MedSurg1 1 Ch 64 Neurological infection, autoimmune disorders and neuropathies

A nurse is assessing a newly admitted client with meningitis. Which of the following findings in this client is most likely?

Positive Brudzinski's sign A positive Brudzinski's sign is a common finding in the client with meningitis. When the client's neck is flexed, flexion of the knees and hips is produced. A positive Kernig's sign is usual with meningitis. The client will develop lethargy as the illness progresses, not increased intake or hyper-alertness.

The nurse is performing an initial assessment on a client who is admitted to rule out myasthenia gravis. Which of the following findings would the nurse expect to observe?

Ptosis and diplopia The initial manifestation of myasthenia gravis in two-thirds of clients involves the ocular muscles; diplopia and ptosis are common. Muscle weakness and hyporeflexia of the lower extremities are associated with Guillain-Barre syndrome. Facial distortion and pain are associated with Bell's palsy and tic douloureux.

Which is the most common cause of acute encephalitis in the United States?

Herpes simplex virus Viral infection is the most common cause of encephalitis. Herpes simplex virus is the most common cause of acute encephalitis in the United States. The Western equine encephalitis virus, West Nile virus, and St. Louis virus are types of arboviral encephalitis that occur in North America, but they are not the most common causes of acute encephalitis.

A client spends most of his time in a wheelchair. The nurse would be especially alert for the development of pressure ulcers in which area?

Ischial tuberosity For a client who sits for prolonged periods, such as in a wheelchair, the ischial tuberosity would be highly susceptible to pressure ulcer development. Areas such as the greater trochanter and lateral malleolus would be susceptible for clients lying on their side. The scapula would be considered a high risk area for clients lying on their back.

Which drug should be available to counteract the effect of edrophonium chloride?

Atropine Atropine should be available to control the side effects of edrophonium chloride. Prednisone, azathioprine, and pyridostigmine bromide are not used to counteract these effects.

Which well-recognized sign of meningitis is exhibited when the client's neck is flexed and flexion of the knees and hips is produced?

Positive Brudzinski sign A positive Brudzinski sign occurs when the client's neck is flexed (after ruling out cervical trauma or injury), and flexion of the knees and hips is produced. Photophobia is sensitivity to light. A positive Kerning sign occurs when the client is lying with the thigh flexed on the abdomen and the leg cannot be completely extended. Nuchal rigidity is neck stiffness.

A female client reports to a nurse that she experiences a loss of urine when she jogs. The nurse's assessment reveals no nocturia, burning, discomfort when voiding, or urine leakage before reaching the bathroom. The nurse explains to the client that this type of problem is called:

stress incontinence. Stress incontinence is a small loss of urine with activities that increase intra-abdominal pressure, such as running, laughing, sneezing, jumping, coughing, and bending. These symptoms occur only in the daytime. Functional incontinence is the inability of a usually continent client to reach the toilet in time to avoid unintentional loss of urine. Reflex incontinence is an involuntary loss of urine at predictable intervals when a specific bladder volume is reached. Total incontinence occurs when a client experiences a continuous and unpredictable loss of urine.

When providing discharge teaching for a client with multiple sclerosis (MS), the nurse should include which instruction?

"Avoid hot baths and showers." The nurse should instruct a client with MS to avoid hot baths and showers because they may exacerbate the disease. The nurse should encourage daytime naps because fatigue is a common symptom of MS. A client with MS doesn't require food or fluid restrictions.

The nurse has been educating a client newly diagnosed with MS. Which statement by the client indicates an understanding of the education?

"I will stretch daily as directed by the physical therapist." A stretching routine should be established. Stretching can help prevent contractures and muscle spasticity. Hot baths are discouraged because of the risk of injury. Clients have sensory loss that may contribute to the risk of burns. In addition, hot temperatures may cause an increase in symptoms. Warm packs should be encouraged to provide relief. Progressive weight-bearing exercises are effective in managing muscle spasms. Clients should not hurry through the exercise activity because it may increase muscle spasticity.

A nurse is teaching a client with a leg ulcer about tissue repair and wound healing. Which statement by the client indicates effective teaching?

"I'll eat plenty of fruits and vegetables." For effective tissue healing, adequate intake of protein, and vitamins A, B complex, C, D, E, and K are needed. Therefore, the client should eat a high-protein diet with plenty of fruits and vegetables to provide these nutrients. The bandage should be secure but not tight enough to impede circulation to the area (which is needed for tissue repair). If the client's foot feels cold, circulation is impaired, thus inhibiting wound healing.

The parents of a client intubated due to the progression of Guillain-Barré syndrome ask whether their child will die. What is the best response by the nurse?

"There are no guarantees, but a large portion of people with Guillain-Barré syndrome survive." The survival rate of Guillain-Barré syndrome is approximately 90%. The client may make a full recovery or suffer from some residual deficits. Telling the parents not to worry dismisses their feelings and does not address their concerns. Progression of Guillain-Barré syndrome to the diaphragm does not significantly decrease the survival rate, but it does increase the chance of residual deficits. The family should be given information about Guillain-Barré syndrome and the generally favorable prognosis. With no prognosis offered, the parents are not having their concerns addressed.

A nurse is completing an assessment of a client who has just been transferred to the rehabilitation facility. During the health history, the nurse asks about the client's activities of daily living (ADLs). About which areas would the nurse gather information? Select all that apply.

-Bathing -Toileting -Eating ADLs refer to those activities related to personal care, such as bathing, using the toilet, and eating. Cleaning and cooking are independent ADLs--activities that are important for independent living.

The nurse is caring for a patient with MS who is having spasticity in the lower extremities that decreases physical mobility. What interventions can the nurse provide to assist with relieving the spasms? Select all that apply.

-Demonstrate daily muscle stretching exercises. -Apply warm compresses to the affected areas. -Allow the patient adequate time to perform exercises Warm packs may be beneficial for relieving spasms, but hot baths should be avoided because of risk of burn injury secondary to sensory loss and increasing symptoms that may occur with elevation of the body temperature. Daily exercises for muscle stretching are prescribed to minimize joint contractures. The patient should not be hurried in any of these activities, because this often increases spasticity.

The nurse is developing a bowel training program for a patient. What education can the nurse provide for the patient that will increase the chance of success of the bowel program? (Select all that apply.)

-Set a daily defecation time that is within 15 minutes of the same time every day. -Have an adequate intake of fiber containing foods. -Have a fluid intake between 2 and 4 L/day. Regularity, timing, nutrition (including increased fiber intake), and fluids (2 to 4 L daily), exercise, and correct positioning promote predictable defecation (National Institute for Health and Clinical Excellence, 2010). A regular time for defecation is established, and attempts at evacuation should be made within 15 minutes of the designated time daily. Enemas and laxatives are only needed if the patient is constipated and then only as needed, not daily.

A nurse is performing a baseline assessment of a client's skin integrity. What are the priority assessments? Select all that apply.

-presence of pressure ulcers on the client -overall risk of developing pressure ulcers -potential areas of pressure ulcer development

At what rate (in drops per minute) should a nurse start an IV infusion if the order is for 1 g of vancomycin (Vancocin) to be given in 180 ml of dextrose 5% in water over 60 minutes? The tubing delivers 15 drops/ml. Enter the correct number only.

45 The nurse should administer 45 drops/minute. The formula is to divide 180 ml by 60 minutes, which yields 3 ml/minute; 3 ml/minute × 15 drops = 45 drops/minute.

A client has a neurological defect and will be transferred to a nursing home because family members are unable to care for the client at home. While receiving a bed bath, the client yells at the nurse, "You don't know what you are doing!" What is the best reaction by the nurse?

Accept the patient's behavior and do not take it personally. Anger is a defense or response to loss; the nurse should consider that the client is using displacement to deal with emotional pain. Having another nurse care for the patient might send a message to the client that may precipitate feelings of guilt or imply to the client that the nurse no longer wants to provide care. Discontinuing the bath abandons the client and would not encourage expression of feelings. Explaining that the client is getting good care is a defensive response that focuses on the nurse rather than the client.

Which of the following is the medication of choice in the treatment of herpes simplex virus (HSV)?

Acyclovir (Zovirax) Acyclovir, an antiviral agent, is the medication of choice in the treatment of HSV. Decadron, vancomycin, and Dilantin may be used in the treatment of meningitis.

During a Tensilon test to determine if a patient has myasthenia gravis, the patient complains of cramping and becomes diaphoretic. Vital signs are BP 130/78, HR 42, and respiration 18. What intervention should the nurse prepare to do?

Administer atropine to control the side effects of edrophonium. Atropine should be available to control the side effects of edrophonium, which include bradycardia, sweating, and cramping.

A nurse is working with a patient to establish a bowel training program. Based on the nurse's understanding of bowel function, the nurse would suggest planning for bowel evacuation at which time?

After breakfast Natural gastrocolic and duodenocolic reflexes occur about 30 minutes after a meal; therefore, after breakfast is one of the best times to plan for bowel evacuation.

The nurse is admitting a client into the rehabilitation unit after an industrial accident. The client's nursing diagnoses include disturbed sensory perception and the nurse identifies that he has decreased strength and dexterity. The nurse should know that this client may need what to accomplish self-care?

Appropriate assistive devices Clients with impaired mobility, sensation, strength, or dexterity may need to use assistive devices to accomplish self-care. An assisted living environment is less common than the use of assistive devices. Family involvement is imperative, but this may or may not take the form of advice. A health care aide is not needed by most clients.

The nurse is caring for a client diagnosed with Guillain-Barre syndrome. His spouse asks about recovery rates. The nurse can correctly relate which of the following?

Approximately 60% to 75% of clients recover completely. Results of studies on Guillain-Barre syndrome indicate that 60% to 75% of clients recover completely.

For a client who has had a stroke, which nursing intervention can help prevent contractures in the lower legs?

Attaching braces or splints to each foot and leg Attaching braces or splints to each foot and leg prevents foot drop (a lower leg contracture) by supporting the feet in proper alignment. Putting slippers on the client's feet can't prevent foot drop because slippers are too soft to support the ankle joints. Crossing the ankles every 2 hours is contraindicated because it can cause excess pressure and damage veins, promoting thrombus formation. Placing hand rolls on the balls of each foot doesn't prevent contractures because hand rolls are too soft to support and hold the feet in proper alignment.

Which is the primary medical management of arthropod-borne virus (arboviral) encephalitis?

Controlling seizures and increased intracranial pressure There is no specific medication for arboviral encephalitis; therefore symptom management is key. Medical management is aimed at controlling seizures and increased intracranial pressure.

Which condition is a rare, transmissible, progressive fatal disease of the central nervous system characterized by spongiform degeneration of the gray matter of the brain?

Creutzfeldt-Jakob disease Creutzfeldt-Jakob disease causes severe dementia and myoclonus. Multiple sclerosis is a chronic, degenerative, progressive disease of the central nervous system characterized by the occurrence of small patches of demyelination in the brain and spinal cord. Parkinson disease is associated with decreased levels of dopamine due to destruction of pigmented neuronal cells in the substantia nigra in the basal ganglia of the brain. Huntington disease is a chronic, progressive, hereditary disease of the nervous system that results in progressive involuntary dancelike movements and dementia.

A client arrives at the emergency department complaining of extreme muscle weakness after minimal effort. The physician suspects myasthenia gravis. Which drug will be used to test for this disease?

Edrophonium (Tensilon) Edrophonium temporarily blocks the breakdown of acetylcholine, thus increasing acetylcholine level in the blood, and relieves weakness. Because of its short duration of action, edrophonium is the drug of choice for diagnosing myasthenia gravis. It's also used to differentiate myasthenia gravis from cholinergic toxicity. Ambenonium is used as an antimyasthenic. Pyridostigmine serves primarily as an adjunct in treating severe anticholinergic toxicity; it's also an antiglaucoma agent and a miotic. Carbachol reduces intraocular pressure during ophthalmologic procedures; topical carbachol is used to treat open-angle and closed-angle glaucoma.

A client is undergoing testing to confirm a diagnosis of myasthenia gravis. The nurse explains that a diagnosis is made if muscle function improves after the client receives an IV injection of a medication. What is the medication the nurse tells the client he'll receive during this test?

Edrophonium (Tensilon) The most useful and reliable diagnostic test for myasthenia gravis is the edrophonium (Tensilon) test. Within 30 to 60 seconds after injection of edrophonium, most clients with myasthenia gravis will demonstrate a marked improvement in muscle tone that lasts about 4 to 5 minutes. Cyclosporine, an immunosuppressant, is used to treat myasthenia gravis, not to diagnose it. Immunoglobulin G is used during acute relapses of the disorder. Azathioprine is an immunosuppressant that's sometimes used to control myasthenia gravis symptoms.

Bell palsy is a disorder of which cranial nerve?

Facial (VII) Bell palsy is characterized by facial dysfunction, weakness, and paralysis. Trigeminal neuralgia, a disorder of the trigeminal nerve, causes facial pain. Ménière syndrome is a disorder of the vestibulocochlear nerve. Guillain-Barré syndrome is a disorder of the vagus nerve.

The nurse is caring for a client with Guillain-Barré syndrome. Which assessment finding would indicate the need for oral suctioning?

Increased pulse rate, adventitious breath sounds An increased pulse rate above baseline with adventitious breath sounds indicate compromised respirations and signal a need for airway clearance. A decrease in pulse rate is not indicative of airway obstruction. An increase of pulse rate with slight elevation of respirations (16 breaths/minute) is not significant for suctioning unless findings suggest otherwise.

A client has been brought to the ED with altered LOC, high fever, and a purpura rash on the lower extremities. The family states the client was reporting neck stiffness earlier in the day. What action should the nurse do first?

Initiate isolation precautions. The signs and symptoms are consistent with bacterial meningitis. The nurse should protect self, other health care workers, and other clients against the spread of the bacteria. Clients should receive the prescribed antibiotics within 30 minutes of arrival, but the nurse can administer the antibiotics after applying the isolation precautions. The nurse can use a cooling blanket to help with the elevated temperature, but this should be done after applying isolation precautions. Prophylaxis antibiotic therapy should be given to people who were in close contact with the patient, but this is not the highest priority nursing intervention.

An older adult experienced a cerebrovascular disease 6 weeks ago and is currently receiving inpatient rehabilitation. The nurse is coaching the client to contract and relax her muscles while keeping her extremity in a fixed position. Which type of exercise is the client performing?

Isometric Isometric exercises are those in which there is alternating contraction and relaxation of a muscle while keeping the part in a fixed position. This exercise is performed by the client. Passive exercises are carried out by the therapist or the nurse without assistance from the client. Resistive exercises are carried out by the client working against resistance produced by either manual or mechanical means. Abduction is movement of a part away from the midline of the body.

Which is a chronic, degenerative, progressive disease of the central nervous system characterized by the occurrence of demyelination in the brain and spinal cord?

Multiple sclerosis The cause of MS is not known, and the disease affects twice as many women as men. Parkinson disease is associated with decreased levels of dopamine caused by destruction of pigmented neuronal cells in the substantia nigra in the basal ganglia of the brain. Huntington disease is a chronic, progressive, hereditary disease of the nervous system that results in progressive involuntary dancelike movements and dementia. Creutzfeldt-Jakob disease is a rare, transmissible, progressive fatal disease of the CNS characterized by spongiform degeneration of the gray matter of the brain.

The most common cause of cholinergic crisis includes which of the following?

Overmedication A cholinergic crisis, which is essentially a problem of overmedication, results in severe generalized muscle weakness, respiratory impairment, and excessive pulmonary secretion that may result in respiratory failure. Myasthenic crisis is a sudden, temporary exacerbation of MG symptoms. A common precipitating event for myasthenic crisis is infection. It can result from undermedication.

A rehabilitation nurse is preparing a presentation for clients and caregivers about issues that clients with disabilities may face. Which of the following would be most appropriate for the nurse to include in the presentation?

Priority setting is helpful in dealing with the impact of the disability. For clients with disabilities, the nurse would emphasize the use of coping strategies and teach the patient how to cope with the disability through priority setting. A loss of sexual functioning does not necessarily correspond to a loss of sexual feeling. Rather, the physical and emotional aspects of sexuality, despite the physical loss of function, continue to be important for people with disabilities. The fatigue associated with disabilities results from numerous factors, such as the physical and emotional demands, as well as the ineffective coping, unresolved grief, disordered sleep patterns, and depression. Although the most obvious care tasks after discharge involve physical care, other elements of the caregiving role include psychosocial support and a commitment to this supportive role.

A nurse is preparing an in-service presentation that focuses on promoting pressure ulcer healing. The nurse is planning to include information about appropriate nutrition. Which of the following would the nurse include as important for overall tissue repair?

Protein Protein is the nutrient important for overall tissue repair. Vitamin C promotes collagen synthesis and supports the integrity of the capillary wall. Water is important to maintain homeostasis. Zinc sulfate acts as a cofactor for collagen formation.

Which of the following is the first-line therapy for myasthenia gravis (MG)?

Pyridostigmine bromide (Mestinon) Mestinon, an anticholinesterase medication, is the first-line therapy in MG. It provides symptomatic relief by inhibiting the breakdown of acetylcholine and increasing the relative concentration of available acetylcholine at the neuromuscular junction. If Mestinon does not improve muscle strength and control fatigue, the next agents used are immunosuppressant agents. Imuran is an immunosuppressive agent that inhibits T lymphocytes and reduces acetylcholine receptor antibody levels. Baclofen is used in the treatment of spasticity in MG.

A client with herpes simplex virus (HSV) encephalitis is receiving acyclovir. To ensure early intervention, the nurse monitors laboratory values and urine output for which type of adverse reactions?

Renal Monitoring of blood chemistry test results and urinary output will alert the nurse to the presence of renal complications related to acyclovir therapy. Complications with the integumentary system will can be observed by the nurse; it is not necessary to review laboratory results or urine output for integumentary reactions. Urine output is not monitored for musculoskeletal or hepatic adverse reactions.

The nurse is assessing a patient at risk for the development of a pressure ulcer. What laboratory test will assist the nurse in determining this risk?

Serum albumin Serum albumin and prealbumin levels are sensitive indicators of protein deficiency. Serum albumin levels of less than 3 g per dL are associated with hypoalbuminemic tissue edema and increased risk of pressure ulcers. Serum glucose is used to assess for diabetes. Prothrombin time is used to assess clotting time and monitor therapeutic levels of anticoagulation medications. Sedimentation rate is used to detect inflammation in the body.

A nurse is performing an admission assessment on a client entering a long-term care facility. She notices a broken area of skin that extends into the dermis on the client's coccyx. How should the nurse document this wound?

Stage II pressure ulcer A stage II pressure ulcer is a break in the skin that extends into the epidermis or the dermis. A stage I pressure ulcer is area of nonblanchable redness that may become cyanotic. A stage III pressure ulcer extends into the subcutaneous tissue. A stage IV pressure ulcer extends into the muscle or bone; most of the true tissue damage isn't easily seen.

The nurse is providing care for a client who has limited mobility after a stroke. In order to assess the client for contractures, the nurse should assess the client's:

range of motion. Each joint of the body has a normal range of motion. To assess a client for contractures, the nurse should assess whether the client can complete the full range of motion. Assessing DTRs, muscle size, or joint pain does not reveal the presence or absence of contractures.

A patient learning to ambulate with crutches advances both crutches and then lifts both feet, moving them forward and landing them in front of the crutches. The patient then repeats this motion. The nurse identifies this as which type of crutch gait?

Swing-through The patient is demonstrating the swing-through gait, in which both crutches are advanced and then both feet are swung forward, landing in front of the crutches. The 4-point gait involves advancing the right crutch, then the left foot, then the left crutch, and then the right foot. The 3-point gait involves advancing the left foot and both crutches, then advancing the right foot, then advancing the left foot and both crutches, and finally advancing the right foot. The swing-to gait involves advancing both crutches and then lifting both feet, swinging them forward and landing them next to the crutches.

Which of the following tests confirms the diagnosis of myasthenia gravis (MG)?

Tensilon test Edrophonium chloride (Tensilon) is an acetylcholinesterase inhibitor that stops the breakdown of acetylcholine. The drug is used because it has a rapid onset of 30 seconds and a short duration of 5 minutes. Immediate improvement in muscle strength after administration of this agent represents a positive test and usually confirms the diagnosis. The presence of acetylcholine receptor antibodies is identified in serum. Repetitive nerve stimulation demonstrates a decrease in successive action potentials. The thymus gland may be enlarged in MG, and a T scan of the mediastinum is performed to detect thymoma or hyperplasia of the thymus.

The nurse is evaluating the progression of a client in the home setting. Which activity of the hemiplegic client best indicates that the client is assuming independence?

The client grasps the affected arm at the wrist and raises it. The best evidence that the client is assuming independence is providing range of motions exercises to the affected arm by grasping the arm at the wrist and raising it. The other options require assistance.

The nurse is caring for a 35-year-old man whose severe workplace injuries necessitate bilateral below-the-knee amputations. How should the nurse anticipate that the client will respond to this news?

The client will experience grief in an individualized manner. Loss of limb is a profoundly emotional experience, which the client will experience in a subjective manner, and largely unpredictable, manner. Psychotherapy may or may not be necessary. It is not possible to accurately predict the sequence or timing of the client's grief. The client may or may not benefit from psychotherapy.

The nurse is assisting with administering a Tensilon test to a patient with ptosis. If the test is positive for myasthenia gravis, what outcome does the nurse know will occur?

Thirty seconds after administration, the facial weakness and ptosis will be relieved for approximately 5 minutes. Thirty seconds after injection, facial muscle weakness and ptosis should resolve for about 5 minutes (Hickey, 2009). Immediate improvement in muscle strength after administration of this agent represents a positive test and usually confirms the diagnosis.

A 45-year-old client is admitted to the facility with excruciating paroxysmal facial pain. He reports that the episodes occur most often after feeling cold drafts and drinking cold beverages. Based on these findings, the nurse determines that the client is most likely suffering from which neurologic disorder?

Trigeminal neuralgia Trigeminal neuralgia, a painful disorder of one or more branches of cranial nerve V (trigeminal), produces paroxysmal attacks of excruciating facial pain. Attacks are precipitated by stimulation of a trigger zone on the face. Triggering events may include light touch to a hypersensitive area, a draft of air, exposure to heat or cold, eating, smiling, talking, or drinking hot or cold beverages. It occurs most commonly in people older than age 40. Bell's palsy is a disease of cranial nerve VII that produces unilateral or bilateral facial weakness or paralysis. Migraine headaches are throbbing vascular headaches that usually begin to occur in childhood or adolescence. Headache pain may emanate from the pain-sensitive structures of the skin, scalp, muscles, arteries, and veins; cranial nerves V, VII, IX, and X; or cervical nerves 1, 2, and 3. Occasionally, jaw pain may indicate angina pectoris.

When developing a plan of care for a patient with impaired physical mobility who must remain on complete bedrest, which of the following would the nurse most likely include to prevent external rotation of the hip?

Trochanter roll A trochanter roll extending from the crest of the ilium to the mid-thigh prevents external rotation of the hip. Range-of-motion exercises are used to maintain muscle strength and joint mobility. Protective boots are used to prevent foot drop. Using a pillow between the legs would help support the body in the correct alignment.

A client is preparing for discharge from the emergency department after sustaining an ankle sprain. The client is instructed to avoid weight bearing on the affected leg and is given crutches. After instruction, the client demonstrates proper crutch use in the hallway. What additional information is most important to know before discharging the client?

Whether the client needs to navigate stairs routinely at home Knowing whether the client must routinely navigate steps at home is most important. If the client must navigate steps, special crutch-walking techniques must be taught to safely navigate the stairs. Although pets, parking on the street, and driving a car with a stick shift can pose problems for the client, these factors aren't important to know before discharging the client with crutches.

A patient has been diagnosed with meningococcal meningitis at a community living home. When should prophylactic therapy begin for those who have had close contact with the patient?

Within 24 hours after exposure People in close contact with patients with meningococcal meningitis should be treated with antimicrobial chemoprophylaxis using rifampin (Rifadin), ciprofloxacin hydrochloride (Cipro), or ceftriaxone sodium (Rocephin). Therapy should be started within 24 hours after exposure because a delay in the initiation of therapy limits the effectiveness of the prophylaxis.

A nurse is teaching a client with a long leg cast how to use crutches properly while descending a staircase. The nurse should tell the client to transfer body weight to the unaffected leg, and then:

advance both crutches. The nurse should instruct the client to advance both crutches to the step below, then transfer his body weight to the crutches as he brings the affected leg to the step. The client should then bring the unaffected leg down to the step.

A neurologic deficit is best defined as a deficit of the:

central and peripheral nervous systems with decreased, impaired, or absent functioning. A client with a neurologic deficit may have decreased, impaired, or absent functioning of the central and peripheral systems.

The primary arthropod vector in North America that transmits encephalitis is the

mosquito Arthropod-borne viruses, or arboviruses, are maintained in nature through biologic transmission between susceptible vertebrate hosts by blood feeding arthropods (mosquitoes, psychodidae, ceratopogonids, and ticks). Arthropod vectors transmit several types of viruses that cause encephalitis. The primary vector in North America is the mosquito.