Table 10 Neurotransmitters involvement in the NMS of PD pathophysiology

From: Presynaptic dopaminergic terminal imaging and non-motor symptoms assessment of Parkinson’s disease: evidence for dopaminergic basis?

Domain

Description

DA

5HT

NA

ACh

1

Cardiovascular dysfunction

 

 Orthostatic hypotension

  

+++

 
 

 Black-out

  

++

 

2

Sleep/Fatigue

 

 EDS

++

++

  
 

 Fatigue

+/-

++

  
 

 Insomnia

    
 

 REM behaviour disorder (RBD)

++

  

++

 

 RLS and periodic limb movements

+++

++

  

3

Mood/ Apathy

 

 Anhedonia

    
 

 Apathy

++

   
 

 Anxiety

+++

+

++

 
 

 Depressed

+

++

+

 

4

Perceptual problems

 

 Hallucinations

+

+++

 

+

 

 Delusions

    
 

 Double vision

++

++

  

5

Attention/memory

 

 Attention deficit

+++

  

++

 

 Memory deficit/ cognitive impairment

++

  

+++

 

 Confusion

+

   

6

Gastrointestinal tract

 

 Dribbling

+

   
 

 Dysphagia

+

  

++

 

 Constipation

+

  

++

7

Urinary

 

 Urgency

+++

   
 

 Frequency

+++

   
 

 Nocturia

+++

   

8

Sexual dysfunction

 

 Loss of libido

+

   
 

 Erectile dysfunction

+

   

9

Miscellaneous

 

 PD-related pain

+

   
 

 Olfactory dysfunction

+++

   
 

 Weight change

+++

++

  
 

 Excessive sweating

+

   
  1. +++: Strong evidence from clinical studies, 3 or more neuroimaging evidence
  2. ++: Moderate evidence from clinical studies, 2–3 neuroimaging evidence
  3. +: Weak evidence from single case reports, or 1 neuroimaging evidence
  4. +/−: Conflicting evidence from 2 or more studies
  5. DA dopamine, 5HT serotonin, NA noradrenergic, ACh acetylcholine, REM rapid eye movement