[Incidental aneurysms and perimesencephalic subarachnoid haemorrhages]. / Aneurismas incidentales en el contexto de hemorragias subaracnoideas perimesencefálicas.

A perimesencephalic subarachnoid hemorrhage refers to the presence of bleeding around the midbrain with a normal angiography, meeting the well established clinical criteria and radiological criteria. Unlike the aneurysmal subarachnoid hemorrhage, it has a good prognosis, the recovery in most cases being complete and satisfactory. On the other hand, between 2 and 5% of the population will develop an intracranial aneurysm in the course of their life, most of them asymptomatic, with the likelihood of finding an incidental aneurysm in patients who have suffered a perimesencephalic hemorrhage. The importance of a proper diagnosis governs the course to follow, being a challenge for vascular treatment teams who must analyse the findings in detail and individualize treatment decisions.

[Histiocytic necrotizing lymphadenitis or Kikuchi's disease. CT radiologic features]. / Linfadenitis necrotizante histiocitaria o enfermedad de Kikuchi. Apariencia radiológica mediante TC.

Histiocytic necrotizing lymphadenitis, Kikuchi Fujimoto's disease (KFD) is characterised by fever and lymphadenopathy, usually large cervical, unilateral lymph nodes. Such clinical presentation demands a work-up to exclude serious medical conditions like malignancy and infections. Foci of necrosis with lymphocytic Histiocytic predominance in association with scarce polymorphonuclear cells on lymph node examination, confirm the diagnosis of KFD. Many different patterns of computed tomographic (CT) appearance of KFD have been reported. We describe the CT scan finding in two patients with this disease. All our cases showed, after two and three weeks of evolution respectively, enlarged lymph nodes with hypodense centres and peripheral ring enhancement. These radiological alterations correlated with the central lymph node necrosis found in the anatomopathological studies. In conclusion, KFD should be considered in patients with fever, cervical lymph node enlargement and CT scan showing hypointense centres and peripheral ring enhancement.

[The use of computed tomography in assessing parotid masses]. / Aplicación de la tomografía computerizada en la valoración de las masas parotídeas.

Thirty-one patients with suspected parotid masses have been studied by computed tomography (CT) without and with contrast to demonstrate the existence of this and to value possible relation between degrees of malignancy and the morphological characteristics of the masses.

[Spinal hematomas: the spinal apoplexy]. / Hematomas espinales: la apoplejía espinal.

INTRODUCTION: Spinal haematomas (SH) are a rare pathology. They can produce a rapid and irreversible neurological deterioration. METHOD: In this retrospective study, we review 8 cases of SH treated in our centre over the last five years. Data collected were: age, sex, predisposing factors, clinical status, radiological features, treatment and outcome. RESULTS: Five patients were female and three male. Age ranged between 13 and 81 years. Five patients were hypertensive. Four had a coagulation disorder. In three patients SH occurred after physical effort. One case appeared after a lumbar puncture and another was secondary to intramedullary cavernous angioma. All patients presented with pain followed by neurological symptoms. Four cases were epidural, two subdural and two were intramedullary. All epidural SH and one subdural SH, were located dorsal to medulla. Five patients were operated on due to progressive neurological deterioration. Only one of them showed neurological improvement. Patients who were not operated on, had a better neurological status and they improved spontaneously. Two of them were discharged without neurological symptoms. CONCLUSIONS: There is controversy over the physiopathology of SH. The triggering mechanisms are unknown. The vessel (artery or vein) and the anatomical compartment in which SH arise are also unknown. Prompt diagnosis and urgent surgical treatment are needed when the patient has neurological symptoms. In these cases, the most important prognostic factor is the preoperative neurological status.

[Haemorrhage in arteriovenous malformations of the brain following radiosurgery: the importance of the latency period]. / Hemorragia de las malformaciones arteriovenosas cerebrales tras la radiocirugía: importancia del período de latencia.

INTRODUCTION: Arteriovenous malformations are abnormal communications between arteries and veins. Treatment can consist in surgery, embolisation and/or radiosurgery. AIM: To assess the influence of radiosurgery on the risk of bleeding and related factors. PATIENTS AND METHODS: Retrospective study of 79 patients who were treated with a 6 MV linear accelerator. Clinical, morphological and dosimetric parameters were collected and a statistical analysis was performed to investigate their relationship with bleeding during the latency period. RESULTS: The mean age was 33.7 years, and 56% of patients were females. The mean volume was 6.16 cm(3). Bleeding occurred before treatment in 52.6% of cases. Altogether 25% had been embolised and 7.6% had been treated earlier using radiosurgery. Six patients suffered a haemorrhage after treatment. Bleeding occurred in 21% of those who had undergone embolisation versus 3.6% in non-embolised individuals (p < 0.02). Bleeding occurred in 33.3% of those who had been treated radiosurgically on more than one occasion, and only 5.7% if they were treated just once (p = 0.02). Bleeding took place in 28.6% of lesions above 10 cm(3) and in 3.2% when they were smaller (p < 0.01). Bleeding occurred in 16.1% of patients if they received less than 17 Gy, and in 2.22% if they received 17 or more (p < 0.01). All haemorrhages took place in treatments with more than one isocentre (p < 0.01) and with a higher homogeneity index (p < 0.01). CONCLUSIONS: Radiosurgery does not modify the risk of bleeding. The factors associated to higher percentages of bleeding are also related to poorer closure outcomes and longer latency periods.

[Encephalopathy with focal lesions due to Mycoplasma pneumoniae]. / Encefalopatía con lesiones focales por Mycoplasma pneumoniae.

Mycoplasma pneumoniae infections usually produce respiratory symptoms, that only exceptionally involve the nervous system. In this case, the infection generally causes an encephalitic picture characterized by impaired consciousness and seizures, and by normal or non-specific neuroradiological findings. However, four cases of M. pneumoniae infection associated with symmetrical lesions in the putamen and its external surrounding areas, and with extrapiramidal symptoms, have been recently published. We present the case of a patient with a clinical picture characterized by confusion, fever, and seizures, associated with a M. pneumoniae infection. The MRI study showed two symmetrical lesions that involved the areas just outside the putamen and disappeared coinciding with her clinical improvement. The present case would support that the encephalopathy associated with the M. pneumoniae infection shows a tendency to involve a particular region of the brain. Our case might represent the minimal expression of these characteristic lesions, which in the most benign cases would involve the areas immediately outside the putamen, and in other instances the putamen as well.

Cerebral tuberculoma--a comparative study in patients with and without HIV infection.

The microbiological, clinical and radiological findings of cerebral tuberculomas in four patients with and in five patients without HIV infection were compared. The study was carried out during the last 14 years. The CT scans were analyzed in a blinded fashion. Cerebral tuberculoma in HIV-negative patients was clinically characterized by seizures, while in HIV-positive patients this finding was absent. All four HIV-infected patients had headache and fever and their CSF showed lymphocytic meningitis. Two HIV-negative and three HIV-positive patients had concurrent extracerebral tuberculosis. In HIV-infected patients, the cerebral tuberculoma was a secondary finding of disseminated tuberculosis. In our small patient samples, the cerebral tuberculoma presented as spontaneous hypodense cerebral lesions in all the HIV-positive patients but as a hyperdense cerebral lesion in the HIV-negative patients. Two patients of each group had ring enhancement lesions. Cerebral tuberculoma was diagnosed in about 4 weeks for HIV-positive patients, but took some 16 weeks for HIV-negative patients, the latter being first suspected of having a cerebral tumor or bacterial abscess. Diagnostic craniotomy was thus necessary for the HIV-negative patients. One patient of each group died as a consequence of cerebral tuberculoma, all the remaining patients improved with treatment.