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R J Witte

Publications and source records attributed to R J Witte.

14 recordsLinked to original sources
PubMed2001

Quantitative and qualitative outcome measures after thalamic deep brain stimulation to treat disabling tremors.

OBJECTIVE: We studied outcome measures after unilateral and bilateral thalamic stimulation to treat disabling tremor resulting from essential tremor and Parkinson's disease. The surgical technique, qualitative and quantitative tremor assessments, stimulation parameters, locations of active electrodes, complications, and side effects are described and analyzed. METHODS: Forty-one patients with essential tremor or Parkinson's disease underwent implantation of 56 thalamic stimulators. Preoperative qualitative and quantitative tremor measurements were compared with those obtained after unilateral and bilateral surgery, with activated and deactivated stimulators. Stimulation parameters and stimulation-related side effects were recorded, and outcome measures were statistically analyzed. RESULTS: Qualitative measurements demonstrated significant improvement of contralateral upper-limb (P < 0.001), lower-limb (P < 0.01), and midline (P < 0.001) tremors after unilateral surgery. Ipsilateral arm tremor also improved (P < 0.01). No differences were observed with the Purdue pegboard task. Quantitative accelerometer measurements were correlated with qualitative assessments and confirmed improvements in contralateral resting (P < 0.001) and postural (P < 0.01) tremors and ipsilateral postural tremor (P < 0.05). Activities of daily living improved after unilateral surgery (P < 0.001) and additionally after bilateral surgery (P < 0.05). Adjustments of the pulse generator were required more frequently for tremor control than for amelioration of side effects. Bilateral thalamic stimulation caused more dysarthria and dysequilibrium than did unilateral stimulation. Stimulation-related side effects were reversible for all patients. Stimulation parameters did not change significantly with time. A significantly lower voltage and greater pulse width were used for patients with bilateral implants. CONCLUSION: Unilateral thalamic stimulation and bilateral thalamic stimulation are safe and effective procedures that produce qualitative and quantitative improvements in resting, postural, and kinetic tremor. Thalamic stimulation-related side effects are mild and reversible.

Activities of Daily Living↗
PubMed2001

Simultaneous thalamic deep brain stimulation and implantable cardioverter-defibrillator.

Thalamic deep brain stimulation is becoming increasingly popular for the control of drug-refractory tremor. Implantable cardiac pacemakers and defibrillators are commonly used therapeutic modalities. Concerns exist about the potential interactions between these 2 devices in the same patient, but no experience has been reported previously. We describe a patient with essential tremor who had a deep brain stimulator implanted into the left ventral intermediate nucleus of thalamus, who subsequently needed an implantable cardioverter-defibrillator. Despite concerns about possible interactions between the 2 types of implanted electrical devices (i.e., a situation similar to drug-drug interactions), the deep brain stimulator and the implanted pacemaker-defibrillator functioned appropriately, and no interaction occurred in our patient.

Aged↗
PubMed2000

Hemangioma of the mandibular branch of the trigeminal nerve in the Meckel cave presenting with facial pain and sixth nerve palsy.

In a 25-year-old woman with episodic periorbital-temporal pain who eventually developed a sixth nerve palsy, magnetic resonance imaging revealed a lesion predominantly in the Meckel cave that was found to be a capillary hemangioma arising from the mandibular division of the trigeminal nerve. Hemangiomas of the Meckel cave must be considered in cases of facial pain with a sixth nerve palsy. even if there are no clinical findings of trigeminal neuropathy.

Abducens Nerve Diseases↗
PubMed2000

Predictors of neuropsychological outcome in patients following microelectrode-guided pallidotomy for Parkinson's disease.

OBJECT: The authors studied neuropsychological performance following microelectrode-guided posteroventral pallidotomy in patients with Parkinson's disease (PD) and evaluated correlations with presurgical and surgical factors. METHODS: Neuropsychological changes 3 months (43 patients) and 12 months (27 patients) after microelectrode-guided pallidotomy for PD are reported in a series of 44 consecutive patients with the disease, who improved neurologically, as measured by the Unified Parkinson's Disease Rating Scale (UPDRS) in both the "off' (p<0.001) and best "on" (p<0.001) states. Findings of the vocabulary subtest of the Wechsler Adult Intelligence Scale-Revised (p<0.01), Letter Fluency (p<0.001), Verbal Fluency for semantic categories (p<0.001), and the Wisconsin Card Sorting Test (p<0.01) showed a significant decline in neuropsychological performance in patients 3 months after undergoing left-sided pallidotomy. Impairment in the language domain (semantic fluency) persisted at the 12-month follow-up examination (p<0.01). Visual memory improved after right-sided pallidotomies (p<0.01 after 3 months), with a nonsignificant trend toward persistent improvement 1 year postsurgery (p<0.02 after 12 months). Preoperative semantic fluency was influenced by patient age (p<0.001) and by the width of the third ventricle (p<0.05), as measured by magnetic resonance imaging. A regression model revealed that semantic fluency 3 months postoperatively was significantly affected by the baseline score (p<0.001), side of surgery (p<0.001), handedness (p<0.01), and patient age (p<0.05). However, postoperative lesion volume, lesion location, number of tracks, number of lesions, distance from anatomical landmarks, or UPDRS score did not significantly contribute to neuropsychological outcome. CONCLUSIONS: Neuropsychological changes in a cohort of patients with PD who underwent pallidotomy and experienced excellent clinical benefits and minimum postoperative complications, emphasize the importance of neuropsychological examinations and further investigation of predictive factors.

Aged↗
PubMed1999

Distinguishing primary angiitis of the central nervous system from cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: the importance of family history.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetically linked neurologic disease characterized by recurrent strokes and progressive or stepwise dementia, with or without migraine-like headaches, seizures, and pseudobulbar palsy. We describe a patient referred with a diagnosis of treatment-refractory primary angiitis of the central nervous system. Meningocortical and skin biopsies confirmed that the patient had CADASIL. Clinical and radiographic differences in these disorders may be subtle, but awareness of them is crucial if the patient is to avoid unnecessary exposure to potentially deleterious immunosuppressive therapy.

Dementia, Multi-Infarct↗
PubMed1996

Neuroradiologic applications of central nervous system SPECT.

Single photon emission computed tomography (SPECT) of the central nervous system (CNS) has many potentially useful interventional neuroradiologic applications. CNS SPECT allows easy and safe evaluation of the collateral circulation during internal carotid balloon test occlusion. The cerebrovascular distribution of intracarotid amobarbital sodium, which is used in the Wada test, can be accurately determined with simultaneous injection of a radiopharmaceutical. Easy and safe evaluation of the extent and distribution of vasospasm associated with subarachnoid hemorrhage or cerebral angiography is also possible with CNS SPECT. Images obtained after administration of acetazolamide can be compared with baseline images to evaluate cerebrovascular reserve before carotid endarterectomy. Seizure foci can be identified if peripheral intravenous injection is performed during an ictus. Thallium-201 imaging can be used to direct stereotactic brain biopsy to check for tumor recurrence. Radiologists need to familiarize themselves and their clinical colleagues with the many uses of this imaging technique.

Aged↗
PubMed1991

Diffuse pulmonary alveolar hemorrhage after bone marrow transplantation: radiographic findings in 39 patients.

Diffuse alveolar hemorrhage is a life-threatening complication after bone marrow transplantation. We investigated the radiographic abnormalities that occurred in 39 transplantation patients with a diagnosis of diffuse alveolar hemorrhage and correlated the findings with the patients' clinical course. The initial radiographic abnormalities after diffuse alveolar hemorrhage developed an average of 11 days after bone marrow transplantation, and the radiographic abnormalities preceded the clinical diagnosis by an average of 3 days. Twenty-seven patients initially had bilateral radiographic abnormalities; 10 initially had unilateral abnormalities (seven in the right lung, three in the left lung). Two patients had normal chest radiographs throughout their clinical course. All 37 patients with radiographic abnormalities had abnormalities involving the central portion of the lung, primarily the middle and lower lung zones. The initial radiographic pattern was interstitial in 27 and alveolar in 10. In 24 patients, radiographic abnormalities were initially judged to be mild; three were severe from the onset. Radiographic abnormalities rapidly worsened in most patients over 6 days. In 30 patients, diffuse bilateral radiographic abnormalities involving all lung zones developed. Eleven patients persisted in having only interstitial radiographic abnormalities; 26 had a confluent alveolar pattern. At the height of radiographic abnormalities, 27 cases were judged to be severe, and only one case was judged to be mild. The mortality rate in patients with diffuse alveolar hemorrhage was 77%. The radiographic abnormalities of diffuse alveolar hemorrhage are nonspecific and usually precede the clinical diagnosis. The clinical course after hemorrhage is short, often resulting in death.

Adolescent↗
PubMed1986

Indium-111 labeled leukocyte imaging following hepatic artery embolization.

The use of In-111 labeled leukocytes for abscess localization is becoming well established. The first report of In-111 imaging following hepatic embolization is presented. A 45-year-old man with adenocarcinoma of the colon and metastatic liver disease was treated for intractable pain using particulate embolization of the hepatic artery. In-111 leukocyte imaging was performed to rule out abscess formation. The distribution of the labeled leukocytes demonstrated hepatic uptake commensurate with Tc-99m sulfur colloid (SC) images. Areas of embolization did not accumulate tracer. Pathologic examination at autopsy correlated with the distribution of the labeled leukocytes. Thus, therapeutic embolization did not alter the normal distribution of this tracer in functional hepatic tissue.

Adenocarcinoma↗
PubMedDate not supplied

Signal intensity artifacts in clinical MR imaging.

Signal intensity artifacts are often encountered during magnetic resonance (MR) imaging. Occasionally, these artifacts are severe enough to degrade image quality and interfere with interpretation. Signal intensity artifacts inherent in local coil imaging include intensity gradients and local intensity shift artifact. The latter can be minimized but not eliminated with optimal coil design and tuning. Improper coil or patient positioning can produce subtle or, in some cases, severe signal intensity artifacts, and each is easily corrected. Signal intensity artifacts and image degradation can also occur in a perfectly functioning coil if protocols are not optimized. Failure of decoupling mechanisms can produce signal intensity artifacts that will not respond to protocol optimization and will worsen with gradient imaging. Improper coil tuning manifests as a shading artifact that can mimic other findings. Signal-degrading artifacts may be caused by a ferromagnetic foreign body in the imager. Signal intensity artifacts can also result from performing ultrafast imaging with coils that were not designed for this type of imaging or from MR imaging system malfunction. Familiarity with the various causes of signal intensity artifacts is necessary to maintain optimal image quality and should be required as part of any MR imaging quality assurance program.

Artifacts↗