Wharen, Robert E.

Abstract A simple and reproducible method of quantitating the amount of hematoporphyrin derivative by fluorescence microscopy in biopsies of tumors from patients undergoing photoradiation therapy is presented, substantiated by laboratory studies of experimental central nervous system tumors and normal rat tissues. The literature regarding the quantitation of hematoporphyrin is reviewed, and implications of this study for the future application of photoradiation therapy and the design of laboratory studies are discussed.

Object The object of this study was to assess the results of unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) for management of advanced Parkinson disease (PD). Methods A clinical series of 24 patients (mean age 71 years, range 56–80 years) with medically intractable PD, who were undergoing unilateral magnetic resonance imaging–targeted, electrophysiologically guided STN DBS, completed a battery of qualitative and quantitative outcome measures preoperatively (baseline) and postoperatively, using a modified Core Assessment Program for Intracerebral Transplantations protocol. The mean follow-up period was 9 months. Statistically significant improvement was observed in the Unified Parkinson's Disease Rating Scale (UPDRS) Part II score (18%), the total UPDRS PART III score (31%), the contralateral UPDRS Part III score (63%), and scores for axial motor features (19%), contralateral tremor (88%), rigidity (60%), bradykinesia (54%), and dyskinesia (69%), as well as the Parkinson's Disease Quality of Life questionnaire score (15%) in the on-stimulation state compared with baseline. Ipsilateral symptoms improved by approximately 15% or less. Performance on the Purdue pegboard test improved in the contralateral hand in the on-stimulation state compared with the off-stimulation state (38%, p < 0.05). The daily levodopa-equivalent dose was reduced by 21% (p = 0.018). Neuropsychological tests revealed an improvement in mental flexibility and a trend toward reduced letter fluency. There were no permanent surgical complications. Of the 16 participants with symmetrical disease, five required implantation of the DBS unit on the second side. Conclusions Unilateral STN DBS is an effective and safe treatment for selected patients with advanced PD. Unilateral STN DBS provides improvement of contralateral motor symptoms of PD as well as quality of life, reduces requirements for medication, and possibly enhances mental flexibility. This method of surgical treatment may be associated with a reduced risk and may provide an alternative to bilateral STN DBS for PD, especially in older patients or patients with asymmetry of parkinsonism.

Abstract 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 &lt; 0.001), lower-limb (P &lt; 0.01), and midline (P &lt; 0.001) tremors after unilateral surgery. Ipsilateral arm tremor also improved (P &lt; 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 &lt; 0.001) and postural (P &lt; 0.01) tremors and ipsilateral postural tremor (P &lt; 0.05). Activities of daily living improved after unilateral surgery (P &lt; 0.001) and additionally after bilateral surgery (P &lt; 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.