Asymmetry of neuroleptic-induced rigidity: development of quantitative methods and clinical correlates.
Twenty-six medicated schizophrenic patients and 14 normal controls underwent laboratory assessment for the presence and asymmetry of neuroleptic-induced rigidity to evaluate the sensitivity, reliability, and validity of a quantitative procedure. Measures of muscle stiffness were made in the upper extremities. Results indicated that 65% of the patients exhibited pathological rigidity. Moreover, 76% of these patients exhibited asymmetric rigidity, while the remaining 24% exhibited bilateral symptoms. Newly treated patients exhibited a greater laterality of rigidity toward the right side compared with patients who were on stable treatment regimens for at least 3 months. Since parkinsonism reflects dopamine receptor blockade by neuroleptic medication, probably in the striatum, we suggest that the lowered susceptibility of the right striatum to drug-induced parkinsonism supports the hypothesis that striatal dopaminergic activity may be asymmetric and more marked in the right striatum among recently treated patients.
Caligiuri
M P
MP
Motor Function Laboratory, VA Medical Center, San Diego, CA 92161.
Bracha
H S
HS
Lohr
J B
JB
D000328:Adult; D000367:Age Factors; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D004409:Dyskinesia, Drug-Induced / Q000175:diagnosis*; D007839:Functional Laterality / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D009048:Motor Skills / Q000187:drug effects; D009127:Muscle Rigidity / Q000139:chemically induced*; D009460:Neurologic Examination / Q000295:instrumentation; D011618:Psychotic Disorders / Q000188:drug therapy*; D012559:Schizophrenia / Q000188:drug therapy*
D014150:Antipsychotic Agents