The added value of parenchymal transcranial Doppler sonography at the Emergency Room: case report of an unusual gait disorder

Background: the growing application of parenchymal transcranial Doppler sonography (pTCS) helps the diagnosis of a wide range of neurological diseases, especially movement disorders. Here, we report a patient with an unusual gait disorder in whom pTCS performed at the Emergency Room rapidly provided diagnostic clues towards a degenerative movement disorder. Case presentation: A 60-year old man presented at the Emergency Room with a rapidly progressive history of walking difficulty, without falls. He had no family history of neurodegenerative or psychiatric diseases. Because of a depressive disorder arisen one year earlier, he was under oral treatment with escitalopram 10 mg and amisulpride 100 mg daily. Neurological examination showed a gait characterized by ataxia, rigidity, and limping; he also had mild oro-facial and hands dyskinesia, some of which were also present during walking. Brain computed tomography was normal. A pTCS performed at the Emergency Room showed hyperechogenicity of the substantia nigra and the caudate nucleus, bilaterally. This pattern is suggestive of Huntington’s disease (HD), as confirmed by the molecular genetic test carried out later. Other laboratory tests, standard electroencephalogram, and 1.5-T brain MRI were normal.Conclusions: to date, this is the first report of HD sonographically detected at the Emergency Room. This supports the view that pTCS can be easily implemented in the diagnostic algorithm and differential diagnosis of movement disorders even in an urgency setting. Notably, conventional MRI did not detect, at this stage, any abnormality; this further highlights the diagnostic utility of pTCS, which also allowed to exclude a drug-induced effect or a different movement disorder. In clinically suspected cases, pTCS can extend the neurological examination by providing diagnostic clues more rapidly and less expensively than neuroimaging.