This 40 year old man has presented with a spontaneous bilateral lower motor neuron (LMN) type facial palsy, a rare and unusual clinical entity where both facial nerves are affected within a 30 day time span.
Bilateral facial nerve palsy is rare, representing less than 2% of all cases of facial palsy. It is essential to appreciate that many of these patients have serious underlying systemic illness.
This is as opposed to unilateral facial nerve palsy, in which Bell's palsy is the commonest etiology.
Important etiologies to consider include infections such as Lyme disease, HIV, infectious mononucleosis or syphilis, Guillain barre syndrome (GBS), brainstem encephalitis, meningitis, diabetes, sarcoidosis and leukemia.
Under most circumstances, differentiation between the above pathologies would be a fairly complex and involved task.
However, examination reveals the presence of a bull's eye rash characteristic of the 'erythema migrans' encountered in Lyme disease; this is virtually pat
hognomonic of the disease, and is sufficient to establish the diagnosis.
Note that in patients with erythema migrans, and a presentation otherwise compatible with Lyme disease, a clinical diagnosis can be established; serological confirmation is not essential (and indeed may give a false negative result in early disease). Neither are the other investigations listed here indicated.
Doxycycline is the drug of choice in patients with Lyme disease. Note that steroids should be avoided in these patients, as the anti-inflammatory effect will facilitate the spread of the organism.
Acyclovir is not indicated in his management. Plasmapheresis is used for the treatment of GBS.
Lyme disease was first recognized in 1975, after a cluster of cases were reported in Lyme, Connecticut. Currently, it is ranked as the most common arthropod borne infection in the United States.
The condition is also prevalent in Europe, Asia and the northern parts of Africa; worldwide, more than 80,000 cases are reported annually.
In the United States, most cases are reported from the Northeastern and Northcentral states, where it is mainly associated with hunting and other outdoor activities.
Lyme disease is a zoonotic infection caused by the spirochete Borrelia burgdorferi. It is transmitted from rodents (the natural reservoir) to humans, via ticks which feed on both hosts.
Hard ticks of the genus Ixodes are the main vector for lyme disease; these also transmit Babesiosis.
Inoculation occurs following a tick bite; the saliva of the tick disrupts the immune system at that site, helping the bacteria to multiply and establish the infection.
In general, a tick needs to be attached for 36 to 48 hours for sufficient bacteria to be transmitted to cause an infection. The incubation period ranges from 3 to 30 days.
The bacteria tend to migrate into the skin away from the bite site. The inflammatory reaction to these migrating bacteria results in the characteristic 'erythema migrans' rash.
The organism can subsequently spread via the lymphatics causing local lymphadenopathy; it can also spread via the bloodstream and give rise to a multisystemic disorder; note that Borrelia shows a distinct tropism for the skin, heart, central nervous system, joints, and eyes.
The exact cause for chronic symptoms is not known yet, but the current hypothesis is that it is an autoimmune process.
The symptoms of Lyme disease are described in three stages.
The first is the early localized stage, characterized by fever with chills, malaise, arthralgia, myalgia and lymphadenopathy, along with the pathognomonic erythema migrans rash; the latter is not universally present though.
The second stage is the early disseminated stage; in untreated patients, the infection spreads systemically potentially resulting in additional erythema migrans lesions in other areas of the body as well as unilateral or bilateral facial nerve palsy, meningitis, arthritis and heart blocks.
Most of these symptoms resolve over a period of weeks to months, even without treatment.
However, in certain patients, lack of treatment can result in progression to the late disseminated stage, which is the third stage of the disease.
During this final stage, around 60% of patients with untreated infection may begin to experience intermittent bouts of arthritis, with severe joint pain and swelling. The large joints are most often affected.
Up to 5% of untreated patients may develop chronic neurological complaints. These include shooting pains, numbness or tingling in the hands or feet, and problems with short-term memory.
Common differential diagnoses include babesiosis, rocky mountain spotted fever, osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, chronic fatigue syndrome, fibromyalgia, multiple sclerosis or acute memory disorders.
The centers for disease control (CDC) recommend a two staged serological testing approach for the diagnosis of Lyme disease.
The first test should be an enzyme immunoassay (EIA) or an immunofluorescence assay (IFA); this should be followed up by a a Western blot for IgG or IgM. Note that both tests need to be positive for confirmation.
While the organism can also be isolated via biopsy of an erythema migrans lesion, this is rarely indicated, as the presence of a typical lesion along with a supportive history alone is sufficient to start treatment.
Administration of doxycycline or amoxicillin for 14 to 21 days is recommended for the treatment of early localized or early disseminated lyme disease associated with erythema migrans, if there is no neurological involvement or third-degree atrioventricular heart block.
Cefuroxime is as effective as doxycycline, and can be used as an alternative agent for individuals who cannot tolerate either doxycycline or amoxicillin.
Macrolides are recommended as the second line drug for patients who cannot tolerate any of the other agents.
For patients with cardiac or neurological involvement, intravenous ceftriaxone or penicillin is recommended. If these drugs are not tolerated, oral doxycycline for 14 to 28 days is recommended.
While antibiotic treatment does not hasten the resolution of facial nerve palsy, antibiotics should still be given to prevent further sequelae.
The late disseminated stage is also treated with intravenous or oral antibiotics for 14-28 days.
Around 10% to 20% of patients with Lyme disease have symptoms that persist after treatment with antibiotics. These include arthralgia, myalgia, cognitive problems, fatigue and sleep disturbances.
This condition is referred to as Post treatment Lyme Disease syndrome (PTLDS). Studies have shown that continuing antibiotic therapy is not helpful and can be harmful for persons with PTLDS.
Prevention of Lyme Disease is an important public health measure in endemic areas; when engaging in outdoor activities, potential exposure should be avoided by measures such as wearing protective clothing and the use of insect repellent.
This should be combined with prompt removal of ticks after activities such as hunting or hiking.
There is currently no recommended regime for antibiotic prophylaxis against the disease.
1. 1) Erythema migrans lesions are almost pathognomonic of Lyme Disease, but are not universally present in all patients.
2. 2) The CDC recommends a two staged serological testing approach for the diagnosis of Lyme disease.
3. 3) Prompt antibiotic treatment in early stage is essential for the prevention of long term sequelae.