Facial nerve enhancement on gadolinium-DTPA in a case with neurosarcoidosis

In a case of neurosarcoidosis with bilateral facial nerve palsy and hydrocephalus, contrast-enhanced magnetic resonance imaging (MRI) study and angiotensin converting enzyme (ACE) activities in cerebrospinal fluid (CSF) were valuable for the diagnosis and the follow up. Facial nerve lesions were demonstrated on gadolinium-DTPA enhanced MRI. The disappearance of enhancement was concomitant with the amelioration of facial nerve palsy after corticosteroid therapy.     

Zoo-FISH delineates conserved chromosomal segments in horse and man

PURPOSE: Evaluation of dynamic Gd-DTPA enhanced MR imaging in the staging of bladder cancer. METHODS: We studied 40 patients with histologically proven bladder cancer. All patients were examined with routine T1- and T2-weighted MRI and late Gd-DTPA enhanced T1-weighted MRI. Additionally, a dynamic study was performed with 10 subsequent short FLASH-2-D gradient echo sequences without delay immediately after bolus injection of Gd-DTPA. Signal intensities of the tumour and of the surrounding tissue as well as image contrast parameters were quantified. RESULTS: The dynamic study showed a higher accuracy in the evaluation of stage pTa to pT2 cancer compared to spin echo MRI (63% and 46%, respectively) and no difference regarding the sensitivity (87.5%). However, overstaging was a problem with both modalities. The contrast-to-noise ratio of bladder tumour and muscle was equal or significant higher with the dynamic study compared to spin echo MRI. A higher signal-to-contrast ratio of bladder tumour and bladder muscle was calculated for the dynamic study compared with the spin-echo MRI (p < 0.01; Mann-Whitney U test). CONCLUSION: Dynamic Gd-DTPA enhanced MRI is recommended to be used additionally in the preoperative staging of bladder neoplasms.     

CT and MRI features of cavernous haemangioma of internal auditory canal

A left internal auditory canal (IAC) cavernous haemangioma is reported in a 45-year-old Saudi male. The lesion was associated with rapidly deteriorating hearing loss and facial nerve dysfunction. CT showed a calcified enhanced IAC lesion while T1 weighted MRI showed an isointense contrast enhancing lesion bulging into the porus acousticus. The imaging features of the three usual IAC lesions--meningioma, acoustic neuroma and cavernous haemangioma--were compared. Calcification/ossification appear more commonly in cavernous haemangioma than in the other two lesions while facial nerve dysfunction is a clinical hallmark of IAC cavernous haemangioma.     

Contrast enhanced magnetic resonance imaging as a method to diagnose early inflammatory changes in the temporomandibular joint in children with juvenile chronic arthritis

OBJECTIVE: Recent studies have stressed early diagnosis of temporomandibular joint (TMJ) involvement in children with juvenile chronic arthritis (JCA) to initiate treatment before destruction of the condylar head and growth alterations take place. TMJ involvement is often asymptomatic, but studies with contrast enhanced magnetic resonance imaging (MRI) in other joints have shown that it is possible to detect the early inflammatory changes. METHODS: Thirty TMJ in 15 children with newly diagnosed JCA (mean age 12.0 years) were examined clinically, with radiographs and with MRI enhanced with gadolinium diethylene thiamine pentaacetic acid (Gd-DTPA). A control group of 10 healthy children (mean age 11.5 yrs) were examined clinically and with MRI. The MRI variables included T1 weighted images before and after administration of Gd-DTPA with and without fat suppression. RESULTS: MRI enhanced with Gd-DTPA indicated inflammatory activity in 87% of the patients. Conventional MRI without contrast medium proved to be insignificant in diagnosing early inflammatory changes. CONCLUSION: Enhanced MRI is very efficient in diagnosing early inflammatory changes of the TMJ and is a more sensitive method than the clinical examination and radiographs.     

Gd-DPTA enhanced MRI in Bell's palsy and herpes zoster oticus: an overview and implications for future studies

Magnetic resonance imaging (MRI) is a new and important tool for use in diagnosing and investigating diseases affecting the facial nerve. In recent gadolinium-DTPA enhanced MRI (Gd-MRI) studies it has unequivocally been demonstrated that ipsilateral facial nerve contrast enhancement, predominantly in the meatal portion, is present in both Bell's palsy and herpes zoster oticus. In this overview, the results of MRI studies performed on patients with acute peripheral facial palsy, especially Bell's palsy and herpes zoster oticus, are discussed. The Gd-MRI pattern in Bell's palsy is very similar to that seen in herpes zoster oticus, and the findings reported so far support the theory that an inflammation may be the cause of the nerve injury in both cases. So far, however, Gd-MRI has not been helpful in evaluating the severity and/or prognosis of the facial palsy. Further studies employing improved techniques, including three-dimensional fast (or turbo) spin echo (3DFSE) MRI with heavily T2-weighted sections and high resolution three-dimensional Fourier transform (3DFT) MRI, need to be conducted in order to determine whether it is possible to follow the course of the disease and whether MRI and/or Gd-MRI are useful prognostic tools in the early stages of palsy.     

MRI of inner ear anatomy using 3D MP-RAGE and 3D CISS sequences

The aim of this study was to compare contrast enhanced 3D MP-RAGE (magnetization prepared rapid gradient echo), unenhanced 3D MP-RAGE and 3D CISS (constructive interference in steady state) in the evaluation of anatomical detail of the inner ear and facial nerve. 60 persons with no abnormalities and no or non-specific symptoms were examined with MRI. All examinations were performed using a 1.5 T MR unit. The detectability of anatomical details was evaluated by agreement of three radiologists. Statistical evaluation of the results was achieved by the two-tailed Wilcoxon's test. In 86-95% of the cases, 3D CISS resulted in excellent visibility of the basal and second turn and apex of the cochlea, the vestibule and semicircular canals, as well as the nerves within the internal auditory canal. There was a significantly better visualization with CISS than with MP-RAGE. Detectability of the extrameatal facial nerve was best using contrast enhanced 3D MP-RAGE in 91-96% of the cases (labyrinthine segment 96.7%; geniculate ganglion 95%; tympanic segment 91.7%; vertical segment 95%). The detection of the meatal seventh nerve was best using CISS, whilst unenhanced MP-RAGE gave significantly better results than contrast enhanced MP-RAGE. These results suggest that unenhanced and contrast enhanced 3D MP-RAGE and 3D CISS sequences are complementary and not alternative MRI techniques. Both T1 and T2 weighted 3D MR imaging of the temporal bone is of advantage when compared with 2D MR sequences due to improved contrast, geometrical resolution and the possibility of adequate reconstruction of anatomical structures.     

High-resolution MRI of pancreatic masses with a new circularly polarized body phased-array coil

A total of 18 patients with clinical suspicion of a pancreatic tumor underwent dynamic contrast-enhanced CT and MRI examinations. A fat-suppressed T1-weighted 2D fast-low-angle-shot (FLASH) sequence and a T2-weighted spin-echo (SE) sequence were applied in a transverse orientation using a circularly polarized (CP) body phased-array coil. The FLASH sequence was repeated after Gd-DTPA administration. The highest spatial resolution was 1.37 x 1.37 x 3.00 mm3. In two cases a half Fourier single-shot turbo-SE sequence (HASTE) was additionally applied. In a comparison between CT and MRI, pancreatic masses could be demonstrated and characterized with excellent image quality. The fat-saturated 2D FLASH sequence yielded the highest contrast-to-noise ratios after Gd-DTPA administration between pancreas and inflammatory or neoplastic lesion. One non-contour deforming carcinoma could be detected only with MRI and was only retrospectively visible on CT with an element of uncertainty. Magnetic resonance imaging using a CP body phased-array coil and fat-suppressed T1- and T2-weighted FLASH, SE, and turbo-SE sequences offers diagnostic possibilities in improved imaging of the pancreas.     

Prediction of facial nerve displacement in extra large vestibular schwannoma

The primary objective in the surgery of extra large vestibular schwannoma is the total removal of the tumour mass while preserving the facial nerve. Preservation of the facial nerve in extra large tumours is reported as being notoriously difficult in the majority of cases. This study was undertaken to evaluate the accuracy in predicting displacement of the facial nerve by preoperative radiological imaging studies in 19 cases of extra large vestibular schwannoma. The direction of displacement of the facial nerve was predicted with preoperative axial and coronal MRI scans and verified intraoperatively. We achieved total removal of tumours in 84.2%, facial nerve displacement was predicted in 80% and we accomplished anatomical preservation in 80%. Prediction of displacement was difficult in tumours with little or no intracanalicular components or with severe bony destruction of the internal acoustic meatus. The preoperative prediction of facial nerve displacement in extra large tumours allows safe internal decompression of the tumour and careful dissection near the predicted area of the facial nerve during the operation. Consequently, a high rate of anatomical preservation of the facial nerve can be achieved.     

Inflammatory central nervous system demyelination: correlation of magnetic resonance imaging findings with lesion pathology

Magnetic resonance imaging (MRI) is widely used to evaluate and monitor disease activity in inflammatory demyelinating central nervous system (CNS) diseases such as multiple sclerosis. The present study aimed at correlating MRI findings with histological parameters in 6 cases of biopsy-proven inflammatory demyelination of the CNS. The earliest stages of demyelinating activity manifested as almost isointense lesions with a massive gadolinium-DTPA (Gd-DTPA) enhancement in T1-weighted scans. In T2-weighted scans, early active lesions formed a border of decreased intensity compared with the lesion center and the perifocal edema. The morphological correlate of this pattern in our patients was activated macrophages in the zone of myelin destruction at the plaque border. Late active lesions were hypointense in T1 and hyperintense in T2 scans. Inactive demyelinated and remyelinating lesions were hyperintense in T2 scans and enhanced inhomogenously after Gd-DTPA application. T1 scans revealed major differences in the degree of hypointensity that correlated with the extent of axonal damage, extracellular edema, and the degree of demyelination or remyelination.     

Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis

OBJECTIVES: To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS: The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS: Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS: It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality.     

A case of gliosarcoma associated with large cyst

A case of gliosarcoma with a large cyst is reported. A 22-year-old female was admitted to our hospital with complaints of blurred vision and headache. Plain skull x-ray films showed a radiolucent area in the right frontal area. Computed tomography (CT) revealed an iso-dense mass in the right frontal lobe with a large cyst. After administration of contrast medium, the solid part and cyst wall were well enhanced and the content of the cyst was slightly enhanced. CT number of the cyst fluid was increased from 64.2 to 83.5 Hounsfield units, after administration of the contrast medium. Axial T1-weighted magnetic resonance image (MRI) revealed an iso-intense mass with marked enhancement by Gd-DTPA in the same area. A large cyst was shown to be located in the dorsal part of the mass. A small round protrusion, 10 mm in diameter, was found on the anterior portion of the mass on this MRI. Right carotid angiogram showed a tumor stain fed by the frontopolar artery. Right frontal lobectomy including the tumor was carried out with a preoperative diagnosis of glioblastoma. The patient received radiation therapy of 60Gy (whole brain 40Gy; focal 20Gy) and chemotherapy postoperatively. Histologically, necrosis, hemorrhage and endothelial hyperplasia were revealed at the tumor lesion. The tumor was composed of proliferation of glial and mesenchymal elements. The glial element appeared as fibrillary astrocytoma and polar spongioblastoma. The mesenchymal element showed sarcoma. As mentioned above, this tumor was diagnosed as gliosarcoma. It was difficult to make a diagnosis of gliosarcoma preoperatively because of the complex findings similar to malignant gliomas in conventional neuroradiological imaging.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cavernous haemangioma of the facial nerve

Facial nerve haemangiomas are probably the most frequent benign tumours involving the facial nerve in its intratemporal portion. Usually facial nerve dysfunction is present when these tumours are of extremely small size, the average tumour being less than 10 mm. We present a case of a 15 mm diameter cavernous haemangioma of the geniculate region, with histological findings of nerve infiltration, without facial nerve symptoms. The atypical clinical presentation justifies the report and subsequent literature review.     

Intraoperative monitoring of facial nerve antidromic potentials during acoustic neuroma surgery

The present paper presents monopolar recording of facial nerve antidromic potentials as an alternative technique to facial electromyography for the continuous monitoring of the facial nerve during acoustic neuroma surgery. The investigation involved 22 patients undergoing acoustic neuroma surgery via a retrosigmoid approach (tumour sizes ranging from 5 to 28 mm). Bipolar electrical stimulation of the marginalis mandibulae was performed to elicit facial nerve antidromic potentials. Stimulus intensity ranged from 2 to 6 mA with a delivery rate of 7/sec. A silver wire monopolar electrode positioned intracranially on the proximal portion of the acoustic facial bundle was used to record antidromic potentials. To define the specific origin of the action potentials and acquire normative data, monopolar and bipolar recordings of facial nerve antidromic potentials were performed in 15 subjects undergoing retrosigmoid vestibular neurectomy for Meniere's disease. The average facial nerve antidromic potential latency was 4.2 (+/- 0.6) msec in subjects with acoustic neuroma and 3.3 (+/- 0.2) msec in subjects with Meniere's disease. Facial nerve antidromic potentials furnished near real-time information about intraoperative facial nerve damage and postoperative facial nerve function during acoustic neuroma surgery. Facial nerve antidromic potentials may provide additional information to conventional EMG. They allow the use of endplate blockers, yield quantitative estimation of facial nerve conduction properties in terms of amplitude and latency, and allow actual continuous monitoring of the facial nerve.     

A case of rheumatoid pachymeningitis

Here we present a 53-year-old woman with rheumatoid pachymeningitis. The subject had rheumatoid arthritis (RA) for 15 years. In April, 1996 she began to experience intermittent headaches. In September, her headaches became severe and continuous. In October, she suddenly developed ptosis of the left eye and diplopia. She also started to have dysphagia and she found it increasingly difficult to eat. She was admitted to our hospital on November 1, 1996. Neurological examinations revealed palsies of the left IIIrd, IVth, and VIth, and bilateral IXth, and Xth cranial nerves. Laboratory findings showed leukocytosis, elevated blood sedimentation rate, and positive CRP. Serum RA titer was positive (30x). The cerebrospinal fluid was normal and bacteriological examination was negative. T1-weighted MRI demonstrated hypertrophic cranial dura extending from the falx cerebri to tentorium cerebelli, which was enhanced markedly by Gd-DTPA. The dura adjacent to the cavernous sinus and the clivus were also thickened, which probably caused her cranial polyneuropathies. The dural biopsy showed massive infiltration of the inflammatory cells throughout the dura, proliferation of collagen fibers, and necrotic granuloma with neutrophilic infiltrations. Neither rheumatoid nodules, nor vasculitis were found. Despite the absence of rheumatoid nodules in the dural biopsy, the clinical features, pathologic specimens, and MRI findings of the thickened dura were most consistent with rheumatoid pachymeningitis. Administration of dexamethason ameliorated her headache on the 4th hospital day, and the cranial polyneuropathies completely disappeared on the 35th hospital day. The dural enhancement previously seen on the contrast T1-weighted MRI was diminished. Serum RA titer was also normalized (10x). Rheumatoid pachymeningitis is an extremely rare disease, and only 16 cases were reported in the literatures. Hypertrophic pachymeningitis should be considered as a diagnostic possibility in RA patients who have prolonged headache, and Gd-DTPA MRI is recommended to demonstrate the dural involvement.     

Quantitative analyses for facial nerve MR imaging

It is clear, from our clinical experience, that the facial nerve in patients with facial palsy is enhanced on magnetic resonance (MR) imaging after intravenous administration of gadolinium diethylenetriamine. However, some problems with clinical reliability persist. There have been reports that normal facial nerves often show enhancement on MR imaging. We also question whether there are any differences in the degree of enhancement between Bell's palsy and Ramsay Hunt syndrome. To solve these problems, analyses were conducted using a personal computer by means of digital image-processing to measure the gray scale levels of enhanced facial nerves on MR imaging films. Seventeen cases of Bell's palsy, eight cases of Ramsay Hunt syndrome and fourteen normal subjects whose facial nerves showed enhancement on MR imaging were selected for the analyses. The concept of a facial nerve/whole image ratio (F/W ratio), analyzing the degree of enhancement of the facial nerve quantitatively, is introduced in this paper. The F/W ratio is the ratio of the gray scale level of the facial nerve region to the highest gray scale level in the skull at the MR imaging film. When the F/W ratios of these subjects were analyzed, no significant differences were found between Bell's Palsy and Ramsay Hunt syndrome in the degree of enhancement; facial palsy cases showed quantitatively larger F/W ratios than normal subjects.     

Word reading in Alzheimer''s disease: cross-sectional and longitudinal analyses of response time and accuracy data

Injection of Fluoro-Gold (FG) into the whiskerpad muscles of rats yields a permanent retrograde labeling of motoneurons in the facial nucleus. Following subsequent resection of 10 mm of the facial nerve, one-third of the facial motoneurons die and the microglia phagocytize the dead FG-labeled neurons, take up FG, and get labeled in vivo. The resulting identification of all FG-labeled cells allows long-term comparative investigations on the behavior of neuronophages. In this study, we used two groups of rats to test whether the quantified expression of five immune-related antigens by neuronophages was related to quantified decline in neuron number (counts after immunostaining for neuron-specific enolase) 3 to 224 days after resection of the facial nerve. Rats of the first group received standard food and those of the second group, pellets containing 1,000 ppm of the calcium channel blocker nimodipine. Image analysis of the number of FG-containing cells and the number and projection area of immunopositive neuronophages in serial sections for each antigen showed that nimodipine significantly attenuated the immunostaining for CR3, MHC class I, and class II antigens (monoclonal antibodies [MAbs] OX-42, OX-18, and OX-6); enhanced the expression of monocyte-macrophage-specific antigen (MAb ED1); and did not change the expression of rat macrophage differentiation antigen (MAb ED2). The altered expressions, however, had no effect on the loss of motoneurons in the lesioned facial nucleus. We conclude that the degree of expression of immune-related antigens by neuronophages has no influence on the delayed neuronal cell death induced by permanent target deprivation.     

The MRI appearance of the optic nerve sheath following fenestration for benign intracranial hypertension

Optic nerve fenestration is carried out in cases of severe benign intracranial hypertension. This study aimed to monitor the optic nerve sheath appearances and orbital changes that occur following this procedure. The eight patients were all female with an average age of 37.3 years and a range of 20-58 years. The duration of symptoms was 2-6 years. Symptoms included headaches, diplopia and visual obscurations. Examination revealed severe papilledema. All investigations, including MRI, biochemical and immunological tests, were negative. Patients had fenestration of a 2 mm x 3 mm segment of the medial aspect of the optic nerve sheath. Imaging was obtained with a 1 T MRI machine using a head coil. Coronal, axial and sagittal 3 mm contiguous sections using STIR sequences with TR 4900 ms, IT 150 ms and TE 60 ms were obtained. Five patients showed clinical improvement. The post-operative MRI findings in four of these included a decreased volume of cerebrospinal fluid (CSF) around the optic nerve sheaths and a localized collection of fluid within the orbit. There were no MRI changes in the three patients with no clinical improvement. Decreased CSF volume around the optic nerve and a fluid collection within the orbit may indicate a favorable outcome in optic nerve fenestration.     

Solid rod short segment anterior fusion in thoracolumbar scoliosis

BACKGROUND: Facial electroneurography (ENoG) is an established and reliable method for assessing neural degeneration in various conditions affecting the facial nerve. The facial nerve may be subclinically involved by parotid tumors, but estimating such involvement preoperatively may be difficult when facial function is normal. The hypothesis that preoperative ENoG: (1) can detect subclinical facial nerve degeneration as a measure of involvement by parotid tumors and (2) can predict facial nerve function following parotidectomy was prospectively evaluated in the present study. METHODS: Twenty-two patients undergoing parotidectomy for tumors were tested preoperatively with ENoG, and their facial nerve function was graded pre- and postoperatively (House-Brackmann system). Eight patients had malignant tumors and 14 benign tumors. RESULTS: In patients with malignant tumors, lower percentage of preoperative ENoG response indicated nerve involvement that was not evident on clinical examination and correlated significantly (p = .035) with postoperative facial nerve dysfunction. Preoperative ENoG reduction of greater than 80% was found in all patients whose facial nerve was infiltrated by tumor. In 14 patients with benign tumors, preoperative ENoG results had no correlation with postoperative facial function. CONCLUSIONS: In malignant tumors, even when facial function is clinically intact, a low preoperative ENoG response may predict facial nerve involvement by the tumor. The lower the preoperative ENoG response, the poorer is the expected postoperative facial nerve function. There was no such correlation in benign parotid tumors.     

MRI studies of multiple sclerosis: implications for the natural history of the disease and for monitoring effectiveness of experimental therapies

The use of magnetic resonance imaging (MRI) in multiple sclerosis (MS) has increased in our understanding of the natural history of the disease course and has provided and important tool for the analysis of new experimental therapies. Studies using MRI as well as pathological studies of MS indicate that the first event in the development of a new MS lesion as seen on T2 weighted images is disruption of the blood brain barrier (BBBD) which can be demonstrated by areas of increased signal on T1 weighted images done after the administration of gadolinium DTPA. When GdDTPA enhanced MRIs are used to monitor disease activity in patients with mild relapsing remitting MS, a considerable degree of disease activity is observed in clinically stable patients. These findings indicate that MS is an active and progressive disease in most patients even during the earliest phases of the disease and before significant clinical disability has occurred. MRI is also an important tool in evaluating new therapies. Using simple baseline vs treatment designs evidence for an effect of a new treatment on MRI parameters such as Gd-DTPA enhanced measure of BBBD can be achieved using a small study cohort and over a short duration. Together these advances should lead to more rapid progress in the understanding of MS and in identifying new treatments.     

Enteropathogenic E. coli: intimacy redefined

A 42 yr old male presented with left facial weakness. MRI showed lesions affecting the distal seventh nerve and third division of the trigeminal nerve. The seventh nerve was biopsied and showed a malignant epithelioid schwannoma. The patient underwent extensive resection followed by irradiation. This is one of very few examples of intracranial malignant peripheral nerve sheath tumors and the first reported example of an intracranial malignant epithelioid schwannoma. The literature is reviewed and completeness of resection appears to be the most pertinent prognostic factor.