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S Baser

Publications and source records attributed to S Baser.

8 recordsLinked to original sources
PubMed2000

Functional outcomes after gamma knife thalamotomy for essential tremor and MS-related tremor.

Twelve patients with a median age of 75 years underwent gamma knife thalamotomy for essential tremor (ET) (n = 9) or MS-related tremor (n = 3). All 11 evaluable patients noted improvement in action tremor. Six of eight ET patients had complete tremor arrest, and the violent action tremor in all three patients with MS was improved. One patient developed transient arm weakness. Stereotactic radiosurgery for ET and MS-related tremor is safe and effective for patients who may be poor candidates for other procedures.

Activities of Daily Living↗
PubMed1999

Outcomes after stereotactically guided pallidotomy for advanced Parkinson's disease.

OBJECT: Parkinson's disease (PD) is a prevalent neurodegenerative disorder that becomes refractory to medication as the disease progresses. Although in the past 5 years increasing numbers of patients have undergone stereotactically guided posteroventral pallidotomy for advanced PD, the safety and efficacy of surgery remains to be documented. The goal in this study was to determine the potential operative morbidity and types of functional outcomes by using validated PD rating scales and a patient survey. METHODS: In a prospective analysis of a consecutive surgical series the authors evaluated 58 patients with advanced PD who ranged in age from 40 to 79 years (mean 67 years) and who had undergone surgery between 1994 and 1997. They used a patient survey and the Unified Parkinson's Disease Rating Scale (UPDRS) to study patients during periods of medication administration ("on") and withdrawal ("off"; mean off score before surgery = 96). Temporary surgical morbidity was found in four patients (6.9%), three of whom developed transient dysarthria and one of whom exhibited transient confusion (1.7%). One patient had persistent dysarthria (1.7%). No patient developed a visual field deficit or sustained a brain hemorrhage. All patients were discharged from the hospital within 24 hours. Significant postsurgical improvements were noted in the UPDRS off-period total and motor scores, as well as in tremor, rigidity, bradykinesia, and contralateral dyskinesia (p < 0.005). Improvements persisted in dyskinesia and tremor for the 21 patients who were evaluated past 1 year. The authors found no improvement in any on-period symptoms except dyskinesia. Thirty-one (61 %) of 51 patients surveyed reported functional gains and/or dramatic improvement in symptoms, 17 (33%) reported symptomatic improvement without functional gains, and three (6%) had minimal or no change in symptoms. No change in the mini mental state examination score was noted during follow up. There were no significant postoperative changes in the use of medication. CONCLUSIONS: In advanced PD associated with either a medically refractory state with significant off periods or levodopa-induced dyskinesias, magnetic resonance imaging-guided pallidotomy with macrostimulation was associated with minimal morbidity and yet significantly reduced dyskinesia and off-period disability. These improvements were of value to the patient and persisted beyond the 1st year.

Adult↗
PubMed1998

Spinal cord stimulation revisited.

The proportion of patients with intractable pain successfully managed with spinal cord stimulation (SCS) remains disputed. We analyze 27 consecutive patients with intractable pain treated with SCS using identical hardware (Itrel II System; Medtronic Neurological, Inc Minneapolis, MN, USA) by a single satisfactory diagnosis 1992 through 1995. A rigid selection protocol was used: 1. A satisfactory diagnosis of the pathologic process resulting in pain was made. 2. A corrective surgical procedure was judged not feasible by surgeons experienced in the particular pathology, e.g., vascular peripheral nerve, spine. 3. Lack of satisfactory response to noninterventional pain management modalities by an interdisciplinary pain clinic. 4. Independent psychological evaluation, including a structured interview was performed by a psychologist specialized in chronic pain management. In the last eight cases, a battery of self-report tests designed to assess psychosocial and behavioral consequences of the chronic pain problem were administered as well. All cases were of nonmalignant pain, except for one patient. Thirteen cases were diagnosed with failed back surgery syndrome (FBSS), one older patient with lumbosacral radiculopathy who refused decompression, one cervical radiculopathy and Klippel-Feil syndrome, six with reflex sympathetic dystrophy (RSD), two with peripheral vascular ischemic disease, one with post-thoracotomy pain syndrome, one with leg pain following resection of angiolipoma, one with traumatic superficial peroneal neuropathy, and one with Pancoast's tumor. Fifteen patients were female and twelve were male. All were Caucasian. Their ages ranged from 27 to 84 years (mean:48). The average follow-up was 21 months (range: 48-6). All patients underwent a three day trial screening with Pisces-Quad/Resume epidural leads connected to a temporary external stimulator. An Itrel II System pulse-generator was internalized in each of the 24 patients who had successful trial (three cervical and twenty-one thoracic-lumbar). There was no morbidity. Pain reduction was sustained in 22 out of the 24 patients who continue to use the stimulator. The same number would choose to receive in an electrical stimulator again. Normalization or improvement in Quantitative Sudomotor Axon Reflex Test (Q-SART) and Thermography was documented in the patients with RSD. We conclude that rigid selection protocol can maximize the proportion of patients with intractable pain who are successfully treated with SCS. Strict neurosurgical technique eliminates infection risk. Hardware selection minimizes incidence of malfunction.

Adult↗
PubMed1997

Flash visual evoked potential monitoring of optic tract function during macroelectrode-based pallidotomy.

Posteroventral pallidotomy (PVP) has received renewed interest as an ablative procedure for the symptomatic treatment of Parkinson's disease. In previous reports, the proximity of the optic tract to the lesion target in the globus pallidus internus has resulted in the occurrence of visual field deficits in as much as 14% of patients. The authors have used intraoperative visual evoked potentials (VEPs) during PVP to reduce this risk. All procedures were performed in awake patients. Flash stimuli were delivered to each eye via fiberoptic sources. Baseline flash VEPs were recorded at O1/Cz (left visual cortex to vertex), Oz/Cz (midline visual cortex to vertex), and O2/Cz (right visual cortex to vertex) for OS, OU, and OD stimulation. Epochs were acquired before and after localization, after macroelectrode stimulation, after temporary thermal lesioning, and after permanent thermal lesioning. Forty-seven patients underwent a total of 59 procedures. Visual evoked potentials were recorded reproducibly in all patients. In 11 procedures, VEP changes were reported, including six amplitude changes (10-80%), six latency shifts (3-10 msec), and one report of "variability." In four procedures, VEP changes prompted a change in target coordinates. One false-positive and one false-negative VEP change were encountered. The only confirmed visual deficit was a superior quadrantanopsia, present on formal fields, but clinically asymptomatic. The authors conclude that VEPs may be useful for procedures performed in the awake patient because of the lack of anesthetic-induced variability. The 1.7% visual morbidity reported here (one in 59 patients) compares favorably with other series using microelectrodes. Visual evoked potentials may be a useful monitoring technique to reduce the incidence of clinically significant visual morbidity during pallidotomy, especially during formal lesioning of the ventral pallidum adjacent to the optic tract.

Journal Article↗
PubMed1991

Computed tomography, magnetic resonance imaging and positron emission tomography with [18F]fluorodeoxyglucose in multiple system atrophy and pure autonomic failure.

We studied 45 patients who had autonomic failure with computed tomography, magnetic resonance imaging and positron emission tomography with [18F]fluorodeoxyglucose to characterize the neuroimaging features of multiple system atrophy and pure autonomic failure and determine the utility of these techniques in distinguishing multiple system atrophy from pure autonomic failure. There were 30 patients with multiple system atrophy and 15 with pure autonomic failure. In the multiple system atrophy group, eight patients had mainly cerebellar signs, seven extrapyramidal and 15 had combinations of cerebellar and extrapyramidal signs. Cerebellar atrophy on computerized tomography and magnetic resonance imaging, signal hypointensity in the posterolateral putamen on magnetic resonance imaging and a generalized reduction in glucose utilization rate with positron emission tomography with [18F]fluorodeoxyglucose, were the main findings and were seen only in the patients with multiple system atrophy. Decreased glucose utilization (hypometabolism) was most prominent in the cerebellum, brainstem, striatum and frontal and motor cortices. These results indicate clear differences, using neuroimaging studies, between multiple system atrophy and pure autonomic failure.

Atrophy↗