NCLEX: Neurologic disorders

Neurologic disorders: Common neurologic disorders

Focus topic: Neurologic disorders

Below are several common neurologic disorders, along with their causes, pathophysiology, signs and symptoms, diagnostic test findings, treatments, and nursing interventions.

Neurologic disorders: Alzheimer’s disease

Focus topic: Neurologic disorders

Alzheimer’s disease is a progressive neurologic disorder that affects the brain and results in cognitive impairments, such as impaired thinking, memory loss, and bizarre behavior. Alzheimer’s disease is the most common form of dementia and the fourth leading cause of death in adults.

What causes it
The cause of Alzheimer’s disease isn’t known; however, several factors appear to have some association with the disease. These include:

  • deficiencies in the neurotransmitters acetylcholine, somatostatin, substance P, and norepinephrine
  • repeated head trauma
  • abnormalities on chromosomes 14 or 21
  • deposits of beta amyloid protein.

Pathophysiology
The brain tissue of patients with Alzheimer’s disease has three distinguishing features:

  • neurofibrillatory tangles (fibrous proteins)
  • amyloid plaques (composed of degenerating axons and dendrites)
  • granulovacuolar degeneration.
    Autopsy commonly reveals an atrophic brain that can weigh 1,000 g or less. Normal brain weight is 1,380 g.

What to look for
The onset of Alzheimer’s disease is insidious. Initial changes are almost imperceptible, but gradually progress to serious problems. Initial signs and symptoms include:

  • forgetfulness and short-term memory loss
  • difficulty learning and remembering new information

Neurologic disorders

  • deterioration in personal hygiene and appearance
  • inability to concentrate.

Later signs and symptoms include:

  • difficulty with abstract thinking and activities that require judgment
  • progressive difficulty communicating
  • severe deterioration in memory, language, and motor function
  • repetitive actions or perseveration (a classic sign)
  • nocturnal wakening, disorientation, and personality changes, such as restlessness and irritability.

What tests tell you

  • Psychometric testing and neurologic examination can help establish the diagnosis.
  • A PET scan measures the metabolic activity of the cerebral cortex and may help confirm an early diagnosis.
  • EEG, CT scan, and MRI may help diagnose later stages of Alzheimer’s disease.
  • Testing for soluble amyloid beta protein precursor helps assess the extracellular deposits of amyloid beta-peptide, which is a major neuropathic sign of Alzheimer’s disease.
  • Additional tests may help rule out other causes of dementia, such as vitamin B12 deficiency and hypothyroidism.

How it’s treated
Although there’s no known cure for Alzheimer’s disease, donepezil, tacrine, and rivastigmine have proven partially effective in improving mental performance. Drug therapy is also used to treat behavioral symptoms, such as aggression, paranoia, depression, and delusions. These drugs include:

  • antipsychotics, such as haloperidol (Haldol), olanzapine ( Zyprexa), quetiapine (Seroquel), and risperidone (Risperdal)
  • anxiolytics, such as alprazolam (Xanax), buspirone (BuSpar), diazepam (Valium), and lorazepam (Ativan)
  • antidepressants, such as amitriptyline, bupropion (Wellbutrin), fluoxetine (Prozac), and paroxetine (Paxil).

What to do

  • Establish an effective communication system with the patient and his family to help them adjust to his altered cognitive abilities.

Neurologic disorders: Returning to a safe haven

Focus topic: Neurologic disorders

  • Protect the patient from injury by providing a safe, structured, and supervised environment.
  • Encourage the patient to exercise, as ordered, to help maintain mobility.
  • Refer family members to appropriate social service agencies that can help the family assess its needs.
  • Evaluate the patient. He should be free from injury; have an established, adequate sleep pattern; and have adequate nutrition.
  • Assess the patient’s family to determine if they have sufficient support systems to help them cope with this crisis.
  • Encourage the patient and his family to express their feelings of loss.

Neurologic disorders: Amyotrophic lateral sclerosis

Focus topic: Neurologic disorders

ALS causes progressive physical degeneration while leaving the patient’s mental status intact. Thus, the patient is keenly aware of each new physical change. The most common motor neuron disease of muscular atrophy, ALS results in degeneration of upper motor neurons in the medulla oblongata and lower motor neurons in the spinal cord.

Onset typically occurs between ages 40 and 70, and most patients die within 3 to 10 years, usually due to aspiration pneumonia or respiratory failure.

Neurologic disorders

 

What causes it

The cause of ALS isn’t known; however, factors associated with ALS include:

  • autosomal dominant inheritance
  • a slow-acting virus
  • a nutritional deficiency in motor neurons related to a disturbance in enzyme metabolism
  • metabolic interference in nucleic acid production by the nerve fibers
  • an autoimmune disorder.
    Precipitating factors for acute deterioration include trauma, viral infections, and physical exhaustion.

Pathophysiology

In ALS, motor neurons located in the anterior horns of the spinal column and motor nuclei located in the lower brain stem die. As they die, the muscles they served begin to atrophy. The loss of motor neurons may occur in the upper and lower motor neuron systems. Signs and symptoms vary according to the motor neurons affected because specific neurons activate specific muscle fibers.

What to look for

The patient with ALS develops fasciculations (twitching, involuntary muscle contractions) accompanied by atrophy and weakness, especially in the muscles of the forearms and hands. Other signs and symptoms include:

  • impaired speech
  • difficulty chewing and swallowing
  • difficulty breathing
  • depression
  • choking
  • excessive drooling

What tests tell you

  • Electromyography and muscle biopsy help determine if the disease is affecting the nerves rather than the muscles.
  • In one-third of all patients with ALS, cerebrospinal fluid (CSF) examination reveals an increased protein level.

How it’s treated

No effective treatment exists for ALS. Management focuses on controlling symptoms and providing the patient and his family with the emotional, psychological, and physical support they need. Care begins with a complete neurologic assessment, which functions as a baseline for future evaluations. Collectively, these assessments will reveal the progression of ALS over time.

What to do

  • Implement a rehabilitation program that maintains as much independence for the patient for as long as possible.
  • Help the patient obtain equipment that will help him move about, such as a walker or a wheelchair. Arrange for a visiting nurse to oversee home care and provide ongoing support, and to teach the family about the illness.
  • Depending on the patient’s muscular ability, help with bathing, personal hygiene, and transfers from wheelchair to bed, as needed. Encourage a regular bowel and bladder routine.
  • Provide meticulous skin care if the patient is bedridden, to prevent skin breakdown. Also, turn him often, keep his skin clean and dry, and use pressure-relieving devices to preserve skin integrity. If the patient has trouble swallowing, give him soft, solid foods and position him upright during meals. He’ll need gastrostomy and nasogastric (NG) tube feedings when he’s no longer able to swallow.
  • Provide the patient and family with information on support groups.

Neurologic disorders: Making informed decisions

Focus topic: Neurologic disorders

  • Provide the patient and his family with emotional support and the information they need to make informed decisions regarding end-of-life care and help them prepare for the eventual death of the patient. Encourage all concerned to start the grieving process. The patient with ALS may benefit from a hospice program.
  • Evaluate the patient. Intervene as needed to maintain adequate respiratory function with a patent airway, clear lungs, and acceptable results from pulmonary function studies. Help maintain a system of communication and as much physical mobility as possible for as long as possible. Note whether the patient expresses feelings of loss. (See ALS teaching tips.)

 

Neurologic disorders

 

Neurologic disorders: Arteriovenous malformation

Focus topic: Neurologic disorders

In AVM, a tangled array of dilated vessels forms an abnormal network of communication between the arterial and venous systems. AVMs are usually located in the cerebral hemispheres. Spontaneous bleeding from these lesions into the subarachnoid space or brain tissue causes the patient’s signs and symptoms.

AVMs range in size from a few millimeters to large malformations extending from the cerebral cortex to the ventricles. Most are present at birth; however, symptoms rarely occur before ages 10 to 30. AVMs are more common in men than in women.

What causes it

Most AVMs are caused by congenital defects in capillary development. Traumatic injury is another possible cause of AVM.

Pathophysiology

AVMs lack the structural characteristics typical of normal blood vessels. The vessels of an AVM are very thin; when more than one artery feeds into the AVM, it appears dilated and tortuous. Because vessels are thin, there’s a risk that an aneurysm will develop. If the AVM is large enough, shunting can deprive surrounding tissue of adequate blood flow. In addition, the thin-walled vessels may ooze small amounts of blood or they may rupture, causing hemorrhage into the brain or subarachnoid space.

What to look for

  • Seizures that are initially focal but become generalized
  • Headache that doesn’t respond to treatment

Neurologic disorders: Mind games

Focus topic: Neurologic disorders

  • Transient episodes of syncope, dizziness, motor weakness, or sensory deficits
  • Tingling, aphasia, dysarthria, visual deficits (usually hemianopsia)
  • Mental confusion
  • Intellectual impairment

What tests tell you

  • Cerebral angiography provides the most definitive diagnostic information by localizing the AVM and enabling visualization of large feeding arteries and large drainage veins.
  • A CT scan can help differentiate an AVM from a clot or tumor, especially when a contrast medium is used.
  • EEG may help localize the AVM.
  • Brain scan immediately after isotope injection will reveal an uptake in the AVM.
  • MRI-magnetic resonance angiography (especially with gadolinium) may provide information that supports a diagnosis of AVM.

How it’s treated

The choice of treatment depends on the size and location of the AVM, the feeder vessels supplying it, and the age and general health of the patient. Possible methods include embolization, proton-beam radiation, Nd:YAG laser surgery, surgical excision, and a combination of embolization and surgery.

What to do

  • Prevent bleeding if hemorrhage hasn’t occurred.
  • Control hypertension and seizure activity, and reduce activities and eliminate stressors that raise the patient’s systemic blood pressure.
  • Maintain a quiet, therapeutic environment.
  • Monitor and control associated hypertension with drug therapy, as ordered.
  • Establish a baseline and then conduct ongoing neuro checks.
  • Monitor the patient’s vital signs frequently.
  • Assess and monitor characteristics of headache, seizure activity, or bruit, as needed.
  • Provide emotional support.
  • Evaluate the patient’s LOC, body temperature, heart rate, respiratory rate, and blood pressure.
  • Assess whether he continues to experience pain or seizures.
  • Provide appropriate pain management.
  • Note whether the patient has expressed feelings of loss to members of the staff, his friends, or his family. Similarly, note whether his family or friends have expressed their understanding of the disease process, treatment options, and outcome. (See AVM teaching tips.)

 

Neurologic disorders

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Neurologic disorders: Bell’s palsy

Focus topic: Neurologic disorders

Bell’s palsy blocks conduction of impulses along the facial nerve (CN VII), which is the nerve responsible for motor innervation of the facial muscles. This block results from an inflammatory reaction around the nerve (usually at the internal auditory meatus).

Bell’s palsy affects all age-groups, but occurs most commonly in patients under age 60. Onset is rapid and, in 80% to 90% of all patients, it subsides spontaneously, with complete recovery in 1 to 8 weeks. Recovery can take longer in elderly patients. If patients experience only partial recovery, contractures may develop on the paralyzed side of the face. Bell’s palsy may recur on the same or opposite side of the face.

What causes it

Bell’s palsy can be caused by:

  • infection
  • hemorrhage
  • tumor
  • meningitis
  • local traumatic injury.

Pathophysiology

Inflammation around CN VII where it leaves bony tissue blocks conduction along the nerve. As a consequence, CN VII can’t adequately stimulate the muscle fibers, and unilateral or bilateral facial weakness or paralysis is the result.

What to look for

Patients may experience incomplete eye closure and Bell’s phenomenon (eye rolling upward as eye is closed). Other signs and symptoms of Bell’s palsy include:

  • unilateral facial weakness or paralysis, with aching at the jaw angle
  • drooping mouth, causing drooling on the affected side
  • distorted taste perception over the affected anterior portion of the tongue
  • markedly impaired ability to close the eye on the weak side
  • inability to raise the eyebrow, smile, show the teeth, or puff out the cheek on the affected side.

What tests tell you

Electromyography helps predict recovery by distinguishing temporary conduction defects from a pathologic interruption of nerve fibers.

How it’s treated

Prednisone, an oral corticosteroid, reduces facial nerve edema and improves nerve conduction and blood flow. Specific antiviral agents can also be helpful. After the 14th day of prednisone therapy, electrotherapy may help prevent atrophy of facial muscles.

What to do

  • Apply moist heat to the affected side of the face to reduce pain, taking care not to burn the skin.
  • Massage the patient’s face with a gentle upward motion two to three times daily for 5 to 10 minutes, and teach him how to perform this massage.
  • Apply a facial sling to improve lip alignment.

Neurologic disorders: Residual effects

Focus topic: Neurologic disorders

  • Give the patient frequent and complete mouth care. Remove residual food that collects between the cheeks and gums.
  • Provide support, and reassure the patient that recovery is likely within 1 to 8 weeks.
  • Assess the effectiveness of pain medications.
  • Assess the patient’s nutritional status. Bell’s palsy shouldn’t interfere with the patient’s ability to maintain adequate nutrition.
  • Note whether the patient has expressed feelings of loss or fear to staff, friends, or family. (See Bell’s palsy teaching tips.)

 

Neurologic disorders

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