Chapter 36: Introduction to the Nervous System

The nurse is admitting a client to the unit who is diagnosed with a lower motor neuron lesion. What entry in the client's electronic record is most consistent with this diagnosis?

"Client demonstrates an absence of deep tendon reflexes." Lower motor neuron lesions cause flaccid muscle paralysis, muscle atrophy, decreased muscle tone, and loss of voluntary control.

To evaluate a client's cerebellar function, a nurse should ask:

"Do you have any problems with balance?" To evaluate cerebellar function, the nurse should ask the client about problems with balance and coordination. The nurse asks about difficulty speaking or swallowing to assess the functions of cranial nerves IX, X, and XII. Questions about muscle strength help her evaluate the client's motor system.

A patient arrives to have an MRI done in the outpatient department. What information provided by the patient warrants further assessment to prevent complications related to the MRI?

"I am trying to quit smoking and have a patch on." Before the patient enters the room where the MRI is to be performed, all metal objects and credit cards (the magnetic field can erase them) must be removed. This includes medication patches that have a metal backing and metallic lead wires; these can cause burns if not removed (Bremner, 2005).

A nurse and nursing student are caring for a client recovering from a lumbar puncture yesterday. The client reports a headache despite being on bedrest overnight. The physician plans an epidural blood patch this morning. The student asks how this will help the headache. The correct reply from the nurse is which of the following?

"The blood will seal the hole in the dura and prevent further loss of cerebral spinal fluid." Loss of CSF causes the headache. Occasionally, if the headache persists, the epidural blood patch technique may be used. Blood is withdrawn from the antecubital vein and injected into the site of the previous puncture. The rationale is that the blood will act as a plug to seal the hole in the dura and prevent further loss of CSF. The blood is not put into the subarachnoid space. The needle is inserted below the level of the spinal cord, which prevents damage to the cord. It is not a lack of moisture that prevents healing; it is more related to the size of the needle used for the puncture.

A client is scheduled for CT scanning of the head because of a recent onset of neurologic deficits. What should the nurse tell the client in preparation for this test?

"You will need to lie still throughout the procedure." Preparation for CT scanning includes teaching the client about the need to lie quietly throughout the procedure. If the client were having an MRI, metal and noise would be appropriate teaching topics. There is no need to fast prior to a CT scan of the brain.

An elderly client is being discharged home. The client lives alone and has atrophy of his olfactory organs. The nurse tells the client's family that it is essential that the client have what installed in the home?

A smoke detector The sense of smell deteriorates with age. The olfactory organs are responsible for smell. This may present a safety hazard for the client because he or she may not smell smoke or gas leaks. Smoke detectors are universally necessary, but especially for this client.

The nurse is completing a neurological assessment and uses the whisper test to assess which cranial nerve?

Acoustic (VIII) Clinical examination of the acoustic nerve, or vestibulocochlear nerve, can be done by the whisper test. Having the client say "ah" tests the vagus nerve. Observing for symmetry when the client performs facial movements tests the facial nerve. The olfactory nerve is tested by having the client identify specific odors.

The nurse caring for an 80-year-old client knows that the client has a pre-existing history of dulled tactile sensation. The nurse should first consider what possible cause for this client's diminished tactile sensation?

Age-related neurologic changes Tactile sensation is dulled in the elderly person due to a decrease in the number of sensory receptors. While thorough assessment is necessary, it is possible that this change is unrelated to pathophysiologic processes.

Working hard to memorize the functions of the cranial nerves is a typical part of nursing school. Not only is it important to correlate the proper nerve number and name, but including the proper function makes this task quite a challenge! Which cranial nerves are enabling you to read this question?

All options are correct. The oculomotor (III), abducens (VI) and trochlear (IV) nerves all work within the functional realm of the eyes. Don't forget the optic (II) nerve!

A client is ordered to undergo CT of the brain with IV contrast. Before the test, the nurse should complete which action first?

Assess the client for medication allergies. If a contrast agent is used, the client must be assessed before the CT scan for an iodine/shellfish allergy, because the contrast agent used may be iodine based. If the client has no allergies to iodine, then kidney function must also be evaluated, as the contrast material is cleared through the kidneys. A suitable IV line for contrast injection and a period of fasting (usually 4 hours) are required before the study. Clients who receive an IV contrast agent are monitored during and after the procedure for allergic reactions and changes in kidney function.

The nurse is performing a neurologic assessment of a client whose injuries have rendered her unable to follow verbal commands. How should the nurse proceed with assessing the client's level of consciousness (LOC)?

Assess the client's eye opening and response to stimuli. If the client is not alert or able to follow commands, the examiner observes for eye opening; verbal response and motor response to stimuli, if any; and the type of stimuli needed to obtain a response. Vital signs and diagnostic testing are appropriate, but neither will allow the nurse to gauge the client's LOC. Inability to follow commands does not necessarily denote an absolute lack of consciousness.

The nurse is performing an assessment of cranial nerve function and asks the patient to cover one nostril at a time to see if the patient can smell coffee, alcohol, and mint. The patient is unable to smell any of the odors. The nurse is aware that the patient has a dysfunction of which cranial nerve?

CN I Cranial nerve (CN) I is the olfactory nerve, which allows the sense of smell. Testing of CN I is done by having the patient identify familiar odors with eyes closed, testing each nostril separately. An inability to smell an odor is a significant finding, indicating dysfunction of this nerve.

The nurse obtains a Snellen eye chart when assessing cranial nerve function. Which cranial nerve is the nurse testing when using the chart?

CN II The nurse assesses vision and thus the optic nerve (cranial nerve II) by use of a Snellen eye chart.

Which posture exhibited by abnormal flexion of the upper extremities and extension of the lower extremities?

Decorticate Decorticate posturing is an abnormal posture associated with severe brain injury, characterized by abnormal flexion of the upper extremities and extension of the lower extremities. Decerebration is an abnormal body posture associated with a severe brain injury, characterized by extreme extension of the upper and lower extremities. Flaccidity occurs when the client has no motor function, is limp, and lacks motor tone.

The nurse is planning the care of a client with Parkinson disease. The nurse should be aware that treatment will focus on what pathophysiologic phenomenon?

Decreased availability of dopamine Parkinson disease develops from decreased availability of dopamine, not acetylcholine, epinephrine, or serotonin.

Which is a sympathetic effect of the nervous system?

Dilated pupils Dilated pupils are a sympathetic effect of the nervous system, whereas constricted pupils are a parasympathetic effect. Decreased blood pressure is a parasympathetic effect, whereas increased blood pressure is a sympathetic effect. Increased peristalsis is a parasympathetic effect, but decreased peristalsis is a sympathetic effect. Decreased respiratory rate is a parasympathetic effect, and increased respiratory rate is a sympathetic effect.

A trauma client in the ICU has been declared brain dead. What diagnostic test is used in making the determination of brain death?

Electroencephalography (EEG) The EEG can be used in determining brain death. MRI, CT, and EMG are not normally used in determining brain death.

A client has undergone a lumbar puncture as part of a neurological assessment. The client is put under the care of a nurse after the procedure. Which important postprocedure nursing intervention should be performed to ensure the client's maximum comfort?

Encourage the client to drink liberal amounts of fluids The nurse should encourage the client to take liberal fluids and should inspect the injection site for swelling or hematoma. These measures help restore the volume of cerebrospinal fluid extracted. The client is administered antihistamines before a test only if he or she is allergic to contrast dye and contrast dye will be used. The room of the client who has undergone a lumbar puncture should be kept dark and quiet. The client should be encouraged to rest, because sensory stimulation tends to magnify discomfort.

What safety actions does the nurse need to take for a client receiving oxygen therapy who is undergoing magnetic resonance imaging (MRI)?

Ensure that no client care equipment containing metal enters the room where the MRI is located. For client safety the nurse must make sure no client care equipment that contains metal or metal parts (e.g., portable oxygen tanks) enters the room where the MRI is located. The magnetic field generated by the unit is so strong that any metal-containing items will be strongly attracted and can literally be pulled away with such great force that they can fly like projectiles toward the magnet.

Which lobe of the brain is responsible for concentration and abstract thought?

Frontal The major functions of the frontal lobe are concentration, abstract thought, information storage or memory, and motor function. The parietal lobe analyzes sensory information such as pressure, vibration, pain, and temperature. The occipital lobe is the primary visual cortex. The temporal lobe contains the auditory receptive areas located around the temples.

A patient sustained a head injury during a fall and has changes in personality and affect. What part of the brain does the nurse recognize has been affected in this injury?

Frontal lobe The frontal lobe, the largest lobe, located in the front of the brain. The major functions of this lobe are concentration, abstract thought, information storage or memory, and motor function. It contains Broca's area, which is located in the left hemisphere and is critical for motor control of speech. The frontal lobe is also responsible in large part for a person's affect, judgment, personality, and inhibitions (Hickey, 2009).

A nurse is caring for a client diagnosed with Ménière disease. While completing a neurologic examination on the client, the nurse assesses cranial nerve VIII. The nurse would be correct in identifying the function of this nerve as what?

Hearing and equilibrium Cranial nerve VIII (acoustic) is responsible for hearing and equilibrium. Cranial nerve XII (hypoglossal) is responsible for movement of the tongue. Cranial nerve II (optic) is responsible for visual acuity and visual fields. Cranial nerve I (olfactory) functions in sense of smell.

A patient has been diagnosed with a deficiency of the major neurotransmitter acetylcholine. Based on this information, the nurse knows to assess the patient for complications associated with:

Heart rate and rhythm. Acetylcholine is a major transmitter of the parasympathetic nervous system and stimulates the vagal nerve to slow the heart rate.

A gerontologic nurse educator is providing practice guidelines to unlicensed care providers. Because reaction to painful stimuli is sometimes blunted in older adults, what must be used with caution?

Hot or cold packs Reaction to painful stimuli may be decreased with age. Because pain is an important warning signal, caution must be used when hot or cold packs are used. The older client may be burned or suffer frostbite before being aware of any discomfort. Any medication is used with caution in the elderly, but not because of the decreased sense of heat or cold. Whirlpool baths are generally not a routine treatment prescribed for the elderly.

Which of the following areas of the brain are responsible for temperature regulation?

Hypothalamus The hypothalamus also controls and regulates the autonomic nervous system and maintains temperature by promoting vasoconstriction or vasodilation. The thalamus acts primarily as a relay station for all sensation except smell. The medulla and pons are essential for respiratory function.

Which cranial nerve is responsible for muscles that move the eye and lids?

Oculomotor The oculomotor (III) cranial nerve is also responsible for pupillary constriction and lens accommodation. The trigeminal (V) cranial nerve is responsible for facial sensation, corneal reflex, and mastication. The vestibulocochlear (VIII) cranial nerve is responsible for hearing and equilibrium. The facial (VII) nerve is responsible for salivation, tearing, taste, and sensation in the ear.

What term is used to describe the fibrous connective tissue that hugs the brain closely and extends into every fold of the brain's surface?

Pia mater The term "meninges" describes the fibrous connective tissue that covers the brain and spinal cord. The meninges have three layers, the dura mater, arachnoid, and pia mater. The pia mater is the innermost membrane that hugs the brain closely and extends into every fold of the brain's surface. The dura mater, the outermost layer, covers the brain and spinal cord. The arachnoid, the middle membrane, is responsible for the production of cerebrospinal fluid. This is not known as "fascia."

A gerontologic nurse planning the neurologic assessment of an older adult is considering normal, age-related changes that may influence the assessment results. Of what phenomenon should the nurse be aware?

Reduction in cerebral blood flow Reduction in cerebral blood flow (CBF) is a change that occurs in the normal aging process. Deep tendon reflexes can be decreased or, in some cases, absent. Cerebral metabolism decreases as the client advances in age. Reaction to painful stimuli may be decreased with age. Because pain is an important warning signal, caution must be used when hot or cold packs are used.

Which cerebral lobe contains the auditory receptive areas?

Temporal The temporal lobe plays the most dominant role of any area of the cortex in cerebration. The frontal lobe, the largest lobe, controls concentration, abstract thought, information storage or memory, and motor function. The parietal lobe contains the primary sensory cortex, which analyzes sensory information and relays interpretation to the thalamus and other cortical areas. The occipital lobe is responsible for visual interpretation.

The spinal cord is composed of 31 pairs of spinal nerves. How many pairs of thoracic nerves are contained within the spinal column?

Twelve There are twelve pairs of thoracic nerves, five lumbar and sacral nerves, eight cervical, and one coccygeal.

A client had a lumbar puncture performed at the outpatient clinic and the nurse has phoned the client and family that evening. What does this phone call enable the nurse to determine?

Whether the client has had any complications of the test Contacting the client and family after diagnostic testing enables the nurse to determine whether they have any questions about the procedure or whether the client had any untoward results. The other listed information should have been elicited from the client and family prior to the test.

A client experienced a stroke that damaged the hypothalamus. The nurse should anticipate that the client will have problems with:

body temperature control. The body's thermostat is located in the hypothalamus; therefore, injury to that area can cause problems with body temperature control. Balance and equilibrium problems are related to cerebellar damage. Visual acuity problems would occur following occipital or optic nerve injury. Thinking and reasoning problems are the result of injury to the cerebrum.

A typical spinal cord functions as a "highway" for sensory and descending motor neurons, providing conduction of impulses to and from the brain. The spinal cord is surrounded and protected by bony vertebrae, and ends between the:

first and second lumbar vertebrae. The spinal cord ends between the first and second lumbar vertebrae, where it divides into smaller sections called the cauda equine.

To assess a client's cranial nerve function, a nurse should assess:

gag reflex. The gag reflex is governed by the glossopharyngeal nerve, cranial nerve IX. The other choices would not be involved in a cranial nerve assessment. Hand grip and arm drifting are part of motor function assessment. Orientation is an assessment parameter related to a mental status examination.

The brain is a complex structure and is divided into three parts: the cerebrum, the cerebellum, and the brain stem. The brain stem consists of the midbrain, pons, and medulla oblongata. Which part of the brain contains regulatory centers for heartbeat, vasomotor activity, and breathing?

medulla oblongata The medulla oblongata contains vital centers concerned with respiration, heartbeat, and vasomotor activity (the control of smooth muscle activity in blood vessel walls).

The nurse is completing the physical assessment of a client suspected of a neurological disorder. The client reports having recently suffered a head trauma. In such a case, the nurse should:

not move or manipulate the client's head while assessing for bleeding or swelling. The nurse evaluates the client's body posture and any abnormal position of the head, neck, trunk, or extremities. The nurse carefully examines the head for bleeding, swelling, or wounds. The nurse does not move or manipulate the client's head during physical assessment, especially if there is a recent history of trauma.

A nurse is completing a neurological assessment and determines that the client has significant visual deficits. Considering the functions of the lobes of the brain, which area will most likely contain the neurologic deficit?

occipital The vision center is located in the occipital lobe. There is little that may interfere with the visual process in the other lobes of the brain.

The nurse has completed evaluating the client's cranial nerves. The nurse documents impairment of the right cervical nerves (CN IX and CN X). Based on these findings, the nurse should instruct the client to

refrain from eating or drinking for now. Significant findings of CN IX (glossopharyngeal) include difficulty swallowing (dysphagia) and impaired taste, and significant findings of CN X (vagus) include weak or absent gag reflex, difficulty swallowing, aspiration, hoarseness, and slurred speech (dysarthria). Based on these findings, the nurse should instruct the client to refrain from eating and drinking and should contact the health care provider. The other instructions are associated with abnormalities of CN II (optic) and CN VIII (acoustic).

Cerebrospinal fluid (CSF) is manufactured in the ventricles and constantly circulates around the brain and spinal cord. The CSF functions as a cushion to protect structures and maintain relatively consistent intracranial pressure. Where does CSF circulate?

subarachnoid space The ventricles manufacture and absorb cerebrospinal fluid (CSF), which constantly circulates in the subarachnoid space of the brain and spinal cord.

The nurse is assessing the client's pupils following a sports injury. Which assessment findings indicate a neurologic concern? Select all that apply.

unequal pupils absence of pupillary response pinpoint pupils Normal assessment findings include that the pupils are equal and reactive to light. Pupils that are unequal, pinpoint in nature, or fail to respond indicate neurologic impairment.