3 Tesla serial magnetic resonance imaging of human African trypanosomiasis (Trypanosoma brucei gambiense) and review of the literature

We report serial magnetic resonance imaging (MRI) findings and follow-up in a case of human African trypanosomiasis (HAT) presenting with limited lesions followed by early and complete resolution. We searched the literature for documented cases and reviewed MRI findings before treatment. A 30-year-old Lebanese man, who had lived in Gabon for six years, presented with a two-year history of rash, anorexia, weight loss, arthralgia, paresthesia, and hypersomnia. Previously, the patient had received corticosteroid therapy for unconfirmed ANCA-associated vasculitis. Physical examination revealed a painless chancre on the left arm located at the site of an old insect bite, enlarged cervical, axillar and inguinal lymph nodes, hepatosplenomegaly and impaired concentration. Blood analysis showed an elevated protein level (90g/L) with hypoalbuminemia (24.2g/L) and elevated IgM (26.4g/L). Bone marrow aspirate and biopsy failed to detect any parasite. Polymerase chain reaction tests on blood and cerebrospinal fluid were positive for Trypanosoma. Serology tests confirmed the diagnosis of HAT due to Trypanosoma brucei gambiense infection. 3T MRI showed lesions in the hypothalamus and basal ganglia, the internal capsule, and the mesencephalon bilaterally. Follow-up MRI showed interval progression of the abnormalities. Treatment with melarsoprol was followed by clinical improvement with regression of the lesions on the three-month MRI, then total resolution at the 10-month follow-up. This case highlights a pattern of mild MRI lesions in T. brucei gambiense HAT with a total and rapid resolution under treatment. The literature review (16 HAT cases with sufficient radiological data, included ours) revealed an MRI pattern of brain lesion distribution that could be helpful for diagnosis and orienting biological tests.

Hemorrhagic presentation of frontal partially calcified pilocytic astrocytoma in an 18-year-old woman: A case report and literature review as "clinical case"

We report an unusual case of a frontal partially calcified pilocytic astrocytoma (PA) (WHO grade 1) in an 18-year-old woman who presented with acute, spontaneous intracerebral hemorrhage. Histopathology revealed the PA was mixed with psammoma bodies and areas of vascular proliferation responsible for a hypervascular pattern. The patient underwent a total gross resection. MRI showed no residual tumor at the 18-month follow-up and her neurological deficits improved after rehabilitation. Only 20 cases, including ours, of hemorrhagic presentation of PA in adults have been reported to date with enough radiological data. Furthermore, hemorrhagic presentation of a calcified PA is extremely rare. To date only two other cases of calcified PA with hemorrhagic presentation have been reported, one in an adult and one in an infant as described by Shibao et al. (2012) and Kapoor et al. (2015) respectively. Endothelial proliferation may be the main cause of bleeding in these lesions. In our case, a hypervascular pattern was exhibited by histopathological findings. A diagnosis of PA should be considered, especially when calcifications are present within a hemorrhagic tumor lesion.

Late onset hereditary episodic ataxia

OBJECTIVE

Episodic ataxias (EA) are hereditary paroxysmal neurological diseases with considerable clinical and genetic heterogeneity. So far seven loci have been reported and four different genes have been identified. Analysis of additional sporadic or familial cases is needed to better delineate the clinical and genetic spectrum of EA.

METHODS

A two generation French family with late onset episodic ataxia was examined. All consenting family members had a brain MRI with volumetric analysis of the cerebellum. Haplotype analysis was performed for the EA2 locus (19p13), the EA5 locus (2q22), the EA6 locus (5p13) and the EA7 locus (19q13). Mutation screening was performed for all exons of CACNA1A (EA2), EAAT1 (EA6) and the coding sequence of KCNA1 (EA1).

RESULTS

Four family members had episodic ataxia with onset between 48 and 56 years of age but with heterogeneity in the severity and duration of symptoms. The two most severely affected had daily attacks of EA with a slowly progressive and disabling permanent cerebellar ataxia and a poor response to acetazolamide. Brain MRI showed in three affected members a decrease in the ratio of cerebellar volume:total intracranial volume, indicating cerebellar atrophy. No deleterious mutation was found in CACNA1A, SCA6, EAAT1 or KCNA1. In addition, the EA5 locus was excluded.

CONCLUSIONS

A new phenotype of episodic ataxia has been described, characterised clinically by a late onset and progressive permanent cerebellar signs, and genetically by exclusion of the genes so far identified in EA.

MR imaging features of isolated cortical vein thrombosis: diagnosis and follow-up

BACKGROUND AND PURPOSE

To our knowledge, very few MR imaging data have been reported in isolated cortical venous thrombosis (ICoVT). The purpose of this study was to describe MR imaging features, including T2*gradient-echo (GE) sequence, in presumed ICoVT.

MATERIALS AND METHODS

MR imaging examinations were performed in 8 patients with ICoVT (MR venography was performed in all patients and digital substraction angiography in 4) at the time of diagnosis and during the follow-up at 15 days (4 patients) and at 3 (8 patients), 6 (6 patients), 12 (3 patients), and 18 months (1 patient). We assessed the presence of a magnetic susceptibility effect (MSE) on T2*GE imaging at each site of cerebral venous thrombosis and the presence or absence of a normal flow void and iso-, hypo-, or hyperintense signal intensity on T1, T2, diffusion-weighted imaging (DWI), and fluid-attenuated inversion recovery (FLAIR) images. Parenchymal signal-intensity changes were also assessed on the same sequences.

RESULTS

MSE was detected on T2*GE imaging at the site of a cortical vein in all subjects at the first MR imaging examination. The occluded vein appeared as hyperintense in 3 patients, iso- to slightly hyperintense in 1 on T1, hypointense in 6 on FLAIR images, and as signal-intensity loss on DWI in 3. At follow-up, persisting signal-intensity abnormalities on T2*GE imaging were detected at the venous sites in all patients, whereas signal-intensity changes on T1- and T2-weighted images were no longer present. Parenchymal hyperintensities on FLAIR and DWI (increased apparent diffusion coefficient [ADC]) were observed in close vicinity to the thrombosis in 6/8 patients. Petechial hemorrhages (n = 3) or hematoma (n = 2) was present on T2*GE imaging in 5/8 patients. During the follow-up, all cerebral tissue signal-intensity changes on T1, T2, and FLAIR images decreased both in volume and intensity. ADC values normalized within the tissue after 3 months in all patients.

CONCLUSIONS

On T2*GE imaging, MSE of hemoglobin products within the thrombus was observed both at the early and late phases of ICoVT and appears to be of high diagnostic value compared with the other signal intensity changes detected on standard MR imaging.

[CT and MRI features of arachnoid cyst of the petrous apex: report of 3 cases]

PURPOSE

To describe the CT and MRI features of 3 cases of arachnoid cyst of the petrous apex.

PATIENTS AND METHODS

Three patients with isolated trigeminal neuralgia, trigeminal hypoesthesia, and sinusitis. Axial and coronal CT images were obtained. T1W, FSE T2W, FLAIR, T2*W and diffusion-weighted MR sequences were obtained.

RESULTS

In all cases, both CT and MRI showed expansile lesions eroding the petrous apex. Lesions were hypodense on CT and isointense to CSF on MRI, without contrast enhancement. In one case, the lesion was contiguous with Meckel's cave with temporal fossa and sphenoid sinus extension. CT and MR imaging features are useful to distinguish arachnoid cysts of the petrous apex from other benign lesions of the petrous apex.

CONCLUSION

CT and MRI imaging features allow diagnosis of arachnoid cyst of the petrous apex because its imaging features, especially on DWI, are different from other cystic lesions of the petrous apex, namely cholesteatoma. It should be considered in patients with trigeminal involvement, especially trigeminal neuralgia.

Orgasmic headache and middle cerebral artery dissection

A patient with a 20 year history of primary orgasmic headache is described who, after suffering an unusually severe episode of orgasmic headache was found to have a middle cerebral artery dissection. This unusual association of primary and secondary orgasmic headache emphasises the need for a thorough diagnostic examination when the orgasmic headache differs from that of previous episodes or is associated with neurological symptoms.

Early epidural blood patch in spontaneous intracranial hypotension

Thirty patients with a typical orthostatic headache were treated by early lumbar epidural blood patch (EBP) without previously performing lumbar puncture or identifying a CSF leak and with or without typical MRI changes. A complete cure was obtained in 77% of patients after one (57%) or two (20%) EBPs. Spontaneous intracranial hypotension with typical orthostatic headache can be diagnosed without lumbar puncture and can be cured by early EBP in a majority of patients.

[Study of the middle ear. Value of multiplanar reconstructions in spiral tomodensitometry]

We point out the interest of computed tomographic reconstructions from spiral acquisition--particularly sagittal reconstructions--in the study of middle ear anatomy and adjacent structures: the facial canal and the chorda tympani. The reference reconstructions are axial and coronal reconstructions. So, we demonstrate the superiority of sagittal reconstructions for the visualization of the lateral process of the malleus, the body and long process of the incus, the third portion of the facial canal, and the chorda tympani. For the other structures of the middle ear and the other parts of the facial canal, these sagittal reconstructions are complementary. Besides, the best type of reconstruction to visualize the stapes and the vestibular window is the axial plane parallel to the stapes axis.

Facial "glomangiomas": large facial venous malformations with glomus cells

BACKGROUND

"Glomangiomas" are benign cutaneous vascular lesions consisting of convoluted, abnormally formed venous channels lined by cuboidal and oval epithelioid, alpha-actin-positive, glomus cells. Three different clinical variants of glomangioma have been recognized: solitary, multiple, and nodular, or plaquelike. Inheritable forms are common.

OBJECTIVE

We describe in 7 patients (2 of them having a familial glomangiomatosis) the rare facial location of glomangiomas to differentiate this type from common facial venous malformation (VM).

METHODS

We analyzed clinical data (photographs), course, investigations (computed tomographic scans in 4 patients, magnetic resonance imaging in 6, arteriography in 2, direct puncture phlebography in 4, and pathologic examinations in all 7), and outcome with treatment.

RESULTS

Lesions were soft, composed of multiple nodules, confluent and plaquelike, deep blue or blue-to-purple, sometimes sagging, one-sided in a cheek, extending to the lips in 5 patients, to the chin in 4, and to the lower eyelid in 4. They were poorly compressible, a finding different from common facial VMs. In a young man extensive back involvement was associated. Among radiologic investigations, only magnetic resonance imaging after gadolinium enhancement offered some differential features with common VMs. However, histopathologic examination clarified the differential diagnosis: although the large tortuous venous channels were reminiscent of capillary-venous malformation, in many vessels the walls contained one or several rows of glomus cells.

CONCLUSION

Multiple plaquelike facial "glomangiomas" mimic a common venous malformation because of their blue hue. However, with experience, one can clinically recognize them, and their pathologic aspect is distinctive. Management should differ slightly from that for common facial VM because sclerotherapy has proven to be less effective. Therefore surgical treatment is the only helpful therapeutic option.

Spinal subdural haematoma: a study of three cases

AIMS

To define the clinical, computed tomography (CT) and magnetic resonance imaging (MRI) features and the role of MRI in the follow-up of spinal subdural haematoma (SSH), and to compare these findings with those of spinal epidural haematomas (SEH).

METHODS

We report three cases of SSH (two women, one male, age: 50-74 years). Two patients were on anticoagulant therapy; in the other case the SSH was spontaneous. All the patients were examined 1-3 days after the onset of the symptoms. All of them had CT, two had MRI and one had angiography. Two patients underwent surgery.

RESULTS

The haematoma was located in the thoracolumbar region (two) and in the thoracic region (one), extending from five (two) to 11 vertebral body levels (one). The haematomas were posteriorly located with lateral extension. The transverse shape differed with the level: biconvex, biloculated or circumferential. The haematomas were hyperdense on CT. On MRI, SSH yielded high signal on both T1 and T2. The integrity of the posterior fat pads, which was well shown on CT and MRI, and the visualization of the dura mater demonstrated the intradural location of these collections, making them easily distinguishable from spinal epidural haematoma. MRI provides better evaluation of the longitudinal extent. Our results are compared with those reported in the literature.

CONCLUSION

MRI is superior to CT for diagnosis and follow-up of SSH. Our findings and those reported in the literature show that the MR features of SSH are quite specific and allow differentiation from SEH.

[Sturge-Weber syndrome. The current neuroradiologic data]

Sturge-Weber syndrome (SWS) is a rare congenital sporadic disease with neuro-ocular and cutaneous vascular findings. Clinically, the full-blown condition consists of a facial port-wine stain (PWS) involving the V1 facial trigeminal skin area, alone or in combination with V2 and V3PWS, seizures and ocular abnormalities (glaucoma and choroidal angioma). Radiologically, a leptomeningeal (pial) capillary and venous malformation, mostly located in the parieto-occipital area, cerebral atrophy and calcifications are demonstrated. An ipsilateral enlarged choroid plexus may be an early anatomic symptom. Developmental venous anomalies (DVA) of the brain are sometimes associated. MR with gadolinium enhancement is the optimal neuro-diagnostic imaging technique for the screening of infants with an at-risk V1PWS, as well as for the follow-up of patients with evidence SWS. Accelerated myelination in the involved hemisphere may be an early diagnostic feature before 6 months of age. Later, hyperintensity of white matter on T2 is considered a symptom of gliosis. Clinically, progression of the diseases is associated with anatomic changes and correlates with the extent of the pial vascular anomaly, extent and severity of cerebral atrophy, and white matter abnormalities. A neonatal neuro-imaging work-up, using CT or MRI, may not demonstrate the pial anomaly and should be repeated after 6 to 12 months in an at-risk infant with V1PWS.

Cranial epidural tuberculoma. A case report

A 33-year-old patient with cranial epidural tuberculoma without history of tuberculosis is described. CT and MR imaging showed a lesion located on both sides of a right frontotemporal bone destruction with epidural extent. Except for a small necrotic core, the lesion enhanced intensely after contrast medium administration. Osteitis and subgaleal abscess were associated. The displaced dura mater delineated the epidural tuberculoma. Diagnosis was verified by histology and identification of Mycobacterium tuberculosis. After removal of the tuberculoma and combination therapy, there was a complete regression of abnormalities. Differential diagnoses are dural tuberculoma, focal tuberculous pachymeningitis and tuberculous epidural empyema.

Cerebral amyloid angiopathy (CAA) with presentation as a brain inflammatory pseudo-tumour

Cerebral amyloid angiopathy (CAA) is frequent but often asymptomatic. It can induce lobar haemorrhage, rapidly progressive dementia or recurrent transient neurological symptoms, other presentations being less frequent. We report 3 patients in their sixties presenting with a space occupying lesion which was the first manifestation of CAA. They were operated with a diagnosis of cerebral tumour. In all three cases, macroscopy was similar, the lesions were superficial in the cerebral cortex and the preoperative diagnoses were glioblastoma, meningioma and cavernoma. Histologically, the lesions consisted of a large inflammatory granuloma with numerous lipophages and siderophages surrounding capillaries with prominent endothelial cells. Vessels in the near cortex and meninges and within the granuloma harboured heavy amyloid deposits immunolabelled by anti-P component, anti-protein beta A4 with a A40 predominance and anti-apolipoprotein E. Adjacent cerebral cortex showed reactive gliosis and rare senile plaques. Amyloidosis is rarely considered among diagnoses of space occupying lesions. In our three cases, CT scan and MRI changes were related to the presence of an inflammatory granuloma around foci of haemorrhage and amyloid laden vessels.

[Tuberculosis of the central nervous system. MRI features and clinical course in 12 cases]

OBJECTIVE

The aim of this study was to characterize the MR findings of various intracranial lesions in the central nervous system (CNS) tuberculosis.

MATERIALS AND METHODS

The MRI findings (T1, T2 and T1 sequence after contrast) of 12 proved cases (10 males, 2 females, 24 to 64 years old, average: 35) of CNS tuberculosis were reviewed; 4 patients were seropositive for HIV.

RESULTS

Several types of lesions were identified: tuberculomas called miliary lesions if they were smaller than 2 mm in diameter (7 cases), in 1 case the tuberculoma was revealed by two large lesions and bi-hemispheric localisations, leptomeningitis (5 cases), infarction (4 cases), abscesses (3 cases with solitary lesions in 2/3 cases), hydrocephalus (3 cases), pachymeningitis (2 cases). A tuberculomas-leptomeningitis association was found in 4 patients. The pachymeningitis form had an unusual aspect in one case. Patients with leptomeningitis showed thick meningeal contrast enhancement involving all basal cisterns, expanding to the sylvian fissures level, and causing narrowing of the sylvian arteries. Massive infarctions resulted from arterial englobement or embols. In three out of five patients, leptomeningitis was the initial presentation. In seropositive patients, tuberculosis was severe with high mortality (3/4 patients), and associated with other multiple lesions.

CONCLUSION

Central nervous system tuberculosis has different appearances, mostly tuberculomas and leptomeningitis. MR with contrast is necessary for follow-up during treatment.

Deep cerebral venous thrombosis: imaging in eight cases

Deep cerebral venous thrombosis (DCVT) is a rare, potentially fatal disease. We carried out a retrospective analysis of eight patients presenting with DCVT, using CT and MRI data. Digital subtraction angiography (DSA), MR angiography (MRA) (2D phase-contrast), and angiography were performed in four, four and two patients, respectively. Direct (venous abnormalities) and indirect (parenchymatous involvement) signs of thrombosis were assessed. Follow-up MRI and MRA were performed on two patients. CT was initially normal in two patients, demonstrated a "cord sign" in deep veins in five and deep venous infarcts in three. When performed within a week of admission (seven patients), MRI showed thrombosis as into intense or high signal in deep veins on sagittal T1-weighted spin-echo images in all patients, and on axial T2-weighted spin-echo images in two. Deep venous infarcts were found in five patients. Direct or indirect signs of sagittal or lateral sinus thrombosis were present on CT in two patients and on MRI in five. CT angiography, MRA and DSA were concordant with MRI findings. CT venography showed persistent flow in thrombosed veins. MRI follow-up demonstrated progressive deep venous recanalisation.

Internal carotid artery dissection causes hypoglossal nerve palsy: CT, MRI, and angiographic findings

A case of unilateral XIIth nerve palsy due to the dissection of the internal carotid artery is reported. The clinical and radiological features are described. In this patient, cranial nerve palsy is probably the result of compression by an enlarging carotid artery due to mural hematoma. Diagnosis is discussed with emphasis on magnetic resonance imaging findings. Magnetic resonance imaging is also useful for follow-up of arterial lesions.

[Facial diplegia in the course of childhood Lyme disease: bilateral enhancement of the facial nerve and MRI after injection of gadolinium]

We report a rare case of Lyme disease presenting as a bilateral seventh cranial nerve palsy and meningitis. The MR appearance was an enhancement of the internal auditory canal segment and mastoid segment of the seventh cranial nerve, in the absence of parenchymal lesions. One should consider Lyme disease in the differential diagnosis of bilateral seventh cranial nerve palsy with enhancement.

[Persistent trigeminal artery and its variant. Contribution of MRI and MR-angiography]

We describe the magnetic resonance imaging and magnetic resonance angiography findings in 5 cases of persistent trigeminal artery, and in two cases of variant trigeminal artery. Six patients underwent complete four-vessel angiography, performed to depict other pathology. Magnetic resonance imaging and magnetic resonance angiography allowed in each case to visualize this artery and to precise its latero or intrasellar situation. The variant is not defined on conventional magnetic resonance imaging, but may be individualized on magnetic resonance angiography. In each case, identification of these persistent artery is crucial if surgery of sellar or gasserian region is planned.

MRI and MRA for diagnosis and follow-up of cerebral venous thrombosis (CVT)

OBJECTIVE

To assess the sensitivity of magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in the diagnosis and the follow-up of cerebral venous thrombosis (CVT). To describe MRI and MRA features in CVT.

MATERIAL AND METHODS

The clinical and neuroradiological studies of 20 patients with proven CVT were reviewed. All patients underwent computed tomography (CT), MRI (with MRA for 15 patients) and digital substraction angiography (DSA). Eleven patients had follow-up after treatment with MRI (nine with MRA).

RESULTS

MRI and MRA together provided the diagnosis of CVT in all cases. The sensitivity of MRI alone was 90%. MRA showed abnormalities in all cases of CVT. Progressive sinus recanalization was demonstrated by follow-up with MRI and MRA at least 15 days after diagnosis and treatment.

CONCLUSION

In most of cases, the combination of MRI and MRA is sufficient to allow diagnosis of CVT and obviates the need for invasive angiography. MR studies are also useful for the follow-up of CVT.

Cerebral developmental venous anomalies associated with head and neck venous malformations

PURPOSE

To study cerebral developmental venous anomalies in patients with extensive venous malformations of the head and neck.

METHODS

All patients had undergone carotid angiography 10 to 15 years previously. Four-vessel cerebral angiography was carried out in 40 patients with venous malformations. All patients had a physical examination, 16 had CT, and 22 were examined with MR imaging. One patient had MR angiography.

RESULTS

Eighteen developmental venous anomalies were noted in 8 (20%) of 40 patients. Four patients had multiple anomalies, and these were bilateral in 1 patient. Developmental venous anomalies seen in association with cervicofacial, cutaneous, and mucosal venous malformations were remarkable in their absence of neurologic events and associated cavernoma; significance of ectatic venous convergence, extension, and preponderance of deep drainage routes; and frequency with which they multiple in occurrence.

CONCLUSION

Developmental venous anomalies have a remarkable prevalence of 20% in patients with extensive superficial venous malformations. Therefore, it is important to search for a cerebral developmental venous anomaly when confronted with a cervicofacial venous malformation.

Primary vertebral and spinal epidural non-Hodgkin's lymphoma with spinal cord compression

We examined eight patients with primary spinal epidural non-Hodgkin's lymphoma presenting with spinal cord compression and proven histologically after laminectomy (7 cases) or biopsy (1 case) by MRI. The most common findings were an isointense or low signal relative to the spinal cord on T1-weighted images (T1WI) and high signal on T2-weighted images (T2WI). Spinal cord compression, vertebral bone marrow and paravertebral extension were assessed. Contrast enhancement was intense in seven of the eight cases and homogeneous in all of them. T2WI (performed in 2 cases) may be useful to distinguish metastatic carcinomas and sarcomas. T1WI demonstrated the full extent of the epidural lesion, which was well-delineated in all cases. When the paravertebral extension is not well-defined, a study with contrast medium should be performed.

Cervical occult spinal dysraphism: MRI findings and the value of a vascular birthmark

Spinal dysraphism is easily recognized in the overt form as a meningocele or myelomeningocele. The closed form or occult spinal dysraphism (OSD) can be overlooked. It occurs predominantly at the lumbosacral level, but OSD at the cervical level, although very rare, also occurs. The value of magnetic resonance imaging investigations in preparation for surgical treatment is emphasized. We discuss the value of various midline posterior skin anomalies as indicators of an underlying developmental defect in the neural axis. Hallmarks for OSD in the inferior third of the back are well known. They can also occur at the cervical level. Among these warning cutaneous midline changes, a vascular stain alone is rarely a clue for OSD whatever the spinal level involved, and specifically in the nuchal area.

MR manifestations of subependymomas

PURPOSE

To provide a description of the MR and enhanced MR appearances of subependymomas.

METHODS

We reviewed the MR examinations of eight cases of pathologically proved subependymomas and correlated them with operative and pathologic reports, and also reviewed the previous published cases of subependymomas documented by MR. Gadopentetate dimeglumine-enhanced MR examination was performed in seven cases.

RESULTS

One patient presented with four subependymomas, two patients had subependymomas of the cervical spine, and the others were intraventricular with no transependymal extension. They were isointense to hypointense relative to normal white matter on T1-weighted images, heterogeneous in five cases. Minimal (n = 1) or no (n = 3) enhancement was noted in four cases, and moderate or marked enhancement was noted in three cases.

CONCLUSION

We conclude that even though there is no specific sign of subependymomas, when confronted with a complete intraventricular lesion or with a spinal lesion causing little or no edema which is minimally enhancing or nonenhancing, one must consider the diagnosis of subependymoma.

Spinal epidural haematoma: report of 11 cases and review of the literature

Spinal epidural haematomas (SEH) are rare; most are caused by trauma, anticoagulant therapy, vascular anomalies, hypertension, blood dyscrasias, epidural anaesthesia or, rarely, spinal surgery. We report 11 cases and review the literature (16 cases). The clinical picture is that of acute spinal cord compression. MRI characteristics are quite specific. On sagittal sections, the SEH appears as a biconvex mass, dorsal to the thecal sac, clearly outlined and with tapering superior and inferior margins. The dura mater is seen as curvilinear low signal separating the haematoma from the cord. Within 24 h of onset, the haematoma is isointense with the cord on T1-weighted images and heterogeneous on T2-weighted images. Later, it gives high signal on both T1- and T2-weighted images. Differential diagnosis must include subdural haematoma, epidural neoplasm and abscess. Complete neurological recovery rapidly follows laminectomy and removal of the clot. In three of our cases, the haematoma resolved spontaneously. MRI is the best examination for diagnostic and follow-up.

Thoracic disc herniation and spinal cord compression. MRI and gadolinium-enhancement

The authors present a study of 6 patients aimed at assessing the role of Magnetic Resonance Imaging with gadolinium-enhancement in the diagnosis of thoracic disc herniation. The results of MRI were compared with the findings of computed tomography, myelography and surgery. In two patients, the signal from the herniated disc was so low on all sequences that thoracic disc herniation was diagnosed only on the mass effect on the cord. The anterior longitudinal epidural venous plexus (AEVP) is displaced posteriorly and thickened in case of thoracic disc herniation. Gadolinium-enhancement of AEVP was marked in these conditions, giving a "tent-like" round configuration, or "lifted band" appearance. The exact volume and mass effect of the thoracic disc herniation were assessed by T1-enhanced images on the sagittal and axial planes.

MRI evaluation of sacral cysts

Sacral cysts or intrasacral sacral meningeal cysts constitute a well-defined entity. Their clinical presentation is protean. Few cases have been reported concerning their MR aspects. From a series of six patients, the authors present the MR images. MRI is the examination of choice to demonstrate their liquid content. MRI provides a good evaluation of the lesion, and sagittal images show the intrasacral development. MRI scan appears to be superior to CT scan.

Paraganglioma of the cauda equina: magnetic resonance imaging

We report the clinical and imaging features of a paraganglioma of the cauda equina. Raised CSF protein caused an unusual appearance of the spinal canal below the obstruction. No specific identifying features were encountered; paraganglioma is uncommon in this site and usually thought to be an ependymoma or a neuroma; histopathological examination is necessary for correct diagnosis.

Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum). Report of a case and review of the literature

The authors report the third published case of a Lhermitte-Duclos disease diagnosed preoperatively with the help of MRI, stressing its possible extension beyond the limits of the posterior fossa. The pertinent literature is reviewed concerning the clinical and radiological picture of this disease, as well as the different pathogenic hypothesis.

[Emergency disobliteration of the carotid prepolygonal segment. Personal experience of 76 cases]

The authors report 76 cases of carotid obstruction, mainly localized at the origin of the carotid artery, that have been operated upon in emergency. Two types of lesions are considered: occlusion and very tight stenosis. The principle of early surgery in cases of acute occlusion is very controverse. According to the facts reported (38 cases) results are rewarding when operative decision is taken under precise conditions judged as favorable: short lapse of time since occlusive onset, absence of intracranial hypertension, absence of comatose state and no sign of brain oedema. Some patients under go surgery in the priviledged condition of being already in a medico-surgical unit (post operative, post angiographic, embolic occlusions). Majority present the most common hemiplegic attack. However difficulty resides in the inefficient mode of transport to hospital and lack of highly specialized units on admission. A very tight stenosis (at extreme a pseudo-occlusive stenosis) with clinical recurrent deficit, modified Loppler's recording and hemodynamic repercussion at angiography is an operative emergency. When results of early surgery on 38 cases of stenosis are compared to those of late operation in 14 similar cases early decision becomes compulsory once tight stenosis of the carotid artery is identified and operative criteria respected. In the light of this report that "wait and see attitude" needs be somewhat revised when confronted to the dramatic ictal hemiplegia.