פרק 14 Chapter 14 Deafness, Dizziness, and Disorders of Equilibrium Flashcards
הצטברות נוזל אנדולימפטי. מחלת מנייר
Labyrinthine disorders are the most common causes of true vertigo. Meniere disease is characterized by paroxysmal attacks of vertigo associated with fluctuating tinnitus and deafness. One or the other of the latter two symptoms may be absent during the initial attacks of vertigo, but invariably they assert themselves as the disease progresses and increase in severity during acute attacks. Meniere disease affects the sexes about equally and has its onset most frequently in the fifth decade of life, although it may begin earlier or later. Cases of Meniere disease usually occurs as a sporadic trait, but hereditary forms, both autosomal dominant and recessive, have been described (see reviews by Konigsmark). The main pathologic changes consist of an increase in the volume of endolymph and distention of the endolymphatic system (endolymphatic hydrops)
איזה ממצאים תמצאו ב-acute left labyrinthitis?
א – ניסטגמוס לשמאל ונטייה ליפול לשמאל במבחן שיווי משקל
ב- ניסטגמוס לשמאל ונטייה ליפול לימין
ג - ניסטגמוס לשמאל מבמט שמאלה וימין במבט ימין
ד – ניסטגמוס לכיוון ימין ונטייה ליפול ימין
ה - ניסטגמוס לכיוון ימין ונטייה ליפול שמאל
ה. ניסטגמוס לכיוון האוזן הבריאה ונופלים על האוזן החולה
Nystagmus of Labyrinthine Origin
This is predominantly a horizontal or vertical unidirectional jerk nystagmus, often with a slight torsional Component, that is evident when the eyes are close to the central position and changes minimally with the direction of gaze. It is more prominent when visual fixation is eliminated (conversely, it is suppressed by fixation).
Vestibular nystagmus of peripheral (labyrinthine) origin beats in most cases away from the side of the lesion and increases as the eyes are turned in the direction of the quick phase (the Alexander law).
In contrast, nystagmus of brainstem and cerebellar origin is most apparent when the patient fixates upon and follows a moving target and the direction of nystagmus changes with the direction of gaze.
Labyrinthine-vestibular nystagmus is horizontal, vertical, or oblique, and that of purely labyrinthine origin characteristically has an additional torsional component. Tinnitus and hearing loss are often associated with disease of the peripheral labyrinthine mechanism; also, vertigo, nausea, vomiting, and staggering may accompany disease of any part of the labyrinthine-vestibular apparatus or its central connections.
בת 27 התלוננה על חוסר שיווי משקל. בהליכה מסביב לכיסא נגד כיוון השעון
(anti-clockwise)
היא נפלה לכיוון הכיסא.
במבחן פוקודה
(FUKUDA)
היא סטתה 90 מעלות לצג שמאל.
איפה המיקום האנטומי של הפגיעה?
א. צרבלרי משמאל
ב. צרבלרי מימין
ג. ווסטיבולרי משמאל
ד. ווסטיבולרי מימין
א. צרבלרי משמאל (נפלה פעמיים לאותו כיוון- לשמאל)
The Unterberger-Fukuda maneuver requires the patient to march in place with eyes closed and arms outstretched. Normally, less than 15 degrees or so of rotation is displayed; asymmetry of labyrinthine function is manifest as excessive rotation away from the diseased side.
related test involves having the patient walk around a chair with eyes closed; an increasing or decreasing radius is indicative of an imbalance between the two sides of the labyrinthine apparatus. Both of these tests, however, often show abnormalities with cerebellar disease as well, in which the patient veers to the affected side
או במילים אחרות:
פגיעה צרבלרית- בשני המבחנים תהיה סטייה לאותו כיוון
פגיעה לבירינטית- מבחן פוקודה יהיה לכיוון ההפוך
Vestibular neuronitis
vestibular neuronitis distinctive disturbance of vestibular function, characterized clinically by a paroxysmal and usually a prolonged single attack of vertigo and by a conspicuous absence of tinnitus and deafness. occurs mainly in young to middle-aged adults (children and older individuals also may be affected), without preference for either sex. The patient frequently gives a history of an antecedent upper respiratory infection of nonspecific type,
Persistence of the symptoms for a day or more differentiates the process from Menire disease. The vertigo is severe as a rule and is associated with nausea, vomiting, and the need to remain immobile.
Nystagmus (quick component) and a sense of body motion are to the opposite side, whereas falling and past pointing are to the side of the affected labyrinth.
In some patients, the caloric responses are abnormal bilaterally, and in some, the vertigo may recur, affecting the same or the other ear.
Auditory function is normal.. Examination discloses vestibular paresis on one side, that is, an absent or diminished response to caloric stimulation of the horizontal semicircular canal If the patient will tolerate small head movements, the previously described rapid-head-impulse test of Halmagyi and Cremer is one of the best means of demonstrating absent function of one lateral semicircular canal
The severe vertigo and associated symptoms subside in a matter of several days, but lesser degrees of these symptoms, made worse by rapid movements of the head, may persist for months. The caloric responses are gradually restored to normal as well. In some patients, there has been a recurrence months or years later, as already mentioned.
Vestibular neuronitis
vestibular neuronitis distinctive disturbance of vestibular function, characterized clinically by a paroxysmal and usually a prolonged single attack of vertigo and by a conspicuous absence of tinnitus and deafness. occurs mainly in young to middle-aged adults (children and older individuals also may be affected), without preference for either sex. The patient frequently gives a history of an antecedent upper respiratory infection of nonspecific type,
Persistence of the symptoms for a day or more differentiates the process from Menire disease. The vertigo is severe as a rule and is associated with nausea, vomiting, and the need to remain immobile.
Nystagmus (quick component) and a sense of body motion are to the opposite side, whereas falling and past pointing are to the side of the affected labyrinth.
In some patients, the caloric responses are abnormal bilaterally, and in some, the vertigo may recur, affecting the same or the other ear.
Auditory function is normal.. Examination discloses vestibular paresis on one side, that is, an absent or diminished response to caloric stimulation of the horizontal semicircular canal If the patient will tolerate small head movements, the previously described rapid-head-impulse test of Halmagyi and Cremer is one of the best means of demonstrating absent function of one lateral semicircular canal
The severe vertigo and associated symptoms subside in a matter of several days, but lesser degrees of these symptoms, made worse by rapid movements of the head, may persist for months. The caloric responses are gradually restored to normal as well. In some patients, there has been a recurrence months or years later, as already mentioned.
Table 14-1
REPRESENTATIVE GENETIC FORMS OF HEARING LOSS
part 1
Table 14-2
DIFFERENTIATION OF PERIPHERAL FROM CENTRAL NYSTAGMUS
Table 14-3
VERTIGINOUS SYNDROMES WITH LESIONS OF DIFFERENT PARTS OF THE VESTIBULAR SYSTEM
what are the structures of the auditory pathway?
שקופית מידע ללא שאלה
A simplified diagram of the vestibulocerebellar and vestibulospinal pathways and connections between vestibular and ocular motor nuclei. The medial longitudinal fasciculi (blue lines) are the main pathways for ascending vestibular impulses
the vestibular reflex pathways
Figure 14-1. The auditory and vestibular systems.
A. The right ear, viewed from the front, showing the external ear and auditory canal, the middle ear and its ossicles, and the inner ear.
B. The main parts of the right inner ear, viewed from the front. The perilymph is located between the wall of the bony labyrinth and the membranous labyrinth. In the cochlea, the perilymphatic space takes the form of two coiled tubes—the scala vestibuli and scala tympani. The endolymph is located within the membranous labyrinth, which includes the three semicircular ducts, the utricle, and the saccule.
C. The organ of Corti. This is the end organ of hearing; it consists of a single row of inner hair cells and three rows of outer hair cells. The stereocilia of the hair cells are embedded in the tectorial membrane.
D. Diagram of a crista ampulla, the specialized sensory epithelium of a semicircular canal. The crista senses the displacement of endolymph during head rotation. The direction of head rotation is indicated by the red arrow, and endolymph flow by the black arrow. The macula is the locus of the sensory epithelium in the utricle and saccule. Note that the tips of the hair cells are in contact with the otoliths (calcareous material), which are embedded in a gelatinous mass called the cupula.
Figure 14-2. The ascending auditory pathways. The lower part of the diagram is a horizontal section through the upper medulla. (Reproduced with permission from Noback CR: The Human Nervous System, 3rd ed. New York, McGraw-Hill, 1981.)
Figure 14-3. A simplified diagram of the vestibulocerebellar and vestibulospinal pathways and connections between vestibular and ocular motor nuclei. The medial longitudinal fasciculi (blue lines) are the main pathways for ascending vestibular impulses. (See text and also Fig. 14-1.)
Figure 14-4. The vestibular reflex pathways. (Reproduced by permission from House EL: A Systematic Approach to Neuroscience. New York, McGraw-Hill, 1979.)
Figure 14-5. Dix-Hallpike maneuver to elicit benign positional vertigo (originating in the right ear).
A. The maneuver begins with the patient seated and the head turned to one side at 45 degrees, which aligns the right posterior semicircular canal with the sagittal plane of the head.
B. The patient is then helped to recline rapidly so that the head hangs over the edge of the table, still turned 45 degrees from the midline. Within several seconds, this elicits vertigo and nystagmus that is right beating with a rotary (counterclockwise) component. An important feature of this type of “peripheral” vertigo is a change in the direction of nystagmus when the patient sits up again with his head still rotated. If no nystagmus is elicited, the maneuver is repeated after a pause of 30 s, with the head turned to the left. Treatment with the canalith repositioning maneuver is shown in Fig. 14-6.
Figure 14-6. Bedside maneuver for the treatment of a patient with benign paroxysmal positional vertigo affecting the right ear. The presumed position of the debris within the labyrinth during the maneuver is shown on each panel. The maneuver is a four-step procedure. First, a Dix-Hallpike test is performed with the patient’s head rotated 45 degrees toward the (affected) right ear and the neck slightly extended with the chin pointed slightly upward.
A. This position results in the patient’s head hanging to the right.
B. Once the vertigo and nystagmus provoked by this maneuver cease, the patient’s head is rotated about the rostral–caudal body axis until the left ear is down.
C. Then the head and body are further rotated until the head is almost facing down. The vertex of the head is kept tilted upward throughout the rotation. The patient should be kept in the final, face down position for about 10 to 15 s. D. With the head kept turned toward the left shoulder, the patient is brought into the seated position.
