Publications (73) View all
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Article: Acute spinal cord swelling in a child with Chiari II malformation.
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ABSTRACT: We report on a patient with Chiari II malformation who developed acute cervical myelopathy and brainstem dysfunction following a shunt failure. A brain and spine magnetic resonance image obtained immediately after admission evidenced swelling of the medulla and upper cervical spinal cord. After emergency placement of an external ventricular drain, the swelling receded, the child's respiratory pattern improved and the motor function of his upper and lower extremities progressively returned to its normal condition. The case reported here suggests that in patients with Chiari type II malformation, spinal cord swelling might have a similar pathophysiology to the periventricular edema observed in the supratentorial compartment, and thus may be independent of the early stages of syringomyelia or syringobulbia.Pediatric Neurosurgery 10/2001; 35(3):145-8. · 0.70 Impact Factor -
Article: Functional assessment of children with cerebral palsy following limited (L4-S1) selective posterior rhizotomy--a preliminary report.
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ABSTRACT: Selective Posterior Rhizotomy (SPR) is effective for reducing spasticity in children with cerebral palsy (CP). Nonetheless, extensive sensory deafferentation associated with this procedure can lead to prolonged postoperative hypotonia that delays the functional recovery of the patient. As lumbar rhizotomy provokes suprasegmental hypotonia, we hypothesized that reducing the extent of the deafferentation to the roots of L4-S1 levels would reduce the risk of postoperative hypotonia. Five patients with spastic cerebral palsy (4 males and 1 females, age range: 4-12 years) underwent limited selective dorsal rhizotomy (LSDR) of three (L4-S1) dorsal roots. All patients were able to walk independently prior to surgery. Functional assessments of these patients were performed pre and post operatively. Assessments included spasticity evaluation, passive range of motion, and sagittal plane kinematics of the hip, knee, and ankle during walking. Following surgery, reduced spasticity, increased passive range of motion and improved joint motion during walking was observed. Specifically, peak hip and knee extension and peak ankle dorsiflexion increased while peak plantarflexion decreased. Strength and motor control were not adversely affected by this procedure in any of the subjects and all patients actually demonstrated improvements. Previous studies have demonstrated that LSDR is highly effective in reducing spasticity and achieving functional outcome in spastic children. The results of this study demonstrated improved function during walking as assessed using gait analysis techniques.Acta Neurochirurgica 10/2001; 143(9):865-72. · 1.52 Impact Factor -
Article: Relevant factors in multiple shunt failures.
Child s Nervous System 08/2000; 16(7):389. · 1.54 Impact Factor -
Article: Relevance of the cerebellar hemispheres for executive functions.
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ABSTRACT: The aim of the present study was to elucidate the role of the cerebellar hemispheres in executive functions. The findings are relevant because of the large number of children who survive cerebellar tumors. Neuropsychologic assessments of four patients (8-21 years of age) who had undergone neurosurgery for removal of tumors in the cerebellar hemispheres were conducted and compared with the assessments of six children who had been diagnosed with temporal lobe tumors or cysts. The executive functions were assessed using the Wisconsin Card Sorting Test. IQs were average in both groups. As expected, patients with cerebellar hemispheric lesions had impaired executive functions. In particular, they appeared to have difficulty generating and testing hypotheses regarding the matching rules on the Wisconsin Card Sorting Test. Patients with temporal lesions had a different pattern of deficits on this test. The findings are consistent with the theories that propose that the cerebellar hemispheres are involved in cognitive processes. The findings also demonstrate that subtle deficits in executive functions can be masked by a normal IQ in survivors of cerebellar tumors and highlight the need to design interventions targeted toward problem-solving skills.Pediatric Neurology 03/2000; 22(2):106-12. · 1.52 Impact Factor -
Article: Parallel and serial search in two teenagers with lesions of the mesial parietal cortex.
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ABSTRACT: Visual-spatial attention was examined in two 14-year-olds who had undergone occipital-parietal craniotomies for removal of mesial parietal tumors, one in the right and one in the left hemisphere. Neither patient showed clinically significant visual neglect. They were administered two visual search tasks from Treisman and Souther [43] that make significantly different demands on visual spatial attention. In feature-present (parallel) search, they searched for the presence of a feature. In feature-absent (serial) search, they searched for its absence. Search rate was estimated from the slope of the function relating display size to response time. Both patients had flat slopes in feature-present search to target-present (TP) displays, indicating that they could conduct parallel search at the same rate as controls. Although the patient with the right-hemisphere lesion also had a flat slope to target-absent (TA) displays, the patient with the left-hemisphere lesion had a steep slope (30 ms/item) in this condition. In feature-absent search, the patients had equally slow search rates compared to controls, suggesting that the mesial parietal cortex is part of the network that mediates serial shifts of attention. Results support the distinction between detection of the target in parallel vs serial search and suggest that processes involved in TP and TA trials in parallel search are also dissociable.Neuropsychologia 12/1999; 37(13):1461-8. · 3.64 Impact Factor
