVasa 2018; 47(2):91-97
- Erythromelalgia is a rare syndrome characterized by the intermittent or, less commonly, by the permanent occurrence of extremely painful hyperperfused skin areas mainly located in the distal extremit...
Erythromelalgia is a rare syndrome characterized by the intermittent or, less commonly, by the permanent occurrence of extremely painful hyperperfused skin areas mainly located in the distal extremities. Primary erythromelalgia is nowadays considered to be a genetically determined neuropathic disorder affecting SCN9A, SCN10A, and SCN11A coding for NaV1.7, NaV1.8, and NaV1.9 neuronal sodium channels. Secondary forms might be associated with myeloproliferative disorders, connective tissue disease, cancer, infections, and poisoning. Between the pain episodes, the affected skin areas are usually asymptomatic, but there are patients with typical features of acrocyanosis and/or Raynaud's phenomenon preceding or occurring in between the episodes of erythromelalgia. Diagnosis is made by ascertaining the typical clinical features. Thereafter, the differentiation between primary and secondary forms should be made. Genetic testing is recommended, especially in premature cases and in cases of family clustering in specialized genetic institutions after genetic counselling. Multimodal therapeutic intervention aims toward attenuation of pain and improvement of the patient's quality of life. For this purpose, a wide variety of nonpharmacological approaches and pharmacological substances for topical and systemic use have been proposed, which are usually applied individually in a step-by-step approach. Prognosis mainly depends on the underlying condition and the ability of the patients and their relatives to cope with the disease.
- Front-Line Treatment Options for Chronic-Phase Chronic Myeloid Leukemia. [Journal Article]
- JCJ Clin Oncol 2018 Jan 20; 36(3):220-224
- The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management ch...
The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 40-year-old woman with a past medical history of hypertension and occasional premature ventricular contractions was found on routine blood work in June 2011 to have mild thrombocytosis, with a platelet count of 405,000. In November 2011, repeat analysis revealed a platelet count of 433,000, and by February 2012 her platelet count was 509,000. She had no evidence of leukocytosis or anemia and no symptoms of early satiety, night sweats, pruritus, or erythromelalgia. She was referred to a hematologist for evaluation of persistent isolated thrombocytosis in March 2012. Her spleen was not palpable, and a quantitative polymerase chain reaction (PCR) test for JAK2/V617F was negative. A bone marrow biopsy and aspiration revealed a mildly hypercellular marrow (70% to 80% cellularity), with an elevated myeloid:erythroid ratio of 5:1, increased megakaryocytes including micromegakaryocytes in the absence of increased blasts. Cytogenetic analysis revealed the presence of the Philadelphia chromosome translocation in 17 out of 20 metaphases. The remaining three metaphases were normal karyotype. Quantitative PCR for BCR-ABL1 yielded a value of 29.6% on the International Scale.
- Indomethacin-Responsive Idiopathic Red Ear Syndrome: Case Report and Pathophysiology. [Journal Article]
- HHeadache 2018; 58(2):306-308
- Characterisation of Nav1.7 functional expression in rat dorsal root ganglia neurons by using an electrical field stimulation assay. [Journal Article]
- MPMol Pain 2017 Jan-Dec; 13:1744806917745179
- Background The Nav1.7 subtype of voltage-gated sodium channels is specifically expressed in sensory and sympathetic ganglia neurons where it plays an important role in the generation and transmission...
Background The Nav1.7 subtype of voltage-gated sodium channels is specifically expressed in sensory and sympathetic ganglia neurons where it plays an important role in the generation and transmission of information related to pain sensation. Human loss or gain-of-function mutations in the gene encoding Nav1.7 channels (SCN9A) are associated with either absence of pain, as reported for congenital insensitivity to pain, or with exacerbation of pain, as reported for primary erythromelalgia and paroxysmal extreme pain disorder. Based on this important human genetic evidence, numerous drug discovery efforts are ongoing in search for Nav1.7 blockers as a novel therapeutic strategy to treat pain conditions. Results We are reporting here a novel approach to study Nav1.7 function in cultured rat sensory neurons. We used live cell imaging combined with electrical field stimulation to evoke and record action potential-driven calcium transients in the neurons. We have shown that the tarantula venom peptide Protoxin-II, a known Nav1.7 subtype selective blocker, inhibited electrical field stimulation-evoked calcium responses in dorsal root ganglia neurons with an IC50of 72 nM, while it had no activity in embryonic hippocampal neurons. The results obtained in the live cell imaging assay were supported by patch-clamp studies as well as by quantitative PCR and Western blotting experiments that confirmed the presence of Nav1.7 mRNA and protein in dorsal root ganglia but not in embryonic hippocampal neurons. Conclusions The findings presented here point to a selective effect of Protoxin-II in sensory neurons and helped to validate a new method for investigating and comparing Nav1.7 pharmacology in sensory versus central nervous system neurons. This will help in the characterisation of the selectivity of novel Nav1.7 modulators using native ion channels and will provide the basis for the development of higher throughput models for enabling pain-relevant phenotypic screening.
- Secondary erythromelalgia: a tryptophan dietary supplement-induced case associated with elevated 5-hydroxyindoleacetic acid (5HIAA) urinary levels. [Case Reports]
- IJInt J Dermatol 2018; 57(1):83-85
- How a Simple Ankle Sprain Turned Into Neuropathic Pain: Complex Reflex Sympathetic Dystrophy Versus Erythromelalgia. [Journal Article]
- WHWorkplace Health Saf 2017 Nov 01; :2165079917736786
- A 36-year-old woman sustained a Grade 2 ankle sprain at work. Two days after the injury, the ankle and foot became red and she complained of "intense burning pain." First diagnosed with complex refle...
A 36-year-old woman sustained a Grade 2 ankle sprain at work. Two days after the injury, the ankle and foot became red and she complained of "intense burning pain." First diagnosed with complex reflex sympathetic dystrophy, the employee was prescribed medications that provided some pain relief; a subsequent temporary nerve block provided additional relief. However, the symptoms returned and she was treated unsuccessfully with surgical sympathectomy. The employee was referred to a neurologist and diagnosed with primary erythromelalgia, a rare pain disorder that can be mistaken as complex reflex sympathetic dystrophy.
- A Novel SCN9A Mutation (F826Y) in Primary Erythromelalgia Alters the Excitability of Nav1.7. [Journal Article]
- CMCurr Mol Med 2017 Oct 09
- Primary erythromelalgia (PE) is a dominant inherited disorder characterized by recurrent pain, redness, and warmth of the extremities that is caused by gain-of-function mutations in the voltage-gated...
Primary erythromelalgia (PE) is a dominant inherited disorder characterized by recurrent pain, redness, and warmth of the extremities that is caused by gain-of-function mutations in the voltage-gated sodium channel Nav1.7. We investigated a three-generation Chinese Han family with PE. The proband is a 15-year old girl presented with skin ulcers, recurrent burning pain, warmth, and redness of the lower extremities that are refractory to all kinds of reported medications. The other two patients presented with similar symptoms but with far less severity that naturally remitted near their forties. Sequence analysis of the Nav1.7-encoding gene SCN9A showed a novel c.2477T>A (p. F826Y) mutation co-segregated with the disease phenotype. The functional effect of F826Y was investigated by voltage-clamp analysis in CHO-K1 cells. Compared with the wild-type (WT) channel, activation of the F826Y mutant channel was shifted by 7.7 mV in a hyperpolarizing direction, whereas steady-state inactivation was shifted by 4.3 mV in a depolarizing direction. These results suggested that F826Y of Nav1.7 could render DRG neurons hyperexcitable, contributing to the pathogenesis of PE. This study provides an example of the extreme intractability of PE and broadens the spectrum of SCN9A mutations responsible for it.
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- A Unique Case for Spinal Cord Stimulation: Successful Treatment of Small Fiber Neuropathy Pain Using Multiple Spinal Cord Stimulators. [Journal Article]
- CRCase Rep Med 2017; 2017:6969285
- Spinal cord stimulators have commonly been used to treat multiple pain conditions. This case report represents a unique case of using multiple spinal cord stimulators for widespread small fiber neuro...
Spinal cord stimulators have commonly been used to treat multiple pain conditions. This case report represents a unique case of using multiple spinal cord stimulators for widespread small fiber neuropathy pain. This case report concerns patient JJ who first presented with generalized neuropathic pain. His pain was an intermittent burning, stinging quality that originally focused in both of his feet and progressed to include his legs and arms and eventually involved his entire body. The pain would last moments to hours at least daily. He reported a poor quality of life. He was diagnosed with small fiber neuropathy with anhydrosis, suggestive of idiopathic erythromelalgia. He had a spinal cord stimulator trial involving both cervical and lower thoracic percutaneous leads. After two spinal cord stimulators were implanted, the patient began to report an improvement in pain. The patient continues to report excellent pain relief. The patient uses the stimulator intermittently as needed, in an abortive fashion for pain flares. The patient is very pleased and has increased his activity. He now attends graduate school full time. This case report hopes to illustrate a unique use of multiple spinal cord stimulators in treating widespread neuropathic pain caused by small fiber neuropathy.