TY - JOUR
T1 - Bradyphrenia and Tachyphrenia in Idiopathic Parkinsonism Appear, in Part, Iatrogenic
T2 - An Observational Study with Systematic Review Background
AU - Wang, Wenjing
AU - Baker, Kieran
AU - Umamahesan, Chianna
AU - Gilmour, Steven
AU - Charlett, André
AU - Taylor, David
AU - Young, Allan H
AU - Dobbs, R John
AU - Dobbs, Sylvia M
N1 - Funding Information:
This study was the result of grants from the Nomis Foundation, Zurich, Switzerland; the Cecil Pilkington Charitable Trust, London, UK; and the Psychiatry Research Trust, London, UK to R.J.D. and S.M.D. Thanks from R.J.D. and S.M.D. also go to Christopher Norris, Louise Barton, Alex and Lyn Orr for their generous donations through the Psychiatry Research Trust. K.B. received a PhD scholarship from the Engineering and Physical Sciences Research Council. Wenjing Wang was a PhD student at the Institute of Psychiatry, Psychology & Neuroscience, King’s College London. A.H.Y. is in receipt of funding from National Institute for Health and Care Research, Maudsley Biomedical Research Centre and King’s College London.
Publisher Copyright:
© 2023 by the authors.
PY - 2023/10/12
Y1 - 2023/10/12
N2 - We question whether bradyphrenia, slowing of cognitive processing not explained by depression or a global cognitive assessment, is a nosological entity in idiopathic parkinsonism (IP). The time taken to break contact of an index finger with a touch-sensitive plate was measured, with and without a warning in the alerting signal as to which side the imperative would indicate, in 77 people diagnosed with IP and in 124 people without an IP diagnosis. The ability to utilise a warning, measured by the difference between log
e-transformed reaction times (unwarned minus warned), was termed 'cognitive efficiency'. It was approximately normally distributed. A questionnaire on self- and partner perception of proband's bradyphrenia was applied. A multivariable model showed that those prescribed levodopa were less cognitively efficient (mean -5.2 (CI -9.5, -1.0)% per 300 mg/day,
p = 0.02), but those prescribed the anti-muscarinic trihexyphenidyl were more efficient (14.7 (0.2, 31.3)% per 4 mg/day,
p < 0.05) and those prescribed monoamine oxidase-B inhibitor (MAOBI) tended to be more efficient (8.3 (0.0, 17.4)%,
p = 0.07). The variance in efficiency was greater within IP (F-test,
p = 0.01 adjusted for any demographic covariates: coefficient of variation, with and without IP, 0.68 and 0.46, respectively), but not so after adjustment for anti-parkinsonian medication (
p = 0.13: coefficient of variation 0.62). The within-participant follow-up time, a median of 4.8 (interquartile range 3.1, 5.5) years (101 participants), did not influence efficiency, irrespective of IP status. Perception of bradyphrenia did not usefully predict efficiency. We conclude that both bradyphrenia and 'tachyphrenia' in IP appear to have iatrogenic components, of clinically important size, related to the dose of antiparkinsonian medication. Levodopa is the most commonly prescribed first-line medication: co-prescribing a MAOBI may circumvent its associated bradyphrenia. The previously reported greater efficiency associated with (low-dose) anti-muscarinic was confirmed.
AB - We question whether bradyphrenia, slowing of cognitive processing not explained by depression or a global cognitive assessment, is a nosological entity in idiopathic parkinsonism (IP). The time taken to break contact of an index finger with a touch-sensitive plate was measured, with and without a warning in the alerting signal as to which side the imperative would indicate, in 77 people diagnosed with IP and in 124 people without an IP diagnosis. The ability to utilise a warning, measured by the difference between log
e-transformed reaction times (unwarned minus warned), was termed 'cognitive efficiency'. It was approximately normally distributed. A questionnaire on self- and partner perception of proband's bradyphrenia was applied. A multivariable model showed that those prescribed levodopa were less cognitively efficient (mean -5.2 (CI -9.5, -1.0)% per 300 mg/day,
p = 0.02), but those prescribed the anti-muscarinic trihexyphenidyl were more efficient (14.7 (0.2, 31.3)% per 4 mg/day,
p < 0.05) and those prescribed monoamine oxidase-B inhibitor (MAOBI) tended to be more efficient (8.3 (0.0, 17.4)%,
p = 0.07). The variance in efficiency was greater within IP (F-test,
p = 0.01 adjusted for any demographic covariates: coefficient of variation, with and without IP, 0.68 and 0.46, respectively), but not so after adjustment for anti-parkinsonian medication (
p = 0.13: coefficient of variation 0.62). The within-participant follow-up time, a median of 4.8 (interquartile range 3.1, 5.5) years (101 participants), did not influence efficiency, irrespective of IP status. Perception of bradyphrenia did not usefully predict efficiency. We conclude that both bradyphrenia and 'tachyphrenia' in IP appear to have iatrogenic components, of clinically important size, related to the dose of antiparkinsonian medication. Levodopa is the most commonly prescribed first-line medication: co-prescribing a MAOBI may circumvent its associated bradyphrenia. The previously reported greater efficiency associated with (low-dose) anti-muscarinic was confirmed.
UR - http://www.scopus.com/inward/record.url?scp=85175371045&partnerID=8YFLogxK
U2 - 10.3390/jcm12206499
DO - 10.3390/jcm12206499
M3 - Article
C2 - 37892637
SN - 2077-0383
VL - 12
JO - Journal of Clinical Medicine
JF - Journal of Clinical Medicine
IS - 20
M1 - 6499
ER -