First Bite Syndrome Following Carotid Endarterectomy.

A 67-year-old man with a high position carotid plaque presented with severe pain in ipsilateral parotid region several days after carotid endarterectomy (CEA). The pain occurred at the first bite of each meal and resolved as further bite. We diagnosed the pain as first bite syndrome (FBS). FBS is infrequent but known as a complication associated with parapharyngeal space surgery. The pain is characterized by sharp pain in the parotid region associated with mastication. The cause is unclear but thought to the result from sympathetic denervation of the parotid gland, followed by parasympathetic nerve hypersensitivity. Only five cases associated with carotid endarterectomy (CEA) have been reported. We should be in mind that CEA for high position plaque is one of the risk factors to cause FBS associated with CEA. Neurologists and vascular surgeons as well as otolaryngologists should all be informed FBS as one of the complications after carotid endarterectomy.

Horner Syndrome After Anterior Cervical Discectomy and Fusion: Case Series and Systematic Review.

BACKGROUND: Horner syndrome is an infrequently seen complication of anterior cervical discectomy and fusion (ACDF). Multicenter studies have reported a very low incidence, less than 0.1%. OBJECTIVE: To identify the incidence in, characteristics of, and postoperative course in patients in whom postoperative Horner syndrome developed after ACDF. METHODS: We performed a retrospective review of all patients who experienced Horner syndrome after ACDF for cervical degenerative disease at a single tertiary care institution between 2017 and 2018. A systematic review was then performed to identify studies investigating prevalence, diagnosis, and treatment of postoperative Horner syndrome after ACDF. RESULTS: Of 1116 patients at our institution who underwent ACDF, the incidence of Horner syndrome was 0.45%. C4/5 and C5/6 were the 2 most common surgical levels. The complication was noted to occur immediately after surgery, and at least partial improvement was identified in all patients an average 3.5 months after surgery (range, 10 days to 6 months). These findings were consistent with our systematic review of 21 studies that showed an incidence of 0.6% (range, 0.02% to 4.0%), the most common surgical level C5/6 (64%), and 82% of patients experiencing at least partial resolution of symptoms within 1 year (60.7% complete, 21.4% partial resolution). CONCLUSION: Horner syndrome occurs in 0.6% of patients undergoing ACDF. Careful postoperative examination should reveal this complication, which may be underdiagnosed or underreported in larger multicenter case series. The majority of patients experience complete resolution of symptoms within 6 months to 1 year and can be treated conservatively and expectantly.

Elevated resting blood pressure augments autonomic imbalance in posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is characterized by increased sympathetic nervous system (SNS) activity, blunted parasympathetic nervous system (PNS) activity, and impaired baroreflex sensitivity (BRS), which contribute to accelerated cardiovascular disease. Patients with PTSD also have chronic stress-related elevations in resting blood pressure (BP), often in the prehypertensive range; yet, it is unclear if elevated resting blood pressure (ERBP) augments these autonomic derangements in PTSD. We hypothesized that compared with normotensive PTSD (N-PTSD), those with ERBP (E-PTSD) have further increased SNS, decreased PNS activity, and impaired BRS at rest and exaggerated SNS reactivity, PNS withdrawal, and pressor responses during stress. In 16 E-PTSD and 17 matched N-PTSD, we measured continuous BP, ECG, muscle sympathetic nerve activity (MSNA), and heart rate variability (HRV) markers reflecting cardiac PNS activity [standard deviation of R-R intervals (SDNN), root mean square of differences in successive R-R intervals (RMSSD), and high frequency power (HF)] during 5 min of rest and 3 min of mental arithmetic. Resting MSNA ( P = 0.943), sympathetic BRS ( P = 0.189), and cardiovagal BRS ( P = 0.332) were similar between groups. However, baseline SDNN (56 ± 6 vs. 78 ± 8 ms, P = 0.019), RMSSD (39 ± 6 vs. 63 ± 9 ms, P = 0.018), and HF (378 ± 103 vs. 693 ± 92 ms2, P = 0.015) were lower in E-PTSD versus N-PTSD. During mental stress, the systolic blood pressure response ( P = 0.011) was augmented in E-PTSD. Although MSNA reactivity was not different ( P > 0.05), the E-PTSD group had an exaggerated reduction in HRV during mental stress ( P < 0.05). PTSD with ERBP have attenuated resting cardiac PNS activity, coupled with exaggerated BP reactivity and PNS withdrawal during stress.

Sympathetic Nerve Injury in Thyroid Cancer.

The double innervation of the thyroid comes from the sympathetic and parasympathetic nervous system. Injury rates during surgery are at 30% but can be minimized by upwardly preparing the thyroid vessels at the level of thyroid capsule. Several factors have been accused of increasing the risk of injury including age and tumor size. Our aim was to investigate of there is indeed any possible correlations between these factors and a possible increase in injury rates following thyroidectomy. Seven studies were included in the meta-analysis. Statistical correlation was observed for a positive relationship between injury of the sympathetic nerve and thyroid malignancy surgery (p 2 = 74%) No statistical correlations were observed for a negative or positive relationship between injury of the sympathetic nerve and tumor size. There was also no statistically significant value observed for the correlation of the patients' age with the risk of sympathetic nerve injury (p = 0.388). Lack of significant correlation reported could be due to the small number of studies and great heterogeneity between them.

Increased Cx32 expression in spinal cord TrkB oligodendrocytes following peripheral axon injury.

Following injury to motor axons in the periphery, retrograde influences from the injury site lead to glial cell plasticity in the vicinity of the injured neurons. Following the transection of peripherally located preganglionic axons of the cervical sympathetic trunk (CST), a population of oligodendrocyte (OL) lineage cells expressing full length TrkB, the cognate receptor for brain derived neurotrophic factor (BDNF), is significantly increased in number in the spinal cord. Such robust plasticity in OL lineage cells in the spinal cord following peripheral axon transection led to the hypothesis that the gap junction communication protein connexin 32 (Cx32), which is specific to OL lineage cells, was influenced by the injury. Following CST transection, Cx32 expression in the spinal cord intermediolateral cell column (IML), the location of the parent cell bodies, was significantly increased. The increased Cx32 expression was localized specifically to TrkB OLs in the IML, rather than other cell types in the OL cell lineage, with the population of Cx32/TrkB cells increased by 59%. Cx32 expression in association with OPCs was significantly decreased at one week following the injury. The results of this study provide evidence that peripheral axon injury can differentially affect the gap junction protein expression in OL lineage cells in the adult rat spinal cord. We conclude that the retrograde influences originating from the peripheral injury site elicit dramatic changes in the CNS expression of Cx32, which in turn may mediate the plasticity of OL lineage cells observed in the spinal cord following peripheral axon injury.

N-(11)C-Methyl-Dopamine PET Imaging of Sympathetic Nerve Injury in a Swine Model of Acute Myocardial Ischemia: A Comparison with (13)N-Ammonia PET.

OBJECTIVE: Using a swine model of acute myocardial ischemia, we sought to validate N-(11)C-methyl-dopamine ((11)C-MDA) as an agent capable of imaging cardiac sympathetic nerve injury. METHODS: Acute myocardial ischemia was surgically generated in Chinese minipigs. ECG and serum enzyme levels were used to detect the presence of myocardial ischemia. Paired (11)C-MDA PET and (13)N-ammonia PET scans were performed at baseline, 1 day, and 1, 3, and 6 months after surgery to relate cardiac sympathetic nerve injury to blood perfusion. RESULTS: Seven survived the surgical procedure. The ECG-ST segment was depressed, and levels of the serum enzymes increased. Cardiac uptake of tracer was quantified as the defect volume. Both before and immediately after surgery, the images obtained with (11)C-MDA and (13)N-ammonia were similar. At 1 to 6 months after surgery, however, (11)C-MDA postsurgical left ventricular myocardial defect volume was significantly greater compared to (13)N-ammonia. CONCLUSIONS: In the Chinese minipig model of acute myocardial ischemia, the extent of the myocardial defect as visualized by (11)C-MDA is much greater than would be suggested by blood perfusion images, and the recovery from myocardial sympathetic nerve injury is much slower than the restoration of blood perfusion. (11)C-MDA PET may provide additional biological information during recovery from ischemic heart disease.

First bite syndrome: a complication of carotid endarterectomy.

First bite syndrome (FBS) is an uncommon pain syndrome characterised by severe cramping or spasm in the parotid region with the first bite of each meal. The proposed pathogenesis is sympathetic denervation of the parotid gland secondary to iatrogenic injury with resultant cross-stimulatory parasympathetic hypersensitivity response. FBS is a potential sequela of surgeries involving the infratemporal fossa, parapharyngeal space and/or deep lobe of the parotid gland, however, only four cases of FBS secondary to carotid endarterectomy have been documented to date. We present a case and management of a 77-year-old man who developed FBS after an ipsilateral carotid endarterectomy, to raise awareness of this complication among surgeons who operate in the neck region.

Renal sympathetic nerve denervation using intraluminal ultrasound within a cooling balloon preserves the arterial wall and reduces sympathetic nerve activity.

AIMS: Circumferential ablation of renal sympathetic nerves using catheter-based ultrasound energy was studied in a preclinical in vivo model. The aim was to investigate the benefit of cooling the arterial wall and the extent of renal nerve injury based on histopathology, and to correlate the injury with kidney norepinephrine levels. METHODS AND RESULTS: Computer simulations of the ultrasound transducer within the cooling balloon demonstrated a circumferentially uniform heating profile. In vivo characterisation was performed in 10 normotensive pigs. Nine were treated bilaterally with ultrasound and survived for seven days (n=8) or were sacrificed acutely (n=1). Acutely, TTC staining of the renal arteries treated with ultrasound energy in the presence of cooling demonstrated viable tissue consistent with preservation of the arterial medial layer. Histological studies demonstrated no endothelial injury and minimal to no injury to the media of the renal arterial wall at seven days. Overall, circumferential nerve damage with up to 76% of nerve bundles affected within 7.5 mm of the arterial lumen was observed. Kidney norepinephrine (NEPI) levels were significantly reduced in all animals compared to a non-treated control animal (n=1) and correlated with the degree of nerve damage. A greater reduction in NEPI and a greater percentage of affected nerves was observed in arteries treated with two or three bilateral ultrasound emissions. CONCLUSIONS: Catheter-based ultrasound delivered within a cooling balloon is effective at targeting the majority of the renal nerves circumferentially, resulting in significantly decreased kidney NEPI levels without damaging the arterial wall in a porcine model.

Risk of sympathectomy after anterior and lateral lumbar interbody fusion procedures.

AIM: The aim of this study was to identify retrospectively, lumbar sympathectomy (SE) using thermography (TG) and to evaluate clinically, the severity of post-sympathectomy (post-SE) dysfunction after anterior and lateral lumbar interbody fusion procedures (ALIF, XLIF). METHODS: Twenty eight patients with suspected SE were referred for TG to both legs. They completed our questionnaire on severity of difficulties after SE. We evaluated the ability of physical examinations to reveal the SE in contrast to TG and compared the symptoms (warmer leg and inhibited leg sweating) of SE with questionnaire responses as subjective measure and TG as objective measure. RESULTS: SE was diagnosed in 0.5% after ALIF at L5/S1, in 15% after ALIF at Th12-L5 and in 4% after XLIF at T12-L5. SE severely reduced the quality of life in two cases. The ability to distinguish differences in leg temperature by palpation after SE was found in 32%. All physical examinations together were insufficient for reliably disclosing SE. Subjective symptoms of SE were often false positive and proven SE by TG was often a clinically false negative. CONCLUSION: This is the first study to examine post-SE dysfunction objectivelya using TG after ALIF and XLIF, and the first to evaluate clinically, the severity of the post-SE syndrome. Before surgery we cannot foresee potentially poor SE results. For this reason, injury to the sympathetic chain during surgery must be avoided. The advantage of TG for identifying SE is its non-invasiveness and reliability.

[Nerve-preserving low anterior rectum resection]. / Nervenschonende offene tiefe anteriore Rektumresektion beim Rektumkarzinom.

AIM: The Performance of an oncological low anterior rectum resection with preservation of the sympathic and parasympathic nerves is illustrated. INDICATION: The total mesorectal excision (TME) by Robert Heald et al. is the gold standard for rectal cancer operations which has lowered drastically the local recurrence rate. As the survival data improve, the new focus is the postoperative quality of life with preserving of the bladder and sexual function. METHOD: We demonstrate an anterior rectal cancer operation with preserving of the sympathetic and parasympathetic nerves step by step. CONCLUSION: The critical parts of preserving the nerves with the N. hypogastricus superior and inferior as well as the neurovascular bundle "erigent pillar" are demonstrated.

Sympathetic nerves stimulate bone marrow function after chemotherapy.

Chemotherapy-induced nerve injury in the bone marrow impairs hematopoietic regeneration.

First bite syndrome following ipsilateral carotid endarterectomy.

First bite syndrome (FBS) is characterized by unilateral pain in the parotid region after the first bite of each meal, usually following ipsilateral neck surgery. The proposed mechanism is sympathetic denervation of the parotid gland, from iatrogenic injury to the sympathetic trunk supplying this gland. Local botulinum toxin injection has emerged as a promising treatment option with favorable results. To date, there are 3 published cases in the literature describing FBS after carotid endarterectomy. We present a case of a 75-year-old gentleman who developed FBS after carotid endarterectomy, to raise the awareness of this unusual and uncommon complication.

Baroreceptor-mediated activation of sympathetic nerve activity to salivary glands.

Salivary gland function is regulated by both the sympathetic and parasympathetic nervous systems. Previously we showed that the basal sympathetic outflow to the salivary glands (SNA(SG)) was higher in hypertensive compared to normotensive rats and that diabetes reduced SNA(SG) discharge at both strains. In the present study we sought to investigate how SNA(SG) might be modulated by acute changes in the arterial pressure and whether baroreceptors play a functional role upon this modulation. To this end, we measured blood pressure and SNA(SG) discharge in Wistar-Kyoto rats (WKY-intact) and in WKY submitted to sinoaortic denervation (WKY-SAD). We made the following three major observations: (i) in WKY-intact rats, baroreceptor loading in response to intravenous infusion of the phenylephrine evoked an increase in SNA(SG) spike frequency (81%, p<0.01) accompanying the increase mean arterial pressure (ΔMAP: +77 ± 14 mmHg); (ii) baroreceptor unloading with sodium nitroprusside infusion elicited a decrease in SNA(SG) spike frequency (17%, p<0.01) in parallel with the fall in arterial blood pressure (ΔMAP: -30 ± 3 mmHg) in WKY-intact rats; iii) in the WKY-SAD rats, phenylephrine-evoked rises in the arterial pressure (ΔMAP: +56 ± 6 mmHg) failed to produce significant changes in the SNA(SG) spike frequency. Taken together, these data show that SNA(SG) increases in parallel with pharmacological-induced pressor response in a baroreceptor dependent way in anaesthetised rats. Considering the key role of SNA(SG) in salivary secretion, this mechanism, which differs from the classic cardiac baroreflex feedback loop, strongly suggests that baroreceptor signalling plays a decisive role in the regulation of salivary gland function.

Evaluation of the damage caused by clamping or section of cervical sympathetic nerve in rabbits.

PURPOSE: To study the macro and microscopic evaluation of the damage caused by clamping or section of cervical sympathetic nerve in rabbits, quantifying the collagen in the lesions. METHODS: Twenty rabbits were divided into two groups of ten, doing in group 1 (section) section of the right cervical sympathetic nerve, while in group 2 (clipping) clipping of the nerve. All rabbits were induced to death on the seventh day after surgery. The macroscopic variables were: consequences of nerve lesion, clip appearance, presence of infection and adhesions around the nerve. Microscopy used hematoxylin-eosin staining to evaluate the stages and the degree of inflammation and necrosis, and F3BA Picrosirius red staining to quantify collagen. Mann-Whitney test was used for comparisons of collagen types I and III between groups. Fisher exact test analyzed the macroscopic variables, the degree of inflammation and necrosis. RESULTS: There was no discontinuity of nerve injury in the clipping group, as well as the clip was closed in all animals. The presence of severe adhesions was significantly higher in the clipping group (p<0.05). There was no significant difference on other variables macroscopically analyzed. There was no significant difference between groups regarding the type of inflammatory process and its intensity, as well as the presence of necrosis and collagen deposition in the nerves. CONCLUSIONS: In the macroscopic evaluation, the section caused discontinuity, which did not occur in the clamping group; there was no development of local infection; the clipping of the cervical sympathetic nerve was linked to the presence of a greater number of adhesions in comparison to the section group. Microscopically, no difference existed in relation to the type and intensity of inflammation reaction between the groups; occurred predominance of chronic and severe inflammation on the specimens; the necrosis was noticed equally in both groups; there was predominance of type I collagen deposition in relation to type III in both groups.

Evaluation of the damage caused by clamping or section of cervical sympathetic nerve in rabbits / Avaliação do dano causado pela clipagem ou secção do nervo simpático cervical em coelhos

PURPOSE: To study the macro and microscopic evaluation of the damage caused by clamping or section of cervical sympathetic nerve in rabbits, quantifying the collagen in the lesions. METHODS: Twenty rabbits were divided into two groups of ten, doing in group 1 (section) section of the right cervical sympathetic nerve, while in group 2 (clipping) clipping of the nerve. All rabbits were induced to death on the seventh day after surgery. The macroscopic variables were: consequences of nerve lesion, clip appearance, presence of infection and adhesions around the nerve. Microscopy used hematoxylin-eosin staining to evaluate the stages and the degree of inflammation and necrosis, and F3BA Picrosirius red staining to quantify collagen. Mann-Whitney test was used for comparisons of collagen types I and III between groups. Fisher exact test analyzed the macroscopic variables, the degree of inflammation and necrosis. RESULTS: There was no discontinuity of nerve injury in the clipping group, as well as the clip was closed in all animals. The presence of severe adhesions was significantly higher in the clipping group (p<0.05). There was no significant difference on other variables macroscopically analyzed. There was no significant difference between groups regarding the type of inflammatory process and its intensity, as well as the presence of necrosis and collagen deposition in the nerves. CONCLUSIONS: In the macroscopic evaluation, the section caused discontinuity, which did not occur in the clamping group; there was no development of local infection; the clipping of the cervical sympathetic nerve was linked to the presence of a greater number of adhesions in comparison to the section group. Microscopically, no difference existed in relation to the type and intensity of inflammation reaction between the groups; occurred predominance of chronic and severe inflammation on the specimens; the necrosis was noticed equally in both groups; there was predominance of type I collagen deposition in relation to type III in both groups.

OBJETIVO: Estudar a lesão provocada pela secção e pela clipagem no nervo simpático cervical de coelhos, avaliando-se a macroscopia, microscopia e quantificando-se o colágeno nas lesões. MÉTODOS: Foram utilizados 20 coelhos, distribuídos em dois grupos de dez, sendo nos animais do grupo 1 (secção) realizada secção do nervo simpático cervical direito, enquanto nos do grupo 2 (clipagem) realizada a clipagem desse nervo. Todos os coelhos foram induzidos à morte no sétimo dia de pós-operatório. As variáveis macroscópicas avaliadas foram: presença de lesão de descontinuidade do nervo, aspecto do clipe, presença de infecção e de aderências ao redor do nervo. A microscopia com hematoxilina-eosina foi feita para avaliar as fases, o grau do processo inflamatório e a presença de necrose; a coloração de Picrosirius red F3BA quantificou o colágeno. Utilizou-se o teste de Mann-Whitney nas comparações dos colágenos tipo I e tipo III entre os grupos. As variáveis macroscópicas, o grau do processo inflamatório e presença de necrose foram analisadas pelo teste de Fisher. RESULTADOS: Não houve lesão de descontinuidade do nervo no grupo clipagem, assim como o clipe encontrou-se fechado em todos os animais desse grupo. A presença de aderências intensas foi significativamente maior no grupo clipagem (p<0,05). Não houve diferença significativa quanto às demais variáveis analisadas macroscopicamente. Não houve diferença significativa entre os grupos quanto ao tipo de processo inflamatório e sua intensidade, assim como quanto à presença de necrose e ao depósito de colágeno nos nervos. CONCLUSÕES: Na avaliação macroscópica, a secção causou lesão de descontinuidade, o que não ocorreu na clipagem; não houve desenvolvimento de infecção local; a clipagem do nervo simpático cervical foi associada à presença de maior quantidade de aderências em relação à secção. Na avaliação microscópica reconheceu-se não haver diferença no tipo e na intensidade do processo inflamatório entre os grupos; ocorreu predomínio de processo inflamatório crônico e acentuado; as necroses ocorreram igualmente em ambos os grupos; houve predomínio de depósito de colágeno tipo I em relação ao tipo III em ambos os grupos.

Sympathetic skin response in electrical burn injury.

BACKGROUND: Electrical burn has been reported to be highly associated with peripheral neuropathy. This study was designed to evaluate the sympathetic skin response (SSR) of electrical burn patients to determine whether the sympathetic nervous system is involved in these patients. MATERIALS AND METHODS: The sympathetic skin response of 28 patients, suffering from electrical burn injury (divided into two groups of high voltage and low voltage exposure) was compared with that of 28 matched subjects, who had never experienced electrical burn. Bilateral palmar and plantar latency and amplitude of SSR were recorded in response to Median and Tibial nerve electrical stimulation. RESULTS: SSR in all recording sites of the electrical burn patients compared showed significantly more prolonged latencies and reduced amplitudes, with their counterparts in the control group with no significant difference between the high voltage and low voltage electrical burns. There was no significant difference in SSR latency, between the entry and exit sites of the electrical current. The SSR amplitude however, showed more reduction in right hand than the left one, in whom the electrical current had entered the body from the right hand. The time lapse between the electrical burn and the SSR study was shown to play no role in the results. DISCUSSION: Increased SSR latency in electrical burn injury may be a sign of autonomic nervous system involvement, through systemic responses to electrical burn.

Traumatic unilateral vasomotor rhinitis.

Vasomotor rhinitis (VMR) is a commonly encountered entity that may be difficult to diagnose. The classic symptoms are clear rhinorrhea and nasal congestion, commonly brought on by exercise, stress, heat, cold, and environmental irritants. The diagnosis is one of exclusion, and management usually involves avoidance of inciting agents and treatment with an anticholinergic nasal spray. We describe a case of VMR in a 22-year-old woman who presented with symptoms of clear, left-sided rhinorrhea and epiphora that had begun shortly after a motor vehicle accident approximately 1.5 years earlier, but which she had not reported at that time. The patient's left carotid canal had been fractured and the surrounding sympathetic plexus injured in the accident, resulting in an overactive parasympathetic system. Both exercise and heat exacerbated her symptoms. Allergy was excluded by negative allergy testing, and the patient did not respond to fluticasone nasal spray. Given the mechanism of injury, the unilaterality of symptoms, and the patient's lack of response to nasal steroids, it was thought that the VMR was due to the earlier traumatic injury, which had resulted in imbalance of the autonomic neural input. A trial of ipratropium was given to directly treat the parasympathetic overactivity. This treatment resulted in immediate improvement in both the nasal and lacrimal secretions.

Genitosensory nerve modulation of paced mating behavior: evidence for pelvic, but not hypogastric, nerve influence.

The pelvic nerve is known to play a role in the behavioral and neurochemical responses exhibited during paced mating behavior. The present study extended the analysis of the contribution of the genitosensory nerves to the display of paced mating behavior to include bilateral hypogastric nerve transection, bilateral pelvic nerve transection, or transection of both the hypogastric and pelvic nerves. Rats with pelvic nerve transection were less likely to exit the male compartment, took longer to exit the male compartment following intromissions, and returned to the male more quickly following intromissions compared to rats with an intact pelvic nerve. In contrast, hypogastric nerve transection alone did not affect paced mating and had no modulating effect on the paced mating behavior of rats with pelvic nerve transection. Our results support the view that key aspects of paced mating behavior are modulated by signals transmitted via the pelvic nerve, without any discernable contribution from the hypogastric nerve.

Thresholds for thermal damage to normal tissues: an update.

The purpose of this review is to summarise a literature survey on thermal thresholds for tissue damage. This review covers published literature for the consecutive years from 2002-2009. The first review on this subject was published in 2003. It included an extensive discussion of how to use thermal dosimetric principles to normalise all time-temperature data histories to a common format. This review utilises those same principles to address sensitivity of a variety of tissues, but with particular emphasis on brain and testis. The review includes new data on tissues that were not included in the original review. Several important observations have come from this review. First, a large proportion of the papers examined for this review were discarded because time-temperature history at the site of thermal damage assessment was not recorded. It is strongly recommended that future research on this subject include such data. Second, very little data is available examining chronic consequences of thermal exposure. On a related point, the time of assessment of damage after exposure is critically important for assessing whether damage is transient or permanent. Additionally, virtually no data are available for repeated thermal exposures which may occur in certain recreational or occupational activities. For purposes of regulatory guidelines, both acute and lasting effects of thermal damage should be considered.

First-bite syndrome complicating carotid endarterectomy: a case report and literature review.

First-bite syndrome (FBS) is an infrequently encountered complication of parapharyngeal space surgery. Patients experience excruciating pain in the ipsiltateral parotid gland region at the first bite of each meal, which improves with subsequent mastication. This is thought to be due to parotid gland sympathetic denervation from surgery with resultant hypersensitivity to parasympathetic impulses. There is no consensus on best treatment for FBS although symptoms tend to improve with time. There are only 2 case reports linking carotid endarterectomy and FBS so far. We report the third case of FBS after carotid endarterectomy to raise awareness among vascular surgeons of the possibility of this complication.