Common neurologic disorders

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

Common neurologic disorders: Cerebral aneurysm

Cerebral aneurysm, a localized dilation of a cerebral artery, results from a weakness in the arterial wall. (See Common sites of cerebral aneurysm.) The incidence is slightly higher in women than in men, especially those in their late 40s to mid-50s, but cerebral aneurysm may occur at any age.

Prognosis is uncertain because cerebral aneurysms can rupture and cause subarachnoid hemorrhage; one-half of all patients suffering subarachnoid hemorrhages die immediately. However, with new and better treatment, the prognosis is improving.

What causes it

Cerebral aneurysm results from congenital vascular disease, infection, or atherosclerosis.

Pathophysiology

Blood flow exerts pressure against a congenitally weak area of arterial wall, causing it to stretch and thin, somewhat like an overblown balloon. At this point, the risk of rupture is high. A rupture is followed by a subarachnoid hemorrhage, in which blood spills into the space normally occupied by CSF. In some cases, blood also spills into brain tissue, where a clot can damage brain tissue or cause a life-threatening increase in ICP.

 

Common neurologic disorders

 

What to look for

Most patients are asymptomatic until the time of bleeding. Premonitory symptoms resulting from oozing of blood into the subarachnoid space include:

  • headache, intermittent nausea
  • nuchal rigidity
  • stiff back and legs

Rupture usually occurs abruptly and may cause:

  • sudden severe headache
  • nausea and projectile vomiting
  • altered LOC, including deep coma
  • meningeal irritation, resulting in nuchal rigidity, back and leg pain, fever, restlessness, irritability, seizures, photophobia, and blurred vision
  • hemiparesis, hemisensory defects, dysphagia, and visual defects
  • diplopia, ptosis, dilated pupils, and an inability to rotate the eye

What tests tell you

  • Angiography can confirm an unruptured cerebral aneurysm.

Unfortunately, diagnosis usually follows the rupture.

  • A CT scan may help detect subarachnoid hemorrhage.
  • MRI may detect vasospasm.

How it’s treated

To reduce the risk of rebleeding, the surgeon may attempt to repair the aneurysm. Usually, surgical repair (by clipping, ligating, wrapping the aneurysm neck with muscle, or using electrothrombosis) takes place within several days after the initial bleed.

Common neurologic disorders: More conservative

The patient may receive conservative treatment if surgical correction poses too great a risk (common with elderly patients and those with heart, lung, or other serious diseases), the aneurysm is in a particularly dangerous location, or vasospasm necessitates a delay in surgery.

Commonly, treatment for the patient who isn’t a good candidate for surgery includes bed rest in a quiet, darkened room for as long as 4 to 6 weeks. The patient must avoid stimulants (including caffeine) and aspirin. He may receive codeine or another analgesic, hydralazine or another antihypertensive (if he’s hypertensive), cortico steroids to reduce edema, and phenobarbital or another sedative. Nimodipine may be prescribed to limit possible neurologic deficits. If the patient is hypotensive, he may receive dopamine to ensure adequate brain perfusion.

An accurate neurologic assessment, good patient care, patient and family teaching, and psychological support can speed recovery and reduce complications. The medical-surgical nurse assumes care for the patient recovering from an aneurysm repair when he’s transferred from the ICU.

What to do

  • Assess neurologic status to screen for changes in the patient’s condition.
  • Administer medications, as ordered.
  • Maintain adequate nutrition.
  • Promote activity based on the patient’s ability.
  • Provide support to the patient and his family, especially if neurologic deficits have occurred.
  • Refer the patient to appropriate health care team members, such as a social services representative and home care organization.
  • Check for a patent airway, normal breath sounds, consistent LOC with no additional neurologic deficits, and adequate hydration and nutrition. (See Cerebral aneurysm teaching tips.)

Common neurologic disorders: Cerebral aneurysm teaching tips

  • The amount of teaching you’ll do depends on the extent of the neurologic deficit.
  • If the patient can’t speak, set up a simple means of communication; try using cards or a slate.
  • Tell the patient’s family to talk to him in a normal tone, even if he doesn’t seem to respond.
  • Provide the patient and his family with information about local support groups and other applicable services.

Common neurologic disorders: Guillain-Barré syndrome

An acute, rapidly progressive, and potentially fatal form of polyneuritis, Guillain-Barré syndrome causes muscle weakness and mild distal sensory loss. About 95% of patients experience spontaneous and complete recovery, although mild motor or reflex deficits in the feet and legs may persist.

What causes it

The precise cause of this syndrome is unknown, but it may be a cell-mediated immunologic attack on peripheral nerves in response to a virus. Precipitating factors may include:

  • mild febrile or viral illness
  • surgery
  • rabies or swine influenza vaccination
  • Hodgkin’s disease or some other cancer
  • systemic lupus erythematosus.

Pathophysiology

The major pathologic manifestation of Guillain-Barré syndrome is segmental demyelination of the peripheral nerves, which prevents normal transmission of electrical impulses. Because this syndrome causes inflammation and degenerative changes in the posterior (sensory) and anterior (motor) nerve roots, signs of sensory and motor loss occur simultaneously. Additionally, autonomic nerve transmission may be impaired. (See Phases of Guillain-Barré syndrome.)

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What to look for

Symmetrical muscle weakness usually appears in the legs first (ascending type) and then extends to the arms and facial nerves within 24 to 72 hours. Other signs and symptoms may include:

  • facial diplegia, possibly with ophthalmoplegia (ocular paralysis)
  • dysphagia, dysarthria
  • hypotonia, areflexia.

What tests tell you

  • Protein levels in CSF begin to rise several days after onset of signs and symptoms and peak in 4 to 6 weeks. White blood cell count in the CSF remains normal but, in severe disease, CSF pressure may rise above normal.
  • Complete blood count (CBC) shows leukocytosis and immature forms early in the illness, but blood studies soon return to normal.
  • Electromyography may show repeated firing of the same motor unit instead of widespread sectional stimulation. Nerve conduction velocities are slowed soon after paralysis develops.

How it’s treated

At the onset of symptoms, the patient should be hospitalized. Monitor respiratory function several times daily because the ascending pathology can lead to respiratory failure. Mechanical ventilation may be necessary. The other key treatment is plasmapheresis, which temporarily reduces circulating antibodies. Patients need less ventilator support if plasmapheresis begins within 2 weeks of onset. High-dose immune globulins and steroids are also used.

What to do

  • Watch for ascending motor loss. Commonly, sensation isn’t lost; in fact, the patient may be hypersensitive to pain and touch.
  • Monitor the patient’s vital signs and LOC.

Phases of Guillain-Barré syndrome

The clinical course of Guillain-Barré syndrome has three phases:

  1. acute phase, which begins when the first definitive symptom develops and ends 1 to 3 weeks later, when no further deterioration is noted.
  2. plateau phase, which lasts for several days to 2 weeks.
  3. recovery phase, which is believed to coincide with remyelination and axonal process regrowth and can last from 4 months to 3 years.

Common neurologic disorders: Take a deep breath

  • Assess respiratory function. Watch for signs of increasing partial pressure of arterial carbon dioxide (PaCO2), such as confusion and tachypnea. Auscultate breath sounds, turn and position the patient, and encourage coughing and deep breathing. If respiratory failure becomes imminent, establish an emergency airway and assist with endotracheal intubation.
  • Provide meticulous skin care to prevent skin breakdown.

Common neurologic disorders: Tanks, I needed that

  • Perform passive ROM exercises within the patient’s pain limits, perhaps using a Hubbard tank to prevent contractures. When the patient’s condition stabilizes, change to gentle stretching and active assistance exercises.
  • Evaluate the patient’s gag reflex. If he has no gag reflex, administer NG feedings, as ordered. If it’s present, position the patient to prevent aspiration.
  • As the patient regains strength and can tolerate a vertical position, be alert for hypotension; prevent it with slow position changes.
  • Inspect the patient’s legs regularly for signs of thrombophlebitis, a common complication of Guillain-Barré syndrome. To prevent thrombophlebitis, apply antiembolism stockings and a sequential compression device and give prophylactic anticoagulants, as ordered.
  • Provide eye and mouth care every 4 hours if the patient has facial paralysis.
  • Watch for urine retention. Measure and record intake and output every 8 hours, and offer the bedpan every 3 to 4 hours. Encourage adequate fluid intake (2 qt [2 L]/day), unless contraindicated. If urine retention develops, the patient may need to use manual pressure over the bladder (Credé’s maneuver) to urinate. Use intermittent catheterization, if necessary.

Common neurologic disorders: Bulking up

  • To prevent or relieve constipation, offer prune juice and a high-bulk diet. If necessary, give daily or alternate-day suppositories (docusate sodium [Colace] or bisacodyl [Dulcolax]), or enemas, as ordered.
  • Refer the patient for physical therapy, as needed.
  • Evaluate the patient for adequate respiratory function with a patent airway and clear lungs, adequate nutritional status, and optimal activity level.
  • Note whether the patient has expressed his feelings about his illness to members of the staff, his friends, or his family. (See Guillain-Barré syndrome teaching tips.)

Common neurologic disorders: Guillain-Barré syndrome teaching tips

  • Before discharge, prepare a home care plan and review it thoroughly with the patient and his family.
  • Reinforce the physical and occupational therapist’s teaching about how to transfer from bed to wheelchair and from wheelchair to toilet or tub as well as how to walk short distances with a walker or a cane.
  • Teach the family how to help the patient eat, compensate for facial weakness, and prevent skin breakdown.
  • Stress the need for a regular bowel and bladder routine. Explain Credé’s maneuver, if complete urinary emptying is a problem.
  • Provide the patient and his family with appropriate referrals to support organizations and public service agencies in the area.
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