פרק 29 Chapter 29: Disturbances of Cerebrospinal Fluid, Including Hydrocephalus, Pseudotumor Cerebri, and LowPressure Syndromes Flashcards
במצב של
benign intracranial hypertension (pseudotumor cerebri)
יש להמנע מהתרופות הבאות, פרט ל-
א. retinoids
ב. estrogens
ג. phenothiazines
ד. tetracyclines
ה. chephalosporines
תשובה ה- צפלוספורינים
טבלה 29-1
Table 29-1CAUSES AND ASSOCIATIONS OF PSEUDOTUMOR CEREBRI
שימוש במינוציקלין
טרומבוס אינו יכול להוביל לPTC
Isolated cortical vein thrombosis on the cerebral convexity does not cause pseudotumor
(but does induce seizures).
Cortical Vein Thrombosis (Superficial
Thrombosis of Cortical Veins)- Certain syndromes occur with sufficient regularity that they suggest thrombosis of a particular vein or sinus. The signature features of isolated thrombosis of superficial cortical veins are the presence of large superficial (cortex and subjacent white matter) hemorrhagic infarctions and a marked tendency to focal seizures. Hemiparesis, incomplete hemianopia, and aphasia, any of which may fluctuate over days, are also characteristic according to Jacobs and colleagues. These variable syndromes reflect the inconstant location of the main surface veins. Thrombosis of the vein of Labbe causes infarction of the underlying superior temporal Lobe, and occlusion of the vein of Trolard implicates the parietal cortex. A concern is the propagation of the clot into the larger draining veins or dural sinuses. Quite often, in our experience, the focal deficit worsens immediately after a focal seizure.The intracranial pressure is not elevated, as it is when the dural venous sinuses are occluded. The diagnosis is made by careful examination of the MRV or by the venous phase of the conventional angiogram. Cortical vein thrombosis should be suspected in the situation of multiple hemorrhagic infarctions in one hemisphere without a source of embolism or atherothrombosis
בת 33, ברקע השמנה, כאבי ראש, פפילאדמה ד”צ וצימצום מתקדם בשדות הראייה. עברה ניתוח Optic nerve sheet fenestration
מימין. מה התוצאות לאחר הניתוח?
(Outcome)
1. ברוב המקרים משתפרת הראייה רק בצד המנותח
2. ברוב המקרים הפחתה דרמטית בכאבי ראש
3. סיבוך של עיוורון בצד המנותח בגלל אירוע איסכמי ברשתית
4. משפר את הלחץ התוך גולגולתי לשנים רבות
5. סבירות גבוהה לביצוע ניתוח חוזר
סיבוך של עיוורון בצד המנותח בגלל אירוע איסכמי ברשתית
Fenestration of the Optic Nerve Sheath
For patients who are losing vision, unilateral fenestration of the optic nerve sheath is a procedure favored by some ophthalmologists. this procedure—which consists of partial unroofing of the orbit and the creation of an intraorbital window opening in the dural–arachnoid sheaths surrounding the optic nerve—effectively preserved or restored vision in 80 to 90 percent of patients. Even when the procedure is performed on only one side, its effect on vision is often bilateral and about two-thirds of patients have some relief of headache as well, although this has been transient in most of our patients.
However, the operation carries a moderately high risk of orbital vascular obstruction and unilateral visual loss,. The causes of visual loss after this operation by various reports have included central retinal artery or vein occlusion, choroidal infarction, optic nerve trauma, hemorrhage into the nerve sheath, and infection. visual loss in 2 to 11 percent of patients. Some of these data come from studies of sheath fenestration for ischemic optic neuropathy, a condition not comparable to the disc swelling of pseudotumor. Follow-up studies have indicated that the reduction in ICP was limited to 1 year or less. As a result of recent reexamination of the complications of this procedure, considered to be lower than in the past, there is renewed interest for the procedure over lumbar peritoneal shunting.
מה לא סימן ללחץ תוך גולגלתי מוגבר?
1. אובסקורציות
2. שיתוק של עצב 6
3. מנינגיזמוס
4. פפילדמה
מנינגיזמוס אינו סימן ללחץ תוך גולגלתי מוגבר.
The clinical manifestations of increased ICP in children and adults are headache, nausea and vomiting, drowsiness, ocular palsies, and papilledema.
בת 18 לאחר טיפול תרופתי לאקנה. פנתה לבירור כאב ראש והפרעות ראייה.בבדיקתה: בצקת בפטמות ובהדמיה מוחית חדרים צרים
(SLIT VENTRICLES)
איזה ממצאים מהבאיים ימצא בסבירות גבוהה בבדיקתה:
1. הפרעה בשדה ראייה ביטמפורלי
2. הפרעה בשדה ראייה תחתון
3. צמצום קונצנטרי של שדה הראייה
4. הגדלה של הכתם העיוור
5. סקוטומה מרכזית
הגדלה של הכתם העיוור
A type of abnormality disclosed by visual field
examination is concentric constriction. This may be a result of severe papilledema, in which case it is usually accompanied by an enlargement of the blind spot. A progressive Constriction of the visual fields, at first unilateral and later bilateral, associated with pallor of the optic discs (optic atrophy), should suggest a chronic meningeal process involving the optic nerves (syphilis, cryptococcosis, sarcoidosis, lymphoma). Long-standing, untreated glaucoma and retinitis pigmentosa are other causes of concentric Constriction. Marked constriction of the visual fields of unvarying degree, regardless of the distance of the visual stimulus from the eye (“gun-barrel” or “tunnel” vision), however, is a sign of hysteria. With organic disease, the constricted visual field naturally enlarges as the distance between the patient and the test object increases.A regional constriction of the field, especially in a nasal quadrant, usually signifies early optic atrophy, as mentioned earlier; it is the first sign that chronic papilledema is threatening the patient’s vision.
Degenerations of the retina are important causes of chronic progressive visual loss. The retinal degenerations assume several forms and many are associated with progressive conditions of the brain or other organs. The most frequent in youth and middle age is retinitis Pigmentosa, a hereditary disease of the outer photoreceptor layer and subjacent pigment epithelium. The retina is thin, and there are fine deposits of black pigment in the shape of bone corpuscles, more in the periphery; later the optic discs become pale. The disorder is marked by constriction of the visual fields with relative sparing of central vision (“gun-barrel” vision), metamorphopsia (distorted vision), delayed recovery from glare, and nyctalopia (reduced twilight vision). The causes of retinitis pigmentosa and related retinal degenerations are diverse.
—-
Bi-Temporal – chiasmatic lesion
Altitudinal – most often vascular
Concentric narrowing of peripheral vision - RP
Central Scotoma- optic nerve
מה מהבאים אינו מעלה לחץ תוך גולגולתי?
1. כשל כבדי
2. אגירת CO2
3. בססת נשימתית
בססת נשימתית אינו מעלה לחץ תוך גולגולתי
Causes of Raised ICP
In clinical practice, there are several mechanisms for elevated ICP:
1. A cerebral or extracerebral mass such as brain tumor;cerebral infarction with edema; traumatic contusion; parenchymal, subdural, or extradural hematoma; or abscess, all of which tend to be localized and deform the adjacent brain. The brain deformation is greatest locally, being compartmentalized to a varying degree by dural partitions.
2. Generalized brain swelling, as occurs in ischemic anoxic states, acute hepatic failure, hypertensive Encephalopathy, hypercarbia, and the Reye hepatocerebral syndrome. In these disorders, the increase in pressure can reduce cerebral perfusion, but tissue shifts are minimal because the mass effect is uniformly distributed throughout the cranial contents.
3. An increase in venous pressure because of cerebral venous sinus thrombosis, heart failure, or obstruction of the superior mediastinal or jugular veins.
4. Obstruction to the flow and absorption of CSF. If the obstruction is within the ventricles or in the subarachnoid space at the base of the brain, hydrocephalus Results. Extensive meningeal disease from any number of causes (infectious, carcinomatous, granulomatous, hemorrhagic) is another mechanism of blockage to CSF flow. If the block is confined to the absorptive Sites adjacent to the cerebral convexities and superior sagittal sinus, the ventricles remain normal in size or enlarge only slightly, because the pressure over the convexities approximates the pressure within the lateral ventricles.
5. Any process that expands the volume of CSF (meningitis, subarachnoid hemorrhage) or increases CSF production (choroid plexus tumor). In this situation, there may be a pressure gradient between the cerebral and spinal compartments, resulting in hydrocephalus.
בחשד ליתר לחץ תוך גולגולתי מטפלים בהיפרוונטילציה כדי- להוציא פחמן דו חמצני וליצור בססת נשימתית
מה מהבאים יעשה ICP מוגבר
1. רמת CO2 גבוהה
2. תירוטוקסיקוזיס
מי מהבאים לא יעשה ICP מוגבר?
1. היפרתירואידיזם
2. עופרת
3. ליתיום
4. גמילה מסטרואידים
רמה גבוהה של פחמן דו חמצני תעלה את הלחץ התוך גולגלתי
היפרתיריאודיזם לא מעלה את הלחץ התוך גולגלתי
Causes of Raised ICP
In clinical practice, there are several mechanisms for elevated ICP:
1. A cerebral or extracerebral mass such as brain tumor;cerebral infarction with edema; traumatic contusion; parenchymal, subdural, or extradural hematoma; or abscess, all of which tend to be localized and deform the adjacent brain. The brain deformation is greatest locally, being compartmentalized to a varying degree by dural partitions.
2. Generalized brain swelling, as occurs in ischemic anoxic states, acute hepatic failure, hypertensive Encephalopathy, hypercarbia, and the Reye hepatocerebral syndrome. In these disorders, the increase in pressure can reduce cerebral perfusion, but tissue shifts are minimal because the mass effect is uniformly distributed throughout the cranial contents.
3. An increase in venous pressure because of cerebral venous sinus thrombosis, heart failure, or obstruction of the superior mediastinal or jugular veins.
4. Obstruction to the flow and absorption of CSF. If the obstruction is within the ventricles or in the subarachnoid space at the base of the brain, hydrocephalus Results. Extensive meningeal disease from any number of causes (infectious, carcinomatous, granulomatous, hemorrhagic) is another mechanism of blockage to CSF flow. If the block is confined to the absorptive Sites adjacent to the cerebral convexities and superior sagittal sinus, the ventricles remain normal in size or enlarge only slightly, because the pressure over the convexities approximates the pressure within the lateral ventricles.
5. Any process that expands the volume of CSF (meningitis, subarachnoid hemorrhage) or increases CSF production (choroid plexus tumor). In this situation, there may be a pressure gradient between the cerebral and spinal compartments, resulting in hydrocephalus.
בת 28, לפני שלושה חודשים עברה הכנסת שאנט עקב הידרוצפלוס על רקע
Aqueductal stenosis.
פונה למיון עם תלונות על איטיות במוטוריקה עדינה ורעד בידיים, היפופוניה והליכה איטית. לאחר מתן דופמין מצבה השתפר. מה צפוי למצוא בבדיקות הדמייה:
- אטרופיה של Caudate nucleus בMRI מוח
- בצקת של Dorsal midbrain בMRI מוח
- Bilateral subdural collection בMRI מוח
- Uptake 18 F-Dopa תקין בCaudate nucleus ובPutamen בבדיקת PET
- אוטמים בגרעיני הבסיס
בצקת של
Dorsal midbrain
- Usually in the context of adult hydrocephalus due to aqueductal stenosis, a rare but distinct parkinsonian syndrome occurs that may be responsive to levodopa. It is particularly prone to occur if there is shunted hydrocephalus and has also been a craniotomy without replacement of the bone. The syndrome usually indicates failure of the shunt. MRI sometimes shows periaqueductal and dorsal midbrain edema, including in the region of the substantia nigra.
Positron emission tomography with 18FDOPA has given evidence of reduced uptake in the caudate and putamen, suggesting a functional failure of the nigrostriatal dopamine system. - Shunt malfunction in children also may be heralded by upward gaze palsy (“setting-sun sign”) or even a dorsal midbrain (Parinaud) syndrome, including abnormal papillary reaction, upper lid retraction, paralysis of convergence, skew deviation, and convergence–retraction nystagmus. Shunting or shunt revision usually leads to reversal of both syndromes, but there may be a delay of days or weeks and it is often difficult to find the ideal pressure setting for the valve
כשל של השאנט
- Usually in the context of adult hydrocephalus due to aqueductal stenosis, a rare but distinct parkinsonian syndrome occurs that may be responsive to levodopa. It is particularly prone to occur if there is shunted hydrocephalus and has also been a craniotomy without replacement of the bone. The syndrome usually indicates failure of the shunt. MRI sometimes shows periaqueductal and dorsal midbrain edema, including in the region of the substantia nigra.
Positron emission tomography with 18FDOPA has given evidence of reduced uptake in the caudate and putamen, suggesting a functional failure of the nigrostriatal dopamine system. - Shunt malfunction in children also may be heralded by upward gaze palsy (“setting-sun sign”) or even a dorsal midbrain (Parinaud) syndrome, including abnormal papillary reaction, upper lid retraction, paralysis of convergence, skew deviation, and convergence–retraction nystagmus. Shunting or shunt revision usually leads to reversal of both syndromes, but there may be a delay of days or weeks and it is often difficult to find the ideal pressure setting for the valve
מי מהבאים לא יכול להוביל לחסימה של ה
aqueduct of silvius?
1. Ependimitis
2. hemorrage
3. coloid cyst
4. tumor
5. perinatal aquired gliosis
- The aqueduct of Sylvius, narrow to begin with, may be occluded by a number of developmental or acquired lesions (genetically determined atresia or forking, perinatally acquired gliosis, ependymitis, hemorrhage, tumor), and lead to dilatation of the third and both lateral ventricles. If the obstruction is in the fourth ventricle, the dilatation includes the aqueduct.
-
Colloid ( Paraphysial) Cyst and Other Tumors of the Third Ventricle The most important of these is the colloid tumor, which is
derived from ependymal cells of a vestigial third ventricular structure known as the paraphysis. The cysts formed in this structure are always situated in the anterior portion of the third ventricle between the interventricular foramina and are attached to the roof of the ventricle. They vary from 1 to 4 em in diameter, are oval or round with a smooth external surface, and are filled with a gelatinous material containing a variety of mucopolysaccharides. The wall is composed of a layer of epithelial cells, some ciliated, surrounded by a capsule of fibrous connective tissue. Although congenital, the cysts practically never declare themselves clinically until adult life, when they block CSF outflow through the foramen of Monro and produce an obstructive hydrocephalus. Suspicion of this tumor is occasioned by intermittent, severe bifrontal-bioccipital headaches, sometimes modified by posture (“ball valve” obstruction) or with crises of headache and obtundation, incontinence, unsteadiness of gait, bilateral paresthesias, dim vision, and weakness of the legs, with sudden falls but no loss of consciousness (“drop attacks”). Stooping may result in an increase or onset of headache and loss of balance. However, this intermittent obstructive syndrome has been infrequent in our experience. More often the patient has no headache and presents with the symptoms comparable to those of normal-pressure hydrocephalus or, as frequently, the tumor is found incidentally on CT or MRI.
On CT and MRI, the lesion density depends on the hydration state of the mucopolysaccharides. These lesions do not restrict diffusion or enhance with contrast.
Subtle behavioral Changes are common and a few patients experience mild confusion and changes in personality that may reach the extreme of psychotic behavior. In our experience, chronic headache or gait difficulty is usually present by that time.
The treatment for many years has been surgical excision, which always carries some risk, but satisfactory results have also been obtained by ventriculoperitoneal shunting of the CSF, leaving the benign growth untouched. Decompression of the cyst by aspiration under stereotactic control has also become an increasingly popular procedure. - Other tumors found in the third ventricle and giving rise mainly to obstructive symptoms are craniopharyngiomas, papillomas of the choroid plexus, and Ependymomas.
-
Ependymomas,
arise from the lining cells in the walls of the ventricles.Approximately 70 percent of them originate in the fourth ventricle. Postmortem, some of these tumors, if small, are found protruding into the fourth ventricle, never having produced local symptoms. Whereas the supratentorial ependymoma occurs at all ages, fourth ventricular ependymomas appear mostly in childhood. In the large series of Fokes and Earle (83 cases), 33 developed in the first decade of life, 6 in the second decade, and 44 after the age of 20 years. Males have been affected almost twice as often as females.
colloid cyst
Colloid:
Tumor of third ventricle.
Cysts always situated in the anterior portion of the third ventricle
Vary from 1-4cm
Oval – filled with gelatinous material
Congenital
declare themselves in adulthood
Block CSF via foramen of Monroe – obstructive hydrocephalus
Intermittent Severe bi-frontal – bioccipital headaches Modified by posture – ball valve obstruction
Crises of headaches, obtundation, incontinence, unsteadiness of gait,Sudden falls, no LOC – DROP ATTACKS
More commonly present with symptoms of NPH or tumor found incidentally
MRI – do not restrict diffusion or enhance with contrast
Rx: VP shunting leaving the benign growth or decompression of cyst
Other tumors of third ventricle – causing obstruction: craniopharyngiomas, papillomas
Of choroid plexus, ependymomas
תיאור של חולה עם נפילות חוזרות ללא אובדן הכרה ובחודשים האחרונים כאבי ראש ושינוי התנהגותי
1. גליומה
2. מניגנגיומה טמפורלית
3. קולואיד ציסט
קולואיד ציסט
Colloid:
Tumor of third ventricle.
Cysts always situated in the anterior portion of the third ventricle
Vary from 1-4cm
Oval – filled with gelatinous material
Congenital
declare themselves in adulthood
Block CSF via foramen of Monroe – obstructive hydrocephalus
Intermittent Severe bi-frontal – bioccipital headaches Modified by posture – ball valve obstruction
Crises of headaches, obtundation, incontinence, unsteadiness of gait,Sudden falls, no LOC – DROP ATTACKS
More commonly present with symptoms of NPH or tumor found incidentally
MRI – do not restrict diffusion or enhance with contrast
Rx: VP shunting leaving the benign growth or decompression of cyst
Other tumors of third ventricle – causing obstruction: craniopharyngiomas, papillomas
Of choroid plexus, ependymomas
Colloid cyst – no enhancement and not in lateral ventricle but always in third
בן 30 , בריא בד”כ, לפני יומיים השתעל בחוזקה. פנה למיון בשל כאב ראש המחמיר משמעותית בעמידה,
מלווה בבחילות והקאות. בבדיקתו קישיון עורף קל, ללא חום. האבחנה הסבירה ביותר היא :
א. INTRACRANIAL HYPOTENSION
ב. PSEUDOTUMOR CEREBRI
ג. SUBARACHNOID HEMORRHAGE
ד. VIRAL MENINGITIS
intracranial hypotension
אין אובסקורציות
Occasionally, there will be unilateral or bilateral sixth nerve palsy or a self-audible bruit from turbulence in the intracranial venous system. Hearing loss is a far less common complication. A rare syndrome that has been attributed to sagging of the frontal lobes in low CSF pressure situations has been described by Wicklund and coworkers. Patients are apathetic and disinhibited and have prominent daytime somnolence.
It has been recognized that low CSF pressure is associated on the MRI with variable dural enhancement by Gadolinium (Fig. 30-5) and, when the syndrome is protracted and severe, there may be small subdural effusions
Figure 29-1. Schematic representation of the bulk flow of CSF from the lateral ventricles, through the third and fourth ventricles, outward from the basal foramina (Luschka and Magendie), upward around the brainstem and basal cisterns to both the convexities of the hemispheres and downward to spinal subarachnoid space. Most absorption is presumed to occur over the cerebral convexities, abutting the sagittal sinus.
Figure 29-2. Schematic depiction of Lundberg waves that are seen with recordings of intracranial pressure. The A-waves (plateau waves) are appreciated only on trend recordings of pressure and consist of spontaneous or induced elevations of pressure to 25 to 50 mm Hg that begin over less than a minute and persist for many minutes before declining to baseline values. B-waves are ballistic deflections that reflect entry of blood into the main basal arteries and conductance vessels of the brain during cardiac systole. The insert shows the dicrotic and reflected “notches” within a B-wave, (P1, P2, and P3 not all of which are always visible); an increase in P2 amplitude above P1 is indicative or reduced intracranial compliance.
Figure 29-3. MRI of adult tension hydrocephalus from a congenital stenosis of the cerebral aqueduct. There is transependymal movement of water that appears as a T2 signal in a rim surrounding the lateral ventricles. The third ventricle, but not the fourth, is enlarged.
Figure 29-4. CT of a patient with normal-pressure hydrocephalus. There is enlargement of all the ventricles, particularly of the frontal horns of the lateral ventricles (left), which is roughly disproportionate to the cortical atrophy (right). The frontal horn span is over 39 mm. Various formulas have been devised to quantitate the imaging features, but they are difficult to apply.
Figure 29-5. Fluid-attenuated inversion recovery (FLAIR) MRI sequence in a patient man with hydrocephalus, shunt failure, and L-dopa-responsive parkinsonism. There is signal change in the dorsal midbrain and periaqueductal region.
Figure 29-6. MRI after gadolinium infusion (T1 sequence) showing
the widespread dural enhancement that is typical of low CSF pressure
after lumbar puncture, spontaneous CSF leakage, or shunt overdrainage.
Similar changes may be found in the spinal dura.
Figure 29-7. MRI with gadolinium infusion showing diffuse rheumatoid pachymeningitis in an older man with minimal systemic disease. He had severe headaches, hydrocephalus, and mental dullness.
