Surgery for Parkinson disease in the United States, 1996 to 2000: practice patterns, short-term outcomes, and hospital charges in a nationwide sample.

Object: The surgical treatment of Parkinson disease (PD) has undergone a dramatic shift, from stereotactic ablative procedures toward deep brain stimulaion (DBS). The authors studied this process by investigating practice patterns, mortality and morbidity rates, and hospital charges as reflected in the records of a representative sample of US hospitals between 1996 and 2000.

Methods: The authors conducted a retrospective cohort study by using the Nationwide Inpatient Sample database; 1761 operations at 71 hospitals were studied.

Orbital compartment syndrome mimicking cerebral herniation in a 12-yr-old boy with severe traumatic asphyxia.

Objective: To report a case of orbital compartment syndrome mimicking cerebral herniation in a boy with severe traumatic asphyxia.

Design: Case report.

Setting: A tertiary-care pediatric intensive care unit.

Microvascular decompression surgery in the United States, 1996 to 2000: mortality rates, morbidity rates, and the effects of hospital and surgeon volumes.

Objective: Microvascular decompression (MVD) is associated with low mortality and morbidity rates at specialized centers, but many MVD procedures are performed outside such centers. We studied short-term end points after MVD in a national hospital discharge database sample.

Methods: A retrospective cohort study was performed by using the Nationwide Inpatient Sample, 1996 to 2000.

Parietal activity and the perceived direction of ambiguous apparent motion.

We recorded from parietal neurons in monkeys (Macacca mulatta) trained to report the direction of an apparent motion stimulus consisting of regularly spaced columns of dots surrounded by an aperture. Displacing the dots by half their inter-column spacing produced vivid apparent motion that could be perceived in either the preferred or anti-preferred direction for each neuron. Many neurons in the lateral intraparietal area (LIP) responded more strongly on trials in which the animals reported perceiving the neurons' preferred direction, independent of the hand movement used to report their percept.

Spinal dural arteriovenous fistulas: experience with endovascular and surgical therapy.

Object: Although the pathophysiology of spinal dural arteriovenous fistulas (AVFs) has recently been elucidated, the optimal treatment strategy for these lesions has yet to be defined. Current management techniques include endovascular embolization or microsurgical obliteration.

Methods: The authors reviewed the records and angiograms of all patients with spinal dural AVFs treated at Massachusetts General Hospital over a 6-year period (1992-1998).

Distinct nature of directional signals among parietal cortical areas during visual guidance.

We examined neuronal signals in the monkey medial superior temporal area (MST), the medial intraparietal area (MIP), and the lateral intraparietal area (LIP) during visually guided hand movements. Two animals were trained to use a joystick to guide a spot to a target. Many neurons responded in a direction-selective manner in this guidance task.

Outcomes following staged bilateral pallidotomy in advanced Parkinson's disease.

The authors assessed clinical outcome for up to one year after staged bilateral pallidotomy in 14 patients with advanced PD. One year after surgery, dyskinesias were virtually abolished and there were significant reductions in "off" time (67%) and activities of daily living "off" scores (24%), as well as nonsignificant reduction in "off" motor score (39%); "on" scores were unchanged. One patient developed a visual field deficit; two had transient confusion.

Stereotactic pallidotomy performed without using microelectrode guidance in patients with Parkinson's disease: surgical technique and 2-year results.

Object: Pallidotomy for the treatment of medically refractory Parkinson's disease (PD) has enjoyed renewed popularity. However, the optimal surgical technique, lesion location, and long-term effectiveness of pallidotomy remain subjects of debate. In this article the authors describe their surgical technique for performing pallidotomy without using microelectrode guidance, and the clinical and radiological results of this procedure.

Dissociation of visual, motor and predictive signals in parietal cortex during visual guidance.

The role of the posterior parietal cortex (PPC) in the visual guidance of movements was studied in monkeys trained to use a joystick to guide a spot to a target. Visual and motor influences were dissociated by transiently occluding the spot and by varying the relationship between the direction of joystick and spot movements. We found a strong segregation of function in PPC during visual guidance.

The importance of accurate lesion placement in posteroventral pallidotomy. Report of two cases.

Pallidotomy has become a widely used treatment for medically refractory Parkinson's disease. However, the optimal lesion size and location within the pallidum have not yet been determined, and the role of repeated pallidotomy remains undefined. The authors present two patients who had unsatisfactory results after their first unilateral pallidotomy but attained dramatic and long-lasting improvement with repeated surgery.

Hydrocephalus requiring urgent external ventricular drainage in a patient with diabetic ketoacidosis and cerebral edema: case report.

Objective And Importance: Neurological deterioration, typically attributed to cerebral edema, is a rare but life-threatening complication in the treatment of diabetic ketoacidosis (DKA). We report the case of a child with DKA who became comatose but demonstrated acute obstructive hydrocephalus, instead of cerebral edema.

Clinical Presentation: An 11-year-old male patient presented with new-onset insulin-dependent diabetes mellitus and DKA.

Role of inferior temporal neurons in visual memory. II. Multiplying temporal waveforms related to vision and memory.

1. In the companion paper we reported on the activity of neurons in the inferior temporal (IT) cortex during a sequential pattern matching task. In this task a sample stimulus was followed by a test stimulus that was either a match or a nonmatch.

Role of inferior temporal neurons in visual memory. I. Temporal encoding of information about visual images, recalled images, and behavioral context.

1. Lesions of the inferior temporal (IT) cortex selectively hamper monkeys in tasks requiring visual memory. A system that recognizes images must be able to encode a current stimulus, recall the code of a previous stimulus, compare the codes of the two stimuli, and make a decision on the basis of the outcome of the comparison.

Rapid determination of cancellous bone mineral loss in ovariectomized rats by a subtraction technique.

We present a rapid technique for determining cancellous bone mineral changes in small experimental animals. We used the distal centimeter of the right femur from ovariectomized (OX) (N = 30) and shamovariectomized (ShOX) (N = 28) rats, aged 90 days at surgery and killed at times from 125-540 days postsurgery. We used dual photon absorptiometry to scan the segment three times: intact, after parasagittal splitting, and after removing all cancellous bone.