Mood and behavioural effects of subthalamic stimulation in Parkinson's disease

Abstract

A B S T R AC T :Postural abnormalities such as postural deviations affect nearly all patients with advanced Parkinson's disease and represent an important source of disability. Although their existence has long been known, their management remains a challenge as they respond poorly to medication, brain surgery, or physiotherapy. Improving management strategies will require better understanding of the mechanisms underlying such postural deformities.In this review on the pathophysiology of Pisa syndrome, we examine the data supporting the central and peripheral hypotheses that attempt to explain these lateral trunk deviations. Although the pathophysiology is very probably multifactorial, the bulk of the data supports central, rather than peripheral, hypotheses. The central hypotheses that are best supported by both animal studies and clinical data include asymmetry of basal ganglia output and abnormalities in the central integration of sensory information. Further studies are needed to elucidate the pathophysiology underlying Pisa syndrome. V C 2014 International Parkinson and Movement Disorder Society

Apathy in Parkinson's disease: clinical features, neural substrates, diagnosis, and treatment

“…[87][88][89] These fi ndings provide evidence of a behavioural spectrum disorder, ranging from a hyperdopaminergic syn drome (including impulse control disorders) to hypodopaminergic levels associated with apathy, anxiety, and depression, as described in the withdrawal dopaminergic syndromes. 83,[90][91][92][93] Besides the emotional-aff ective syndrome, apathy might also be associated with a disruption of cognitive func tions. This form of apathy is generally associated with an impairment in those executive functions (selection, planning, working memory, and set-shifting) needed to elaborate an action plan.…”

“…It is potentially reversible and both occurrence and improvement depend on patient management. 92,102 Panel 2 describes the clinical features of early reversible postoperative apathy. In a 2013 randomised study 103 comparing STN-DBS to best medical treatment in Parkinson's disease, the frequency of apathy did not diff er during the 2 years of follow-up, showing absence of early postoperative apathy when STN-DBS is accompanied by optimised medical treatment.…”

“…STN-DBS itself has a positive eff ect on offperiod apathy, contributing to improvement of off -period cognitive and emotional aspects in apathy. 92,[104][105][106] However, with regard to the on-period motivational aspects of the antiparkinsonian drugs, a slowly progressive desensitisation of the psychotropic eff ects of dopaminergic treatment after drug decrease 107 explains why the hypodopaminergic withdrawal syndrome in patients on chronic STN-DBS typically occurs with a substantial delay of several months after surgery 83,92 (unlike the much more acute withdrawal syndrome after cessation of dopamine agonists in patients not receiving chronic STN-DBS). 93 The potential to reverse postoperative apathy after D2 or D3 receptor stimulation with oral dopamine receptor agonists 108,109 clearly suggests a Parkinson's disease-related symptom that has been unmasked by a decrease in drug treatment.…”

“…Review opposite motivational state-in untreated de-novo Parkinson's disease, 155 in more advanced stages of Parkinson's disease during non-motor off -periods, 91,92 in parallel with progressive cognitive deterioration, or in the context of a rapid decrease in dopaminergic drugs after deep brain stimulation, leading to a hypodopaminergic withdrawal syndrome or Parkinson's disease-related apathy. 83,90,91,93 Impairments of motivation therefore appear in Parkinson's disease as a continuum of abnormal behaviours that range from the syndrome of apathy to impulse control disorders and other behavioural addictions.…”

Deep Brain Stimulation for Movement Disorders of Basal Ganglia Origin: Restoring Function or Functionality?

“…The STN is much smaller than the GPi, making inadvertent activation of nonmotor areas and extrinsic fiber systems and side effects more likely. The greater proximity and potential overlap of motor, associative, and limbic territories in this nucleus (compared with the larger GPi) contributes to the fact that DBS at this location is more likely to produce nonmotor effects than GPi DBS [225]. Another (unexplained) difference between these procedures is that the levodopa dose can usually be reduced in patients treated with STN DBS but not with GPi DBS.…”