Pulsed Radiofrequency of the Trigeminal Ganglion for Treating Postherpetic Neuralgia of the Ophthalmic Branch

Postherpetic neuralgia (PHN) is a painful, long-lasting condition as a consequence of nerve damage resulting from a herpes zoster infection. Although there are many different treatments available to reduce pain duration and severity, PHN is often refractory to them and no single therapy shows an effective cure for all cases of PHN, especially for those involving the ophthalmic branch of the trigeminal nerve. Pulsed radiofrequency (PRF) is a minimally invasive procedure for pain treatment that has been practiced over the past decade. However, its clinical efficacy and safety for treating PHN involving the ophthalmic branch of the trigeminal nerve have not been evaluated. Objective. This study aimed to evaluate the efficacy and safety of PRF for treating PHN involving the ophthalmic branch of the trigeminal ganglion. Study Design. An observational study. Setting. All patients received PRF of the ophthalmic branch of the trigeminal nerve, pain intensity was assessed by a visual analogue scale (VAS), and complications before and after PRF stimulation were noted. Methods. Thirty-two patients with PHN of the ophthalmic branch were treated by PRF of the ophthalmic branch with controlled temperature at 42°C for 8 min. Pain relief, corneal reflex, sleep quality, and satisfaction were assessed for all patients. Results. Thirty out of 32 patients (93.75%) reported significant pain reduction after PRF treatment. Twenty-eight of them (87.5%) were satisfied with their sleep and obtained a pain score lower than 3 following the procedure. Only two patients had a recurrence of the severe burning pain and returned to the hospital for other medical therapies 2 weeks after the PRF procedure. No patient lost the corneal reflex. Limitations. This study is an observational study and a nonprospective trial with a short-term follow-up period. Conclusion. PRF of the trigeminal ganglion of the ophthalmic branch can significantly reduce pain sensation and improve sleep quality and satisfaction.

The Influence of Broilers’ Body Weight on the Efficiency of Electrical Stunning and Meat Quality under Field Conditions

Water-bath stunning represents the most-applied stunning system in poultry slaughtering, but within the European Union, specific indications on electric parameters that should be used, such as voltage, are missing. The objective of this study was to evaluate the efficiency of two commercially available types of electrical equipment (A and B) on broilers with different live body weights and the influence of the tested parameters on meat quality. Experimental trials in a European Union-approved slaughterhouse were carried out using two different stunners. 6600 broilers, divided into three weight groups, were stunned applying different protocols based on the same current frequencies and intensity but different voltages. The state of unconsciousness (presence of corneal reflex and wings flapping) and post-mortem defects (pectoral hemorrhages and dark meat) were evaluated by blinded trained operators. The presence of corneal reflex and petechiae were the most reported consciousness signs and post-mortem injuries, respectively. Different weights played an important role within stunner A, registering statistical differences (p < 0.01) among groups. Considering injuries, an inverse relationship between body weight and lesions was found. The results highlighted the effectiveness of both stunning systems applying the best combination of electrical parameters considering the weight of the animal and ensuring its well-being.

Revisiting the Corneal and Blink Reflexes for Primary and Secondary Trigeminal Facial Pain Differentiation

Trigeminal neuralgia is often misdiagnosed at initial presentation due to close connotation with dental pain and is often over diagnosed for the very same reasons leading to numerous unnecessary surgical procedures such as peripheral neurectomy and alcohol injections, while the actual cause may remain elusive for decades. Evaluation of the neurosensory system may disclose the correct anatomical location of the etiology. The neurological examination may be clouded by the sensory deficits subsequent to previous peripheral surgical procedures. The corneal and blink reflexes are integral measures of the trigeminal and facial neurosensory assessment, and their abnormal function may facilitate the identification of intrinsic disease of the brain stem. These reflexes can be employed to discover pathological lesions including intracranial space-occupying trigeminal, lateral medullary, cerebral hemispheric lesions, and degenerative diseases of the central nervous system. Dental surgeons and oral and maxillofacial surgeons should consider corneal reflex in neurological assessment of patient presenting with trigeminal neuralgia-like symptoms. Failure to evaluate corneal sensitivity may lead to delayed or inaccurate diagnosis and unsuitable or redundant treatment interventions. This simple noninvasive reflex can be performed by chair-side and may provide significant information regarding the origin of facial pain and is an invaluable part of clinical methods especially in remote and peripheral healthcare center practitioners where sophisticated radiographic investigations such as computed tomography and magnetic resonance imaging may not be available.

Limited usefulness of the observation of eye bulb rotation and neuro-ophthalmic responses for assessing the depth of equine anesthesia: an observational study comparing three protocols

The observation of the neuro-ophthalmic responses is an established basic tool for monitoring the depth of anesthesia in horses. However, their usefulness during balanced anesthesia in the clinic is questionable. The aim of this study was to compare the usefulness of neuro-ophthalmic responses during 3 commonly used anesthetic protocols. An observational study was performed on 22 horses, 5 maintained only with isoflurane (ISO group), 12 maintained with isoflurane and a constant rate infusion of ketamine (ISO+KET group), and 5 maintained with isoflurane and a constant rate infusion of detomidine (ISO+DET group). The occurrence of all five responses was noted: spontaneous palpebral and provoked palpebral response, corneal response, nystagmus and eye bulb rotation. The most consistent with the literature and most useful for anesthetic depth assessment was the observation of spontaneous palpebral reflex in all of the groups (p = 0.788) and the most significant differences were visible for the observation of the provoked palpebral reflex (p = 0.015) for all groups. The reflexes in the group ISO+DET were less consistent with the literature than in other groups, making them least useful. The group ISO seemed to have the reflexes’ observations most consistent with the literature expectations. The corneal reflex was always present and nystagmus always absent which confirmed the observations from literature. The above results suggest that neuro-ophthalmic responses, especially eye bulb rotation and provoked palpebral reflexes, should not be the only indicators in assessing the depth of anesthesia during maintenance with ketamine or detomidine with concurrent isoflurane.

Basilar artery dolichoectasia an unusual and rare cause of secondary trigeminal neuralgia: a clinical report

Objective: Patients with Trigeminal Neuralgia often consults a dentist for relief of their symptoms as the pain seems to be arising from teeth and allied oral structures. Basilar artery Dolichoectasia is an unusual and very rare cause of secondary Trigeminal Neuralgia as it compresses the Trigeminal nerve Root Entry Zone. Case reports: We report three cases of Trigeminal Neuralgia caused by Basilar artery Dolichoectasia compression. The corneal reflex was found absent in all three of the cases along with mild neurological deficits in one case. Multiplanar T1/T2W images through the brain disclosed an aberrant, cirsoid (S-shaped) and torturous Dolichoectasia of basilar artery offending the Trigeminal nerve Root Entry Zone. Discussion: Based on these findings we propose a protocol for general dentist for diagnosis of patients with trigeminal neuralgia and timely exclusion of secondary intracranial causes. Conclusion: General dentists and oral surgeons ought to consider this diagnosis in patients presenting with chronic facial pain especially pain mimicking neuralgia with loss of corneal reflex or other neurosensory deficit on the face along with nighttime pain episodes. Timely and accurate diagnosis and prompt referral to a concerned specialist can have an enormous impact on patient survival rate in such cases. KEYWORDS Basilar artery; Cirsoid dolichoectasia; Corneal reflex; Trigeminal neuralgia.

Centrality of Hirschberg Reflex in Young Emmetropic Population of Pakistan

Purpose: To find out the Centrality of Hirschberg reflex in young emmetropic females and to correlate it with asthenopia. Study Design: Cross-sectional study Place and Duration of Study: Outpatients department of Khalid Eye Hospital, Karachi, from January to December 2019. Methods: Six hundred young emmetropic females 10 to 25 years of age were included. We performed the Hirschberg test and Jackson cross cylinder to assess the astigmatism and observed near point of convergence to find out convergence insufficiency. Results: Out of 600 young emmetropic females only one hundred and ninety had a central Hirschberg corneal reflex along with an astigmatism of 0.25 to 0.50 which was observed in one hundred and sixty five patients. One hundred and twenty five had a receded near point of convergence. Conclusion: Acentrality of Hirschberg can be a cause of asthenopia among young emmetropic females. Key Words: Asthenopia, Astigmatism, Emmetropia, Hirschberg corneal reflex.

Comparative analysis of spontaneous blinking and the corneal reflex

Ocular surface health, the cognitive status, psychological health or human neurological disorders, among others, can be assessed by studying eye blinking, which can be differentiated in spontaneous, reflex and voluntary. Its diagnostic potential has provided a great number of works that evaluate their characteristics and variations depending on the subject's condition (sex, tiredness, health, …). The objective of this study was to analyse the differences in blinking kinematics of spontaneous and reflex blinks, distinguishing between direct and consensual reflexes, using a self-developed, non-invasive and image processing-based method. A video-oculography system is proposed using an air jet driven by a syringe to induce reflex and a high-speed camera to record the blinking of both eyes. The light intensity diffused by the eye changes during blinking and peaks when the eyelid closes. Sixty-second sequences were recorded of 25 subjects blinking. Intensity curves were off-line fitted to an exponentially modified Gaussian (EMG) function, whose σ , μ and τ parameters were analysed. A two-way analysis of variance (ANOVA) of these parameters was conducted to test the influence of the subject, the eye and blink type. In the closing phase, direct and consensual corneal reflexes are faster than spontaneous blinking, but there was no significant difference between them, nor between right and left eyes. In the opening phase, the direct corneal reflex was the slowest and significant differences appeared between right and left eyes.

Evaluation of the Lambs’ State of Consciousness Signs during Halal and Traditional Slaughtering

The aim of this study was to evaluate the persistence of two signs of consciousness (rhythmic breathing and corneal reflex) in lambs slaughtered according to the traditional method and Halal ritual rite. A total of 240 lambs were examined and divided into two equal groups (n = 120 each). Lambs of group A were subjected to the stunning phase by the action of an electric current on the brain, while lambs of group B were slaughtered according to the religious Halal method without prior stunning. Rhythmic breathing (RB) and corneal reflex (CR) were used as indicators of prolonged brain function, and their evaluation was carried out by the operators in three subsequent steps at 15 s, 30 s, and 90 s post-bleeding, respectively. The stunning of the lambs reduced the animal’s state of consciousness and, consequently, reduced suffering, pain, and distress. Indeed, the lambs of group B showed longer duration consciousness than the animals stunned by electrodes. The permanence of the reflexes in Halal slaughter could be reduced by introducing a reversible stunning method to make the animal temporarily unconscious. Moreover, given that our results revealed consciousness also after 90 s post-cut, the assessment of the animal’s state of consciousness in wider time intervals than those commonly used is recommended.

Is a Simple Sensorimotor Reaction Really Simple?

The simple sensorimotor reaction (SSR) is widely used in psychophysiological research. It was previously shown, that the SSR latency is not constant. We studied changes in the SSR latency as a function of the waiting time from the moment of the previous response to the moment of the start of the stimulation. We performed the stimulation using light, sound and air impulse. As a response, we used a “labial sound”, a finger touch and blinking of the eyes. In all cases, where the objects of the study were humans, the SSR latency had constant and variable components. The constant SSR component was the shortest in response to closing the eyes to sound (120 ms). For “lip reaction” and finger response to sound it was 174–178 ms and 178–182 ms, respectively, but for “lip reaction” and finger response to light it was 220–226 ms. The variable SSR component represented exponential latency decay with an increase in the waiting time interval. In this case, the decay consisted of at least two components, with an apparent relaxation time in the range 30–150 ms and 600–1300 ms. Alternating stimulation of paired organs of the reception or alternating fingers reduced the apparent relaxation time of the SSR latency decay. Moreover, the latency of the human corneal reflex during eye stimulation with an air pulse also had the latency decay with three components of apparent relaxation time 9.5, 68.2 and 1,086 ms and the constant latency of 34.2 ms.The latency of the corneal reflex in a young cat was constant and had a value of 14.6 ms. Thus, it has been shown, that the SSR latency has a complex structure and, like any conditioned reflex, is strongly influenced by the cortex. We believe that a choice is made in the centers for analysis of receiving signals from reception organs and centers sending signals to reacting organs, i.e. essentially, the SSR is also a choice reaction.