Memory for time of training modulates performance on a place conditioning task in marmosets

In rodents, the expression of a reward-conditioned place preference (CPP) is regulated in a circadian pattern such that the preference is exhibited strongly at the circadian time of prior training but not at other circadian times. Because each animal is trained only at a single circadian phase, the concept of time as a context cue is derived from a rhythmic internal state rather than learned explicitly from the external cues. We now report that the same "time memory" is expressed following context conditioning in the common marmoset (Callithrix jacchus). Animals were trained at a specific time to discriminate between an unpaired context and a context paired with food reward. Marmosets were then tested for preference at circadian times that were either the same or different from the training time. Preference was expressed only when training and testing times matched. The results show that time of day learning can be generalized to this new world primate implying that a similar circadian mechanism might regulate craving for reward in diverse mammals including human beings.

[Malignant course of a ganglioglioma: case report]

We present the case of a 8-years-old boy, admitted with a history of headache, nausea and vomiting. Cerebral angiography showed a non-vascular mass on frontal lobe. The patient underwent craniotomy and the lesion was removed. Neuropathological study revealed that the tumor was a ganglioglioma. The patient received pos-operative radiotherapy. On follow-up, 16 years after, a computed tomographic scan showed a recurrence of the tumor, and a second surgery revealed a glioblastoma multiform. Gangliogliomas are rare tumors of the central nervous system containing neoplastic ganglion cells and low grade neoplastic glial cells. The malignant degeneration occurs only in the glial component, so the prognosis of these tumors is related to the grade of that component.

[Brain metastasis of malignant melanoma. Analysis of 13 cases]

The authors present a retrospective review of 13 patients with the diagnostic of intracranial metastatic malignant melanoma. Their ages ranged from 28 to 84 years. The time interval from diagnosis of primary tumor to development of cerebral metastases ranged from 6 to 60 months. There was preoperative evidence of extracranial disease in 9 patients. All patients underwent craniotomy, and the 30-day mortality was zero. The patients survived 2 to 55 months after surgery. Medium survival time for all patients was 14 months. The excision of metastatic melanoma from the brain, although not curative, may increase survival in patients with this metastatic cancer. The criteria for consideration of surgery, radiotherapy and chemotherapy are discussed.

[Giant intracranial aneurysm in a 9 year-old child. Case report]

The case of a 9-year-old girl with intracranial hemorrhage due to a giant aneurysm of distal middle cerebral artery is reported. Cerebral aneurysms are rare in children, particularly in the first decade of life. Aneurysms in childhood occur more frequently in peripheral branches and they are more often giant in size. Clinical features and pathogenesis of this lesion are discussed.

[Chronic subdural hematoma: analysis of 35 cases]

Thirty five patients with chronic subdural hematoma were treated surgically between 1988 and 1995. The patients, aged 19 to 80 years, were graded retrospectively according to the Bender scale. The clots were removed via burr-holes with irrigation of the subdural space to ensure as complete an evacuation of subdural collection, and craniotomy with membranectomy. The mortality rate was 16.6% with craniotomy and 0% with burr-hole. The patients who died, 80% were in grade III or IV. The pathogenesis and surgical treatment of chronic subdural hematoma has been controversial, and still remains obscure.

[Benign chondroblastoma of the occipital bone. A case report]

Benign chondroblastoma is a rare bone tumor of immature cartilage cell derivation. This lesion classically occur at the ends of long bones in young persons. Chondroblastoma arising from the occipital bone is extremely rare. We report the case of a 16 year old girl with a benign condroblastoma in the occipital bone, and discuss the clinical, radiological and treatment aspects of this tumor.

[Thoracic epidural angiolipoma. Report of a case]

Angiolipomas of the spine are rare (40 cases in the literature). When they are intraspinal, these masses are epidural in more than 90% of the cases. Angiolipomas are benign tumors containing vascular and mature adipose elements. The clinical symptomatology is non specific, but computed tomography and mostly MRI provide a precise diagnosis. With one additional case and a review of the literature, we define the main characteristics of these tumors.

[Traumatic diabetes insipidus: a case report]

This case report refers to a thirty-nine years old female patient with severe head injury and other body injuries who developed symptoms of diabetes insipidus. The patient died eleven days after hospital admission during which magnetic resonance imaging and computerized tomography were done, showing characteristic hypothalamic lesions. This stimulated the authors to review the literature and call attention to the prevention and prognosis of endocrine syndromes which may appear in patients secondarily and late, and whose morbidity may be decreased with early diagnosis and treatment.

[Cystic meningioma]

Cystic meningiomas are uncommon lesions. CT image may simulate a glial or a metastatic tumor with cystic or necrotic changes. The correct radiological evaluation and the recognition of this kind of tumor are important for surgical treatment since they are potentially curable neoplasms. In this paper the authors report their experience with the treatment of three cases of cystic meningiomas, and discuss some characteristics of these lesions.

[Carpal tunnel syndrome: retrospective study of 106 cases and complications]

The authors present a short review of anatomic and pathophysiological bases of the carpal tunnel syndrome, and its surgical treatment and complications. They report the cases of two patients who developed sympathetic alterations with hand edema and vascular changes (Raynaud phenomenon), and propose an explanation which they name "sympathetic denervation". This is the only complication of their series and it occurred during the immediate post-operative period, coinciding with removal of immobilization of the wrist on the 22nd post-operative day.

[Air in extradural hematoma: report of 2 cases]

The authors report two cases of the presence of free air in acute extradural hematomas. This is not an unusual radiological finding which has been infrequently reported in the literature.

[False aneurysm of the median meningeal artery: the importance of angiographic diagnosis. A case report]

The purpose of this paper is to report a case of false aneurysm of the middle meningeal artery. The authors emphasize the value of "common" carotid angiography in diagnosis and treatment of this rare lesion.

[The epidemiology of Chagas' disease in a rural area of the city of Teresina, Piauí, Brazil]

In the rural areas of Teresina, 129 triatomines were captured distributed in (a) artificial ecotopes; a house with one Triatoma brasiliensis, one Panstrongylus geniculatus, Rhodnius pictipes, and one Rhodnius prolixus and in a uninhabited chicken house (7 Rhodnius nasutus). (b) Natural ecotopes; Pahus Orbignya martiana (41 Rhodnius neglectus, 33 Rhodnius prolixus and 41 Rhodnius nasutus) and Copernicia cerifera (3 Rhodnius neglectus). The 22.6% of captured triatomines were infected by flagellates similar to Trypanosoma cruzi. Twenty-eight sylvatic mammals were captured and examined. Seven Didelphia albiventris, 2 Rattus rattus and a Tamandua tetradactyla were infected with flagellates. The flagellates found in both triatomines and mammals were morphologically indistinguishable from Trypanosoma cruzi. Serology by the indirect immunofluorescence test for Chagas disease revealed two positive seroreactions of positivity among 123 inhabitants examined.

[Dura mater displacement in lateral cisternal punctures]

Report of an anatomic study of the lateral cisternal punctures (at the atlanto-occipital and C1-2 interspaces), carried out on fresh cadavers. Direct visualization of the internal surface of the dura mater (DM) at the cranio-cervical junctions was possible by removing the calvarium and brain (sectioned at the upper cervical spinal cord). Dislocation ("tenting") of the DM over the needle was observed in all occasions (n = 42), measuring 3.46 mm (2-6 mm).

[Pure spinal leptomeningeal cysticercosis]

An adult female patient presented with an exclusively spinal leptomeningeal infestation by cysticercosis (restricted to the cauda equina), verified in surgery. The rôle of the vertebral vein system in the spread of cysticercosis larvae is discussed. A commentary on the possibility that cysticercosis of the basal cisterns may be due to ascending migration of primarily spinal cysticerel, as originally proposed by Isamat de la Riva, is stated.

[Pharyngeal pain during lateral suboccipital puncture]

Oropharyngeal pain was referred by five fully conscious and collaborative patients during lateral suboccipital puncture (LSP) of the cisterna magna, performed for myelography and/or cerebrospinal fluid collection. The anastomotic connections between the lower cranial nerves, the sympathetic nerves and the upper cervical spinal nerves are reviewed, with emphasis on the relationship between the first cervical nerve (C1), the superior cervical ganglion of the sympathetic trunk, and the spinal accessory nerve (nerve XI), and their central connections. The authors conclude that pharyngeal pain during LSP is provoked by the stimulation of afferent visceral fibers of C1, or of the gray communicating branches of the superior cervical ganglion to C1.

[Multiple cerebral abscesses: apropos of 2 cases]

The authors summarize the current concepts regarding pathogenesis and surgical management of multiple brain abscesses, and report their experience with two recent cases with computerized tomographic follow-up.