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N J Patronas

Publications and source records attributed to N J Patronas.

At least 91 records · Page 5Linked to original sources

Some examples of balloon technology in neurosurgery.

Examples are presented of the use of a compression balloon to treat trigeminal neuralgia, of a dilating balloon to release a web obstruction of the internal carotid artery, of detachable balloons to seal carotid-cavernous and vertebral-venous fistulas, of a temporary occlusive balloon to aid in thrombogenic treatment of a giant aneurysm, and of a temporary occlusive balloon with double or triple-lumen capacity to assist in angiographic diagnosis and to provide reversible carotid occlusion.

Adolescent↗

Multiple meningiomas in the spinal canal.

Previous experimental and clinical observations suggest that radiation is a causative factor in the development of meningiomas. We report a rare case of three spinal meningiomas in a patient who had prior irradiation in the spinal region. The myelographic technique to evaluate multiple spinal canal tumors is outlined.

Adult↗

Microvascular embolization of cerebral arteriovenous malformations: A technical variation.

A useful variation of an established technique is described for embolization of cerebral arteriovenous malformations. Silastic sponge emboli that fit into No. 16, 17, and 18 stub adapters are passed through standard-sized transfemoral catheters. Of 28 treated patients, obliteration was regarded as very successful in 16. Partial success was achieved in four. Eight were regarded as failures because the reticulum was too large for these microemboli.

Adult↗

Hyperemic and ischemic problems of surgical treatment of arteriovenous malformations.

Three patients with arteriovenous malformations are described who showed signs of massive hyperemia in the vascular territory of the normal brain proximal to arterial ligation. One additional patient had evidence of ischemia of the brain in the territory distal to ligation (steal), and in another both mechanisms were considered as operative hazards.

Adolescent↗

Bronchial web diagnosed by bronchography.

Bronchial webs are rare lesions which often go unrecognized. The authors describe a patient who presented with right-lower-lobe bronchiectasis and at-electasis secondary to a web in the right-lower-lobe bronchus. This is the first known instance where such a lesion has been demonstrated by bronchography. The etiology of this and similar lesions reported in the literature remains obscure.

Bronchi↗

Ventricular shapes, distortions, and deformities: mirrors of past cerebral insults. A study based on early sonographic follow-up studies.

Ventricular distortions and deformities often represent the endpoint of neuropathologic reactions that evolve early in life. Once fully developed, they may offer no clues as to preceding etiologic agents or pathogenesis. Serial sonography in the neonatal period of 14 patients with periventricular leukomalacia provided documentation of the evolution of certain ventricular patterns. When recognized early, these ventricular changes have prognostic significance because periventricular leukomalacia can produce serious neurologic sequelae. If found later in childhood, periventricular leukomalacia can be suggested as the original pathology. Ventricular deformities can be generalized (12 patients) or focal (11 patients); the various types of distortions are seen frequently in combination. The generalized form of ventricular expansion consisted of uniform expansion of the parieto-occipital components (hydroporencephaly), following extensive periventricular white matter necrosis. Hydroporencephaly is a new form of ex vacuo hydrocephalus in the pediatric age group. Focal changes are caused by more localized white matter cavitations with ventricularization of ensuing porencephalic cysts. These changes result in a footprint-shaped ventricular pattern (10 patients) or in frontal/occipital (polar) ventricular pointing (4 patients). White matter necrosis in other areas may lead to ventricles with bumpy contours (5 patients).

Brain Damage, Chronic↗

Effect of moderate level x-radiation to brain on cerebral glucose utilization.

The effect of x-radiation in doses used in treatment of brain malignancies has previously been established largely by histologic examination of the tissue or by observation of a deficit in function. At moderate dose levels such effects are usually delayed and are vascular in origin. We have used the 2-[14C]deoxyglucose method for the quantitative measurement of local cerebral glucose utilization to learn whether x-radiation administered to rat brain in a dose below that which is known to result in any histologic change may nevertheless affect the brain's local rates of glucose utilization. Measurements were made 4 days and 4 weeks after exposure of groups of rats to 1,500 rad. Rates of glucose utilization in 54 gray and eight white matter structures in both groups were compared with rates in sham-irradiated controls. Statistically significantly lower rates were found in 16 structures in rats 4 days after radiation and in 25 structures 4 weeks after radiation exposure. A weighted average rate for the brain as a whole was approximately 15% below that of the controls for both radiated groups, but this difference was short of being of statistical significance. It is clear from this study that the metabolic rates of some brain structures are reduced following moderate doses of x-radiation.

Animals↗

Radiologic screening for von Hippel-Lindau disease: the role of Gd-DTPA enhanced MR imaging of the CNS.

Thirty-seven members of a family with von Hippel-Lindau disease (VHL) were prospectively screen for CNS hemangioblastomas; 10 family members were previously known to have VHL. Radiographic studies included noncontrast magnetic resonance (MR) imaging of the head (all patients) and spine (34 patients) and contrast-enhanced CT (CCT) of the head (all adult patients). Eleven patients had Gd-DTPA enhanced MR (CMR) of the head and 10 patients had CMR of the spine. Sixteen patients had radiographic evidence of CNS hemangioblastomas and all but six patients were symptomatic. Using comparable studies, CMR of the head demonstrated more lesions than the other modalities (31, 22, and 19 for CMR, MR, and CCT, respectively). Furthermore, CMR better separated tumor from edema, as well as cystic from solid components. Contrast enhanced MR was superior to noncontrast MR of the spine in lesion detection (31 vs. 4; p less than 0.001). Noncontrast MR was particularly limited in four patients with syringomyelia. We conclude that postcontrast MR of the head and spine is the best currently available means of detecting hemangioblastomas associated with VHL.

Adolescent↗

Meningeal Gd-DTPA enhancement in patients with malignancies.

Nineteen patients with malignant diseases and pathologically enhancing meninges were studied by pre- and postcontrast (Gd-diethylene-triamine pentaacetic acid) magnetic resonance (MR) scans. Two patterns of enhancement were recognized: the dural (14 patients) and the leptomeningeal (mainly pial) (5 patients). Positive cytology was found in only 3 of the 14 patients with dural enhancement (21%), whereas in the remaining 11 patients we noted either nonspecific CSF findings such as elevated protein, high white blood cell count, and low glucose or entirely normal CSF. Four patients (80%) in the group with leptomeningeal enhancement showed positive cytology and one had normal CSF analysis. We conclude that meningeal enhancement as seen on MR imaging is a nonspecific finding and correlates well with positive cytology only when the more rare form of leptomeningeal enhancement is encountered.

Adult↗

Intravascular thrombosis as a possible cause of transient cortical brain lesions: CT and MRI.

Cortical brain lesions were identified on MRI and CT in 14 patients with a variety of diseases. Each of these patients developed neurologic symptoms, the most prominent of which were seizures, depressed mental status, and blurred vision or cortical blindness. Both the imaging and the neurologic abnormalities resolved spontaneously within a period ranging from 5 to 30 days. Due to location and evolution of the lesions over time we hypothesize that they are secondary to small cortical venous thromboses.

Adolescent↗

MRI of choroidal plexus involvement in intracranial cryptococcosis.

OBJECTIVE: The sensitivity of medical imaging in the diagnosis of intracranial cryptococcosis is poor. MRI can provide additional information in establishing this diagnosis. MATERIALS AND METHODS: We present two cases of CNS cryptococcosis (HIV negative) studied by MRI and discuss the involvement of the ventricles and the choroid plexuses. RESULTS: The choroid plexuses are unusually enlarged and they enhance intensely. Intraventricular loculations were also noted including entrapment of CSF in the temporal horns. CONCLUSION: The constellation of these findings is highly suggestive of cryptococcosis.

Adult↗

Orbital involvement in Wegener granulomatosis: MR findings in 12 patients.

PURPOSE: Our goal was to characterize the MR features of orbital Wegener granulomatosis (WG). METHOD: Twelve patients with pathologically proven WG were studied with MRI. Enhanced and unenhanced T1-weighted sequences with conventional and fat-suppressed techniques were used. T2-weighted images were also obtained. Signal intensity measurements were made in each orbital lesion on the T2-weighted images and compared with that of normal fat. The degree of enhancement was also evaluated by measuring the change in signal intensity of each lesion between the unenhanced and enhanced studies. RESULTS: Seventeen orbital lesions were identified in the 12 patients. Fifteen of the lesions examined by T2-weighted sequences demonstrated a marked decrease in signal intensity. The unenhanced, non-fat-suppressed T1-weighted sequences provided the best contrast between lesion and normal structures. All of the WG lesions enhanced, but the degree of enhancement varied. The enhancement characteristics were best appreciated on the fat-suppressed T1-weighted technique. CONCLUSION: MRI is an excellent imaging modality to evaluate orbital involvement in WG. A marked decrease in the T2 signal is a characteristic feature of this entity. The unenhanced, non-fat-suppressed T1-weighted sequence is the preferred method for lesion detection and for definition of the pattern of anatomic involvement when utilizing MRI.

Adult↗

MR virtual angioscopy of thoracic aortic atherosclerosis in homozygous familial hypercholesterolemia.

PURPOSE: The thoracic aorta is an important site of atherosclerotic disease in patients with homozygous familial hypercholesterolemia (HFH). Thoracic aortic atherosclerosis in patients with HFH was assessed with contrast-enhanced MR angiograms using exoscopic and endoscopic virtual angioscopy reconstructions and maximum intensity projections (MIPs). METHOD: Contrast-enhanced MR angiograms of the thoracic aorta of 15 patients with HFH and 8 normal volunteers were obtained. Perspective surface reconstructions of the MR angiograms including virtual angioscopy views were evaluated by three radiologists blinded to the diagnosis. RESULTS: Thoracic wall irregularity was depicted on 8 of 15 (53%) patient scans and only 1 of 8 (13%) normal subject scans using surface reconstructions. Wall irregularity scores of patients with HFH were significantly increased compared with controls (2.0 +/- 0.9 vs. 1.0 +/- 0.6; p = 0.008). There was excellent interobserver agreement (weighted kappa = 0.82 +/- 0.12). Virtual endoscopy views added diagnostic confidence compared with exoscopic surface renderings alone. MIP reconstructions were unable to depict wall irregularity. CONCLUSION: MR angiography with virtual angioscopy of the thoracic aorta depicts nonstenotic wall irregularity of thoracic aortic atherosclerosis in patients with HFH. This may be important for assessing disease progression and response to treatment and may be generalizable to routine (non-HFH) atherosclerosis.

Adult↗

MR of slow CSF flow in the spine.

PURPOSE: To evaluate a slow-flow MR sequence in normal CSF flow and in CSF flow disturbance in cases of spinal stenosis. METHOD: The method was tested for flow sensitivity and applied to 67 sites of spinal canal compromise. RESULTS: Phantom studies show that flow can be depicted at a velocity of 0.5-1 mm/sec. On clinical images, stagnant CSF is black, flowing CSF is bright. Typically, in high-grade (90%-100%) stenosis, CSF above and below the site of spinal canal compromise (SCC) is black. With intermediate stenosis (50%-89%), CSF above the SCC remains white but becomes black distal to the SCC. Low-grade stenosis shows only localized flow disturbances. CONCLUSION: This easy-to-use sequence can solidify the MR diagnosis of high-grade stenosis when a distinct flow pattern is recognized. Flow patterns for intermediate and low-grade stenosis are less reliable.

Cerebrospinal Fluid↗