title: The "brittle response" to Parkinson's disease medications: characterization and response to deep brain stimulation.
abstract: Formulate a definition and describe the clinical characteristics of PD patients with a "brittle response" (BR) to medications versus a "non-brittle response" (NBR), and characterize the use of DBS for this population.
  
  
  
  An UF IRB approved protocol used a retrospective chart review of 400 consecutive PD patients presenting to the UF Center for Movement Disorders and Neurorestoration. Patient records were anonymized and de-identified prior to analysis. SPSS statistics were used to analyze data.
  
  
  
  Of 345 included patients, 19 (5.5%) met criteria for BR PD. The BR group was comprised of 58% females, compared to 29% in the NBR group (P = .008). The former had a mean age of 63.4 compared to 68.1 in the latter. BR patients had lower mean weight (63.5 vs. 79.6, P = <.001), longer mean disease duration (12.6 vs. 8.9 years, P = .003), and had been on LD for more years compared to NBR patients (9.8 vs. 5.9, P = .001). UPDRS motor scores were higher (40.4 vs. 30.0, P = .001) in BR patients. No differences were observed regarding the Schwab and England scale, PDQ-39, and BDI-II. Sixty-three percent of the BR group had undergone DBS surgery compared to 18% (P = .001). Dyskinesias were more common, severe, and more often painful (P = <.001) in the BR group. There was an overall positive benefit from DBS.
  
  
  
  BR PD occurred more commonly in female patients with a low body weight. Patients with longer disease duration and longer duration of LD therapy were also at risk. The BR group responded well to DBS.
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martinez-Ramirez
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Juan
authors.initials: J
authors.lastname: Giugni
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America; Department of Neurosurgery, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Vinata
authors.initials: V
authors.lastname: Vedam-Mai
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Aparna
authors.initials: A
authors.lastname: Wagle Shukla
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Irene A
authors.initials: IA
authors.lastname: Malaty
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Nikolaus R
authors.initials: NR
authors.lastname: McFarland
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Ramon L
authors.initials: RL
authors.lastname: Rodriguez
authors.affiliation: Department of Neurosurgery, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Foote
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America; Department of Neurosurgery, Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation; D020820:Dyskinesias / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy*; D016896:Treatment Outcome
references.citation: Stereotact Funct Neurosurg. 2012;90(6):386-93
references.pmid: 22922491
references.citation: Ann Neurol. 2000 Apr;47(4 Suppl 1):S122-9; discussion S129-30
references.pmid: 10762139
references.citation: Br Med J (Clin Res Ed). 1982 Apr 3;284(6321):1001-2
references.pmid: 6802383
references.citation: Arch Gerontol Geriatr. 2009 Nov-Dec;49(3):351-4
references.pmid: 19136159
references.citation: Mov Disord. 2001 May;16(3):448-58
references.pmid: 11391738
references.citation: J Parkinsons Dis. 2012;2(3):189-98
references.pmid: 23938226
references.citation: Parkinsonism Relat Disord. 2000 Jul 1;6(3):171-173
references.pmid: 10817957
references.citation: Mov Disord. 2013 Jul;28(8):1064-71
references.pmid: 23630119
references.citation: Diabetes Technol Ther. 2012 Sep;14(9):835-48
references.pmid: 22731792
references.citation: Am J Clin Nutr. 2013 Jun;97(6):1307-13
references.pmid: 23576047
references.citation: J Neurol. 1999 Dec;246(12):1127-33
references.pmid: 10653303
references.citation: Mov Disord. 1998 Nov;13(6):885-94
references.pmid: 9827611
references.citation: N Engl J Med. 2004 Dec 9;351(24):2498-508
references.pmid: 15590952
references.citation: Arch Neurol. 2006 Dec;63(12):1756-60
references.pmid: 17172616
references.citation: J Pharmacol Exp Ther. 2007 Oct;323(1):277-84
references.pmid: 17660384
references.citation: Arch Neurol. 2006 Feb;63(2):205-9
references.pmid: 16476808
references.citation: Ann Neurol. 2010 Jul;68(1):18-27
references.pmid: 20582993
references.citation: Neurosurgery. 2011 May;68(5):1233-7; discussion 1237-8
references.pmid: 21273927
references.citation: Mov Disord. 1994 Jul;9(4):390-4
references.pmid: 7969204
references.citation: Ann Neurol. 1990 Jan;27(1):18-23
references.pmid: 2301923