Search PubMed⌕ Search

Biomedical subjects

B Mokri

Publications and source records attributed to B Mokri.

At least 19 recordsLinked to original sources
PubMed2004

Paradoxical postural headaches in cerebrospinal fluid leaks.

Two patients with cerebrospinal fluid (CSF) leak, one at the level of fourth thoracic spine and another with undetermined level of leak, presented with paradoxical postural headaches in that the headaches were present when in a horizontal position and resolved if the patients were upright. One patient improved spontaneously and the other responded to a targeted epidural blood patch. Paradoxical postural headache is yet another headache type that can be associated with CSF leak and CSF volume depletion. Its mechanism is uncertain, but it could be related to congestion and dilatation of cerebral venous sinuses and large veins.

Female↗
PubMed2002

Spontaneous CSF leaks mimicking benign exertional headaches.

Spontaneous CSF leaks are increasingly recognized, and a broader clinical and imaging spectrum of the disorder is emerging. The headaches of CSF leaks are typically orthostatic, but sometimes especially with chronicity the orthostatic features are blurred into lingering chronic daily headaches. Additional types of headache are also increasingly recognized. Two patients with spontaneous CSF leaks presented with intermittent transient severe headaches provoked by Valsalva-type manoeuvres. Orthostatic features were absent and the patients were asymptomatic if they avoided the provoking manoeuvres. One patient had been treated for 6 years for benign exertional headaches and had failed many medical treatments, including courses of indomethacin. He was found to have a leak from cribriform plate. The second patient had been symptomatic for several months, had diffuse pachymeningeal gadolinium enhancement on head magnetic resonance imaging, spinal meningeal diverticula, and CSF leak at the thoracic spine level. Headaches that mimic benign exertional headaches are yet another mode of the still broadening clinical presentation of spontaneous CSF leaks.

Adult↗
PubMed2001

The efficacy of epidural blood patch in spontaneous CSF leaks.

Of 25 consecutive patients with spontaneous CSF leaks treated with epidural blood patch (EBP), nine patients (36%) responded well to the first EBP. Of 15 patients who received a second EBP, five became asymptomatic (33%). Of eight patients who received three or more EBP (mean 4), four patients (50%) responded well.

Adolescent↗
PubMed2001

The Monro-Kellie hypothesis: applications in CSF volume depletion.

More than two centuries ago, Alexander Monro applied some of the principles of physics to the intracranial contents and for the first time hypothesized that the blood circulating in the cranium was of constant volume at all times. This hypothesis was supported by experiments by Kellie. In its original form, the hypothesis had shortcomings that prompted modification by others. What finally came to be known as the Monro-Kellie doctrine, or hypothesis, is that the sum of volumes of brain, CSF, and intracranial blood is constant. An increase in one should cause a decrease in one or both of the remaining two. This hypothesis has substantial theoretical implications in increased intracranial pressure and in decreased CSF volume. Many of the MRI abnormalities seen in intracranial hypotension or CSF volume depletion can be explained by the Monro-Kellie hypothesis. These abnormalities include meningeal enhancement, subdural fluid collections, engorgement of cerebral venous sinuses, prominence of the spinal epidural venous plexus, and enlargement of the pituitary gland.

Brain↗
PubMed2001

Spontaneous intracranial hypotension.

Spontaneous intracranial hypotension (SIH) is typically manifested by orthostatic headaches that may be associated with one or more of several other symptoms, including pain or stiffness of the neck, nausea, emesis, horizontal diplopia, dizziness, change in hearing, visual blurring or visual field cuts, photophobia, interscapular pain, and occasionally face numbness or weakness or radicular upper-limb symptoms. Cerebrospinal fluid (CSF) pressures, by definition, are quite low. SIH almost invariably results from a spontaneous CSF leak. Only very infrequently is this leak at the skull base (cribriform plate). In the overwhelming majority of patients, the leak is at the level of the spine, particularly the thoracic spine and cervicothoracic junction. Sometimes, documented leaks and typical clinical and imaging findings of SIH are associated with CSF pressures that are consistently within limits of normal. Magnetic resonance imaging of the head typically shows diffuse pachymeningeal gadolinium enhancement, often with imaging evidence of sinking of the brain, and less frequently with subdural fluid collections, engorged cerebral venous sinuses, enlarged pituitary gland, or decreased size of the ventricles. Radioisotope cisternography typically shows absence of activity over the cerebral convexities, even at 24 or 48 hours, and early appearance of activity in the kidneys and urinary bladder, and may sometimes reveal the level of the leak. Although various treatment modalities have been implemented, epidural blood patch is probably the treatment of choice in patients who have failed an initial trial of conservative management. When adequate trials of epidural blood patches fail, surgery can offer encouraging results in selected cases in which the site of the leak has been identified. Some of the spontaneous CSF leaks are related to weakness of the meningeal sac, likely in connection with a connective tissue abnormality.

Blood Patch, Epidural↗
PubMed2001

Spontaneous intracranial hypotension.

Spontaneous intracranial hypotension (SIH) is typically manifested by orthostatic headaches that may be associated with one or more of several other symptoms, including pain or stiffness of the neck, nausea, emesis, horizontal diplopia, dizziness, change in hearing, visual blurring or visual field cuts, photophobia, interscapular pain, and occasionally face numbness or weakness or radicular upper-limb symptoms. Cerebrospinal fluid (CSF) pressures, by definition, are quite low. SIH almost invariably results from a spontaneous CSF leak. Only very infrequently is this leak at the skull base (cribriform plate). In the overwhelming majority of patients, the leak is at the level of the spine, particularly the thoracic spine and cervicothoracic junction. Sometimes, documented leaks and typical clinical and imaging findings of SIH are associated with CSF pressures that are consistently within limits of normal. Magnetic resonance imaging of the head typically shows diffuse pachymeningeal gadolinium enhancement, often with imaging evidence of sinking of the brain, and less frequently with subdural fluid collections, engorged cerebral venous sinuses, enlarged pituitary gland, or decreased size of the ventricles. Radioisotope cisternography typically shows absence of activity over the cerebral convexities, even at 24 or 48 hours, and early appearance of activity in the kidneys and urinary bladder, and may sometimes reveal the level of the leak. Although various treatment modalities have been implemented, epidural blood patch is probably the treatment of choice in patients who have failed an initial trial of conservative management. When adequate trials of epidural blood patches fail, surgery can offer encouraging results in selected cases in which the site of the leak has been identified. Some of the spontaneous CSF leaks are related to weakness of the meningeal sac, likely in connection with a connective tissue abnormality.

Cerebrospinal Fluid Pressure↗
PubMed2001

Posture-related headaches and pachymeningeal enhancement in CSF leaks from craniotomy site.

Cerebrospinal fluid (CSF) leak is recognized to cause headaches that typically but not invariably have orthostatic features (present in upright posture, relieved by recumbency). Head magnetic resonance imaging (MRI) typically shows diffuse pachymeningeal enhancement. A 24-year-old woman, after resection of a right temporoparietal glioma, developed CSF leak from the craniotomy site, resulting in subgaleal fluid collection and associated with diffuse pachymeningeal gadolinium enhancement as well as posture-related headaches. The headaches, however, were present in a recumbent position and relieved after several minutes of being in an upright position. It is postulated that CSF leak took place when the patient was recumbent and ceased when she was upright, a position in which there is decrease in intracranial pressure. After cessation of the leak, along with disappearance of subgaleal collection of CSF, both the headaches and the pachymeningeal enhancement resolved.

Adult↗
PubMed2000

Absent headache despite CSF volume depletion (intracranial hypotension).

CSF volume depletions, whether from leak or shunt overdrainage, typically cause low CSF opening pressures, orthostatic headaches, and diffuse pachymeningeal gadolinium enhancement on MRI. The authors report three patients-two with overdraining CSF shunts and one with proven CSF leak-with the typical pachymeningeal enhancement but without headaches. In CSF leaks and CSF shunt overdrainage, like MRI abnormalities and CSF alterations, the clinical features also show considerable variability. The independent variable remains the CSF volume depletion.

Aged↗
PubMed2000

False pituitary tumor in CSF leaks.

The authors describe five patients with typical clinical and MRI features of CSF leak and large enhancing pituitaries. The source of CSF leak was identified and surgically repaired in three patients. This was followed by disappearance of clinical symptoms and resolution of MRI abnormalities, including the pituitary enlargement. Enhancing enlargement of pituitary is another head MRI abnormality in CSF leaks, likely reflecting a secondary pituitary hyperemia.

Adenoma↗
PubMed2000

Spinal manifestations of vertebral artery dissection.

Among 111 patients with vertebral artery dissection (VAD), two presented with spinal manifestations: one with a C5-C6 radiculopathy and the other with a cervical myelopathy. Of 13 previously reported cases of spinal manifestations of VAD (mean age 37 years), ischemic cervical myelopathy was noted in seven; cervical radiculopathy, often at C5-C6 and primarily motor, in five; and hemorrhagic complications in one, with chest pain being part of the presentation.

Adult↗
PubMed2000

Cerebrospinal fluid volume depletion and its emerging clinical/imaging syndromes.

Cerebrospinal fluid (CSF) volume depletion, due to CSF leakage or CSF shunt overdrainage, is typically indicated when patients present with orthostatic headaches, with or without several other symptoms: neck or interscapular pain, nausea, emesis, diplopia, changes in hearing, visual blurring, facial numbness or weakness, and radicular upper-limb symptoms. Cerebrospinal fluid pressures typically are quite low and head magnetic resonance images typically reveal diffuse pachymeningeal gadolinium enhancement, with or without evidence of sagging of the brain and less frequently with subdural fluid collections, enlarged cerebral venous sinuses or pituitary gland or decreased ventricular size. Magnetic resonance imaging has revolutionized detection of spontaneous CSF leaks, leading to identification of far more cases and recognition of several clinical/imaging forms of presentation of the disorder. These forms, which are different from the "typical" presentation, include a group with consistently normal CSF pressures (normal pressure), another group without abnormal meningeal enhancement (normal meninges), and a group without headache (acephalic). Each of these forms can be seen in a setting of documented and ongoing CSF volume depletion. Awareness of CSF volume depletion is increasing, and its clinical and imaging spectrum is broadening.

Arachnoid↗
PubMed2000

Surgical treatment of spontaneous spinal cerebrospinal fluid leaks.

Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension. In this report the authors review the indications for surgery, surgical techniques, and surgery-related outcomes for these lesions. The major presenting symptoms include postural headaches, nausea, vomiting, and diplopia. Often, there is no history of traumatic injury. The most common cranial magnetic resonance (MR) imaging features include pachymeningeal gadolinium enhancement and sagging of the brain. On spinal MR images, diverticula are frequently noted. In cases in which symptoms are severe and refractory to less invasive measures, surgical intervention is indicated. Tears in the dura or leaking diverticula that are identified as the sources of the CSF leak often can be ligated or repaired. When a source of CSF egress is not found intraoperatively, packing the epidural space with blood-soaked Gelfoam or muscle at the appropriate level can lead to relief of symptoms. Occasionally the dural defect is large, irregular, or has attenuated borders that may not be possible to repair with sutures. These may be repaired by packing the defect with muscle or blood-soaked Gelfoam. Indications for and outcomes of surgery in patients with this condition will become more defined as surgeons gain experience with these procedures.

Cerebrospinal Fluid Pressure↗
PubMed1999

Absent pachymeningeal gadolinium enhancement on cranial MRI despite symptomatic CSF leak.

CSF leak is recognized to cause orthostatic headaches and diffuse pachymeningeal gadolinium enhancement (DPMGE) on MRI. We report six patients with typical symptoms and documented CSF leaks without DPMGE. Two had normal meninges from the onset; one initially had normal meninges, but subsequently DPMGE developed. In three, the initially noted DPMGE resolved while they were still symptomatic with documented continued CSF leaks. Absent DPMGE does not rule out CSF leak. When clinical manifestations suggest this disorder, additional diagnostic studies should be pursued.

Adolescent↗
PubMed1999

Thrombosis related to the use of L-asparaginase in adults with acute lymphoblastic leukemia: a need to consider coagulation monitoring and clotting factor replacement.

L-asparaginase (L-asp) has become an important component of combination chemotherapy for acute lymphoblastic leukemia (ALL). However, L-asp can produce depletions in many of the clotting factors with an associated risk for thrombosis and hemorrhage. Three consecutive patients seen at the Mayo Clinic with L-asp related thrombosis are described and an in-depth review of the literature is provided. Two of the 3 patients developed central nervous system (CNS) complications with evidence of thrombosis and hemorrhagic infarction. Two of the patients also developed extensive upper extremity thrombosis. The results of comprehensive hemostatic surveys showed marked abnormalities in all 3 patients. Many of the thrombotic complications related to L-asp involve the CNS, as illustrated in 2 of our patients. These patients should be treated aggressively since full recovery is possible. The precise cause of thrombosis is yet to be determined but is likely multifactorial. The optimal treatment and prevention of thrombosis in this group of patients remains poorly defined.

Adult↗
PubMed1999

Spontaneous cerebrospinal fluid leaks: from intracranial hypotension to cerebrospinal fluid hypovolemia--evolution of a concept.

Intracranial hypotension causes orthostatic headaches and diffuse pachymeningeal gadolinium enhancement on magnetic resonance imaging with or without subdural fluid collections or imaging evidence of descent of the brain. A review of the literature and my experience and investigations in the past decade reveal a broadening clinical and imaging spectrum of the syndrome. Besides the classic clinical-imaging syndrome of orthostatic headaches, diffuse pachymeningeal gadolinium enhancement, and low cerebrospinal fluid (CSF) pressure, several modes of presentation are recognized, including (1) the typical clinical-imaging syndrome with CSF pressures consistently within normal limits, (2) absence of diffuse pachymeningeal gadolinium enhancement with presence of low CSF pressures and typical clinical manifestations, and (3) absence of headaches despite low CSF pressures and presence of diffuse pachymeningeal gadolinium enhancement. Furthermore, in some patients with headaches, the orthostatic headaches may evolve into lingering chronic daily headaches, although they may be more prominent in upright positions. What determines the various clinical and imaging features of this syndrome seems to be the loss of CSF volume as the independent variable, while other manifestations, including clinical features, CSF pressures, and imaging abnormalities, are variables dependent on the CSF volume. The term CSF hypovolemia is proposed for this syndrome because the term intracranial hypotension no longer seems adequate to embrace all the variations that have emerged.

Cerebrospinal Fluid Pressure↗
PubMed1998

Orthostatic headaches caused by CSF leak but with normal CSF pressures.

OBJECTIVE: To report that the syndrome of orthostatic headaches caused by CSF leak can be seen with persistently normal CSF pressures. BACKGROUND: CSF leak or shunt overdrainage is known to cause orthostatic headaches and diffuse pachymeningeal gadolinium enhancement (DPGE), typically associated with unmeasurable or very low CSF pressures. METHODS: Of 40 consecutive patients with orthostatic headaches and DPGE, all had low or unmeasurable CSF pressures, except seven patients who had consistently normal CSF pressures and are thus reported. All had undergone multiple CSF examinations. RESULTS: Two patients had overdraining shunts, and five had documented CSF leaks. One refused treatment, but the other six patients responded to surgical treatment or epidural blood patch with complete resolution of symptoms and related MRI abnormalities. CONCLUSIONS: Some patients with symptomatic CSF leaks may have CSF opening pressures that are consistently within normal limits. In the presence of convincing clinical features and imaging abnormalities, a normal CSF pressure should not discourage the clinician from searching for a source of CSF leak.

Adult↗