Early Lyme Disease.

The disease starts after an infected tick expels its salivary gland and abdominal contents into the skin of a human.   In about 60-70% of cases, a rash may develop at the site of the tick bite.  This rash is most often circular with a clear edge, but oblong and other shaped rashes may occur as well in response to the tick bite.   This rash is known as erythema migrans or EM.  This rash usually starts about 3-30 days after the tick bite.  Sometimes this rash is mistaken as a “spider bite”.    It is called “migrans” because it grows in size, gradually expanding over several days to greater than 2 inches across; some rashes can cover very large areas, such as an entire back.  If the center of the rash clears, the rash may take on a bull’s-eye appearance.  The rash is usually not itchy or painful.   Sometimes, other rashes occur in other parts of the body far away from the initial tick bite. This is because the spirochete gets transmitted quite rapidly in the bloodstream after the initial tick bite. Whereever the blood goes, there too will the Borrelia spirochete travel.   In early Lyme disease, patients often experience moderate to severe flu-like symptoms (fatigue, chills, fever, headache, and muscle and joint aches, swollen lymph nodes).  In about 18% of cases, the classic well known CDC clinical features of Lyme disease are not present.  In these cases, the only symptoms may be marked fatigue and flu-like symptoms.   Given that fatigue and flu-like symptoms may often arise from other causes, Lyme disease may not even be considered in the differential diagnosis and the patient may suffer for many months with an unrecognized, untreated infectious illness. 

Late Disseminated Lyme Disease.  If not caught early, the infection may then spread to many other parts of the body.  This can occur over a period of days, affecting the central nervous system (brain), the peripheral nervous system (nerves), the cardiovascular system (causing pericarditis and/or 2nd or 3rd degree heart block and possible death if not treated immediately), the liver (causing mild hepatitis), the eyes (causing conjunctivitis). and the  muscles and joints (causing migrating swelling, tenderness, and/or pain).   

The typical constellation of symptoms associated with disseminated Lyme disease may include severe fatigue with a need for naps during the day, low grade fevers, muscle and joint pains, sleep disturbance, irritability, headaches, light or sound sensitivity, sharp stabbing or shooting pains, and/or numbness and tingling.

When Lyme disease first affects the nervous system, one may see symptoms of meningitis, encephalitis, or cranial neuritis.

a. Meningitis is characterized by headaches that fluctuate in intensity from mild to severe with or without associated nausea, vomiting, light sensitivity, neck stiffness, or pain on eye motion. If a spinal tap is done at this time, the spinal fluid (CSF) will usually show elevated white blood cells and elevated protein.

b. Encephalitis is commonly accompanied sleepiness, mood swings and irritiability, atypical spontaneous tearfulness or personality change, cognitive problems (typically with word finding problems, memory loss, slowed mental speed), balance problems, and sensory hyperarousal (e.g., vision, hearing).  An EEG at this stage may show mild slowing. A brain MRI may be normal or show white matter hyperintensities suggestive of inflammation.

c. Cranial neuritis.  CN VII Palsy (facial nerve weakness) is a form of cranial neuritis that is thought by many physicians to be common, however studies suggest that it may be seen in as few as 10% of patients with neurologic Lyme disease.   However, in a patient from a Lyme endemic area or in an individual who has previously visited a Lyme endemic area, a presentation of a facial nerve palsy should lead the physician to test for Lyme disease.  If the CN VII palsy affects both sides of the face, then Lyme disease should be even more strongly considered as very few diseases cause a bilateral facial nerve palsy.   Typically, a cranial neuritis occurs within days to weeks of the initial infection bya  tick.   If patients experience abnormalities in facial sensation, the cause may be inflammation of the trigeminal cranial nerve (CN V).  If central vision appears cloudy or if there is pain on eye movements, these could be signs of an optic neuritis. Pseudotumor cerebri is an intracranial increase in pressure that is not due to a tumor but because of the increase in pressure, there may be pressure on the optic nerve. This pressure could cause visual loss; in rare cases of Lyme optic neuritis from Lyme-induced pseudotumor cerebri, blindness may occur if not detected and treated early. If CN III, IV, or VI are affected, the patient may present with double vision.  With involvement of CN VIII, patients may experience ringing in the ears (tinnitus), loss of hearing, vertigo, or ataxia.

d. Radiculoneuritis. When the infection in Lyme disease affects the nerve roots, it is called radiculoneuropathy. Typical symptoms include radicular pain and symmetric or asymmetric sensory abnormalities, such as numbness or tingling.   The radicular pain may be experienced as sharp stabbing or burning or shooting pains that radiate down a dermatomal distribution, such as into the limbs or across the trunk. There may also be elements of motor weakness.  Differential diagnosis should exclude other causes of distal paresthesias, such as diabetic and toxic-metabolic neuropathies, or other causes of radicular pain, such as structural compression.

Late Neurologic Lyme Disease

a. Encephalopathy.  Patients may develop cognitive problems from Lyme disease either early or many months or years after the initial infection.  The cognitive problems most commonly include problems with short-term memory, problems with verbal fluency such as in name or word retrieval, and problems with slower speed of thinking.   Patients typically report that they have “Brain Fog”.  On a practical level, adults may have difficultly in following the normal speed of conversations, children may find it difficult to write down the homework assignments quickly enough or even forget whether or not they did the homework the night before. Because of the slower processing speed, normal tasks take on a greater burden and the individual may feel mentally slow.  In untreated neurologic Lyme disease, the encephalopathy can be moderate to severe, while in later stage treated Lyme disease the encephalopathy is often more subtle – mild to moderate in magnitude. Rarely the encephalopathy may manifest as dementia.

b. Encephalomyelitis.  This is more common in Europe than in the United States, perhaps because there are other genospecies of Borrelia burgdorferi in Europe, including Borrelia garinii which is more  neurotropic.  Encephalomyelitis may be characterized by encephalitis with confusion and/or severe psychiatric disorders, chorea, cerebellar ataxia, and/or seizures. Patients may have a constellation of symptoms and signs (such as white matter hyperintensities) that appear quite similar to the manifestations of multiple sclerosis.  In MS, typically there are oligoclonal bands in the CSF while in Lyme disease these would be less common.

c. Neuropsychiatric Lyme Disease.  Neuropsychiatric symptoms can emerge either early or late in the disseminated phase of infection.   These symptoms commonly appear as cognitive symptoms (as in the encephalopathy above) and as irritability, easy tearfulness, anxiety, and depression.  Rarely, patients with undetected Lyme disease may present with obsessive compulsive disorder, paranoia, auditory/visual hallucinations, or full blown mania.  Sleep disturbances are also common in Lyme disease, with patients more often reporting a need for many hours of sleep, including daytime naps.  Sensory hyperarousal occurs in about 50% of patients with later stage neurologic Lyme disease, most often affecting hearing and/or vision.  These patients may resort to wearing earplugs, sound protectors, and/or sunglasses indoors.  Normal sensory stimulation may over-stimulate, causing confusion and triggering a limbic alarm as if one had been assaulted.  While psychiatric problems can arise during the course of Lyme disease (or many other central nervous system infections), it is critical to remember that most psychiatric disorders have nothing to do with Lyme disease.  It is also important to note that when patients with Lyme disease experience a psychiatric disorder, treatment for the psychiatric disorder should not be delayed; psychiatric consultation should be obtained so that an adjunctive treatment plan with the internist can be initiated.