Ch. 10 - Nervous System Flashcards

Question

meninges

Answer 1

Three protective membranes that surround the brain and spinal cord.

Answer 2

Phagocytic glial cell that removes waste products from the central nervous system.

Answer 3

Uppermost portion of the brainstem. motor nerve Carries messages away from the brain and spinal cord to muscles and organs; efferent nerve.

Answer 4

Carries messages away from the brain and spinal cord to muscles and organs; efferent nerve.

Answer 5

Covering of white fatty tissue that surrounds and insulates the axon of a nerve cell. Myelin speeds impulse conduction along axons.

Answer 6

Macroscopic cord-like collection of fibers (axons) that carry electrical impulses.

Answer 7

Nerve cell that is necessary for impulses to be carried throughout the nervous system; parenchyma of the nervous system.

Answer 8

Chemical messenger released at the end of a nerve cell. It stimulates or inhibits another cell, which can be a nerve cell, muscle cell, or gland cell. Examples of neurotransmitters are acetylcholine, norepinephrine, dopamine, and serotonin.

Answer 9

Glial cell that forms the myelin sheath covering axons. Also called oligodendrocyte.

Answer 10

Involuntary autonomic nerves that regulate normal body functions such as heart rate, breathing, and muscles of the gastrointestinal tract.

Answer 11

Essential, distinguishing tissue of any organ or system. The parenchyma of the nervous system includes the neurons and nerves that carry nervous impulses. Parenchymal cells of the liver are hepatocytes, and parenchymal tissue of the kidney includes the nephrons, where urine is formed. Note the pronunciation: pah-REN-kih-mal

Answer 12

Nerves outside the brain and spinal cord: cranial, spinal, and autonomic nerves.

Answer 13

Thin, delicate inner membrane of the meninges.

Answer 14

Large, interlacing network of nerves. Examples are lumbosacral, cervical, and brachial (brachi/o means arm) plexuses. The term originated from the Indo-European plek, meaning to weave together.

Answer 15

Part of the brain anterior to the cerebellum and between the medulla and the rest of the midbrain. It is a bridge connecting various parts of the brain. In Latin, pons means bridge.

Answer 16

Organ that receives and transmits a stimulus to sensory nerves. The skin, ears, eyes, and taste buds are receptors.

Answer 17

Nerve extending from the base of the spine down the thigh, lower leg, and foot. Sciatica is pain or inflammation along the course of the nerve.

Answer 18

Carries messages toward the brain and spinal cord from a receptor; afferent nerve.

Answer 19

Pairs of nerves, arising one on each side of the spinal column. They transmit messages to and from the spinal cord.

Answer 20

Agent of change in the internal or external environment that evokes a response. It may be light, sound, touch, pressure, or pain.

Answer 21

Connective and supporting tissue of an organ. Glial cells make up the stromal tissue of the brain.

Answer 22

Depression or groove in the surface of the cerebral cortex; fissure.

Answer 23

Autonomic nerves that influence bodily functions involuntarily in times of stress.

Answer 24

Space through which a nervous impulse travels between nerve cells or between nerve and muscle or glandular cells. From the Greek synapsis, a point of contact.

Answer 25

Main relay center of the brain. It conducts impulses between the spinal cord and the cerebrum; incoming sensory messages are relayed through the thalamus to appropriate centers in the cerebrum. Latin thalamus means room. The Romans, who named this structure, thought this part of the brain was hollow, like a little room.

Answer 26

Tenth cranial nerve (cranial nerve X). Its branches reach to the larynx, trachea, bronchi, lungs, aorta, esophagus, and stomach. Latin vagus means wandering. Unlike the other cranial nerves, the vagus leaves the head and “wanders” into the abdominal and thoracic cavities.

Answer 27

Canals in the brain that contain cerebrospinal fluid. Ventricles are also found in the heart—they are the two lower chambers of the heart.

Answer 28

cerebellum

Answer 29

cerebrum cerebral cortex = Cortical means pertaining to the cortex or outer area of an organ.

Answer 30

dura mater e.g. subdural hematoma *Remember: Hematomas are not tumors of blood, but are collections of blood.

Answer 31

brain Chronic traumatic encephalopathy (CTE) is a progressive degenerative disease associated with repetitive brain trauma (concussion). anencephaly : A congenital brain malformation; not compatible with life and may be detected with amniocentesis or ultrasonography of the fetus.

Answer 32

glial cells e.g. glioblastoma : This is a highly malignant tumor (-blast means immature). Gliomas are tumors of glial (neuroglial) cells.

Answer 33

membranes, meninges meningioma = Slowly growing, benign tumor myelomeningocele = Neural tube defect caused by failure of the neural tube to close during embryonic development. This abnormality occurs in infants born with spina bifida.

Answer 34

A subdural hematoma results from the tearing of veins between the dura and arachnoid membranes. It often is the result of blunt trauma, such as from blows to the head in boxers or in elderly patients who have fallen out of bed. An epidural hematoma occurs between the skull and the dura as the result of a ruptured meningeal artery, usually after a fracture of the skull. An intracerebral hematoma is caused by bleeding directly into brain tissue, such as can occur in the case of uncontrolled hypertension (high blood pressure).

Answer 35

spinal cord (means bone marrow in other contexts) e.g. poliomyelitis Polio- means gray matter. This viral disease affects the gray matter of the spinal cord, leading to paralysis of muscles that rely on the damaged neurons. Effective vaccines developed in the 20th century have made “polio” relatively uncommon.

Answer 36

nerve root (of spinal nerves) radiculopathy : Sciatica is a radiculopathy affecting the sciatic nerve root in the back. A herniated disk is a common cause leading to pain, weakness, or numbness down the leg. radiculitis : This condition often results in pain and loss of function.

Answer 37

sheath (refers to the meninges) intrathecal injection : Chemicals, such as chemotherapeutic drugs, can be delivered into the subarachnoid space.

Answer 38

vagus nerve (10th cranial nerve) vagal : This cranial nerve has branches to the head and neck, as well as to the chest.

Answer 39

sensitivity to pain hypalgesia : Diminished sensation to pain. (Notice that the o in hypo- is dropped.) Hyperalgesia is increased sensitivity to pain.

Answer 40

Don’t confuse these combining forms. Myel/o means spinal cord or bone marrow, while my/o means muscle. Another pair to watch out for is pyel/o (renal pelvis of the kidney) and py/o (pus).

Answer 41

diseases of peripheral nerves. They can affect motor, sensory, and autonomic functions. Polyneuropathies affect many nerves, while mononeuropathies affect individual nerves.

Answer 42

deep sleep (coma) comatose : A coma is a state of unconsciousness from which the patient cannot be aroused. Semicomatose refers to a stupor (unresponsiveness) from which a patient can be aroused. In an irreversible coma (brain death), there is complete unresponsitivity to stimuli, no spontaneous breathing or movement, and a flat electroencephalogram (EEG) tracing.

Answer 43

feeling, nervous sensation anesthesia : Lack of normal sensation (e.g., absence of sense of touch or pain). Two common types of regional anesthesia are spinal and epidural (caudal) blocks. An anesthesiologist is a physician who administers anesthesia. Anesthetics are agents that reduce or eliminate sensation. hyperesthesia : Abnormally intense sensation to a particular stimulus, such as a light touch with a pin. Diminished sensitivity to pain is called hypesthesia. paresthesia : Par- (from para-) means abnormal. Paresthesias include tingling, burning, and “pins and needles” sensations.

Answer 44

movement hyperkinesis : Amphetamines (CNS stimulants) are used to treat hyperkinesia in children, but the mechanism of their action is not understood. dyskinesia : Condition marked by involuntary, spasmodic movements. Tardive (occurring late) dyskinesia may develop in people who receive certain antipsychotic drugs for extended periods.

Answer 45

seizure narcolepsy : Sudden, uncontrollable compulsion to sleep (narc/o = stupor, sleep). Amphetamines and stimulant drugs are prescribed to prevent attacks.

Answer 46

word, phrase dyslexia : This is a developmental reading disorder occurring when the brain does not properly recognize, process, and interpret language.

Answer 47

weakness hemiparesis = Affects either right or left side (half) of the body. Paresis also is used by itself to mean partial paralysis or weakness of muscles.

Answer 48

speech aphasia = Difficulty with speech. Motor (also called Broca or expressive) aphasia is present when the patient knows what he or she wants to say but cannot say it. The patient with sensory aphasia has difficulty understanding language and may pronounce (articulate) words easily but use them inappropriately.

Answer 49

paralysis (loss or impairment of the ability to move parts of the body) hemiplegia = Affects the right or left half of the body and results from a stroke or other brain injury. The hemiplegia is contralateral to the brain lesion because motor nerve fibers from the right half of the brain cross to the left side of the body (in the medulla oblongata). paraplegia = Originally, the term paraplegia meant a stroke (paralysis) on one side (para-). Now, however, the term means paralysis of both legs and the lower part of the body caused by injury or disease of the spinal cord or cauda equina. quadriplegia = Quadri- means four. All four extremities are affected. Injury is at the cervical level of the spinal cord.

Answer 50

action apraxia = Movements and behavior are not purposeful. A patient with motor apraxia cannot use an object or perform a task. Motor weakness is not the cause.

Answer 51

strength neurasthenia = Nervous exhaustion and fatigue, often following depression.

Answer 52

to cut off, cut short syncopal = Syncope (SIN-ko-pe) means fainting; sudden and temporary loss of consciousness caused by inadequate flow of blood to the brain. The term comes from a Greek word meaning cutting into pieces—thus, a fainting spell meant one’s strength was “cut off.” * HINT: Syncopal means pertaining to fainting and is an adjective. A patient can experience a syncopal episode.

Answer 53

order, coordination ataxia = Condition of decreased coordination. Persistent unsteadiness on the feet can be caused by a disorder involving the cerebellum.

Answer 54

Abnormal accumulation of fluid (CSF) in the brain. If circulation of CSF in the brain or spinal cord is impaired, fluid accumulates under pressure in the ventricles of the brain. To relieve pressure on the brain, a catheter (shunt) can be placed from the ventricle of the brain into the peritoneal space (ventriculoperitoneal shunt) or right atrium of the heart so that the CSF is continuously drained from the brain. Hydrocephalus also can occur in adults as a result of tumors and infections.

Answer 55

Congenital defects in the lumbar spinal column caused by imperfect union of vertebral parts (neural tube defect). In spina bifida occulta, the vertebral defect is covered over with skin and evident only on x-ray or other imaging examination. Spina bifida cystica is a more severe form, with cyst-like protrusions. In meningocele, the meninges protrude to the outside of the body, and in myelomeningocele (or meningomyelocele), both the spinal cord and meninges protrude (Figure 10-14A and B). The etiology of neural tube defects is unknown. Defects originate in the early weeks of pregnancy as the spinal cord and vertebrae develop. Prenatal diagnosis is helped by imaging methods and testing maternal blood samples for alpha-fetoprotein.

Answer 56

Brain disorder marked by gradual and progressive mental deterioration (dementia), personality changes, and impairment of daily functioning. Characteristics of AD include confusion, memory failure, disorientation, restlessness, and speech disturbances. Anxiety, depression, and emotional disturbances can occur as well. The disease sometimes begins in middle life with slight defects in memory and behavior, but can worsen after the age of 70. On autopsy there is frequently atrophy of the cerebral cortex and widening of the cerebral sulci, especially in the frontal and temporal regions (Figure 10-15A and B). Microscopic examination shows senile plaques resulting from degeneration of neurons and neurofibrillary tangles (bundles of fibrils in the cytoplasm of a neuron) in the cerebral cortex. Deposits of amyloid (a protein) occur in neurofibrillary tangles, senile plaques, and blood vessels. The cause of AD remains unknown, although genetic factors may play a role. A mutation on chromosome 14 has been linked to familial cases. There is as yet no effective treatment.

Answer 57

Degenerative disorder of motor neurons in the spinal cord and brainstem. ALS manifests in adulthood. Signs and symptoms are weakness and atrophy of muscles in the hands, forearms, and legs; difficulty in swallowing and talking and dyspnea develop as the throat and respiratory muscles become affected. Etiology (cause) and cure for ALS both are unknown. A famous baseball player, Lou Gehrig, became a victim of this disease in the mid-1900s, so the condition became known as Lou Gehrig disease.

Answer 58

Chronic brain disorder characterized by recurrent seizure activity. Seizures are abnormal, sudden discharges of electrical activity within the brain. Seizures often are symptoms of underlying brain pathologic conditions, such as brain tumors, meningitis, vascular disease, or scar tissue from a head injury. Tonic-clonic seizures (grand mal or ictal events) are characterized by a sudden loss of consciousness, falling down, and then tonic contractions (stiffening of muscles) followed by clonic contractions (twitching and jerking movements of the limbs). These convulsions often are preceded by an aura, which is a peculiar sensation experienced by the affected person before onset of a seizure. Dizziness, numbness, and visual or olfactory (sense of smell) disturbances are examples of an aura. Absence seizures are a form of seizure consisting of momentary clouding of consciousness and loss of awareness of the person’s surroundings. These include petit mal seizures in children. Drug therapy (anticonvulsants) is used for control of epileptic seizures. After seizures, there may be neurologic symptoms such as weakness called postictal events. In temporal lobe epilepsy, seizures begin in the temporal lobe (on each side of the brain near the ears) of the brain. The most common type of seizure is a complex partial seizure. Complex means impaired consciousness and partial indicates not generalized. Commonly these patients have seizures that cause them to pause in whatever they are doing, become confused, and have memory problems. The term epilepsy comes from the Greek epilepsis, meaning a laying hold of. The Greeks thought a victim of a seizure was laid hold of by some mysterious force. The word ictal originates from the Latin ictus, meaning a blow or a stroke.

Answer 59

Hereditary disorder marked by degenerative changes in the cerebrum leading to abrupt involuntary movements and mental deterioration. In this genetic condition, symptoms typically begin in adulthood and include personality changes, along with choreic (meaning dance-like) movements (uncontrollable, irregular jerking movements of the arms and legs and facial grimacing). It is also known as Huntington chorea. The genetic defect in patients with Huntington disease is located on chromosome 4. Patients can be tested for the gene; however, no cure exists, and management is symptomatic.

Answer 60

Destruction of the myelin sheath on neurons in the CNS and its replacement by plaques of sclerotic (hard) tissue. One of the leading causes of neurologic disability in persons 20 to 40 years of age, MS is a chronic disease often marked by long periods of stability (remission) and worsening (relapse). Demyelination (loss of myelin insulation) prevents the conduction of nerve impulses through the axon. See Figure 10-16A. Demyelination causes paresthesias, muscle weakness, unsteady gait (manner of walking), and paralysis. There may be visual (blurred and double vision) and speech disturbances as well. Areas of scarred myelin (plaques) can be seen on MRI scans of the brain (Figure 10-16B). Etiology is unknown but probably involves an autoimmune disease of lymphocytes reacting against myelin. There are now many helpful disease-modifying drugs for treating MS. These drugs affect either the inflammation or the immunological abnormalities in the CNS associated with this illness.

Answer 61

a brain disorder in which at least two or more seizures appear spontaneously and recurrently. Having a single seizure does not mean that the affected person has epilepsy.

Answer 62

Autoimmune neuromuscular disorder characterized by weakness of voluntary muscles. MG is a chronic autoimmune disorder. Antibodies block the ability of acetylcholine (neurotransmitter) to transmit the nervous impulse from nerve to muscle cell. Onset of symptoms usually is gradual. Brainstem signs are prominent and include ptosis of the upper eyelid, double vision (diplopia), and facial weakness. Respiratory paralysis is the main clinical concern. Therapy to reverse symptoms includes anticholinesterase drugs, which inhibit the enzyme that breaks down acetylcholine. Immunosuppressive therapy is used, including medications such as corticosteroids (prednisone) and other immunosuppressive drugs. Thymectomy is also a method of treatment and is beneficial to many patients.

Answer 63

Paralysis (partial or complete loss of motor function). Cerebral palsy is partial paralysis and lack of muscular coordination caused by loss of oxygen (hypoxia) or blood flow to the cerebrum during pregnancy or in the perinatal period. Bell palsy (or Bell’s palsy) (Figure 10-17) is paralysis on one side of the face. The likely cause is a viral infection, and therapy is directed against the virus (antiviral drugs) and nerve swelling (corticosteriods).

Answer 64

Degeneration of neurons in the basal ganglia, occurring in later life and leading to tremors, weakness of muscles, and slowness of movement. Primary symptoms of Parkinson disease are tremors in hands, arms, legs, jaw, and face; rigidity or stiffness of limbs and trunk; bradykinesia (shuffling gait), stooped posture, and masklike facies. This slowly progressive condition is caused by a deficiency of dopamine, a neurotransmitter made by cells in the basal ganglia. Motor disturbances include stooped posture, shuffling gait, and muscle stiffness (rigidity). Other signs are a typical “pill-rolling” tremor of hands and a characteristic masklike lack of facial expression. Therapy with drugs such as levodopa plus carbidopa (Sinemet) to increase dopamine levels in the brain is palliative (relieving symptoms but not curative). Many patients may have clinical features of Parkinson’s (parkinsonism) and yet not have the disease itself. They would not benefit from antiparkinsonian medication. Some patients with Parkinson's may benefit from stimulation by electrodes placed surgically in the brain. Implantation of fetal brain tissue containing dopamineproducing cells is an experimental treatment but has produced uncertain results.

Answer 65

Involuntary spasmodic, twitching movements; uncontrollable vocal sounds; and inappropriate words. These involuntary movements, usually beginning with twitching of the eyelid and muscles of the face accompanied by verbal outbursts, are called tics. Although the cause of Tourette syndrome is not known, it is associated with either an excess of dopamine or a hypersensitivity to dopamine. Psychological problems do not cause Tourette syndrome, but physicians have had some success in treating it with the antipsychotic drug haloperidol (Haldol), antidepressants, and mood stabilizers.

Answer 66

Viral infection affecting peripheral nerves. Blisters and pain spread along peripheral nerves (see Figure 10-19A) and are caused by inflammation due to a herpesvirus (herpes zoster), the same virus that causes chickenpox (varicella). Reactivation of the chickenpox virus (herpes varicella-zoster), which remains in the body after the person had chickenpox, occurs. Painful blisters follow the underlying route of cranial or spinal nerves. Shingrix is a vaccine to prevent shingles. It is recommended for people 50 years of age and older.

Answer 67

Inflammation of the meninges; leptomeningitis. This condition can be caused by bacteria (pyogenic meningitis) or viruses (aseptic or viral meningitis). Signs and symptoms are fever and signs of meningeal irritation, such as headache, photophobia (sensitivity to light), and a stiff neck. Lumbar punctures are performed to examine CSF. Physicians use antibiotics to treat the more serious pyogenic form, and antivirals for the viral form.

Answer 68

Brain disease and dementia occurring with AIDS. Many patients with AIDS develop neurologic dysfunction. In addition to encephalitis and dementia (loss of mental functioning), some patients develop brain tumors and other infections.

Answer 69

Abnormal growth of brain tissue and meninges. Most primary brain tumors arise from glial cells (gliomas) or the meninges (meningiomas). Types of gliomas include astrocytoma (Figure 10-19B), oligodendroglioma, and ependymoma. The most malignant form of astrocytoma is glioblastoma multiforme (-blast means immature) (see Figure 10-19B). Tumors can cause swelling (cerebral edema) and hydrocephalus. If CSF pressure is increased, swelling also may occur near the optic nerve (at the back of the eye). Other symptoms include severe headache and new seizures. Gliomas at times can be removed surgically. Brain tumors are also treated with chemotherapy and radiotherapy. Steroids are used to reduce cerebral edema. Meningiomas usually are benign and surrounded by a capsule, but they may cause compression and distortion of the brain. Tumors in the brain also may be single or multiple metastatic growths. Most arise from the lung, breast, skin (melanoma), kidney, and gastrointestinal tract and spread to the brain.

Answer 70

Type of traumatic brain injury caused by a blow to the head. There is usually no evidence of structural damage to brain tissue, and loss of consciousness may not occur. Rest is very important after a concussion because it allows the brain to heal. Doctors commonly recommend avoiding demanding mental and physical activities until symptoms have fully resolved.

Answer 71

Bruising of brain tissue resulting from direct trauma to the head. A cerebral contusion may be associated with edema and an increase in intracranial pressure. A skull fracture may be present. Subdural and epidural hematomas occur (see Figure 10-12), leading to permanent brain injury with abnormalities such as altered memory or speech as well as development of epilepsy.

Answer 72

Disruption in the normal blood supply to the brain; stroke. This condition, also known as a cerebral infarction, is the result of impaired oxygen supply to the brain. There are three types of strokes: 1. Thrombotic —blood clot (thrombus) in the arteries leading to the brain, resulting in occlusion (blocking) of the vessel. Atherosclerosis leads to this common type of stroke as blood vessels become blocked over time. Before total occlusion occurs, a patient may experience symptoms that point to the gradual occlusion of blood vessels. These short episodes of neurologic dysfunction are known as transient ischemic attacks (TIAs). 2. Embolic —an embolus (a dislodged thrombus) travels to cerebral arteries and occludes a vessel. This type of stroke occurs very suddenly. 3. Hemorrhagic —a cerebral artery breaks and bleeding occurs. This type of stroke can be fatal and results from advancing age, atherosclerosis, or high blood pressure, all of which result in degeneration of cerebral blood vessels. With small hemorrhages, the body reabsorbs the blood and the patient makes good recovery with only slight disability. In a younger patient, cerebral hemorrhage usually is caused by mechanical injury associated with skull fracture or rupture of an arterial aneurysm (weakened area in the vessel wall that balloons and may eventually burst). The major risk factors for stroke are hypertension, diabetes, smoking, and heart disease. Other risk factors include obesity, substance abuse (cocaine), and elevated cholesterol levels. Thrombotic strokes are treated with antiplatelet or anticoagulant (clotdissolving) therapy. Tissue plasminogen activator (tPA) may be started shortly after the onset of a stroke. Surgical intervention with carotid endarterectomy (removal of the atherosclerotic plaque along with the inner lining of the affected carotid artery) also is possible.

Answer 73

Severe, recurring, unilateral, vascular headache. A migraine may be associated with an aura (peculiar sensations that precede the onset of illness). Symptoms of aura are temporary visual and sensory disturbances, including flashes of light and zigzag lines. Sensitivity to sound (phonophobia) and light (photophobia) are associated with the migraine itself. The etiology of pain in migraines is not fully established, but there are clearly changes in cerebral blood vessels. Treatment to prevent a migraine attack includes medications such as sumatriptan succinate (Imitrex) that target serotonin receptors on blood vessels and nerves. Drugs of this type reduce inflammation and restrict dilation of blood vessels.

Answer 74

Form of seizure consisting of momentary clouding of consciousness and loss of awareness of surroundings.

Answer 75

Enlarged, weakened area in an arterial wall, which may rupture, leading to hemorrhage and CVA (stroke).

Answer 76

Malignant brain tumor of astrocytes (glial brain cells).

Answer 77

Peculiar symptom or sensation occurring before the onset (prodromal) of an attack of migraine or an epileptic seizure.

Answer 78

Mental decline and deterioration.

Answer 79

Destruction of myelin on axons of neurons (as in multiple sclerosis).

Answer 80

CNS neurotransmitter, deficient in patient with Parkinson disease.

Answer 81

Clot of material that travels through the bloodstream and suddenly blocks a vessel.

Answer 82

Manner of walking.

Answer 83

Pertaining to a sudden, acute onset, as with the convulsions of an epileptic seizure.

Answer 84

Relieving symptoms but not curing them.

Answer 85

Removal of the thymus gland (a lymphocyte-producing gland in the chest); used as treatment for myasthenia gravis.

Answer 86

Transient ischemic attack. TIAs can occur with all three types of strokes: thrombolytic, embolic, and even hemorrhagic (if minor.) They are characterized by a limited time course of neurologic deficits.

Answer 87

Involuntary movement of a small group of muscles, as of the face; characteristic of Tourette syndrome.

Answer 88

Major (grand mal) convulsive seizure marked by sudden loss of consciousness, stiffening of muscles, and twitching and jerking movements.

Answer 89

Samples of CSF are examined. CSF analysis measures protein, glucose, and red (RBC) and white (WBC) blood cells as well as other chemical contents of the CSF. CSF analysis also can detect tumor cells (by cytology), bacteria, and viruses. These studies are used to diagnose infection, tumors, or multiple sclerosis.

Answer 90

X-ray imaging of the arterial blood vessels in the brain after injection of contrast material. Contrast is injected into the femoral artery (in the thigh), and x-ray motion pictures are taken. These images diagnose vascular disease (aneurysm, occlusion, hemorrhage) in the brain.

Answer 91

Computerized x-ray technique that generates multiple images of the brain and spinal cord. Contrast material may be injected intravenously to highlight abnormalities. The contrast leaks through the blood-brain barrier from blood vessels into the brain tissue and shows tumors, aneurysms, bleeding, brain injury, skull fractures, and blood clots. Operations are performed using the CT scan as a local road map. CT scans also are particularly useful for visualizing blood and bone.

Answer 92

Magnetic field and pulses of radiowave energy create images of the brain and spinal cord. MRI is better than CT at evaluation of brain parenchyma. It is excellent for viewing brain damage related to infection, inflammation or tumors. It also is used to look for causes of headaches, to help diagnose a stroke, and to detect bleeding problems and head injury. Contrast material may be used to enhance images. Magnetic resonance angiography (MRA) produces images of blood vessels using magnetic resonance techniques.

Answer 93

Radioactive glucose is injected and then detected in the brain to image the metabolic activity of cells. PET scans provide valuable information about the function of brain tissue in patients, to detect malignancy and to evaluate brain abnormalities in Alzheimer disease, stroke, schizophrenia, and epilepsy (Figure 10-22). Combined PET-CT scanners provide images that pinpoint the location of abnormal metabolic activity within the brain.

Answer 94

Sound waves detect blood flow in the carotid and intracranial arteries. The carotid artery carries blood to the brain. These studies detect occlusion in blood vessels.

Answer 95

Recording of the electrical activity of the brain. EEG demonstrates seizure activity resulting from brain tumors, other diseases, and injury to the brain. It can also help define diffuse cortical dysfunction (encephalopathies).

Answer 96

CSF is withdrawn from between two lumbar vertebrae for analysis. A device to measure the pressure of CSF may be attached to the end of the needle after it has been inserted. Injection of intrathecal medicines may be administered as well. Some patients experience headache after LP. An informal name for this procedure is “spinal tap.”

Answer 97

Use of a specialized instrument to locate and treat targets in the brain. The stereotactic instrument is fixed onto the skull and guides the insertion of a needle by three-dimensional measurement. A Gamma Knife (high-energy radiation beam) is used to treat deep and often inaccessible intracranial brain tumors and abnormal blood vessel masses (arteriovenous malformations) without surgical incision. Proton stereotactic radiosurgery (PSRS) delivers a uniform dose of proton radiation to a target and spares surrounding normal tissue.

Answer 98

Alzheimer disease myasthenia gravis alpha-fetoprotein; elevated levels in amniotic fluid and maternal blood are associated with congenital malformations of the nervous system, such as anencephaly and spina bifida magnetic resonance angiography

Answer 99

amyotrophic lateral sclerosis—Lou Gehrig disease magnetic resonance imaging arteriovenous malformation; congenital tangle of arteries and veins in the cerebrum multiple sclerosis blood-brain barrier hemiparesis

Answer 100

central nervous system patient-controlled analgesia cerebrospinal fluid positron emission tomography chronic traumatic encephalopathy peripheral nervous system

Answer 101

cerebrovascular accident proton stereotactic radiosurgery electroencephalography seizure gamma-aminobutyric acid (neurotransmitter) traumatic brain injury

Answer 102

intracranial pressure (normal pressure is 5 to 15 mm Hg) transcutaneous electrical nerve stimulation; technique using a batterypowered device to relieve acute and chronic pain lumbar puncture transient ischemic attack; temporary interference with the blood supply to the brain monitored anesthetic care temporal lobe epilepsy tissue plasminogen activator; a clotdissolving drug used as therapy for stroke

Ch. 10 - Nervous System Flashcards

from The Language of Medicine, 12th Edition (133 cards)