Raul Marino

Microsurgical Anatomy of the Temporal Lobe: Part 1: Mesial Temporal Lobe Anatomy and Its Vascular Relationships as Applied to Amygdalohippocampectomy

OBJECTIVE We review the anatomy of the mesial temporal lobe region, establishing the relationships among the intraventricular, extraventricular, and surrounding vascular structures and their angiographic characterization. We also demonstrate the clinical application of these anatomic landmarks in an anatomic temporal lobectomy plus amygdalohippocampectomy. METHODS Fifty-two adult cadaveric hemispheres and 12 adult cadaveric heads were studied, using a magnification ranging from 3x to 40x, after perfusion of the arteries and veins with colored latex. RESULTS The intraventricular elements are the hippocampus, fimbria, amygdala, and choroidal fissure; the extraventricular elements are the uncus and parahippocampal and dentate gyri. The uncus has an anterior segment, an apex, and a posterior segment that has an inferior and a posteromedial surface; the uncus is related medially to cisternal elements and laterally to intraventricular elements. The anterior segment is related to the proximal sylvian fissure, internal carotid artery, proximal M1 segment of the middle cerebral artery, proximal cisternal anterior choroidal artery, and amygdala. The apex is related to the oculomotor nerve, uncal recess, and amygdala; the posteromedial surface is related to the P2A segment of the posterior cerebral artery inferiorly, to the distal cisternal anterior choroidal artery superiorly, and to the head of the hippocampus and amygdala intraventricularly. The choroidal fissure is located between the thalamus and fimbria; it begins at the inferior choroidal point behind the head of the hippocampus and constitutes the medial wall of the posterior two-thirds of the temporal horn. CONCLUSION Not only is the knowledge of these relations useful to angiographically characterize the mesial temporal region, but it has also proven to be of extreme value during microsurgeries involving this region.

Transient mutism following a posterior fossa approach to cerebellar tumors in children: a critical review of the literature

Transient mutism has been known as a rare complication following a posterior fossa approach to cerebellar tumors and its cause has not been clearly elucidated. The cerebellar mutism is not accompanied by cranial nerve deficits and disorders of consciousness. Since 1985 only 23 cases of mutism following removal of a cerebellar tumor in children have been reported in the literature. Two additional cases have been operated upon in our department. Extensive injury to the vermian and paravermian cerebellar area, involving the hemispheric cortex, cerebellar peduncles, fibers from the dentato-thalamocortical pathway, and dentate and interpositum nuclei may be the most important anatomical substrate of mutism. The mechanism of such transient mutism seems to be a complex of two or more factors (vascular disturbances due to manipulation or retraction of the cerebellar region around the IV ventricle and emotional factors). On the basis of these 25 cases the major features of the cerebellar mutism are discussed.

Angioleiomyoma of the cavernous sinus: Case report

OBJECTIVE AND IMPORTANCE:Angioleiomyomas (ALMs) are relatively rare, benign, vascular soft tissue tumors that occur most frequently in the extremities of middle-aged individuals. To date, only two cases of intracranial ALMs have been described, both with little emphasis on the clinical, surgical, and radiological aspects. Neither of these reported cases of ALM involved the cavernous sinus. Furthermore, there is no previous intracranial ALM magnetic resonance imaging scan described in the literature. This report presents the first case of cavernous sinus ALM, emphasizing the clinical, radiological, and surgical aspects. CLINICAL PRESENTATION:A 52-year-old man had a 2-year history of horizontal diplopia and frontal headache. Facial numbness and impaired visual acuity in the previous 6 months were also reported. Physical examination revealed paralysis of right Cranial Nerves III, IV, and VI. A decrease in optical acuity was also noted. Computed tomographic and magnetic resonance imaging scans demonstrated a mass lesion located in the right cavernous sinus, which enhanced homogeneously with administration of intravenous contrast medium. INTERVENTION:A total resection was performed via a right frontotemporal craniotomy and a pretemporal approach with peeling of the middle fossa. The postoperative course was uneventful. Histological examination identified the ALM, with no recurrence noted during follow-up. CONCLUSION:It is unknown why intracranial ALMs have not been reported more frequently in the literature. Although ALMs are a rare occurrence, misinterpretation of this lesion may also have contributed to the lack of reported cases. Before surgery, ALMs can be distinguished from meningiomas and schwannomas but not from hemangiomas. The prognosis of intracranial ALM is good, as suggested in this case as well as the two previously reported cases.

Aspectos epidemiológicos da epilepsia em São Paulo: um estudo da prevalência

Several studies on epidemiology of epilepsy were carried out in different parts of the world. However, the majority of their data was collected from hospitals, clinics, individual physicians and or small communities. Although these studies have contributed to our knowledge as to the risk factors of epilepsy, some of them have prevented us from further generalization, since the prevalence rates of the phenomena were not known for the entire population where from they were derived. Latin America has remained without epidemiological data, specially prevalence rates, for many years. A house-to-house survey was programmed by the Brazilian League of Epilepsy in the urban area of S. Paulo City the third largest cosmopolitan city in the world: 13 million inhabitants in 1980. A significant sample of 2011 houses was chosen by statistical means. A total of 7603 interviews were performed by 50 senior medical students and nurses, and 388 persons were considered suspect and further referred to our University Hospital for other studies; 348 of these were examined, and in 91 the diagnosis of epilepsy was confirmed, thus producing a prevalence rate 11.9 per 1000.

Congruence of the topography of intracranial calcifications and epileptic foci

Nodular intracranial calcifications (NIC) are frequent findings in CT scans of epileptic patients in countries where granulomatous central nervous disease such as neurocysticercosis is endemic. In 34 consecutive epileptic patients with NIC submitted to EEG, CT and CSF analysis, the correlation between the electroclinical localization of the focus and the topography of the NIC was studied. Twenty-nine patients had partial (Group I) and 5 had primarily generalized seizures (Group II). Twenty group I and 1 group II patients showed abnormal EEGs. CSF abnormalities consisted of increased protein content (n = 3) and positive Weinbergs reaction (n = 2). In 2 cases, viable neurocysticercotic vesicles were seen. Twenty-one patients had single NICs. No correlation could be established in group II patients. Within group I, 15 patients had a positive and 14 a negative correlation. Sixty-six percent of the patients with single NICs had negative correlations. These findings strongly suggest that the calcifications themselves are not the epileptogenic lesions in at least 50% of the studied cases.

Headache in acromegaly : dramatic improvement with the somatostatin analogue SMS 201-995

Two acromegalic patients with severe headache, persisting after pituitary adenomectomy followed by radiotherapy in one, were treated with the somatostatin analogue SMS 201-995. Both had been resistant to conventional headache therapy and experienced dramatic and rapid relief after the first injection of the analogue. This result persisted with long-term treatment of the drug. Although the mechanism of action of SMS 201-995 in pain remains unclear, the rapid and efficacious analgesic effect of this compound may be one more indication for its use in pituitary tumors associated with cephalalgias.

Hydrocephalus due to diffuse villous hyperplasia of the choroid plexus: Case report and review of the literature

Diffuse villous hyperplasia of the choroid plexus (DVHCP) that causes hydrocephalus by overproduction of cerebrospinal fluid is a very rare lesion and difficult to diagnose initially. We present a male infant who was diagnosed with communicating hydrocephalus at 16 months of age and treated initially by ventriculoperitoneal shunt. In the postoperative course, he developed massive ascites. Magnetic resonance imaging obtained after the operation revealed DVHCP. Resection of the choroid plexus of the left lateral ventricle was performed, and postoperatively, his ascites was resolved. We review the literature and discuss the diagnosis and treatment of this rare entity.

MR AND CT IMAGING IN THE DYKE-DAVIDOFF-MASSON SYNDROME : REPORT OF THREE CASES AND CONTRIBUTION TO PATHOGENESIS AND DIFFERENTIAL DIAGNOSIS

Cerebral hemiatrophy or Dyke-Davidoff-Masson syndrome is a condition characterized by seizures, facial asymmetry, contralateral hemiplegia or hemiparesis, and mental retardation. These findings are due to cerebral injury that may occur early in life or in utero. The radiological features are unilateral loss of cerebral volume and associated compensatory bone alterations in the calvarium, like thickening, hyperpneumatization of the paranasal sinuses and mastoid cells and elevation of the petrous ridge. The authors describe three cases. Classical findings of the syndrome are present in variable degrees according to the extent of the brain injury. Pathogenesis is commented.

Anterior callosotomy as a substitute for hemispherectomy.

Two patients with epilepsy and large hemispheric lesions underwent section of the frontal fibres of the corpus callosum for the treatment of seizures refractory to medical treatment. A severely retarded girl of 18 had encephalotrigeminal angiomatosis (Sturge-Weber syndrome) with multiple daily absences, tonic-clonic, myoclonic, atonic and adversive seizures since infancy. All types of fits--with the exception of adversive seizures and rare tonic-clonic fits--disappeared after anterior callosotomy. Another moderately retarded girl of 18 had an old cystic lesion over the entire territory of the left middle cerebral artery. She had had right hemiplegia since infancy and frequent brief absences and massive myoclonus triggered by unexpected sensory stimuli since the age of six years. Following anterior callosotomy there was an almost complete disappearance of the absences and a marked reduction of her startle myoclonus. Frontal callosotomy is a useful procedure in epileptics with large hemispheric lesions and carries less risk than hemispherectomy or total commissurotomy.

Reflections on a stereotactic and functional journey: the blessing and inspiration of working among giants.

THE AUTHOR REPORTS some of his early personal neurosurgical experiences spent among some of the great figures in neurosurgery and among some of the founders and pioneers of functional neurosurgery, stereotaxy, and clinical neurophysiology during the mid-1960s. This historical vignette represents recognition of the legacy of those many creative pioneers in this field of study, primarily in the areas of development of functional and stereotactic methods, epilepsy surgery, human neurophysiology, pain, movement disorders, neuroendocrine surgery, and psychiatric illnesses.