Tick paralysis in children: electrophysiology and possibility of misdiagnosis

Tick Paralysis: A Thorough Examination May Prevent Unnecessary Harm

Tick paralysis is a relatively uncommon tick-borne illness that is often overlooked and misdiagnosed. Therefore, it is not unusual for cases to undergo unnecessary work-up and interventions that may delay correct diagnosis and treatment, placing the patient at risk for catastrophic consequences. We present the case of a four-year-old female who developed ascending flaccid paralysis, initially misdiagnosed with Guillain-Barré syndrome (GBS). She was placed in the pediatric intensive care unit (PICU) for mechanical ventilation after failing to respond to intravenous immunoglobulin (IVIG) administration and plasmapheresis. Later in her hospital course, she was correctly diagnosed to have tick paralysis.

Tick Paralysis Case Series: An 11-Year Institutional Case Series

OBJECTIVES

The aims of the study were to identify and to describe cases of pediatric tick paralysis presenting to an emergency department in southern Louisiana during an 11-year period.

METHODS

We conducted a retrospective chart review of patients aged 0 to 18 years with a diagnostic code of toxic effect of venom, tick-borne viral encephalitis, Guillain-Barré syndrome, acute infective polyneuritis, or abnormality of gait from July 2005 to June 2016. Data were collected on visit month, patient age, race and sex, tick's attachment site, location of tick removal, symptoms and length of symptoms, initial diagnosis, time to appropriate diagnosis, and hospital length of stay.

RESULTS

Nine patients aged 2 to 10 years presented with lower limb weakness and varying degrees of upper extremity ataxia or paralysis, areflexia, dysarthria, diplopia, or petechia. Five cases were accurately and rapidly diagnosed; 4 cases involved a delay in accurate diagnosis. Treatment of the misdiagnosed cases ranged from septic workup to neurologic workup, including magnetic resonance imaging. The tick was discovered by the patients' relative in 4 cases, by a primary care or emergency care physician at another facility in 3 cases, and by 1 of our emergency care physicians in 2 patients.

CONCLUSIONS

The incidence of tick paralysis in southern Louisiana is unknown. However, our case series indicates that it is likely higher than expected. Although most cases in our facility were quickly diagnosed and treated through tick removal, delayed diagnosis results in unnecessary tests, procedures, and medical costs. All of our cases fully recovered after tick removal.

Electrodiagnostic Abnormalities in Tick Paralysis: A Case Report and Review of Literature

OBJECTIVE

To study the electrodiagnostic abnormalities in tick paralysis.

METHODS

A 7-year-old girl with acute onset proximal muscle weakness and an engorged dog tick attached to her scalp was evaluated.

RESULTS

The routine motor nerve conduction study showed normal compound muscle action potential amplitude. The stimulated jitter analysis of the orbicularis oculi muscle showed normal jitter with no blocking. The quantitative electromyography of the proximal muscles showed decreased mean duration of the motor unit potentials.

CONCLUSION

We propose toxin-mediated direct skeletal muscle involvement as one of the reasons for muscle weakness in tick paralysis.

A Comparative Meta-Analysis of Tick Paralysis in the United States and Australia

CONTEXT

Tick paralysis is a neurotoxic envenoming that mimics polio and primarily afflicts children, especially in hyperendemic regions of the Western United States of America (US) and Eastern Australia.

OBJECTIVE

To compare the epidemiology, clinical and electrodiagnostic manifestations, and outcomes of tick paralysis in the US versus Australia.

METHODS

A comparative meta-analysis of the scientific literature was conducted using Internet search engines to identify confirmed cases of tick paralysis in the US and Australia. Continuous variables including age, time to tick removal, and duration of paralysis were analyzed for statistically significant differences by unpaired t-tests; and categorical variables including gender, regional distribution, tick vector, tick attachment site, and misdiagnosis were compared for statistically significant differences by chi-square or Fisher exact tests.

RESULTS

Tick paralysis following ixodid tick bites occurred seasonally and sporadically in individuals and in more clusters of children than in adults of both sexes in urban and rural locations in North America and Australia. The case fatality rate for tick paralysis was low, and the proportion of misdiagnoses of tick paralysis as Guillain-Barré syndrome (GBS) was greater in the US than in Australia. Although electrodiagnostic manifestations were similar, the neurotoxidromes differed significantly with prolonged weakness and even residual neuromuscular paralysis following tick removal in Australian cases compared with US cases.

DISCUSSION

Tick paralysis was a potentially lethal envenoming that occurred in children and adults in a seasonally and regionally predictable fashion. Tick paralysis was increasingly misdiagnosed as GBS during more recent reporting periods in the US. Such misdiagnoses often directed unnecessary therapies including central venous plasmapheresis with intravenous immunoglobulin G that delayed correct diagnosis and tick removal.

CONCLUSION

Tick paralysis should be added to and quickly excluded from the differential diagnoses of acute ataxia with ascending flaccid paralysis, especially in children living in tick paralysis-endemic regions worldwide.

Neurotoxin-induced paralysis: a case of tick paralysis in a 2-year-old child

BACKGROUND

Tick paralysis is an arthropod-transmitted disease causing potentially lethal progressive ascending weakness. The presenting symptoms of tick paralysis overlap those of acute inflammatory diseases of the peripheral nervous system and spinal cord; thus, the condition is often misdiagnosed, leading to unnecessary treatments and prolonged hospitalization.

PATIENT

A 2-year-old girl residing in northern New York and having no history of travel to areas endemic to ticks presented with rapidly progressing ascending paralysis, hyporeflexia, and intact sensory examination. Investigation included blood and serum toxicology screens, cerebrospinal fluid analysis, and brain imaging. With all tests negative, the child's condition was initially mistaken for botulism; however, an engorged tick was later found attached to the head skin. Following tick removal, the patient's weakness promptly improved with no additional interventions.

CONCLUSION

Our patient illustrates the importance of thorough skin examination in all cases of acute progressive weakness and the necessity to include tick paralysis in the differential diagnosis of paralysis, even in nonendemic areas.

Medication, toxic, and vitamin-related neuropathies

PURPOSE OF REVIEW

Although medication, toxic, and vitamin-related neuropathies are rare causes of neuropathy, they are important to recognize because they are treatable and preventable. It is often difficult to conclusively demonstrate that a particular agent is the cause of neuropathy, but understanding the specific electrodiagnostic and clinical patterns produced by these agents is critical for making these assessments.

RECENT FINDINGS

The clinical and electrodiagnostic features for many of these neuropathies have been well established. The exact mechanism by which some of these agents produce neuropathy is only now beginning to be revealed. These mechanisms are critical for both understanding the normal function of nerves as well as eventually devising specific treatments.

SUMMARY

A large number of medications and toxins can produce neuropathy. This article reviews the clinical characteristics, electrodiagnostic features, and mechanism of action (when known) of those agents that produce the most severe, or perhaps the most unique features of, neuropathy.

Tick paralysis caused by Amblyomma maculatum on the Mexican Pacific Coast

Tick paralysis is a rare entity in which it is necessary to identify the cause and remove the arthropod to have a rapid remission of symptoms. In the absence of an early diagnosis, the outcome can be fatal, as toxins are released from the tick's saliva as it feeds. To the best of the authors' knowledge, this is the first clinical report of the disease in Mexico and Latin America. A 22-year-old man from a rural area, who was in contact with cattle, developed ascending flaccid paralysis secondary to Amblyomma maculatum tick toxin. He presented flaccid paraplegia and arreflexia that progressed until causing dyspnea. The clinical symptoms subsided 48 h after the ticks spontaneously detached. The ticks were discovered by nursing personnel while the patient was being transferred to a regional hospital with the diagnosis of Guillain-Barré syndrome. The patient was asymptomatic on discharge from hospital and showed no further motor deterioration at a 1-month follow-up.

Nerve root enhancement on spinal MRI in pediatric Guillain-Barré syndrome

Guillain-Barré syndrome diagnosis is based on clinical presentation and supportive diagnostic testing. In its early stage, no single, reliable diagnostic test is available. However, a finding of nerve root enhancement on spinal magnetic resonance imaging may be useful. We evaluated the frequency of nerve root enhancement on spinal magnetic resonance imaging in children with Guillain-Barré syndrome. At a single tertiary pediatric center, we conducted a retrospective chart review of children with Guillain-Barré syndrome who had complete spinal or lumbosacral spinal magnetic resonance imaging with gadolinium administration from January 2002-January 2009. Twenty-four consecutive patients were identified. Spinal nerve root enhancement with gadolinium was present in 92% (22/24) of children with Guillain-Barré syndrome on initial spinal magnetic resonance imaging (95% confidence interval, 0.745-0.978). This finding increased to 100% of patients, after two patients underwent repeat spinal magnetic resonance imaging that did reveal nerve root enhancement. Patterns of enhancement were variable, but involved the thoracolumbar nerve roots in all patients. Enhancement of nerve roots with gadolinium on initial spinal magnetic resonance imaging was frequently present in these children with Guillain-Barré syndrome. Spinal magnetic resonance imaging is a sensitive diagnostic test and should be considered an additional diagnostic tool in select cases.

A 60-year meta-analysis of tick paralysis in the United States: a predictable, preventable, and often misdiagnosed poisoning

Tick paralysis (TP) is a neurotoxic poisoning primarily afflicting young girls in endemic regions. Recent case series of TP have described increasing misdiagnoses of TP as the Guillain-Barré syndrome (GBS). A meta-analysis of the scientific literature was conducted using Internet search engines to assess the evolving epidemiology of TP. Fifty well-documented cases of TP were analyzed over the period 1946-2006. Cases were stratified by demographics, clinical manifestations, and outcomes. Misdiagnoses were subjected to Yates-corrected chi-square analyses to detect statistically significant differences in proportions of misdiagnoses between earlier and later reporting periods. TP occurred seasonally and sporadically in individuals and in clusters of children and adults of both sexes in urban and rural locations. The case fatality rate (CFR) for TP was 6.0% over 60 years. The proportion of misdiagnoses of TP as GBS was significantly greater (chi(2) = 7.850, P = 0.005) in more recently collected series of TP cases, 1992-2006, than the proportion of misdiagnoses in earlier series, 1946-1996. TP was a potentially lethal poisoning that occurred in children and adults in a seasonally and regionally predictable fashion. TP was increasingly misdiagnosed as GBS during more recent reporting periods. Such misdiagnoses often directed unnecessary therapies such as central venous plasmapheresis with intravenous immunoglobulin G, delayed correct diagnosis, and tick removal, and could have increased CFRs. TP should be added to and quickly excluded from the differential diagnoses of acute ataxia and ascending flaccid paralysis, especially in children living in TP-endemic regions of the USA.

Abducens nerve palsy following a tick bite: A case report

Neuromuscular paralysis caused by salivary proteins of ticks is a well-known complication after tick bites in Australia, North America, and South Africa. Symptoms may include general weakness, difficulty walking, ascending paralysis, and bulbar paralysis with diplopia, culminating in respiratory failure. In Europe, toxin-mediated paralysis has rarely been noted. We report a case of cranial nerve paralysis with delayed onset after a tick bite in northern Germany.

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.

Toxic neuropathies

Many substances, organic and manufactured, may induce peripheral nerve damage when exposed to them. The expected clinical phenotype is of a distal, sensory or sensorimotor polyneuropathy, often painful, with axonal characteristics on electrodiagnostic and histopathologic analysis. Treatment is limited; often, the only effective management is supportive care and avoidance from or removal of the offending toxin. Fortunately, the majority of toxic neuropathies are self-limited and improves gradually after toxin elimination.

Ticks and tick paralysis: imaging findings on cranial MR

Tick paralysis is an acute, progressive, and potentially fatal muscle paralysis secondary to a toxin secreted by a pregnant tick during a bite. Although tick bites can occur anywhere on the body, ticks are frequently overlooked on the scalp because of overlying hair. Children with acute neurologic symptoms frequently undergo MR scanning that may incidentally reveal the offending tick. Timely identification and removal of the tick leads to rapid recovery from tick paralysis. We report the MRI findings at 1.5 T of tick paralysis with an attached tick.

Prevention of arthropod-related disease

Arthropods of medical importance include vespids, ticks, mosquitoes, mites, flies, and fleas. They spread illness as disease vectors, are associated with lethal allergic reactions, and produce potentially deadly toxins. Strategies for prevention of illness include avoidance, vector reduction programs, chemoprophylaxis, and repellents. Strategies must be tailored to regional risks.

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.

Parelaphostrongylus tenuis and other parasitic diseases of the ruminant nervous system

There are many parasites that affect the ruminant central nervous system. Clinical signs can vary dramatically based on the location and mobility of the parasite. Clinical disease can occur due to the physical presence of the parasite and the resulting host immune response or the toxin produced by the parasite. Differentiating the cause of disease is particularly important because prognosis,treatment, and subsequent control measures vary dramatically depending on the disease process. This article focuses on the pathogenesis,treatment, and control of some of the more common parasitic diseases of the ruminant central nervous system.

Variants and Mimics of Guillain Barré Syndrome

BACKGROUND

The clinical and pathologic spectrum of Guillain Barre Syndrome (GBS) has expanded to include both demyelinating and axon loss forms. GBS may also have atypical presentations. For these reasons, clinicians are more likely to overlook unrelated disorders that mimic GBS.

REVIEW SUMMARY

In this article, the classic presentation and variants of GBS are briefly reviewed. Disorders that mimic GBS are reviewed in detail, including those caused by neurotoxins, heavy metals, chemical toxins, drugs, vasculitis, hereditary disorders, infections, critical illness, and myelopathy. Illustrative case studies accompany a number of the descriptions.

CONCLUSIONS

Failure to recognize the mimics of GBS can lead to erroneous diagnosis, inappropriate treatment, and significant morbidity. Appropriate diagnosis requires a combination of careful history and examination, and accurate interpretation of diagnostic testing.

Tick paralysis presenting in an urban environment

We report the case of a 17-month-old female with tick paralysis presenting to an urban Los Angeles emergency department. The tick was later identified as the North American wood tick, Dermacentor andersoni, and was likely obtained while the family was vacationing on a dude ranch in Montana. We discuss the epidemiology of tick paralysis, a differential diagnosis for health care providers, and methods of detection and removal. Given the increasing popularity of outdoor activities and ease of travel, tick paralysis should be considered in cases of acute or subacute weakness, even in an urban setting.