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Neurological Assessment & DIAGNOSTICS Developed by: Trudy Jordan, R.N., B.S.N. 1997 Objectives: Upon completion of this module, the learner will be able to:
NOTE: When scoring best motor response, the examiner should test each extremity separately and take the best response elicited. Each extremity should always be compared with the opposite extremity. Abnormal motor responses include flexion and extension and are usually seen in the unconscious patient. Flexion is denoted by decorticate posturing either spontaneously or in response to a painful stimuli. Decorticate posturing is where the patient pulls their arms up to the chest and the legs are extended with internal rotation and a plantar flexion. Extension is denoted by decerebrate posturing either spontaneously or in response to a noxious stimuli. The patient will clench his teeth, with arms stiffly extended at the sides and outwardly rotated. Legs will also be extended with a plantar flexion. A patient can also exhibit a mixture of both flexion and extension. One arm will posture decorticate while the other arm will posture decerebrate. It has been noted that decorticate posturing will show a less serious prognosis than decerebrate posturing. In the unconscious patient assessment must include the use of a noxious stimuli to elicit a response. Acceptable noxious stimulation can be achieved in several ways. NAIL BED PRESSURE is easy to perform and less painful to the patient. A pen is firmly pressed onto the nail. This should be done on each extremity and compared. Another acceptable noxious stimuli is the TRAPEZIUS PINCH. This allows for total body observation to the stimuli but cannot be performed on obese patients. The last acceptable noxious stimuli is a PINCH TO THE INNER ASPECT OF THE ARM OR THIGH. This pinch is most sensitive to elicit a response. Other widely used noxious stimuli that are considered unacceptable are the sternal rub, supraorbital pressure, and nipple pinching. These types of stimuli should be avoided. Frequent rubbing of the sternum can cause excoriation to the area and opening of the skin which may lead to infection. Supraorbital pressure should always be avoided as it can cause increased chance of damage or fractures with the facial trauma patient, or patients with frontal craniotomies or facial surgery. Patients presenting with lateralizing or mixture signs (signs that occur only on one side of the body), can assist in the localization of a lesion or tumor to one side of the brain. Usually the presence of lateralizing signs indicates an emergency situation and possible cranial herniation. The physician should be notified immediately if these signs occur.
- List the components of a complete neurological examination.
- Discuss the acceptable and unacceptable methods to apply noxious stimuli.
- Describe appropriate and abnormal pupil response.
- Describe alterations in respiratory patterns associated with neurological alterations.
- State vital sign changes associated with neurological deterioration.
- Identify the differences in comatose, persistent vegetative states, and brain death.
- Discuss the different diagnostic procedures utilized to diagnose and follow brain injury.
- Describe the various laboratory studies done and their significance in the brain injured patient.
- READ THE INFORMATION IN THIS MODULE COMPLETELY.
- Complete the examination. Make sure that you provide your license number. CEU’s cannot be issued without a license number.
- Complete an evaluation form at the end of the test.
- Call Staff Development at extension 1285 for any questions regarding this self-directed study module.
CONTACT HOURS: 2.0
INTRODUCTIONMr Lansing was admitted to the second floor telemetry unit from the Emergency Department after suffering a cerebrovascular accident (CVA). Upon admission Mr. Lansing is awake, alert, and oriented. His pupils are equal and reactive to light. He is able to move all extremities with only mild weakness on the left hand side. These findings are documented on his admission notes. Later that evening, the nurse goes into Mr. Lansing’s room to give him his evening medications. He appears asleep. Upon trying to arouse Mr. Lansing, the nurse discovers that he is unresponsive. He does not respond to any noxious stimuli and his arms are showing decorticate posturing. She checks his pupils and finds that his right pupil is dilated and not reactive to a light source. His heart rate is low and he has a slow, irregular respiratory pattern. From this quick assessment, the nurse understands that Mr. Lansing has re-bleed and that he is experiencing increased intracranial pressure. She immediately calls the physician and the patient is transported to the Intensive Care Unit where he will undergo close observation and diagnostic studies. A thorough, accurate, well documented neurological assessment upon admission of a patient suffering from neurological changes related to a disease process provides a baseline for all staff who care for them. This allows for anyone caring for the patient to pick up on even subtle changes that may indicate neurological deterioration. These subtle changes can provide for early, definitive action by the physician and therefore increasing the prognosis of the patient to full recovery. Neurological changes can occur due to a variety of disease processes or injury. They include:
- MASS LESIONS – such as tumors, edema, blood clots, fluid, and abscesses.
- BLOOD FLOW DISRUPTIONS – from hemorrhages related to stroke or trauma or ischemia.
- METABOLIC DISORDERS – such as electrolyte disturbances, decreased oxygen levels, chemical imbalances, and high levels of toxins in the body.
- INFECTIONS ? both bacterial and viral
- TRAUMA ? related to vehicle accidents and behavior that can place one at risk such as the use of mind altering drugs, non-use of safety restraints and helmets, and firearms.
THE NEUROLOGICAL CLINICAL ASSESSMENTThe goal of the neurological clinical assessment is to provide baseline data on a patient?s condition which will be used for further assessments. It will help denote any improvements in the status of the patient, as well as, any deterioration. The assessment includes three major areas. They are patient history, physical examination, and vital signs. Each area will be discussed.
PATIENT HISTORYPatient history needs to be comprehensive and well documented. It includes many areas, but in the neurologically challenged patient, must be focused toward the progression of signs and symptoms leading to admission. It should include the events preceding admission as well as precipitating factors and clinical manifestations. Also in patient history, present illnesses should be documented and any history of seizures, loss of consciousness, or the use of anticonvulsants. Family history of any neurological dysfunction should be noted. It is also important to talk with family to better understand the patients typical behavior patterns prior to their present illness. Patients suffering from neurological deficits will frequently experience behavioral changes depending upon the area of the brain affected. All these factors combined provide a base for which a plan of care can be initiated.
PHYSICAL EXAMINATIONNeurological physical examination consist of five parts. It includes level of consciousness, motor movements, papillary response, eye movements, and respiratory patterns. Each area will be discussed separately.
LEVEL OF CONSCIOUSNESSAssessing a patients level of consciousness is one of the most important and most sensitive indicator of neurological deterioration. Level of consciousness is usually the first to deteriorate before any other neurological changes are noted. Changes in level of consciousness are usually subtle and require close observation to be noted. It is the first assessment to be done and should be very thorough so that follow-up checks can be done quickly and efficiently. Some of the most common causes for an altered level of consciousness can be depicted by looking at the acronym A.E.I.O.U. ? T.I.P.P.S. This stands for: Alcohol Trauma Epilepsy Infection Insulin Psychological Opiates Poison Urates Shock Level of consciousness is composed of two components. The first component is arousal or alertness. This evaluates the reticular activating system of the brain which is responsible for consciousness or the ?awake state?. It tests the patients ability to appropriately respond to verbal or noxious stimuli. The second component is content of consciousness or awareness. This is a higher level of functioning that is controlled by the cerebral cortex. It tests the patients orientation to person, place, and time. This can be assessed by asking the patient a variety of questions while assessing the appropriateness of their answers. The questions should be simple and direct without either verbal or physical coaching. With each assessment the same questions should be utilized, as changes in the patients answers can indicate an increasing degree of confusion or disorientation.
CATEGORIES OF CONSCIOUSNESSIt is generally accepted that the five categories of consciousness are used to denote a patients level of consciousness. But they are not always accurate secondarily to their vague definitions and the interpretation of each may vary from health care worker to health care worker.
- ALERT: the patient gives an immediate response to a minimal external stimuli.
- LETHARGIC: drowsiness or inaction. Requires an increase in a stimuli to be awakened.
- OBTUNDED: a duller indifference to an external stimuli. The response of the patient is minimally maintained.
- STUPOROUS: arousal only by vigorous and continual external stimulation.
- COMATOSE: inability to produce any voluntary response regardless of the amount of stimulation given.
TOOLS TO ASSESS CONSCIOUSNESSThe examination should be done systematically to assist in determining the type and degree of stimuli required to produce a response from a patient. The least amount of stimuli should be used first and progress to noxious stimulation if needed.
THE GLASCOW COMA SCALEThe Glascow Coma Scale evaluates responses to eye opening, verbal response, and motor response and is scored from 15 to 3. a score of 7 or less indicates coma. The lower the score, the poorer the patients prognosis. It provides information on level of consciousness only and is not considered a complete neurological examination. It is not sensitive enough to determine a patients sensorium. This indicator should be completed serially to assist in the identification of subtle changes in the patients level of consciousness. It must be noted that the patient must be maximally stimulated prior to scoring and the tester should always rate the ?best? response.
GLASCOW COMA SCALE
|EYE OPENING||4 3 2 1||Spontaneous To Speech To Pain No response|
|VERBAL RESPONSE||5 4 3 2 1||Oriented Confused Inappropriate Words Incomprehensible Sounds No response|
|BEST MOTOR RESPONSE||6 5 4 3 2 1||Obeys Commands Localizes to Pain Withdraws to Pain Abnormal Flexion Extension No response/Flaccid|
PUPILLARY RESPONSE AND EYE MOVEMENTOne of the most important components of the neurological examination is pupil response and eye movements, especially in the unconscious patient or the patient on neuromuscular blocking agents and sedation. Pupil response and eye movements are one of the few ways of appropriately evaluating these types of patients. Serial evaluations should be done with good documentation and technique. PUPIL RESPONSE Pupil response is a function of the autonomic nervous system. The parasympathetic nervous system controls the III cranial nerve (oculomotor) and causes the pupil to constrict when stimulated. Any compression on the oculomotor nerve will cause a pupil to become dilated and non-reactive. The sympathetic nervous system control pupil activity via the hypothalamus and will cause the pupil to dilate when stimulated. Any injury to the lower brain stem will result in a pinpoint and non-reactive pupil. Pupil response is also affected by medications, direct trauma, and eye surgery.
PUPIL RESPONSE ASSESSMENTAssessment of the pupil includes the size of the pupil measured in millimeters, the shape of the pupil (round, irregular, or oval), and the degree of reactivity to light. Both eyes should be assessed for equality. Size of the pupil should always be done with a pupil gauge. 17% of the population present with unequal pupils, called anisocoria. Other than this 17%, pupils should be equal in size. Inequality in patients previously having equal pupils is to be considered significant and may indicate increasing intracranial pressure or eminent danger of herniation.. The size of the pupils can be altered. Large pupils are a resultant from extreme stress or the use of cycloplegic agents, such as atropine. Extremely small pupils are the resultant of lower brain stem compression, narcotics, or bilateral damage to the pons. The shape of the pupil is also assessed. Normally the pupil is round. An irregular shaped or oval pupil may indicate increased intracranial pressure. Oval shaped pupils also may indicate cranial nerve III compression in its early stages. The degree of reactivity is accomplished by the use of a pen light or flash light. What ever the light source, it should create a narrow bright beam. The room should be slightly dimmed. The examiner should start from the outer most corner of the eye and rotate the light toward the nose. You should never shine the light directly on the pupil as it will cast a reflection. Reactivity of the pupil should be brisk.
EYE MOVEMENTSEye movement is controlled by cranial nerves III, IV, and VI. These movements are also called Extraocular movements (EOM?s). these nerves allow the eye to look in six directions. When testing an individual, eye movement in all six directions should be completed by having the person follow the examiners finger. Observation for symmetry of eye movements should be documented. If the patient is unconscious, the examiner can test for the Oculocephalic reflex or the Oculovestibular reflex. The Oculocephalic reflex is also termed ?Dolls Eyes?. This procedure can not be done on a patient with any possible cervical trauma, until it is ruled out. The procedure is performed by holding the patients eyes open and briskly turning their head from side to side. If the reflex is intact the eyes should deviate to the opposite side from which the head is turned. If the reflex is absent or abnormal and not intact one of two things will occur. First, the eyes can remain mid-line or move with the head. This would indicate significant brain stem injury. Second, if the eyes rove or they move in opposite directions from one another, this would indicate some degree of brain stem injury. The Oculovestibular reflex is also termed the ?Cold Caloric Test? and is carried out by a physician. This test is the final clinical assessment for lower brain stem function. This test is not to be performed on a conscious patient. The procedure consists of injecting 20 ? 50cc of ice water into the external ear canal. This is an extremely noxious stimuli and can cause the patient to posture either decorticate or decerebrate. The normal response with cold water injection should be a rapid deviation of the eyes toward the irrigated ear. In an abnormal response, the patient will present with dysconjugate eye movement which would indicate a brain stem lesion. An absent response is indicative of little or no brain stem functioning. VITAL SIGNS The last major area to focus on for a complete neurological examination is to assess the patient?s vital signs. Patients experiencing neurological changes or damage due to disease processes or injury will also experience vital sign deviations. Changes in vital signs can indicate neurological deterioration. RESPIRATORY PATTERNS Changes in a patients respiratory patterns can assist in identifying the level of brain stem injury. There is a correlation between level of consciousness, the level of the injury, and the respiratory pattern observed. Assessment of respiratory status should also include the effectiveness of gas exchange as well as airway maintenance with secreation control. Reflexes such as cough, gag, and swallowing may be diminished or absent. It is not uncommon for hypoventilation to occur with an altered level of consciousness. Continued hypoventilation can cause further neurological damage and an increase in intracranial pressure secondary to hypoxia. Various types of respiratory patterns can be seen with neurological compromise. They include Cheyne-Stokes related to deep bilateral lesions of cerebrum and some cerebellar lesions. Neurogenic hyperventilation appears with lesions to the midbrain and pons. Apneustic respirations occur with lesions to the mid and lower pons. Cluster breathing indicates a lesion of the lower pons or upper medulla. Ataxic respirations are seen with lesions of the medulla.
CARDIAC ALTERATIONSHypertension is frequently seen in patients presenting with cranial injury. Normally immediately post-injury the bodies compensatory mechanisms send it into a hyper dynamic state but cerebral auto regulation is lost. In this hyper dynamic state the heart rate, blood pressure, and cardiac output all increase. This forces more blood flow to the brain. With the loss of auto regulation, the increase of blood flow to the brain will increase intracranial pressure and enhance neurological symptomatology. After the hyper dynamic state has subsided, a low cardiac output may ensue. This then leads to decreased cerebral perfusion and hypoxia causing further insult. In the presence of increased intracranial pressure, this drop in blood pressure is unable to overcome the increased cranial pressure and further compounds the hypoperfusion and hypoxia. Increased intracranial pressure frequently causes stimulation of the vagus nerve which will cause bradycardia. The bradycardia leads also to decreased cerebral perfusion and hypoxia. Any rapid changes in intracranial pressure can also cause multiple cardiac dysrhythmias, such as premature ventricular contraction (PCV?s), atrioventricular blocks, and ventricular fibrillation (VF). Three clinical manifestations which are usually a late finding are seen in ?Cushing?s Triad?. They include bradycardia, systolic hypertension, and bradypnea. These symptoms occur in response to intracranial hypertension or a herniation syndrome. Interventions are initiated specifically for each component of the triad. COMA, PERSISTENT VEGETATIVE STATE & BRAIN DEATH ? WHAT ARE THE DIFFERENCES? COMA ? by definition, coma is the pathologic state in which neither arousal or awareness are present. It is maintained sleeplike state of unresponsiveness with the inability to be aroused. Non-purposeful reflex movements (decerebrate or decorticate posturing) may be present. PERSISTENT VEGETATIAVE STATE ? Occurring anywhere from hours to days after a comatose state, wakefulness returns without evidence of any purposeful behavior or cognition. The patient will remain in a decorticate posturing and ventilation may be spontaneous. BRAIN DEATH - a persistent comatose state with an established cause. On EEG there is no evidence of cerebral functioning (no response to noxious stimuli and no posturing). There will be no evidence of brain stem functioning (pupils will be fixed, there will be no corneal, blink, doll?s eyes, or cold water caloric reflexes, and the patient will be apneic without ventilation.) this state is diagnosed by repeat EEG?s for three days. PATIENT CARE FOR THESE STATES INCLUDE:
- Nutrition: via feeding tube or hyperalimentation
- Pulmonary care: suctioning, pulmonary toilet, & chest PT
- Skin care: frequent positioning, bathing, turning
- Frequent patient care conferences: physician, nurse, family, case management
RAPID NEURO ASSESSMENTCONSCIOUS PATIENT UNCONSCIOUS PATIENT 1. LEVEL OF CONSCIOUSNESS 1. LEVEL OF CONSC. Ask a variety of questions Use Glascow Coma Scale Prefer recent/past events 1. FACIAL MOVEMENTS Observe summetry of the face Speech patterns (slurring) 3. PUPILS & EYE MOVEMENT 2. PUPILS Reactivity/Size/Shape Reactivity/Size/Shape Extraocular movements 4. MOTOR ASSESSMENT 3. MOTOR ASSESSMENT Simultaneous hand grips Assess each extremity individually Arms outstretched to assess drift Use of noxious stimulation Raise both legs against resistance Nail bed pressure Dorsi & Plantarflex feet against Trapezius pinch Resistance Inner aspect of arm/leg 5. SENSORY ASSESSMENT 4. RESPIRATORY EFFORT Bilateral stroking of cheeks Spontaneous vs ventilated Arms, legs, and feet for Associated breathing patterns identification of the area and any differences in sensation 6. VITAL SIGNS 5. VITAL SIGNS Note changes of áBP, â Special attention to Arterial BP HR, âRR ICP, if monitored Once the initial complete neurological examination is completed, these rapid neurological examinations should take less than 4 minutes to complete. If deviations from the previous examination is noted, then special attention can be place on that abnormality and the physician notified for further definitive treatment. DIAGNOSTIC TESTING FOR THE NEUROLOGICALLY CHALLENGED PATIENT Diagnostic testing is usually done in conjunction with complete neurological examination finding. If the findings indicate that some form of neurological injury has occurred the nurses role takes on a trigone of activities which include:
- Patient and Family Education
- Patient preparation for the procedure
- Keen awareness of potential complications that may occur
- Severe headache
- Head trauma
- Loss of consciousness
- Suspicion of a lesion or tumor
- Intracerebral hemorrhage (stroke)
- Suspected vascular lesions
- Intracerebral edema
CEREBRAL ANGIOGRAPHYA cerebral angiogram is an invasive procedure as a radiopaque dye is injected into the intracranial vasculature. As the dye circulates, it passes from the arterial circulation, through the capillary bed, and into the venous circulation. Serial x-rays are taken during this movement. As with cardiac catheterization, it provides information on vessel patency, any occlusions or irregularities. Indications for cerebral angiography include:
- Cerebral aneurysm
- Arteriovenous anomalies
- Carotid artery disease
- Cerebral vascular tumors
- Embolism formation
- Allergic Reaction to the dye
LUMBAR PUNCTUREThis is also considered an invasive procedure as there is entry via a needle into the subarachnoid space. The purpose of a lumbar puncture is two-fold. It can be used to obtain diagnostic information by obtaining samples of cerebrospinal fluid and obtaining pressure reading. But it can also be done to apply therapeutic measures, such as removal of bloody or purulent CSF, injection of medications that need to bypass the blood/brain barrier, and the administration of spinal anesthesia. This procedure can be performed in one of two ways. First is where a needle is introduced at the level of L4 ? L5. the other is by Cistenal puncture where the needle is introduced in the back of the neck at C1 ? C2 into the cisterna magna. This approach is used least.
CEREBRAL BLOOD FLOW STUDIESThe goal of cerebral blood flow studies is to measure the amount of blood flowing to various areas of the brain. Normal values of blood flow is 50 ? 55cc/100gm cerebral tissue/minute. These studies are not readily accepted for accuracy. Uses for this study include:
- Evaluation of cerebral vasospasm post cerebral bleed.
- Evaluation of cerebral blood flow during surgical procedures such as cerebral aneurysm repair.
- Evaluation of blood flow after surgical repair
- Evaluation of blood flow after arteriovenous malformation repair.
DOPPLER ULTRASOUNDSThese procedures are simple, easy, and non-invasive. They provide information on the velocity or speed of blood flow through cerebral vessels. Velocity changes depending on the size of the vessel. It is measured by the use of ultrasonic waves. The higher the velocity of blood flow through a vessel, the narrower the vessel. There are two main types of Doppler ultrasounds. The first is an Extracranial Doppler, which is used to observe the velocity of blood flow through the carotid arteries. The second is a Transcranial Doppler which can assess velocity blood flow through areas of the skill where the bone is relatively thin, such as the temporal area.
ELECTROPHYSIOLOGY STUDIESThese two tests are used to assess the progression of a disease state, eveluate symptoms associated, and observe ongoing neurological functioning. EEG (Electroencephalogram) An EEG is relatively easy and is non-invasive. By using electrodes it can monitor electrical impulses in the brain or ?brain waves?. In observing brain waves, the EEG can detect and localize abnormal activity in the brain as waves will move slower in areas of injury. Indications for an EEG include: 1. Focal seizure identification 2. Infarction identification 3. Metabolic disorders 4. Head injuries 5. Confirmation of brain death
EVOKED POTENTIALSEvoked potentials are non-invasive and are used to observe the sensory pathways as a stimuli goes from the brain stem to the cerebral cortex. A small electrical shock is the initiating stimuli. This test is frequently used in patients that have been placed in a therapeutically induced coma, usually to control increased intracranial pressure. But, they may also be used to determine any brain stem or spinal cord injuries to the trauma patient.
LABORATORY STUDIESABG?s (Arterial blood gases); ABG?s are a very important lab test to be monitored, especially in the comatose patient who are ventilated and not spontaneously breathing. If increased intracranial pressure is suspected, hyperventilation is required as increased CO2 is a potent vasodilator. When levels are elevated it allows increased blood flow to the brain which further increases intracranial pressure. Levels should be maintained between 25 ? 35mmHg. Oxygen is also extremely important for proper brain functioning. Sa02 should be maintained at greater than 90%, and if the patient is ventilated, maintained with the lowest Fi02 possible. Serum Glucose: Glucose and oxygen are to two major components required by the brain for proper functioning. Glucose levels must be maintained to provide adequate energy for impulse transmission. Electrolytes: Monitoring of electrolytes is imperative to prevent potentially further insult on the injured brain. Metabolic disorders can disturb proper functioning and can be the actual cause for neurological insult.CBC?s: Hemoglobin and hematocrit need to be monitored to provide adequate blood flow to the brain. Appropriate levels will also provide for adequate transport of oxygen and glucose to the brain. White blood cell counts also are monitored to either rule out or assess for any infectious process that may be occurring. Drug and alcohol levels As drugs and alcohol can alter level of consciousness, they should be drawn and monitored upon admission if their use is suspected. You have now completed the self-directed study module on neurological assessment and diagnostics. We hope this has been a positive learning experience for you. Please complete the Self Assessment examination associated with this module. Be sure to sign the assestment portion of the answer sheet including your license number. CEU?s cannot be issued without a license number. Please be sure to do the evaluation of this module. Upon completion, please return the examination, evaluation, and answer sheet to Staff Development. Upon receipt, you will be issued a certificate.
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