Although it is commonly recognised that diseases of the thyroids can simulate extrapyramidal disorders, a review of the causes of Parkinsonism in the neurology literature shows that they are not usually mentioned or, if so, only very briefly. The development of hypothyroidism in a patient with Parkinson s disease can go undetected, since the course of both diseases can involve similar clinical features. Generally speaking there is always an insistence on the need to conduct a thyroidal hormone study in any patient with symptoms of Parkinson, but no emphasis is put on the need to continue to rule out dysthyroidism throughout the natural course of the disease, in spite of the fact that the concurrence of both pathological conditions can be high and that, in the same way hypothyroidism can simulate Parkinson s disease, the latter can also conceal hypothyroidism.

CASE REPORT:

We report the case of a female patient who had been suffering from Parkinson s disease for 17 years and started to present on off fluctuations that did not respond to therapy. Hypothyroidism was observed and the hormone replacement therapy used to resolve the problem allowed the Parkinsonian fluctuations to be controlled.

CONCLUSIONS:

We believe that it is very wise to suspect hypothyroidism in patients known to be suffering from Parkinson s disease, and especially so in cases where the clinical condition worsens and symptoms no longer respond properly to antiparkinsonian treatment. These observations stress the possible role played by thyroid hormones in dopaminergic metabolism and vice versa.