Table 1: Major nonmotor symptoms (NMS) in PD (adapted from [3]).

(a) Neuropsychiatric symptoms:
 (1) Depression
 (2) Anxiety
 (3) Apathy
 (4) Hallucinations, delusions, illusions
 (5) Delirium (may be drug induced)
 (6) Cognitive impairment (dementia, MCI)
 (7) Dopaminergic dysregulation syndrome (usually related to
  levodopa)
 (8) Impulse control disorders (related to dopaminergic drugs).
(b) Sleep disorders:
 (1) REM sleep behaviour disorder (possible premotor
  symptoms)
 (2) excessive daytime somnolence, narcolepsy type “sleep
  attack”
 (3) restless legs syndrome, periodic leg movements
 (4) insomnia
 (5) sleep disordered breathing
 (6) non-REM parasomnias (confusional wandering)
(c) Fatigue:
 (1) central fatigue (may be related to dysautonomia)
 (2) peripheral fatigue.
(d) Sensory symptoms:
 (1) pain
 (2) olfactory disturbance
 (3) hyposmia
 (4) functional anosmia
 (5) visual disturbance (blurred vision, diplopia; impaired
  contrast-sensitivity).
(e) Autonomic dysfunction:
 (1) bladder dysfunction (urgency, frequency, nocturia)
 (2) sexual dysfunction (may be drug-induced)
 (3) sweating abnormalities (hyperhydrosis)
 (4) orthostatic hypotension.
(f) Gastrointestinal symptoms:
 (1) dribbling of saliva
 (2) dysphagia
 (3) agueusia
 (4) constipation
 (5) nausea
 (6) vomiting.
(g) Dopaminergic drug-induced behaviour NMS:
 (1) hallucinations, psychosis, delusions
 (2) dopamine dysregulation syndrome
 (3) impulse control disorders.
(h) Dopaminergic drug-induced other NMS:
 (1) ankle swelling
 (2) dyspnea
 (3) skin reactions
 (4) subcutaneous nodules
 (5) erythematous
(i) Nonmotor fluctuations:
 (1) dysautonomia
 (2) cognitive/psychiatric
 (3) sensory/pain
 (4) visual blurring
(j) Other symptoms:
 (1) weight loss
 (2) weight gain.