Spontaneous intracranial hypotension: clinical and neuroimaging findings in six cases with literature review.

Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches.

Pain and osteolysis of the thoracic spine--a case of a rare monostotic fibrous dysplasia manifestation.

We describe a case of a young farmer from Central Macedonia, Greece suffering of a mild back pain more than one year. His medical history included hypercholesterolaemia (IIa type) and two episodes of spontaneous pneumothorax of unknown origin two and three years ago respectively. A full imaging survey revealed a single osteolytic lesion at the seventh thoracic vertebra. A CT guided needle biopsy was performed. Diagnosis based on clinical, imaging and histological findings was monostotic fibrous dysplasia of the thoracic spine. We discuss the clinical features and treatment of this non neoplastic condition which may simulate bone osteolytic tumor. Furthermore a possible correlation of concomitant conditions existing in our patient such as the metabolic disorder of hypercholesterolaemia and especially the history of spontaneous pneumothorax episodes with fibrous dysplasia within the spectrum of connective tissue disorder is discussed.

Magnetic resonance imaging in 120 patients with intractable partial seizures: a preoperative assessment.

The aim of this study was to describe magnetic resonance imaging (MRI) findings in patients with medically intractable epilepsy and to compare different magnetic resonance (MR) sequences in order to establish a dedicated and shorter scan time imaging protocol of choice. One hundred and twenty patients with seizures that were refractory to medical treatment were assessed by MRI with spin-echo (SE) T1, fast spin-echo (FSE) T2, fluid-attenuated inversion recovery (FLAIR), inversion recovery (IR) and contrast-enhanced T1 SE sequences. Pathological scans were acquired in 78 patients. Hippocampal sclerosis was detected in 30 patients (25%), cerebral, tumoral, mass lesions in 12 patients (10%), vascular malformations in nine patients (7.5%), cortical infarcts in eight patients (6.7%), cerebral infections in four patients (4.2%) and developmental disorders in 15 patients (12.5%). The most common location of the lesions was the temporal lobe (60%). Coronal, thin (slice thickness 4-5 mm) images have proven to be the most useful in the assessment of the hippocampus. FLAIR and IR are particularly useful in the detection of lesions abutting cerebrospinal fluid (CSF) spaces and developmental disorders, respectively, while T1 SE sequences before and after the intravenous administration of gadolinium offer great facility in identifying space-occupying lesions and infections. MRI is the most important diagnostic tool for the assessment of epileptogenic foci, thus playing the primary role in indicating the type of treatment to be applied.

Cortical laminar necrosis in brain infarcts: serial MRI.

High-signal cortical lesions are observed on T1-weighted images in cases of brain infarct. Histological examination has demonstrated these to be "cortical laminar necrosis", without haemorrhage or calcification. We report serial MRI in this condition in 12 patients with brain infarcts. We looked at high-signal lesions on T1-weighted images, chronological changes in signal intensity and contrast enhancement. High-signal cortical lesions began to appear about 2 weeks after the ictus, were prominent at 1-2 months, then became less evident, but occasionally remained for up to 1.5 years. They gave high signal or were isointense on T2-weighted images and did not give low signal at any stage. Contrast enhancement of these lesions was prominent at 1-2 months, and less apparent from 3 months, but was seen up to 5 months.

CT and MR imaging findings in cerebral toxocaral disease.

We report serial MR findings in a 54-year-old woman with eosinophilic meningoencephalitis due to Toxocara canis infection, a parasitic disease contracted through exposure with soil contaminated by the eggs of the roundworm. MR imaging revealed several enhancing subcortical and white matter lesions in both lobes. Antihelminthic chemotherapy yielded marked improvement of the neurologic deficits and cerebral lesions. The specific MR findings-low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and contrast enhancement-and the clinical and epidemiologic features of CNS involvement are herein reviewed.

Intradural extramedullary spinal canal secondary neoplasms: MR findings in 30 patients.

The purpose of this study was to describe magnetic resonance findings of intradural spinal canal secondaries and to select the best way of investigating this condition. Thirty patients with a known malignancy [breast carcinoma (n = 14), lung carcinoma (n = 10), other sites (n = 6)] and unexplained neurologic signs were studied with pre- and post-contrast T1-weighted images and T2-weighted images. Cerebrospinal fluid cytology was available in 16 patients and positive in 11 patients. In all the patients, post-contrast T1-weighted images demonstrated abnormal enhanced lesions. Most of them were nodular, located on the conus medullaris and the cauda equina. Few lesions appeared at the thoracic or cervical levels, as nodular or thin areas of enhancement. Pre-contrast T1-weighted sequences failed or were equivocal to detect the lesions. Eighteen of 30 patients had cerebral metastases. Fourteen had osseous metastases. In conclusion, post-contrast T1-weighted sequence is the optimal modality for the diagnostic of intradural spinal canal metastases. Axial and coronal images may be a useful adjunct to precise anatomic changes. T1-weighted and T2-weighted sequences remain necessary when further information is expected on vertebra or soft tissue.

[Radiosurgical irradiation of 49 cerebral arteriovenous malformations using linear accelerator]. / Irradiation radiochirurgicale de 49 malformations artérioveineuses cérébrales au moyen d'un accélérateur linéaire.

During 1990 we treated 49 cases of arterio-veinous malformations (AVMs) using radiosurgery. We employed 15 MV X-Ray minibeams of a Saturne 43 Linac, eight additional collimators, 6-20 mm, the O Betti armchair and the Talairach stereotactic frame. Irradiation consisted of delivering 25 Gy at the periphery of the nidus corresponding to the 60-70% peripheral isodose range. We used the "Associated Target Methodology" and the three-dimensional treatment planning system Artemis-3D, both of which have been developed in our radiotherapy department. In December 1992, 44 out of 49 patients who had been treated were available for analysis with a 2-3-year follow-up. The overall obliteration rate was 33/44 (75%). According to the number of isocenters the obliteration rate was: 22/26 (85%) for one isocenter. In 18 multi-isocenters irradiation cases overall obliteration rate was 11/18 (61%). Two isocenters were used in nine of these 18 cases, the obliteration rate was 6/9; while when three isocenters were used it was 2/4 and in five cases of four isocenters irradiation the obliteration rate was 3/5. Obliteration rate for lesions < or = 4200 mm3 was 31/37 (84%). For greater volumes (5500 mm3 to 19000 mm3; median 9200 mm3) the obliteration rate was 2/7 whereas three others were partially (75 to 90%) obliterated and two remained inchanged. Before radiosurgery 21 cases received other treatment (mostly embolizations), the obliteration rate in this group was 15/21 (71.5%) while in previously untreated AVMs it was 18/23 (78%). A control arteriography was performed between 6 to 18 months after radiosurgery in 44 patients; three others refused the arteriography but are alive and well; two others had palliative irradiation, one of whom is dead. Out of 28 AVMs checked between 6 to 12 months 17/28 were obliterated (61%). In four cases, epilepsy was the first symptom; one has not suffered a further crisis whereas three others experienced a decrease in the number of crises. Two patients had recurrence of bleeding four and six months after irradiation (recurrence rate 2/44 = 5%). There were no lasting neurological consequences.