TABLE 1.

Comparison of paraneoplastic, autoimmune and vascular Progressive supranuclear palsy (PSP) with neurodegenerative PSP.

	Neurodegenerative PSP	Paraneoplastic PSP	Autoimmune PSP	Vascular PSP	Infectious PSP
Disease course	Insidious onset and slow progression (years) (Golbe, 2014; Levin et al., 2016; Höglinger et al., 2017)	Rapid progression (months) (Tan et al., 2005; Adams et al., 2011; Dash et al., 2016; Takkar et al., 2020)	Rapid progression (months) or long disease duration (up to 18 years) (Gaig et al., 2017; Hierro et al., 2020)	Sudden onset and rapid, gradual progression (Josephs et al., 2002; Lanza et al., 2014)	Rapid progression (Magherini et al., 2007)
Cerebrospinal fluid	No established markers (Höglinger et al., 2017)	Possible: -elevated protein (Tan et al., 2005; Adams et al., 2011; Ohyagi et al., 2017) -elevated IgG (Adams et al., 2011) -pleocytosis (lymphocyte↑) (Tan et al., 2005; Dash et al., 2016) -onconeuronal antibodies (Dash et al., 2016; Simard et al., 2020)	Possible: -normal or inflammatory (Hierro et al., 2020; González-Ávila et al., 2021)	Limited data	-Polymerase chain reaction (+) for Tropheryma whipplei (Höglinger et al., 2017) - elevated IgG, (+) VDRL test (Veneral Diseases Research Laboratory) (Murialdo et al., 2000)
MRI	Midbrain atrophy (Höglinger et al., 2017)	Normal or uncharacteristic changes without midbrain atrophy (Tan et al., 2005; Adams et al., 2011; Dash et al., 2016; Ohyagi et al., 2017)	Limited data	Ischaemic changes in white matter and in basal ganglia (Josephs et al., 2002; Lanza et al., 2014)	Group of enhancing lesions/single mass, without midbrain atrophy (Panegyres et al., 2006; Peregrin and Malikova, 2015)
Additional symptoms associated with neoplastic disease	Limited data	Possible: -haemoglobin↓, cachaexia, fever (Tan et al., 2005) -history of neoplastic disease (Takkar et al., 2020) -paraneoplastic neurological symptoms, e.g., polyneuropathy (Tan et al., 2005)	Limited data	Limited data	Limited data
Risk factors of cerebrovascular disease	Hypertension (Rabadia et al., 2019)	Limited data	Limited data	Present (hypertension, diabetes, smoking, prior stroke, stenosis of carotid arteries) (Winikates and Jankovic, 1994; Lanza et al., 2014)	Limited data
Non-characteristic features in the clinical picture	Not applicable	Possible, e.g., -horizontal gaze palsy and anterocollitis (Takkar et al., 2020)	Possible, e.g., -response to immunotherapy (Hierro et al., 2020) -sleep disorders, facial dyskinesia (González-Ávila et al., 2021)	Possible, e.g., -pathologic reflexes, unilateral paresis, facial nerve palsy (Josephs et al., 2002) -loss of bladder control, asymmetric symptoms involving mainly the lower body (Winikates and Jankovic, 1994)	Possible, e.g., -response to antibiotics, pupillary dysfunction (Murialdo et al., 2000) -gastrointestinal symptoms, lymphadenopathy, weight loss, oculomasticatory myrhythmia (Magherini et al., 2007) -lack of square wave jerks, more impaired upward than downward saccades (Averbuch-Heller et al., 1999)