Effekt av dyp hjernestimulator i bilaterale nucleus subthalamicus hos parkinsonpasienter med sentralt smertesyndrom : en pilotstudie

Abstract

Bakgrunn Pasienter med Parkinsons sykdom kan i tillegg til deres motoriske symptomer, oppleve å være rammet av forstyrrende ikke-motoriske symptomer, hvorav smerter er det symptomet som rapporteres mest. Hos denne pasientgruppen er det beskrevet fem ulike smertekarakteristika: muskel-skjelettsmerte, nevropatisk smerte, dyston smerte, akatisi og primær, sentral smerte. Man vet i dag ikke den eksakte patofysiologi bak den sentrale smerten hos disse pasientene, men mange studier har konkludert med at det er sentrale lesjoner i basalgangliene og endringer i hjernens nevrotransmittersubstanser som spiller en viktig rolle. Det har heller ikke blitt forsket mye på behandling av sentral smerte hos parkinsonpasienter. Vi ønsket derfor å utføre en studie som kunne vurdere effekten av dyp hjernestimulator (DBS/deep brain stimulation) i bilaterale nucleus subthalamicus (STN) hos pasienter med Parkinsons sykdom, for å se om disse pasientene har mindre smerter, og da særlig om den sentrale smerten er redusert etter operasjonen. Ved å ta i bruk smerteskjemaet painDETECT og den nevrofysiologiske testen Termotest, ønsket vi å studere nærmere hvordan smertesituasjonen var før og etter en DBS-operasjon for denne pasientgruppen.

ABSTRACT

Objective: To explore and examine the effect of bilateral subthalamic nucleus deep brain stimulation (STN DBS) on central pain in patients with Parkinson’s disease.

Design: Literature study, including a pilot project.

Background: Parkinson’s disease (PD) is a chronic, progressive, incurable neurodegenerative disease. Although its main features are motor disturbances the non-motor complications of PD represent a considerable illness burden. Pain is a frequent, but poorly studied feature and five different types have been described in patients with PD. One of these types, likely to be experienced by 10% of patients with PD, is thought to be of a central origin. The exact pathophysiology behind this central, neuropathic pain is unknown, but both central lesions in the basal ganglia and changes in the brains neurotransmitters are likely to play a role. There is little knowledge about ways to treat this type of pain in these patients today.

Patients and methods: The literature study and the pilot project are both based on a non-systematic search in PubMed. PainDETECT screening questionnaire and the neurophysiologic test Thermotest were used to assess pain threshold in patients with PD both with their STN DBS turned on and off, representing the situations before and after surgery with DBS. 10 persons offered to participate, 8 of whom chose to follow through.

Results: With only 8 patients participating in this study, we were unable to draw any conclusions from our results. The painDETECT screening questionnaire indicated a possibility of less than 15% that the patients participating experienced pain of a central, neuropathic origin. The results achieved using the Thermotest do however imply a slightly raised threshold for heatpain in patients with PD after surgery with STN DBS. The explanation for this remains unknown