Freezing of gait in Parkinson’s disease: pathophysiology, risk factors and treatments

Table 2 A list of the evidence supporting and refuting the following variable as a risk factor of freezing of gait

	Supporting evidence^a	Refuting evidence^a
Demographic risk factors
Male sex	[16, 17, 25]	[18,19,20,21,22,23,24, 26]
Low education level	[22]	[19, 23, 24]
Onset age		[16, 17, 20,21,22,23, 25, 26]
Age		[18, 19, 21,22,23,24,25]
Baseline longer disease duration	[20, 23]	[16,17,18,19, 21]^b
Motor symptoms
Gait disorders	[16,17,18,19,20,21, 23]	[22]
Motor phenotype	[16, 17, 21, 22]	[18, 19, 25]
Motor fluctuation	[21]	[23]
Balance, festination and falls	Festination and falls [23], balance [20]	Balance [19]
Non-motor symptoms
Cognitive disturbance	[16, 17, 22,23,24]	[18,19,20,21]
Depression	[19, 20, 22]	[16, 23, 24]
Anxiety	[18]	[16, 23, 24]
Sleep	Insomnia [22], daytime sleepiness [24]	RBD [16, 18, 24], daytime sleepiness [16, 23]
Others	Speech problems [20], hallucination [23]
Neuroimaging and fluid parameters
Lower striatal DAT update	[16, 17, 25]
White matter hyperintensities	[26]
CSF Aβ42	[16]
Medication use
High LEDD	[21]	[18, 19, 23, 26]
Dopamine agonist		[22]

Demographic information, motor symptoms, non-motor symptoms, neuroimaging, fluid parameters, and medication use were all included
DAT Dopamine transporter, CSF Cerebrospinal fluid, LEDD Levodopa equivalent daily doses
^aOnly the prospective studies that followed early-stage PD patients over time and the retrospective studies that clearly recorded the clinical manifestation prior to FOG onset were cited here
^bBaseline disease duration instead of the whole disease duration was analyzed in those cited studies. Relatively short disease duration might be the reason for failure to identify disease duration as a risk factor

ISSN: 2047-9158