Primary writing tremor is considered to be a task-specific tremor occurring when handwriting. We describe the clinical and electrophysiological features of 5 patients. Two of the patients had a family history of the tremor. Alcohol was effective in reducing the tremor in 3 of the patients. Two patients showed a co-contraction and three alternate contractions between agonist and antagonist muscles. The frequency of the tremors was 5 to 6 Hz. Primidone and propranolol were effective in reducing tremor. Considering the clinical and electrophysiological features, it is suggested that primary writing tremor might be a variant of essential tremor. (J Korean Neurol Assoc 19(1):52~55, 2001
Essential Tremor ; Handwriting ; Humans ; Muscles ; Primidone ; Propranolol ; Tremor* ; Writing*

BACKGROUND: Essential tremor is one of the most common types of movement disorders. Although it is sometimes prefaced with the term 'benign', it often causes significant disabilities. Clinical characteristics and responses to various drugs have not been investigated systematically in Korea. Therefore, we studied the clinical features, electrophysiologic findings, and drug responsiveness of essential tremor. METHODS: Forty-five patients were included in the study by clinical criteria for essential tremor. We investigated their clinical features including tremor type, involved sites, family history, and responsiveness to alcohol. We used an electromyography study to evaluate the contraction patterns between agonist and antagonist muscles and the frequency of tremor. Primidone and propranolol were prescribed to all the patients (N=30) with a sufficient washout period (more than 2weeks) for drug responsiveness. Drug responsiveness was estimat-ed with self-assessment scales. RESULTS: The mean age of patients at the onset of the tremor was 45 years and the average duration of the tremor was 11.1 years. Kinetic tremor was dominant in 17 patients (37.8%) and postural tremor in 28 patients (62.2%). Family history was found in 18 patients (40%) and alcohol reduced tremors in 18 (64.8%) out of 28 patients with sufficient alcohol intake. Co-contraction was seen in 18 patients (40%), alternative contraction in 15 (33.6%), and mixed contraction in 3 (6.7%). Mean frequency was 6.7 Hz. Propranolol reduced tremor in 24 patients (80%), and primidone in 27 patients (90%). CONCLUSIONS: It was concluded that essential tremor was heterogenous clinically and electrophysiologically. Primidone was found more effective than propranolol in reducing tremor.
Electromyography ; Essential Tremor* ; Humans ; Korea ; Movement Disorders ; Muscles ; Primidone ; Propranolol ; Self-Assessment ; Tremor ; Weights and Measures

Anticonvusant therapy with any of several agents, especially phenytoin, phenobarbital, and primidone causes disturbances in bone mineral metabolism. Anticonvulsants stimulate the hepatic microsomal mixed-oxidase enzymes and hence increase the rate of clearance of vitamin D and its metabolism. The severity of clinical manifestations in any given individual appears to be a function of the combined effects of variety of factors including drug type and total drug dose, dietary vitamin D intake, sunlight exposure, and physical activity level. We report a case of osteomalacia associated with long term carbamazepine therapy in a 21-year-old male with less exposure to sunlight.
Anticonvulsants ; Carbamazepine* ; Humans ; Male ; Metabolism ; Motor Activity ; Osteomalacia* ; Phenobarbital ; Phenytoin ; Primidone ; Sunlight ; Vitamin D ; Young Adult

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) were performed in 2008. The number of participating laboratories were 114, which is similar with that of the previous year. Average response rates were 97.8% in both trials slightly lower than that of the previous year. Two kinds of control materials were requested to be tested in each trial so that each laboratory could know the possible systematic error. The average drug item was 6.3 per laboratory, which was decreased slightly from 6.8 in recent 5 years, and the maximum was 18 items. The most common test items were valproic acid, digoxin, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 52.1% of participating laboratories, followed by cyclosporine, vancomycin, tacrolimus, lithium, methotrexate, amikacin, tobramycin, gentamycin, acetaminophen, salicylate, free phenytoin, primidone, and amitryptyline. The widely used TDM analyzers were Abbott TDx/TDxFLx (35.3%), followed by Abbott AxSym (26.5%) and Roche Cobas Integra (17.3%), Abbott IMx (3.3%), and Siemens Viva E (3.0%). The inter-laboratory coefficients of variations showed similar tendency comparing with those of the previous years. The number of participating laboratories for drug of abuse tests were 17, which is similar to that of the previous year. Average drug item were 3.7 for the 1st trial. We found the relatively good performance as we got the correct answers for all laboratories except 2 laboratories. In conclusion, the TDM external quality assessment of 2008 showed grossly similar pattern comparing with that of previous year.
Acetaminophen ; Amikacin ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring ; Gentamicins ; Korea ; Lithium ; Methotrexate ; Phenobarbital ; Phenytoin ; Primidone ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) were performed in 2007. Number of participating laboratories were increased to 109, by 5.63% increase comparing with the previous year. Response rates reached 98.7% for both trials slightly lower than that of the previous year. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.3 per institution, which was decreased slightly from 6.8 in recent 5 years. The most common test items were valproic acid, digoxin, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 55% of the participating laboratories, followed by cyclosporine, vancomycin, lithium, tacrolimus, methotrexate, amikacin, gentamicin, salicylate, tobramycin, acetaminophen, primidone, free phenytoin, and amitryptyline. The inter-laboratory coefficients of variations showed simliar tendency comparing with those of the previous years. We started the proficiency test for drug of abuse from 2007 and got the response from 13 and 17 laboratories in the 1st and 2nd trial, respectively. Average drug items were 3.4 for the 2nd trial. We found the relatively good performances as we got the correct answers from all laboratories except 4 for each one mistake. In conclusion, the TDM external quality assessment of 2007 showed grossly similar pattern comparing with those of previous year and drug of abuse proficiency testing showed a relatively good performance.
Acetaminophen ; Amikacin ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring ; Gentamicins ; Korea ; Lithium ; Methotrexate ; Phenobarbital ; Phenytoin ; Primidone ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) were performed in 2007. Number of participating laboratories were increased to 109, by 5.63% increase comparing with the previous year. Response rates reached 98.7% for both trials slightly lower than that of the previous year. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.3 per institution, which was decreased slightly from 6.8 in recent 5 years. The most common test items were valproic acid, digoxin, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 55% of the participating laboratories, followed by cyclosporine, vancomycin, lithium, tacrolimus, methotrexate, amikacin, gentamicin, salicylate, tobramycin, acetaminophen, primidone, free phenytoin, and amitryptyline. The inter-laboratory coefficients of variations showed simliar tendency comparing with those of the previous years. We started the proficiency test for drug of abuse from 2007 and got the response from 13 and 17 laboratories in the 1st and 2nd trial, respectively. Average drug items were 3.4 for the 2nd trial. We found the relatively good performances as we got the correct answers from all laboratories except 4 for each one mistake. In conclusion, the TDM external quality assessment of 2007 showed grossly similar pattern comparing with those of previous year and drug of abuse proficiency testing showed a relatively good performance.
Acetaminophen ; Amikacin ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring ; Gentamicins ; Korea ; Lithium ; Methotrexate ; Phenobarbital ; Phenytoin ; Primidone ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin

Three trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Pathology (KAQACP) were performed in 2002. Participating laboratories were 79 similar to the previous year. Response rates were 96.3% for 1st, 2nd, and third trials. In the first trial, 20 test items among 27 ones were responded from as least from one laboratory as follows: acetaminophen, amikacin, amitriptyline, carbamazepine, cyclosporine, digoxin, free phenytoin, gentamicin, lithium, methotrexate, phenobarbital, phenytoin, primidone, quinidine, salicylate, tacrolimus (FK-506), theophylline, tobramycin, valproic acid and vancomycin. In the second and third trial, the test items were same with those of 1st trial except the exclusion of quinidine. We included tacrolimus with a whole blood control material in addition to cyclosporine from the first trial. The most common test items were valproic acid, digoxin, phenytoin, carbamazepine, theophylline, and phenobarbital which were peformed in more than 77% of participating laboratories. The most widely used TDM analyzer was Abbott TDx/TDxFLx (56%), but its proportion were decreased slightly comparing with the previous years. In conclusion, we added tacrolimus from the year of TDM proficiency testing in 2002 and found grossly similar pattern comparing with those of previous years.
Acetaminophen ; Amikacin ; Amitriptyline ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring* ; Gentamicins ; Korea* ; Lithium ; Methotrexate ; Pathology, Clinical ; Phenobarbital ; Phenytoin ; Primidone ; Quinidine ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) Subcommittee of Korean Association of Quality Assurance for Clinical Pathology (KAQACP) were performed in 2004. Number of participating laboratories were increased to 89, by 11.3% increase comparing with the previous year. Response rates were 100.0% for both trials just like the previous year. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.8 per institution, which was elevated slightly from 6.5 in recent 5 years. The most common test items were valproic acid, digoxin, phenytoin, carbamazepine, theophylline, and phenobarbital which were peformed in more than 71% of participating laboratories, followed by cyclosporine, lithium, tacrolimus, vancomycin, methotrexate, amikacin, gentamycin, salicylate, tobramycin, acetaminophen, primidone, free phenytoin, and amitryptyline. The most widely used TDM analyzer was Abbott TDx/TDxFLx (41.6%), followed by Roche Cobas Integra (21.3%), and Abbott AxSym (20.2%). The inter-laboratory coefficients of variations were not greatly improved comparing with previous years. We also determined cyclosporine and tacrolimus with reference method using liquid chromatography-tandem mass spectrometry. In conclusion, the TDM external quality assessment of 2004 showed grossly similar pattern comparing with those of previous year, except the 11.3% increase of participating laboratories.
Acetaminophen ; Amikacin ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring* ; Gentamicins ; Korea* ; Lithium ; Mass Spectrometry ; Methotrexate ; Pathology, Clinical ; Phenobarbital ; Phenytoin ; Primidone ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Pathology (KAQACP) were performed in 2003. Number of participating laboratories were 80 which is similar to those of the previous year. Response rates were elevated to 100.0% for both trials. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 7.0 per institution, which was elevated slightly from 6.5 in recent 5 years. The most common test items were valproic acid, digoxin, phenytoin, carbamazepine, theophylline, and phenobarbital, which were peformed in more than 75% of participating laboratories, followed by cyclosporine, lithium, methotrexate, tacrolimus, vancomycin, amikacin, gentamycin, salicylate, tobramycin, acetaminophen, primidone, free phenytoin, and amitryptyline. The most widely used TDM analyzer was Abbott TDx/TDxFLx (52%), but its proportion were decreased slightly comparing with the previous years. The interlaboratory coefficients of variations were not greatly improved comparing with previous years. In conclusion, the TDM external quality assessment of 2003 showed grossly similar pattern comparing with those of previous year, except that the response rate was elevated to 100% and two levels of control material were used in each trials.
Acetaminophen ; Amikacin ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring* ; Gentamicins ; Korea* ; Lithium ; Methotrexate ; Pathology, Clinical ; Phenobarbital ; Phenytoin ; Primidone ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Pathology (KAQACP) were performed in 2005. The number of participating laboratories were increased to 95, by 6.7% comparing with the previous year. Response rates were 100.0% for both trials just like the two previous years. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.7 per institution, which was elevated slightly from 6.5 in recent 5 years. The most common test items were digoxin, valproic acid, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 65% of participating laboratories, followed by cyclosporine, lithium, vancomycin, tacrolimus, methotrexate, amikacin, gentamycin, tobramycin, salicylate, primidone, acetaminophen, free phenytoin, amitryptyline, and ethosuximide. The most widely used TDM analyzer was Abbott TDx/TDxFLx (41.7%), followed by Abbott AxSym (23.3%), and Roche Cobas Integra (19.2%). The inter-laboratory coefficients of variations were not much improved comparing with previous years. We also determined cyclosporine with reference method using liquid chromatography-tandem mass spectrometry. In conclusion, the TDM external quality assessment of 2005 showed grossly similar pattern comparing with those of previous year with increasing participating laboratories.
Acetaminophen ; Amikacin ; Carbamazepine ; Cyclosporine ; Digoxin ; Drug Monitoring* ; Ethosuximide ; Gentamicins ; Korea* ; Lithium ; Mass Spectrometry ; Methotrexate ; Pathology, Clinical ; Phenobarbital ; Phenytoin ; Primidone ; Tacrolimus ; Theophylline ; Tobramycin ; Valproic Acid ; Vancomycin