NMR-based metabolomic investigation of dogs with acute flaccid paralysis due to tick paralysis.

BACKGROUND: Acute flaccid paralysis (AFP) is a complex clinical syndrome with various aetiologies. If untreated, AFP may lead to death due to failure of respiratory muscles. Tick paralysis, which is a noninfectious neurologic syndrome of AFP, occurs following tick attachment, engorgement, and injection of tick saliva toxins. There is no specific diagnostic test for tick paralysis, and mortality increases as definitive diagnosis is delayed. Although metabolomic investigation of tick saliva was conducted, there is a lack of research on metabolomic evaluation of hosts affected by tick paralysis. OBJECTIVES: Thus, the aim of this study is to investigate metabolomic changes in serum samples of dogs with tick paralysis due to Rhipicephalus sanguineus using NMR-based metabolomics and to identify potential diagnostic/prognostic markers. MATERIALS AND METHODS: Forty dogs infested with R. sanguineus, with clinical findings compatible with AFP and with a confirmed tick paralysis diagnosis ex juvantibus, constituted the Paralysis Group. Ten healthy dogs, which were admitted either for vaccination and/or check-up purposes, constituted the Control Group. After the confirmation tick paralysis, medical history, vaccination and nutritional status, body surface area and estimated tick numbers of all the dogs were noted. Physical examination included body temperature, heart and respiratory rate, capillary refill time evaluation and Modified Glasgow Coma Scale calculation. Serum samples were extracted from venous blood samples of all the dogs and were prepared for NMR analysis, and NMR-based metabolomics identification and quantification were performed. RESULTS: NMR-based serum metabolomics of the present study revealed distinct up/down-regulated expressions, presenting a promising avenue. Moreover, it was observed that energy metabolism and especially liver functions were impaired in dogs with tick paralysis, and not only the respiratory system but also the kidneys were affected. CONCLUSION: It was concluded that the present approach may help to better understand the pathological mechanisms developing in cases of AFP due to tick paralysis.

Elective cricothyrotomy in a dog with transient laryngeal paralysis secondary to Australian paralysis tick (Ixodes holocyclus) envenomation.

The tube cricothyrotomy (CTT) has recently been introduced to small animal medicine as a viable surgical airway access procedure; however, there are no reports documenting its clinical use. The author's objective is to describe the clinical application, complications, and management of an elective CTT in a dog. Furthermore, the characteristics of CTT that may be clinically advantageous over temporary tube tracheostomy (TT) will be discussed. A 2-year-old female spayed German shepherd dog required mechanical ventilation (MV) due to unsustainable work of breathing as a result of tick paralysis and aspiration pneumonia. After successful weaning from MV, the dog was diagnosed with laryngeal paralysis. A surgical airway was performed using CTT to allow extubation and patient management whilst conscious. Complications included frequent tube suctioning due to accumulation of airway secretions in the tube and a single dislodgement event. The dog made an uneventful recovery with complete stoma healing by the second intention within 15 days. To the authors' knowledge, this is the first clinical report of an elective CTT performed to successfully manage upper airway obstruction in the dog. Its efficacy, clinical management and patient outcome are described.

Rare Cause of Facial Palsy: Case Report of Tick Paralysis by Ixodes Holocyclus Imported by a Patient Travelling into Singapore from Australia.

BACKGROUND: Ticks are blood-sucking arachnids that feed on all classes of vertebrates, including humans. Ixodes holocyclus, also known as the Australian Paralysis Tick, is capable of causing a myriad of clinical issues in humans and companion animals, including the transmission of infectious agents, toxin-mediated paralysis, allergic and inflammatory reactions, and mammalian meat allergies in humans. The Australian Paralysis Tick is endemic to Australia, and only two other exported cases have been reported in the literature. CASE REPORT: We report the third exported case of tick paralysis caused by I. holocyclus, which was imported on a patient into Singapore. We also discuss the clinical course of the patient, the salient points of management, and the proper removal of this tick species. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: With increasing air travel, emergency physicians need to be aware of and to identify imported cases of tick paralysis to institute proper management and advice to the patient. We also describe the tick identification features and proper method of removal of this tick species.

Symptomatic thoracic arachnoid cyst with coexisting tick paralysis: case report and review of the literature.

Tick paralysis is an uncommon phenomenon resulting from the release of a neurotoxin from the salivary glands of an engorged, gravid female tick about 5-7 days after attachment. The neurotoxin produces ascending weakness, mimicking other ascending paralytic processes. We present a case of a child presenting with weakness of the lower extremities and frequent falls who was found to have a compressive thoracic arachnoid cyst and a large distal syrinx. After surgical decompression, the patient made significant improvement in her leg strength, but quickly developed an ascending quadriparesis, followed by respiratory depression. Subsequent imaging and physical examination revealed an engorged tick embedded in her scalp. The tick was removed, and the patient made a rapid and complete clinical recovery. We present a unique case of concomitant tick paralysis and a symptomatic spinal intradural arachnoid cyst, and review the literature on tick paralysis.

Facial nerve paralysis due to intra-aural Hyalomma tick infestation.

We present the case of a 33 year-old man from a village of the north-eastern part of central Anatolia admitted to the otolaryngology department of Yeditepe University Hospital with right facial asymmetry and pain on the right ear. A tick of the genus Hyalomma was observed in the external auditory canal of the right ear and it was removed with fine cup forceps under otomicroscopy. We are of the opinion that in patients presenting with sudden acute ear pain and facial palsy, the ear canal should be examined to exclude an infestation by ticks.

Tick paralysis caused by Dermacentor andersoni (Acari: Ixodidae) is a heritable trait.

The heritability of the ability to cause paralysis was examined in crosses of virulent and avirulent Dermacentor andersoni (Stiles) (Acari: Ixodidae). Virulence was assessed using hamster bioassay. Paralysis was caused by the virulent parental strain but not by the avirulent parental strain. Four crosses were made: Avirulent female x Avirulent male (AA cross), Virulent female x Virulent male (VV cross), Avirulent female x Virulent male (AV cross), and Virulent female x Avirulent male (VA cross). The proportion of females that produced fertile egg masses was similar among the crosses; however, VV females produced fewer fertile eggs. This was attributed to the long-term laboratory colonization of the virulent strain. All crosses had similar levels of larval and nymphal engorgement and adult eclosion. The ability to cause paralysis was detected in progeny of all crosses except the AA cross. Both heterogeneous crosses caused paralysis, but the virulence was slightly less than for the VV cross. Virulence was similar among the AV and VA crosses, indicating that virulent males were as likely as females to pass the trait to progeny. Time to paralysis was faster for the VV cross compared with the heterogeneous crosses.

Tick paralysis: atypical presentation, unusual location.

We present 2 unrelated cases of tick paralysis presenting within a 2-month period in the greater Philadelphia region, a geographic area in which this disease is highly unusual. Our first patient demonstrated early onset of prominent bulbar palsies, an atypical presentation. Our second patient, residing in a nearby but distinct community, presented with ascending paralysis 2 months after the first. The atypical presentation of our first patient and the further occurrence within a few months of a second patient, both from the Northeastern United States where this diagnosis is rarely made, suggest the need to maintain a high index of suspicion for this disease in patients presenting with acute onset of cranial nerve dysfunction or muscle weakness. Through simple diagnostic and therapeutic measures (ie, careful physical examination to locate and remove the offending tick), misdiagnosis and unnecessary morbidity can be avoided.

Pediatric tick paralysis: discussion of two cases and literature review.

This report describes two cases of tick paralysis in children diagnosed within a 3-month period (May-July 2002) in rural South Carolina. Differing presenting symptoms consisted of acute onset of ataxia in one patient and acute ascending paralysis in the other. Ticks were present on the scalp of both patients and were removed immediately. Both girls demonstrated improvement of signs and symptoms within hours and complete recovery within 24 hours of tick removal. The diagnosis of tick paralysis must be considered in any patient, particularly children, who present with either acute ataxia or acute ascending paralysis. As in any clinical encounter, careful history and thorough general and neurologic examinations must be performed to exclude the possibility of tick attachment.

Effects of the paralysis tick, Ixodes holocyclus, on the electrocardiogram of the Spectacled Flying Fox, Pteropus conspicillatus.

OBJECTIVE: To evaluate cardiac electrical function in the Spectacled Flying Fox (bat) infested with Ixodes holocyclus. DESIGN: Prospective clinical investigation of bats treated for naturally occurring tick toxicity. PROCEDURE: ECGs were performed on bats with tick toxicity (n = 33), bats that recovered slowly (n = 5) and normally (n = 5) following treatment for tick toxicity, and on normal bats with no history of tick toxicity (n = 9). RESULTS: Bats with tick toxicity had significantly prolonged corrected QT intervals, bradycardia and rhythm disturbances which included sinus bradydysrhythmia, atrial standstill, ventricular premature complexes, and idioventricular bradydysrhythmia. CONCLUSIONS: The QT prolongation observed on ECG traces of bats with tick toxicity reflected delayed ventricular repolarisation and predisposed to polymorphic ventricular tachycardia and sudden cardiac death in response to sympathetic stimulation. The inability to document ventricular tachycardia in bats shortly before death from tick toxicity may be explained by a lack of sympathetic responsiveness attributable to the unique parasympathetic innervation of the bat heart, or hypothermia-induced catecholamine receptor down-regulation. Bradycardia and rhythm disturbances may be attributable to hypothermia.