The combination of dopa-responsive parkinsonian syndrome and motor neuron disease

Idiopathic Parkinson's syndrome (IPS) and motor neuron disorders (MND) are generally considered as distinct clinicopathological entities. However, cooccurrence of different neurodegenerative disorders is more frequent than would be expected. Therefore, there is an ongoing discussion whether some entities represent parts of a common spectrum.

We describe clinical hallmarks and treatment options in a group of 8 patients who had combined features of both a dopa-responsive parkinsonian syndrome and MND.

All patients exhibited a typical clinical picture of IPS, and all were treated with levodopa or other dopaminergic drugs with good clinical response. The patients also showed clinical and electrophysiological signs of upper and/or lower motor neuron degeneration. Noticeably, in contrast to well-known distinct entities like the amyotrophic lateral sclerosis-parkinsonism/ dementia complex in southwest New Guinea, we did not observe any cognitive decline during the observation period except in 1 patient.

This comorbidity of two neurodegenerative diseases supports the ongoing discussion of a pathophysiological and clinical overlap of disease processes. Due to the potent pharmacological options for the IPS symptoms in these overlap syndromes, these patients should be offered optimal symptomatic dopaminergic therapy.