Isolation and characterization of the tsetse thrombin inhibitor: a potent antithrombotic peptide from the saliva of Glossina morsitans morsitans

A case of cranial hypertrophic pachymeningitis of unknown etiology in a patient with 15-year history of headaches, cranial nerve palsies, and gait disturbance is reported. A 77-year-old woman was brought to our institute in a coma. CT revealed intracerebral hemorrhage in the right temporal lobe and thickening of the falx and tentorium. Fifteen years previously the patient had undergone CT scanning because of headaches, cranial nerve palsies, and progressive gait disturbance and a thickened tentorium, mild hydrocephalus and edematous change in the right temporal lobe had been reported. Since the etiology of her symptoms was unclear at the time, she did not receive adequate treatment. Her symptoms gradually progressed thereafter, and her visual acuity and hearing deteriorated. MR imaging in 1994 showed the thickened tentorium as a hypointense area with hyperintense edges on Gd-DTPA enhanced images. Angiography revealed narrowing of posterior portion of the superior sagittal sinus. The patient's condition rapidly deteriorated due to the intracranial hypertension and she subsequently died. Autopsy revealed a thickened tentorium with xanthochromic surface. This hypertrophic change was also seen in the dura mater of the posterior and middle cranial fossa. Microscopic examination of the thickened tentorium revealed extensive fibrous tissue with a chronic inflammatory infiltrate, predominantly of lymphocytes. No specific lesions were revealed by staining with hematoxylin-eosin, PAS, Gram's or Ziehl-Neelsen stains. The patient had no inflammatory or infectious diseases of other organs, and a diagnosis of idiopathic cranial hypertrophic pachymeningitis of unknown etiology was made. Considering the above findings, the thickened tentorium depicted as a hypointense area on the T1- and T2-weighted images and the Gd-enhanced edges of the tentorium are thought to be represent fibrous tissue and inflammatory regions, respectively.     

Fatal hemorrhage from rupture of the intracranial internal carotid artery caused by aspergillus arteritis

To the best of our knowledge, this is the first reported case of combined intracranial and extracranial hemorrhage due to aspergillus cerebral arteritis. Knowledge of the imaging and the importance of early diagnosis and treatment are emphasized. A 78 year old man developed progressive right-sided visual impairment and diplopia. Magnetic resonance imaging demonstrated a mass lesion located in the right orbital apex, with extension to the cavernous sinus and the right middle cranial fossa. Cerebral angiography showed no aneurysmal dilatation. He was scheduled for transnasal biopsy. However, the patient died of massive epistaxis and intracranial hemorrhage. Postmortem examination revealed an aspergillus granuloma of the orbit and the skull base involving the intracranial and extracranial internal carotid artery. Aspergillus fumigatus was identified by culture. The characteristic feature of the fungal infection is a low-intensity signal on T2-weighted magnetic resonance images. This finding may be useful in diagnosing fungal infection.     

Sphenoethmoidal mucoceles with intracranial extension--three case reports

Three unusual cases of sphenoethmoidal mucoceles with rare intracranial extension are reported. A 64-year-old female presented with a 7-month history of right visual disturbance. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated a huge mass in the right middle fossa. She underwent right frontotemporal craniotomy. Postoperatively, her proptosis and cranial nerve dysfunction had improved markedly. A 53-year-old female complained of headache, nausea, and dizziness. CT and MR imaging revealed a cystic mass filling the right sphenoid sinus. The cystic lesion was evacuated through the transnasal approach. She was doing well postoperatively and has been asymptomatic. A 39-year-old male complained of headache, vomiting, and right visual disturbance. CT and MR imaging demonstrated a homogeneous mass occupying the sphenoid sinus. Sphenoidotomy exposed the cyst extending superiorly into the anterior cranial fossa. He recovered from the visual disturbances and has been asymptomatic since. MR imaging provides confirmation of the diagnosis of sphenoethmoidal mucocele and is important for preoperative evaluation.     

Postoperative sella: evaluation with fast spin echo T2-weighted high-resolution imaging

OBJECTIVE: The purpose of this study was to investigate the magnetic resonance features of the postoperative sella with fast spin echo (FSE) T2-weighted high-resolution imaging and to evaluate the benefits of the sequence using a follow-up magnetic resonance imaging protocol after transsphenoidal surgery. METHODS: Coronal spin echo (SE) T1-weighted and FSE T2-weighted images were prospectively obtained in 24 patients after surgery for pituitary adenomas. We observed the signals and the contour of normal structures, fluid collection, implanted materials, and mass lesions, including granulation tissue and adenoma. RESULTS: The pituitary gland was delineated in 51 of 59 FSE T2-weighted images, 90.2% of which presented clear boundaries. Whereas the gland was detected in 49 of 58 SE T1-weighted images, only 20.4% showed the boundaries. A mass lesion was identified in each of 12 patients with good resolution on FSE T2-weighted images. SE T1-weighted images detected mass lesions in 7 of 12 patients without distinctive boundaries. Contrast enhancement had little advantage in clarifying the boundaries between normal and abnormal structures. For the detection of mass lesions in the sella, the kappa values for interobserver agreement were 0.8 for FSE T2-weighted images and 0.25 for SE T1-weighted images. CONCLUSION: FSE T2-weighted imaging is a reliable method with which to assess the sella with sufficient resolution after transsphenoidal surgery. The combination of unenhanced SE T1-weighted and FSE T2-weighted images may reduce the use of contrast material after pituitary surgery.     

Hypertrophic cranial pachymeningitis with spinal epidural granulomatous lesion

A 67-year-old woman with a one-year history of tinnitus and headache had multiple cranial nerve palsies of V, VII, VIII, IX, X, XI and spastic paraparesis. She also had a secretory otitis media. Gd-DTPA-enhanced magnetic resonance imaging (MRI) revealed hypertrophy of the dura of the posterior fossa and spinal epidural mass which extended from C7 to T10. A biopsy of the epidural mass showed chronic granulomatous change. These lesions were completely cured with administration of antibiotics. We believe this case of double-lesion of hypertrophic cranial pachymeningitis and spinal epidural granulomatous lesion originated from a bacterial infection secondary to the secretory otitis media.     

Human fetal pituitary gland in holoprosencephaly and anencephaly

The normal prenatal development of the human pituitary gland and the gland-supporting sella turcica has recently been investigated. The sella turcica area constitutes a developmental boundary area in the cranial base. Posterior to the area the cranial base has developed close to the notochord, and anterior to the region the cranial base development is dependent chiefly on neural crest cell migrations. In the present study the sella turcica region was analyzed in two fetuses with holoprosencephaly (cyclopia and median cleft) and four fetuses with anencephaly combined with rachischisis in the neck region (GA 16-20 weeks). The sella turcica region was investigated radiologically and histologically. Adenohypohyseal gland tissue was localized by immunohistochemical hormonal marking. In both types of malformation an open craniopharyngeal canal was seen in the base of the sella turcica with adenohypophyseal glandular tissue located in the sella turcica, in the canal, and in the pharyngeal connective tissue at the external side of the cranial base. In conclusion, severe malformations of the pituitary gland occur in both holoprosencephaly, which is a polytopic field defect located anterior to the sella turcica, and in anencephaly associated with notochordal insufficiency posterior to the sella turcica. This might indicate that the sella turcica area, bounding different developmental fields, is involved in various craniofacial malformations. It is consequently recommended that examination of the pituitary gland should become a part of the routine autopsy of prenatal material when malformations in the face, brain, and cranial base occur.     

Hemiatrophy of the tongue due to hypoglossal schwannoma shown by MRI

Schwannomas account for 8.5% of all intracranial tumours; more than 90% arise from the 8th cranial nerve. Only 42 cases of schwannoma of the hypoglossal nerve have been reported. A 59 year-old woman developed right hemiatrophy of the tongue, clearly demonstrated on MRI, as was a small hypoglossal schwannoma. High signal was seen in the atrophic side of the tongue on both T1- and T2-weighted images, as described in the literature.     

Fracture of the sella turcica

Fracture involving the sella turcica is a rare complication of head trauma, but extremely important due to its strategic location adjacent to vital vascular and nervous structures. Of 14 cases reviewed, nine had at least one cranial nerve paralysis, with endocrine abnormalities and cerebrospinal fluid otorrhea seen to a lesser degree. The radiographic findings of sphenoid sinus fluid (13 of 14 cases), pneumocephalus, and unusual vascular occlusions are discussed.     

Cholesterol granuloma in the middle cranial fossa: report of two cases

We report two cases of cholesterol granuloma in the middle cranial fossa. On CT the lesions appeared as a nonspecific, nonenhancing soft-tissue mass with bone erosion. On MRI they were seen as areas of high signal intensity surrounded by a low-intensity peripheral zone on both T1- and T2-weighted images. Cholesterol granuloma is thought to occur when pneumatised cells in the temporal bone become obstructed. Although this lesion usually occurs in the petrous bone, it can extend to the middle cranial fossa. The diagnosis and surgical management are discussed.     

Primary intraosseous hemangioma of the orbit: CT and MR appearance

An 8-year-old girl had acute onset of blurred vision, proptosis, and lateral and vertical gaze palsies on the right. CT and MR examinations showed an expansile mass involving the greater wing of the right sphenoid bone. Pathologic analysis of the surgical specimen revealed a capillary hemangioma. The lesion was inhomogeneous but predominantly isointense with gray matter on T1-weighted images. On T2-weighted images the lesion was inhomogeneous with areas of both high and low signal intensity. The rim enhanced uniformly, and there was inhomogeneous enhancement of the bulk of the lesion.     

The primary empty sella an endocrine study on 12 cases

Twelve patients (10 women and 2 men) with a primary empty sella turcica were studied. Endocrine function tests were performed as follows: growth hormone (GH) was measured after insulin-induced-hypoglycaemia, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) after LH-releasing hormone, thyrotrophin (TSH) and prolactin after thyrotrophin-releasing hormone; pituitary reserve of adrenocorticotrophin (ACTH) was determined by measurement of plasma cortisol after lysine-vasopressin and 11 deoxycortisol after metyrapone. Five of the patients (group A) had no endocrine disturbance. Seven patients (group B) had a hypothalamo-pituitary disorder. Two of them had panhypopituitarism which appeared in one case after meningoencephalitis and in the other after a severe cranial trauma. In two cases an amenorrhoea-galactorrhoea syndrome with increased prolactin level (68 and 230 ng/ml) led to a diagnosis of a prolactin producing adenoma, which was confirmed by surgery. Finally three cases of amenorrhoeagalactorrhoea, with normal prolactin level, and/or diabetes insipidus remained unexplained. However, no causal relationship could be demonstrated between the pituitary disturbance and the "empty sella". Primary empty sella turcica is therefore a neuroanatomical and neuroradiological entity with no endocrine implication. A pituitary disorder might suggest a microadenoma or an incidentally associated disease.     

The increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood during vagal afferents stimulation or after angiotensin II infusion

It has previously been demonstrated that the cardiodepressant activity is present in the bovine hypothalamic extract and in the fluid incubating the posterior pituitary lobe "in situ". The present study was an attempt to reveal if the cardiodepressant factor and vasopressin were simultaneously released from the pituitary into blood. The samples of venous blood flowing from the sella turcica and, for comparison, from the posterior paw were collected in anaesthetized rats. Blood from the sella turcica was collected with a fine cannula inserted into the internal maxillary vein. The concentration of vasopressin in blood plasma was determined by radioimmunoassay and cardiodepressant activity--using a biological test on a spontaneously discharged pacemaker tissue of the right auricle of the right heart atrium. Stimulation of the central ends of the cut vagus nerves or intra-arterial infusion of angiotensin II simultaneously caused an increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood. The cardiodepressant activity and vasopressin concentration was also enhanced to some degree in blood outflowing from the posterior paw. Present results indicate that both vasopressin and the cardiodepressant factor are released into blood from the posterior pituitary lobe.     

The pattern-evoked potential in compression of the anterior visual pathways

Pattern evoked responses have been recorded in 19 patients with compression of the optic nerve, chiasm or tract, verified at operation. These included 4 patients with orbital tumours, 5 with intracranial meningiomas, 2 with craniopharyngiomas and 8 with pituitary tumours. The evoked response was abnormal in all except one of these patients. The pattern of abnormalities in the response, however, differed from that in the earlier series of patients with primary demyelinating disease. The incidence of delayed responses was much lower, and the magnitude of the delays was smaller. Absent responses were particularly characteristic of patients with intracranial meningiomas. Tumours arising in the region of the sella turcica were associated with a high incidence of abnormalities of the waveform of the response, and asymmetry of the field of the occipital evoked potential was especially characteristic of this group. Most, but not all, asymmetric cases were associated with field defects.     

Isolated cranial nerve palsies in multiple sclerosis

During a 10 year period 24 patients with definite multiple sclerosis with isolated cranial nerve palsies were studied (third and fourth nerve: one patient each, sixth nerve: 12 patients, seventh nerve: three patients, eighth nerve: seven patients), in whom cranial nerve palsies were the presenting sign in 14 and the only clinical sign of an exacerbation in 10 patients. MRI was carried out in 20 patients and substantiated corresponding brainstem lesions in seven patients (third nerve: one patient, sixth nerve: four patients, eighth nerve: two patients). Additional abnormal findings of electro-oculography, or masseter reflex, or blink reflex, or combinations of these were found in 20 patients and interpreted in favour of a brainstem lesion at the level of the respective cranial nerve. In 11 of 14 patients with isolated cranial nerve palsies as the presenting sign of multiple sclerosis, dissemination in space was documented by MRI, and in the remaining three by evoked potentials. In patients with multiple sclerosis with isolated cranial nerve palsies, MRI is the most sensitive method of documenting dissemination in space and electrophysiological testing the most sensitive at disclosing brainstem lesions.     

Imaging features and clinical significance of perineural spread or extension of head and neck tumors

Perineural spread of head and neck tumors is a form of metastatic disease in which tumor disseminates to noncontiguous regions along the endoneurium or perineurium. Both computed tomography (CT) and magnetic resonance (MR) imaging can help detect perineural spread, although MR imaging is the modality of choice because of its multiplanar capability, its superior soft-tissue contrast, and the decreased amount of artifact from dental hardware. Perineural spread most commonly occurs in adenoid cystic carcinoma and squamous cell carcinoma. Nerve enlargement may lead to foraminal enlargement and, ultimately, to foraminal destruction, findings that are best seen at CT. Extension through the foramen ovale and involvement of the Meckel cave is best seen on coronal T1-weighted MR images, and nerve enhancement is best seen on fat-suppressed T1-weighted MR images. Other radiologic findings include obliteration of fat planes at foraminal openings, neuropathic atrophy, cavernous sinus enlargement, and replacement of the trigeminal subarachnoid cistern with soft tissue. The pathway of perineural tumor spread is predictable with knowledge of the pertinent cranial nerve anatomy; however, patients with radiologically or pathologically proved perineural spread may have normal nerve function at clinical examination. Therefore, it is imperative that the radiologist be familiar with both normal cranial nerve anatomy and the radiologic appearance and assessment of perineural tumor extension.     

Pyogenic liver abscesses: a comparison of older and younger patients

The purpose of the present study was to analyze the morphology of the sella turcica in children born with myelomeningocele. Profile radiographs from 16 children (nine females and seven males) born with myelomeningocele were analysed. The contour of the anterior wall of the sella turcica in myelomeningocele patients, instead of following the normal cranio-caudal direction, was always in an obliquely antero-posterior direction. The sella turcica thus appeared broad cranially with a diverging anterior wall, or with both diverging anterior and posterior walls. This appearance gave and impression of a wide sella turcica in myelomeningocele with less depth than normal. The investigation has drawn attention to the fact that congenital malformations in the axial skeleton, even though, as in the case of myelomeningocele, they are located far from the cranial base, may have manifested themselves in the cranial base as well. The pathogenetic relationship between these manifestations is to be found in the early embryonic structure, the notochord. With the concept of embryological developmental fields, defined as areas with a common developmental origin, such as the notochordal field involved in myelomeningocele, new ways seem to be emerging for an improvement of aetiologically based diagnosis and treatment.     

The accuracy of CT and MR evaluation of the sella turcica for detection of adrenocorticotropic hormone-secreting adenomas in Cushing disease

PURPOSE: To document the accuracy of CT and MR of the sella turcica for detecting adrenocorticotropic hormone-secreting adenomas in Cushing disease. METHODS: The radiologic findings of the sella turcica prior to transsphenoidal surgery are reviewed in 141 patients who had biochemical evidence of pituitary-dependent Cushing disease. Axial thin-collimation CT scans with sagittal and coronal reformations before and after contrast enhancement were obtained in 125 patients. Seventy-eight patients had MR examinations with a 1.5-T superconducting magnet. In 11 of the patients gadolinium-enhanced MR scans were also obtained. The preoperative interpretation of the imaging studies was correlated with the surgical findings and patients follow-up. RESULTS: The sella turcica was enlarged in 43 cases (30%). In 125 patients reformatted or direct coronal thin-collimation CT scans were available. Seventy-eight of the patients had MR. In the 12 patients with pituitary macroadenomas, the accuracy of CT (n = 10) and MR (n = 10) in respect to detection of the lesion was 100%. Of the 98 microadenomas assessed by CT, 47 (48%) were directly depicted as distinct hypodense lesions. In only 31 of 73 cases (42%), however, could CT predict the precise anatomic location and extent of the lesions. Only patients in whom the hypercortisolism was corrected by later surgery were considered for the correlation analysis. Of the 52 microadenomas assessed by MR, 28 (53%) were directly depicted as distinct lesions of reduced signal intensity on T1-weighted images, and in only 21 of 41 cases (52%) did MR show good correlation to the surgical findings. Some degree of partially empty sella was found in 22% of the patients. CONCLUSIONS: Although both the sensitivity and the diagnostic accuracy of imaging methods of the sella turcica have been considerably improved in comparison with previous reports, they still provide only a minor contribution to the diagnosis and differential diagnosis of Cushing syndrome.     

Deep benign fibrous histiocytoma of the knee: CT and MR features with pathologic correlation

Magnetic resonance imaging and pathologic findings in a 28-year-old patient with a giant deep benign fibrous histiocytoma in the popliteal fossa of the right knee are described. The MR imaging findings include a well-delineated oval mass with low signal intensity on T1-, and high signal intensity on T2-weighted, images, and marked peripheral contrast enhancement. To the best of our knowledge, this is the first report on the MR findings in this entity.     

A case of crushing head injury with bilateral abducens and facial nerve palsies

A 20-year-old male was admitted to our hospital suffering from a crushing head injury. At accident, his head had been compressed by the printing machine on both temporal regions. He remained at dull conscious. On admission one hour after the injury, he showed bilateral sixth-nerve and seventh nerve palsies and bleeding from the nose. CT scan showed marked pneumocephalus, traumatic subarachnoid hemorrhage, fluid collections in the bilateral sphenoid sinuses and right mastoid air cells. Bone CT disclosed bilateral temporal bone fractures. MRI did not show cerebral parenchymal damage. He recovered fully conscious at four hours after the injury, but cranial nerve palsies sustained over 30 days after the injury. Bilateral decompression of the facial canal were performed at day 31. At one year after the injury, bilateral abducens nerve palsies and facial nerve palsies recovered incompletely (grade III). The case report and the mechanism of such cranial nerve injuries by low-velocity crushing head injury is described.     

Mucocele of the sphenoid sinus presenting as spontaneous pneumocephalus

A 60 year old woman presented with headaches and a destructive lesion in the sella turcica. She refused treatment but returned seven years later with a spontaneous pneumocephalus and dementia. A mucocele of the sphenoid sinus was discovered. Her symptoms resolved after removal of the mucocele and obliteration of the sphenoid sinus.