Severe dysphagia as a presentation of Parkinson’s disease
A 74-year-old man presented in March 2007 with recent pneumonia, on a 1-year background of difficulty swallowing and 13 kg of weight loss. Neurological examination revealed generalized muscle wasting and involuntary tongue movements at rest and on protrusion that were thought to be fasciculations. A diagnosis of motor neuron disease (MND) was suspected. Magnetic resonance imaging (MRI) was unremarkable and electromyography (EMG) revealed mild generalized denervation. Videofluoroscopy confirmed a markedly abnormal swallow.
Two years after symptom onset, he had developed facial hypomimia with mild head and chin tremor. The involuntary movements of the tongue now appeared to be a tremor rather than fasciculations. He had an asymmetric upper limb rest tremor, with mild rigidity and bradykinesia in both upper limbs (see Video). Parkinson's disease (PD) was suspected and a dopamine transporter scan (DaTSCAN) showed bilateral absence of uptake in the putamen, and reduced uptake in the right caudate. The patient was started on 300 mg of levodopa daily and 6 months later he had gained weight. Repeat videofluoroscopy showed objective improvement of his swallow.
To date, his PD has slowly progressed. His swallow has not deteriorated and he has gained approximately 10 kg. Examination reveals a persisting tongue tremor with asymmetrical Parkinsonism. After taking L-dopa the patient demonstrates subtle improvement in his clinical signs and develops orofacial dystonia. There are no pyramidal signs, muscle fasciculations, or additional features of bulbar or pseudobulbar dysfunction. Cognition is normal. He scored 16/40 in the University of Pennsylvania Smell Identification Test (severe hyposmia).
Dysphagia is typically a feature of advanced PD, despite the lower brainstem being pathologically involved in early stages of the disease.1 The dysphagia encountered in PD can occur at oral, pharyngeal and esophageal levels.2 The videofluoroscopy findings are varied and nonspecific, and are well described in a recent review.2
There is only a single case report in which dysphagia definitely preceded Parkinsonism and another report that describes 2 cases in which prominent dysphagia was an early feature of PD, possibly preceding Parkinsonism.3, 4 There have also been 4 cases of isolated progressive dysphagia as the manifestation of Lewy-body disease found postmortem.5, 6
In our case, dysphagia clearly preceded the onset of the typical motor features of PD by at least 1 year, leading to an appearance suggestive of MND. Although they are phenomenologically different, MND and PD may show clinical overlap. A recent case series documents primary lateral sclerosis presenting with an atypical Parkinsonian appearance, acknowledging the potential for confusion.7 In our case, there were no additional features to suggest that this was a pseudobulbar or bulbar presentation of dysphagia.
Early dysphagia in the context of Parkinsonism should also lead to consideration of the Parkinsonian variant of multiple system atrophy (MSA-P). However, our patient lacks other suggestive clinical or imaging features of MSA and the clinical course is in keeping with PD with asymmetry of signs, slow progression, response to L-dopa, presence of tongue tremor, and marked hyposmia. In conclusion, Lewy-body pathology can have pleomorphic clinical presentations and PD should be included in the differential diagnosis of isolated dysphagia when appropriate.
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