Electric Shock-like Sensation Research Articles

Radiological and clinical biomarkers in patients with central post stroke pain

Background. Central post-stroke pain (CPSP) occurs following cerebrovascular accidents and is a neuropathic pain syndrome that is characterized by stimulation-independent pain; shooting, burning, or electric shock-like sensation and paresthesia. Multiple pathogenetic theories have been proposed for the CPSP including disinhibition, central sensitization, thalamic changes, and altered function of spinothalamic tract (STT). Investigations such as MRI DTI can help to understand the pathogenesis of CPSP. Objective. To determine the radiological and clinical biomarkers in cases with CPSP. Methods. This case-control study was retrospectively conducted upon 60 persons divided into 20 CPSP cases (group 1), 20 cases with no CPSP (group 2) and 20 healthy controls (group 3). All subjects had Routine MRI and complete neurological examination including “Sensory testing but stroke patients were evaluated by quantitative assessment of neuropathic pain, the National Institutes of Health Stroke Scale (NIHSS), Ashworth scale, Modified Rankin Scale (MRS) and Hamilton depression rating scale (HAM-D scale). Results. Significant differences existed among studied groups as regard motor examination, sensory examination, NIHSS score and Hamilton depression score. A non-significant difference was detected among the groups regarding MRS findings. A significant difference existed between groups 1 and 2, between groups 1 and 3 while no significant difference was detected between groups 2 and 3 for all FA readings and all ADC readings in ipsilateral affected side assessed at internal capsule, midbrain, and pons. No significant difference existed between groups 1 and 2, between groups 1 and 3 and between groups 2 and 3 as regard FA readings and ADC readings in contralateral side assessed at internal capsule, midbrain, and pons. Conclusion. Our study highlighted the significance of white matter tracts (WMT) other than the conventional pain pathways in CPSP and can thus serve as a predictive marker for CPSP onset or a prognostic marker after any drug therapy or neuromodulatory treatment.

Our Experience on Unusual Manifestations of Hansen’s Disease - A Case Series

Abstract Hansen’s disease is caused by an acid–fast bacillus – Mycobacterium leprae. Diagnosis of Hansen’s disease is mainly clinical. Hence, it is crucial to be aware of its diverse manifestations. We hereby report three such cases of Hansen’s disease with uncommon presentation. Case 1: A 26-year-old male presented with progressive numbness and multiple skin lesions over both upper and lower limbs in the past 3 years. Case 2: A 26-year-old male presented with tingling sensation of both upper limbs and lower limbs along with multiple skin lesions all over the body in the past 10 months. Case 3: A 39-year-old male presented with multiple joint pain, electric shock-like sensation of both upper limbs, and weakness of both hands along with skin rashes all over the body in the past 1 month. Skin examination of all these patients revealed multiple hypoanesthetic erythematous patches in the involved areas. Nerve conduction study was suggestive of asymmetric sensory motor axonal polyneuropathy. Skin biopsy from the lesions of the first patient revealed epithelioid granulomas suggesting borderline tuberculoid leprosy. Ziehl–Neelsen stain was positive for both fragmented and intact bacilli in the second and third cases, suggesting lepromatous leprosy. All of them were treated successfully with antileprosy drugs. It is essential to consider leprosy as a differential diagnosis in all patients presenting with symptoms of peripheral neuropathy, so that an early diagnosis and treatment is possible.

EFFECTS OF MLS-LASER ON NEUROPATHIC PAIN IN DIABETIC SENSОMOTOR NEUROPATHY

About 20-50 % of patients with diabetes and about 60 % of those with diabetic neuropathy develop neuropathic pain, which is characterized by tingling, burning, sharp, shooting, or stabbing sensations, and even electric shock-like sensations. Painful diabetic neuropathy can significantly affect the quality of life of patients with diabetes, the ability to perform daily activities and negatively affect mood. According to the 2021 consensus of an international panel of experts regarding the treatment of painful distal symmetric polyneuropathy, non-pharmacological forms of treatment should also be considered due to unsatisfactory pharmacotherapy. A number of studies have demonstrated the role of photobiomodulation as a non-pharmacological method of treating painful diabetic neuropathy. The purpose of this placebo-controlled, longitudinal study was to investigate the effect of high-energy MLS-laser therapy on neuropathic pain. Material and methods: A total of 69 cases of patients with type 2 diabetes and painful diabetic neuropathy of the lower extremities were followed, divided into two groups: an experimental - 41 patients received high-energy laser radiation and a control (placebo) group - 28 patients, with a "mock" laser treatment. For objectification of pain, the Bulgarian version of the short form of the McGill pain questionnaire, version SF-MPQ-2, which includes the visual analog scale (VAS), was used. Comparisons between groups were performed with parametric or non parametric tests depending on the distribution of the variables, the number of the compared groups and the study pre test – post test design. Results: The pain index, reported by the McGill questionnaire, in the experimental group, decreased by - 63.2 % at the end of the nine-day treatment and by - 56.1 % at the 90th day after the start of treatment compared to the value before therapy. In the control group, there was a minimal change at the end of treatment (day 21), which did not persist until the end of the observation period (day 90). Conclusions: MLS laser therapy significantly increases the pain threshold and should be considered a safe, non-pharmacological adjunct to standard therapy in patients with painful diabetic peripheral neuropathy.

A Case of Multiple Sclerosis Presenting with Thoracic Lhermitte's Sign

Lhermitte's sign (LS) is a transient symptom consisting of an electric shock-like sensation radiating ascending along the spinal cord during forward flexion of the neck. It may be associated with sensory complaints such as hypo or hyperesthesia. Although it is more common in cervical lesions, it can also be seen less frequently in thoracic lesions. LS is classified as one of the paroxysmal pain syndromes of multiple sclerosis (MS). It can also be seen in cervical spondylosis, disc herniation, trauma, spinal cord malignancies, vitamin B12 deficiency, cisplatin toxicity and radiation myelotoxicity. In cases of thoracic myelitis, LS should be considered and confirmed by neuroradiological and neurophysiological examinations. In this article, we aimed to present a case of MS with Lhermitte sign due to a lesion in the thoracic spinal cord, as a rare but possible example of spinal cord pathology in the thoracic region.

Treatment of dural tear with nerve root herniation after unilateral biportal endoscopic decompression using an epidural blood patch: a case report.

We present a case of a dural tear associated with nerve root herniation following unilateral biportal endoscopic decompression (UBED) that was successfully treated using a computed tomography-guided epidural blood patch. A 60-year-old man underwent UBED for radicular pain because of spinal stenosis at L4-5. A left partial hemilaminectomy and flavectomy were performed; however, the left dorsolateral side dura mater was torn during the procedure. TachoComb® was applied at the dural tear site, and the pain was relieved following UBED. However, 3 weeks post-UBED, the patient reported severe pain with an electric shock-like sensation in the left buttock and posterior thigh region with no other neurologic symptoms. The pain was aggravated by standing and spinal motion. Follow-up lumbar spinal magnetic resonance imaging was performed. Axial images indicated protrusion of the left S2 nerve root through the left dorsolateral side of the dura mater. The patient was further diagnosed with nerve root herniation following a dura mater tear. A computed tomography-guided epidural blood patch was performed, with successful therapeutic results. The outcome of this study indicates that a small dural tear that occurs during minimally invasive spinal surgery can be efficiently treated using an epidural blood patch prior to open surgery.

Clinical features of anti-leucine-rich glioma-inactivated 1 encephalitis in northeast China

AimTo examine the clinical characteristics, laboratory tests, imaging and electroencephalography presentation, treatment, and prognosis of anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis and improve the awareness of this disease. MethodWe performed a retrospective analysis of the clinical data of 41 patients who were diagnosed with anti-LGI1 encephalitis. Their clinical characteristics, laboratory tests, and imaging and electroencephalography data were collected, and the treatment results and prognosis were evaluated. The modified Rankin Scale (mRS) was used to evaluate neurological function. ResultsA total of 41 patients were included in the study, the average follow-up time is 33.0 months.The initial symptoms included cognitive impairment (n = 16, 39.0%),faciobrachial dystonic seizures (FBDS) (n = 12, 29.3%), grand mal seizures (n = 5, 12.2%) hallucinations (n = 4, 9.8%), loss of consciousness (n = 2, 4.9%), nausea and vomiting (n = 1, 2.4%),and head discharge-like sensation and radiate one limb (n = 1, 2.4%). There were 20 and 21 patients in the good (mRS ≤ 2) and poor (mRS > 2) prognosis groups, respectively. In the good prognosis group, the initial symptoms included faciobrachial dystonic seizures (FBDS) (n = 6, 30.0%), cognitive impairment (n = 6, 30.0%), hallucinations (n = 4, 20.0%), grand mal seizures (n = 3, 15.0%), loss of consciousness (n = 2, 10.0%), and nausea and vomiting (n = 1, 5.0%). There were 10 patients with hyponatremia. Magnetic resonance imaging (MRI) showed limbic system involvement in 12 patients (60.0%).17 patients (85.0%) recovered, 2 (10.0%) showed significant improvement, and 1 (5.0%) died after a mean follow-up period of 36.9 months. In the poor prognosis group, the initial symptoms included FBDS (n = 6, 28.5%), cognitive impairment (n = 10, 47.6%), grand mal seizures (n = 2, 9.5%), and electric shock-like sensation in the left limbs (n = 1, 4.7%). There were 20 patients with hyponatremia. MRI showed limbic system involvement in 11 patients (52.4%). 11 patients (52.4%) recovered, 8 (38.1%) showed significant improvement, and 2 (9.5%) died after a mean follow-up period of 29.0 months. ConclusionsThe clinical characteristics of anti-LGI1 encephalitis include hyponatremia, FBDS, epileptic seizures, hallucinations, cognitive impairment, and loss of consciousness, while the rarely seen characteristics are nausea, vomiting, and other autonomic dysfunctions and electric shock-like sensation. The appearance of hallucinations often indicates a good prognosis.Hyponatremia and elevated cerebrospinal fluid protein levels can be used as indicators that affect the prognosis of patients.Limbic system involvement has nothing to do with prognosis.Attention should be paid to early diagnosis and timely first-line immunotherapy.

Neuropathic Pain Related to Peripheral Neuropathies According to the IASP Grading System Criteria.

Neuropathic pain is defined as pain caused by a lesion or disease of the somatosensory system. Neuropathic pain represents a broad category of pain conditions, common complications of peripheral neuropathies, which are characterized by a combination of positive symptoms, including paresthesia and/or dysesthesia and sensory deficits in the painful area. In the present paper, we aimed to assess neuropathic pain frequency and clinical characteristics of peripheral neuropathies due to different aetiologies according to grading system criteria of the International Association for the Study of Pain for a definitive diagnosis of neuropathic pain. Epidemiological studies applying these criteria have been conducted in patients with diabetes, brachial plexus injury, and other traumatic nerve injuries. Neuropathic pain was diagnosed in 37–42% of patients with diabetic peripheral neuropathy, 56% of patients with brachial plexus injury, and 22% of patients with intercostobrachial neuropathy. The most frequent neuropathic pain type was ongoing pain (described as burning or pressing), followed by paroxysmal pain (electric shock-like sensations) and allodynia (pain evoked by brushing and pressure). By providing information on the frequency, clinical signs, and variables associated with neuropathic pain due to different aetiologies, these studies contribute to improving the clinical management of this condition.

Assessment of the neuropathic component in a chronic low back pain syndrome

Background/Aim. Chronic low back pain syndrome (CLBPS) is the most common cause of functional disability and loss of working ability in developed countries. Some research shows that neuropathic pain (NP) is present in almost 50% of patients with CLPBS. The aim of this study was to determine the characteristics of NP and its impact on quality of life (QoL) in patients with CLBPS. Methods. Patients were tested using three questionnaires for NP: Pain Detect Questionnaire, Leeds Assessment of Neuropathic Symptoms and Signs, and Douleur Neuropathique 4 questions. Thirty-two patients diagnosed with NP based on current clinical criteria and with positive results for NP on all three NP questionnaires formed an experimental group. A control group consisted of 32 patients with CLBPS who did not fulfill clinical criteria for NP and were negative for NP on all three questionnaires. Hamilton depression and anxiety rating scales (Ham-D and Ham-A, respectively) and Short Form (SF)-36 questionnaire were also applied. Results. According to magnetic resonance imaging (MRI), disc herniation was typically detected in the experimental group, while degenerative changes were commonly found in the control group. Patients from the experimental group had significantly greater intensity of pain, pain radiation in the legs, and the pain was usually presented as episodes of sudden attacks with mild pain between them. The most distinctive features of NP were allodynia, electric shock sensation, and hypoesthesia to prick. Patients from the experimental group also had significantly higher depression and anxiety scores, as well as worse QoL compared to the control group, especially in mental domains. Predictors of worse QoL in the patients with CLBPS were a higher level of anxiety and depression. Conclusion. The presence of allodynia, electric shock-like sensations, and hypoesthesia to prick in patients with CLBPS suggest NP. CLBPS patients with NP had worse scores in mental domains of QoL compared to CLPBS patients without NP.

Improvement of Upper Limb and Hand Functions of Stroke Patients by Balancing Acupuncture Combined with Motor Relearning Training

To observe the therapeutic effect of balance acupuncture combined with motor relearning training for upper limb and hand functions of stroke patients. Sixty-two stroke patients were randomly divided into balance acupuncture group (n＝31) and routine acupuncture group (n＝31). For patients of the balance acupuncture group, Piantan, Jiantong and Wantong points on the healthy side were used. When Jiantong point taken, the acupuncture needle was removed after the patient experienced an electric shock-like spreading needling sensation. When Wantong point employed, the needle was removed after the patient experienced a local, intensified or spreading needling sensation. When Piantan point used, the needle was retained after the patient experienced an electric shock-like needling sensation, then, the motor relearning training was conducted, and the needle was removed immediately after the training. For patients of the routine acupuncture group, Jianyu(LI 15), Jianzhen (SI 9), Quchi (LI 11), etc. were needled with the needles retained for 30 min after getting needling sensations. The motor relearning training was also carried out after removal of the needle. The treatment in both groups was performed once daily, 6 days a week, and lasted for 8 weeks. The Fugl-Meyer score and motor function scale (MAS) of the upper limb, and the fine performance score and motor function score of the hand were assessed before and after the treatment. Following treatment, the Fugl-Meyer score and MAS of the upper limbs, and the motor function score and fine performance score of the hand were significantly increased in both groups compared with pre-treatment in each group (P<0.05 ), suggesting a functional improvement of both upper limb and hand. The therapeutic effect of the balance acupuncture was obviously superior to that of routine acupuncture in improving functions of both the upper limb and hand (P<0.05)．. Balance acupuncture combined with motor relearning training is helpful to improve the comprehensive function of the upper limb and hand in stroke patients.

A Review of Neuropathic Pain: From Diagnostic Tests to Mechanisms.

Neuropathic pain develops when the somatosensory nervous system is affected by a lesion or disease. Diagnostic tests aimed at assessing somatosensory afferent pathway damage are therefore useful for diagnosing neuropathic pain. Neuropathic pain manifests with a range of different symptoms such as ongoing burning pain, squeezing or pressure pain, paroxysmal electric shock-like sensations, stabbing pain, or mechanical dynamic allodynia. The various types of neuropathic pain are associated with different underlying nerve fiber abnormalities. This article summarizes the available methods of somatosensory afferent pathway assessment and discusses the potential pathophysiology underlying the most representative neuropathic pain types, i.e., ongoing burning pain, paroxysmal pain, and mechanical dynamic allodynia. Funding: Pfizer, Italy.

Neuropathic Pain in Patients with Burning Mouth Syndrome Evaluated Using painDETECT.

This study set out to identify the neuropathic component of pain experienced by burning mouth syndrome (BMS) patients evaluated using painDETECT, a diagnostic tool that could easily be introduced into clinical practice. This study included 64 patients (33 BMS and 31 suffering nociceptive pain). Each completed the painDETECT neuropathic pain questionnaire, the Hospital Anxiety and Depression Scale, and pain intensity was also measured using a visual analogue scale (VAS). Pain among BMS patients (evaluated by VAS) was 6.1 ± 1.9, and 4.3 ± 1.7 among nociceptive patients ( P < 0.001). PainDETECT obtained total scores ≥ 19 in 21% of BMS patients, indicating the presence of neuropathic pain. When painDETECT pain descriptors were analyzed comparing the BMS group with nociceptive pain subjects, statistically significant differences were found for burning sensation ( P < 0.010), prickling ( P < 0.001), electric shock-like sensation ( P = 0.046), thermal sensation ( P < 0.001), and numbness ( P = 0.002). Logistic regression analysis found that VAS scoring was the strongest determinant predicting neuropathic pain. The present study suggests that almost a third of BMS patients present neuropathic pain, which is strongly associated with the intensity of pain measured using VAS. These data could provide the basis for further research.

ADR Reporting by the General Public: Lessons Learnt from the Dutch and Swedish Systems.

Consumer reporting of adverse drug reactions (ADRs) has existed in several countries for decades, but throughout Europe the role of consumers as a source of information on ADRs has not been fully accepted until recently. In Europe, The Netherlands and Sweden were among the first countries to implement consumer reporting well before it was mandated by law throughout the EU. Consumer reporting is an integral part of the spontaneous reporting systems in both The Netherlands and Sweden, with yearly numbers of reports constantly increasing. Consumer reporting forms and handling procedures are essentially the same as for healthcare professional reporting; the message in the reports, not the type of messenger, is what is of importance. Studies have established the significant contribution of consumer reporting to ADR signal detection. Combining all reports regardless of reporter type is recommended since it yields the largest critical mass of reports for signal detection. Examples of signals where consumer reports have been of crucial importance for signal detection are electric shock-like sensations associated with the use of duloxetine, and persistent sexual dysfunction after discontinuation of selective serotonin reuptake inhibitors. An example of consumer reporting significantly strengthening a detected signal is Pandemrix(®) (influenza H1N1 vaccine)-induced narcolepsy. Raising public awareness of ADR reporting is important, but time- and resource-consuming. The minimum effort taken should be to passively inform consumers, e.g. via stakeholders' homepages and via drug product information leaflets. Another possibility of reaching out to this target group could be through co-operation with other (non-government) organizations. Information from consumer reports may give a new perspective on ADRs via the consumers' unfiltered experiences. Consumers' views may change the way the benefit-harm balance of drugs is perceived and assessed today, and, being the ultimate users of drugs, consumers could have a relevant influence in the regulatory decision-making processes for drugs. All stakeholders in pharmacovigilance should embrace this new valuable source of information.

Resolution of Lhermitte's sign with Spinal Cord Stimulation

Dear Editor, No specific treatment exists for Lhermitte's sign or an electric shock-like sensation that extends down the spine and shoots into the limbs lasting just a few seconds elicited during movement of cervical spine, particularly flexion of the neck. This symptom has been reported in various medical-like cervical spondylosis, multiple sclerosis, vitamin B12 deficiency, and pernicious anemia ⇓. Many times, this transient symptom is self-limiting and will resolve over a period of 6 months. However, for those patients whose symptoms are not so fortunate, few options are available. Pharmacological treatment is initially analgesics, short-course opioid medications, muscle relaxants, and tapering doses of oral steroids. Persistent symptoms may be improved with neuropathic pain medications like gabapentin, pregabalin, tricyclic antidepressants, clonazepam, baclofen, carbamazepine, amitriptyline, and phenytoin ⇓. The following case report utilizes neuromodulation after all other conservative methods failed to provide pain relief for this patient. The patient is a 60-year-old man with a history of worsening chronic neck pain without incident and reported “electricity running down my back and legs” when turning his head downward. A magnetic resonance imaging (MRI) scan demonstrated severe spondylosis at C5-6, a moderate degree of cervical stenosis, and a concern for development of myelopathy. As the thoracic and lumbar MRI was absent of disease, the patient's neurosurgeon diagnosed the traveling electric shock pain down the patient's legs as …

Clinical aspects of envenomation caused by Tityus obscurus (Gervais, 1843) in two distinct regions of Pará state, Brazilian Amazon basin: a prospective case series

BackgroundScorpion envenomations are a major public health problem in Brazil, whose most dangerous cases are attributable to the genus Tityus. This study was designed to compare the clinical and demographic features of envenomations by Tityus obscurus in two areas of the state of Pará located in the Amazon basin.Were compared demographic findings, local and systemic signs and symptoms of human envenomations caused by T. obscurus that occurred in western and eastern areas of the state.ResultsForty-eight patients with confirmed envenomation by T. obscurus were evaluated from January 2008 to July 2011. Most of them came from the eastern region, where male and female patients were present in similar numbers, while males predominated in the west. Median age groups were also similar in both areas. Most scorpion stings took place during the day and occurred significantly more frequently on the upper limbs. The time between the sting and admission to the health center was less than three hours in both areas. Most eastern patients had local manifestations while in the west, systemic manifestations predominated. Local symptoms were similar in both areas, but systemic signs and symptoms were more common in the west. Symptoms frequently observed at the sting site were local and radiating pain, paresthesia, edema, erythema, sweating, piloerection and burning. The systemic manifestations were significantly higher in patients from the west. Futhermore, neurological symptoms such as general paresthesia, ataxia, dysarthria, myoclonus, dysmetria, and electric shock-like sensations throughout the body were reported only by patients from the west.ConclusionThe present study shows that two regions of Para state differ in the clinical manifestations and severity of confirmed envenomation by T. obscurus which suggests a toxicity variation resulting from the diversity of T. obscurus venom in different areas of the Brazilian Amazon basin, and that T. serrulatus antivenom can be successfully used against T. obscurus.

Retrosigmoid approach for resection of petrous apex meningioma

We present the case of a 50-year-old female with a 1-year history of right-side facial numbness, as well as an electric shock-like sensation on the right-side of the face and tongue. She was previously diagnosed with vertigo and trigeminal neuralgia. MRI was obtained showing a large right cerebellopontine angle mass. A retrosigmoid approach was performed and total removal was achieved after dissection of tumor from brainstem and cranial nerves IV, V, VI, VII and VIII. Pathology confirmed the diagnosis of a meningioma (WHO Grade I). The patient was discharged neurologically intact on the third postoperative day free of complications. The video can be found here: http://youtu.be/-tR0FtMiUDg .

Reappraising neuropathic pain in humans—how symptoms help disclose mechanisms

Neuropathic pain--that is, pain arising directly from a lesion or disease that affects the somatosensory system--is a common clinical problem, and typically causes patients intense distress. Patients with neuropathic pain have sensory abnormalities on clinical examination and experience pain of diverse types, some spontaneous and others provoked. Spontaneous pain typically manifests as ongoing burning pain or paroxysmal electric shock-like sensations. Provoked pain includes pain induced by various stimuli or even gentle brushing (dynamic mechanical allodynia). Recent clinical and neurophysiological studies suggest that the various pain types arise through distinct pathophysiological mechanisms. Ongoing burning pain primarily reflects spontaneous hyperactivity in nociceptive-fibre pathways, originating from 'irritable' nociceptors, regenerating nerve sprouts or denervated central neurons. Paroxysmal sensations can be caused by several mechanisms; for example, electric shock-like sensations probably arise from high-frequency bursts generated in demyelinated non-nociceptive Aβ fibres. Most human and animal findings suggest that brush-evoked allodynia originates from Aβ fibres projecting onto previously sensitized nociceptive neurons in the dorsal horn, with additional contributions from plastic changes in the brainstem and thalamus. Here, we propose that the emerging mechanism-based approach to the study of neuropathic pain might aid the tailoring of therapy to the individual patient, and could be useful for drug development.

Capturing Brain Metrics of Neuropathic Pain Using Nuclear Magnetic Resonance

SUMMARYNeuropathic pain is typically caused by a lesion or dysfunction in the nervous system that results in both negative (i.e., reduced sensitivity) and positive symptoms (i.e., paraesthesia, spontaneous ongoing pain with shooting, electric shock-like sensations and abnormal responses to evoked pain). Intriguingly, chronic pain disorders manifest profound alterations in brain structure and function, and thus, modern nuclear magnetic resonance (NMR) techniques have allowed us to begin to dissect the complexities of how neuropathic pain affects the brain. NMR approaches can be used as an independent measure to improve our understanding of key changes in brain structure, function and chemistry in chronic neuropathic pain. Accordingly, NMR techniques provide neurobiological metrics that allow us to understand the neurobiological basis of chronic neuropathic pain. Additionally, although at an early stage, NMR methods can also be useful to define clinical metrics to predict chronification of neuropathic pain and responses to drugs. This article provides a review of NMR techniques and their capacity to study spontaneous pain and evoked pain, as well as structural, functional and neurochemical alterations that have repeatedly been associated with chronic neuropathic pain. Finally, the importance for quantifying disease state and treatment efficacy in neuropathic pain using NMR techniques is discussed.

Ciguatoxins activate specific cold pain pathways to elicit burning pain from cooling

Ciguatoxins are sodium channel activator toxins that cause ciguatera, the most common form of ichthyosarcotoxism, which presents with peripheral sensory disturbances, including the pathognomonic symptom of cold allodynia which is characterized by intense stabbing and burning pain in response to mild cooling. We show that intraplantar injection of P-CTX-1 elicits cold allodynia in mice by targeting specific unmyelinated and myelinated primary sensory neurons. These include both tetrodotoxin-resistant, TRPA1-expressing peptidergic C-fibres and tetrodotoxin-sensitive A-fibres. P-CTX-1 does not directly open heterologously expressed TRPA1, but when co-expressed with Na(v) channels, sodium channel activation by P-CTX-1 is sufficient to drive TRPA1-dependent calcium influx that is responsible for the development of cold allodynia, as evidenced by a large reduction of excitatory effect of P-CTX-1 on TRPA1-deficient nociceptive C-fibres and of ciguatoxin-induced cold allodynia in TRPA1-null mutant mice. Functional MRI studies revealed that ciguatoxin-induced cold allodynia enhanced the BOLD (Blood Oxygenation Level Dependent) signal, an effect that was blunted in TRPA1-deficient mice, confirming an important role for TRPA1 in the pathogenesis of cold allodynia.

Spinal anaesthesia and neuromyelitis optica: cause or coincidence?

Spinal anaesthesia and neuromyelitis optica: cause or coincidence?

Fenómeno de Lhermitte en tres pacientes oncológicos

Lhermitte's sign was first described by Pierre Marie and Chatelin in 1917. Lhermitte published his report in 1920 and reviewed this in 1924. This phenomenon is characterized by the occurrence of an electric shock-like sensation going along the spine in a cervico-caudal direction with flexion of the neck, and may also be felt in the upper and lower limbs. Clinical cases. Case 1. A 49 year-old woman diagnosed as having breast cancer and being treated with cisplatin presented with Lhermitte's sign. On physical examination the osteotendinous reflexes were absent but the abdominal cutaneous reflexes were present. There was reduced sensitivity to vibration. Case 2. An 80 year-old man, previously operated on for adenocarcinoma of the colon, without further treatment, presented with progressive weakness of all four limbs and Lhermitte's syndrome. On examination there was obvious weakness of all four limbs, with the sensory level at C3. A cervical MR scan showed a metastasis in the vertebral body of C3 with epidural involvement and compression of the spinal cord. Case 3. A 54 year-old man was being treated by radiotherapy for cancer of the larynx. He presented at the onset of Lhermitte's sign but MR and physical examination were normal. Lhermitte's sign is non-specific, although in oncological patients a detailed clinical history and examination should be done seeking data regarding chemotherapy, radiotherapy and spinal compression.