Search results for "brain diseases"
showing 10 items of 67 documents
The pterygoid reflex in man and its clinical application
1992
A technique for eliciting and recording the stretch reflex (R) of the medial pterygoid muscle (Pter) is described. The latency was 6.9 ± 0.43 ms in 23 healthy volunteers (mean age 23.7 years) showing a side-to-side difference of 0.29 ± 0.21 ms. The PterR latencies were little shorter and side-to-side difference little greater than of the masseter reflex. Observations in 5 selected patients with small brainstem lesions suggest that the neurons of the PterR afferents form a cluster within the caudal portion of the trigeminal mesencephalic nucleus. Testing the masseter and pterygoid reflexes provides a more precise localization of small ponto-mesencephalic lesions. © 1992 John Wiley & Sons, In…
Endoscopic Procedures through the Foramen Interventriculare of Monro under Stereotactical Conditions
1994
The foramen interventriculare of Monro is an anatomical narrowness for the endoscopic access to the third ventricle. The effective mechanical angle to pass the foramen interventriculare from a frontal bore hole depends on the diameter in the plane of entrance, the depth of the foramen, and the diameter of the endoscope. Under the pathological conditions of a hydrocephalus internus the foramen interventriculare is enlarged. By means of stereotactical guidance, it is possible to reach the third ventricle accurately without damaging anatomical structures around the foramen interventriculare. The endoscopic technique under stereotactical guidance using a rigid endoscope is sufficient and safe t…
Frameless Neuronavigation Applied to Endoscopic Neurosurgery
2000
Objective: We retrospectively analyzed the indications, surgical techniques, and applicability of frameless neuronavigation to endoscopic procedures in a heterogeneous group of 15 patients. Material and Methods: In 8 patients indications for surgery were cystic lesions, in 3 patients intraventricular tumors, and in 4 patients occlusive hydrocephalus. The mean age was 39 years (range 9 - 76 years). The follow-up period ranged from 5 - 24 months (mean 10 months). Frameless neuronavigation was accomplished with the “operating arm system” in 10 cases and with the “optical tracking system” in 5 cases (RADIONICS, Burlington, USA). Results: In all 15 cases, neuronavigation sufficiently provided an…
Limitations of the trail making test part-B in assessing frontal executive dysfunction.
2015
AbstractPart B of the Trail Making Test (TMT-B) is one of the most widely used neuropsychological tests of “executive” function. A commonly held assumption is that the TMT-B can be used to detect frontal executive dysfunction. However, so far, research evidence has been limited and somewhat inconclusive. In this retrospective study, performance on the TMT-B of 55 patients with known focal frontal lesions, 27 patients with focal non-frontal lesions and 70 healthy controls was compared. Completion time and the number of errors made were examined. Patients with frontal and non-frontal lesions performed significantly worse than healthy controls for both completion time and the number of errors.…
Blurring the boundaries between frame-based and frameless stereotaxy: feasibility study for brain biopsies performed with the use of a head-mounted r…
2015
OBJECT Frame-based stereotactic interventions are considered the gold standard for brain biopsies, but they have limitations with regard to flexibility and patient comfort because of the bulky head ring attached to the patient. Frameless image guidance systems that use scalp fiducial markers offer more flexibility and patient comfort but provide less stability and accuracy during drilling and biopsy needle positioning. Head-mounted robot-guided biopsies could provide the advantages of these 2 techniques without the downsides. The goal of this study was to evaluate the feasibility and safety of a robotic guidance device, affixed to the patient’s skull through a small mounting platform, for …
Pontine lesions mimicking acute peripheral vestibulopathy
1999
OBJECTIVES Clinical signs of acute peripheral vestibulopathy (APV) were repeatedly reported with pontine lesions. The clinical relevance of such a mechanism is not known, as most studies were biased by patients with additional clinical signs of brainstem dysfunction. METHODS Masseter reflex (MassR), blink reflex (BlinkR), brainstem auditory evoked potentials (BAEPs), and DC electro-oculography (EOG) were tested in 232 consecutive patients with clinical signs of unilateral APV. RESULTS Forty five of the 232 patients (19.4%) had at least one electrophysiological abnormality suggesting pontine dysfunction mainly due to possible vertebrobasilar ischaemia (22 patients) and multiple sclerosis (ei…
Stereotactic biopsies guided by an optical navigation system: technique and clinical experience.
2002
Frame-based stereotactic biopsies are time-consuming procedures making necessary head fixation in a ring, explicit coordinate calculation and setting of the parameters. Frameless systems make many of these intermediate steps unnecessary, impose less mechanical restrictions regarding access to the lesions, and with slight modifications can be used to perform stereotactic biopsies. A special adaptation designed to fix the holder and the biopsy instrument is described. The neuronavigation optical tracking system of Radionics was used. CT scans were performed with 6 skin markers. Calibration was performed after head fixation in the Mayfield clamp. Mean calibration error was 2.19 +/- 0.81 mm. Th…
Frontal subregions mediating Elevator Counting task performance.
2010
Deficits in sustained attention may lead to action slips in everyday life as irrelevant action sequences are inappropriately triggered internally or by the environment. While deficits in sustained attention have been associated with damage to the frontal lobes of the brain, little is known about the role of the frontal lobes in the Elevator Counting subtest of the Test of Everyday Attention. In the current study, 55 frontal patients subdivided into medial, orbital and lateral subgroups, 18 patients with posterior lesions and 82 healthy controls performed the Elevator Counting task. The results revealed that patients with medial and left lateral prefrontal lesions were significantly impaired…
Endoscopic Treatment of Mesencephalic Ependymal Cysts: Technical Case Report
1998
OBJECTIVE: To evaluate the results of different neuroendoscopic surgical procedures for the treatment of mesencephalic ependymal cysts. METHODS: The clinical records of five patients treated for symptomatic mesencephalic ependymal cysts were retrospectively studied. Two patients had been operated on using an endoscope-assisted microsurgical technique and three patients using a pure endoscopic procedure. RESULTS: Adequate fenestration of the cysts was achieved in all of the patients. Two of the patients were symptom-free, and the other three had improved significantly after a mean follow-up duration of 14 months. There was no surgical morbidity. CONCLUSION: Mesencephalic ependymal cysts can …
Dyke-Davidoff-Masson syndrome: case report of fetal unilateral ventriculomegaly and hypoplastic left middle cerebral artery
2013
Prenatal ultrasonographic detection of unilateral cerebral ventriculomegaly arises suspicion of pathological condition related to cerebrospinal fluid flow obstruction or cerebral parenchimal pathology. Dyke-Davidoff-Masson syndrome is a rare condition characterized by cerebral hemiatrophy, calvarial thickening, skull and facial asymmetry, contralateral hemiparesis, cognitive impairment and seizures. Congenital and acquired types are recognized and have been described, mainly in late childhood, adolescence and adult ages. We describe a female infant with prenatal diagnosis of unilateral left ventriculomegaly in which early brain MRI and contrast enhanced-MRI angiography, showed cerebral left…