RESUMO
BACKGROUND AND PURPOSE: Central post-stroke pain (CPSP) is a severe chronic neuropathic pain condition defined as a spontaneous pain or allodynia corresponding to a vascular lesion. It usually evolves weeks after stroke, and can distinctively impair the quality of life. Treatment is complex and mostly unsatisfactory. We hypothesized that the anti-epileptic drug levetiracetam (LEV) improves CPSP compared with placebo. The purpose of this study was to examine the efficacy and tolerability of LEV in patients with CPSP. METHODS: In a double-blind, placebo-controlled, crossover study design patients with CPSP lasting at least 3 months and a pain score ≥ 4 on the 11-point Likert scale were treated over two 8-week periods with a maximum dose up to 3000 mg LEV or placebo. Primary endpoint was a median pain lowering ≥ 2 in the final treatment week compared with the last baseline week. Secondary outcome measures comprised additional pain ratings, depression, sleep quality, quality of life and patients' global impression of change. RESULTS: Of 42 patients, 33 [61.5 years (40-76); 38% women] completed the study. Side effects and withdrawals were more frequent in the LEV (n = 5) group than in the placebo group (n = 1). Patients treated with LEV did not show any improvement of pain or changes in secondary outcome parameters compared with placebo. CONCLUSIONS: LEV is not effective in treatment for CPSP. The mode of action of LEV does not exert an analgesic effect in chronic CPSP.
Assuntos
Anticonvulsivantes/uso terapêutico , Neuralgia/complicações , Neuralgia/tratamento farmacológico , Piracetam/análogos & derivados , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico , Adulto , Idoso , Anticonvulsivantes/efeitos adversos , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Levetiracetam , Masculino , Pessoa de Meia-Idade , Medição da Dor , Piracetam/efeitos adversos , Piracetam/uso terapêutico , PlacebosRESUMO
A simple method has been developed for control and prevention of polarization fade on a single output lead from a remotely located fiber-optic interferometer. The method has been demonstrated using a fiber-optic Michelson interferometer. In contrast to a previously suggested method, only a single detector is required. The technique has application for passive, remotely located sensors. Extension to balanced homodyne detection schemes and coherent communications is discussed.