Response of parkinsonian swallowing dysfunction to dopaminergic stimulation
- aDepartment of Aged Care Services, bDepartment of Speech Pathology, cDepartment of Neurology, Austin and Repatriation Medical Centre, Heidelberg, Victoria, Australia
- Dr Andrew J Hughes, Department of Neurology, Austin and Repatriation Medical Centre (Repatriation Campus), Heidelberg West, Victoria, Australia 3081.
- Received 20 December 1996
- Revised 23 April 1997
- Accepted 22 May 1997
OBJECTIVES To determine the degree of dopaminergic response of swallowing dysfunction in Parkinson’s disease.
METHODS Fifteen patients with idiopathic Parkinson’s disease and symptomatic dysphagia were studied. All had motor fluctuations in response to long term levodopa therapy. On two separate days, after overnight withdrawal of all antiparkinsonian medication, a modified barium swallow using cinefluoroscopy and different food consistencies was performed before and after administration of oral levodopa and subcutaneous apomorphine.
RESULTS Despite all patients having an unequivocal motor response to both agents, there were few significant responses in any of the quantitative or qualitative criteria of swallowing dysfunction assessed. The oral preparatory phase, generally considered a more voluntary component of swallowing, showed a response, but not with all consistencies. In a subgroup of patients the pharyngeal phase time also improved.
CONCLUSIONS These findings suggest that parkinsonian swallowing dysfunction is not solely related to nigrostriatal dopamine deficiency and may be due to an additional non-dopamine related disturbance of the central pattern generator for swallowing in the pedunculopontine nucleus or related structures in the medulla.