Eye-of-the-Tiger Sign with an Unexpected Pathological Diagnosis

Background: Clinical diagnosis of atypical parkinsonisms may be challenging. The eye-of-the-tiger sign on brain MRI, typical of neurodegeneration with brain iron accumulation, has been anecdotally observed in cases clinically diagnosed as atypical parkinsonisms. Objectives: To show how clinical syndromes and even neuroimaging sometimes may lead the neurologist to a misunderstanding, just as to emphasize the important role of pathology to establish the final diagnosis in these cases. Methods: Clinico-pathological case. Results: A 67-year-old-woman presented with progressive painful stiffness and allodynia in her left arm. On examination, she presented parkinsonism without tremor with greater involvement of left limbs. She developed dystonia, with myoclonic tremor and hypoesthesia involving her left arm, as well as an impairment of balance with falls, a significant axial involvement with disabling rigidity, supranuclear gaze abnormalities, facial dystonia, dysphonia, severe dysphagia, and anarthria. There was no response to levodopa. Syndromic diagnosis and findings on neuroimaging are discussed. Afterwards, the underlying pathology is revealed. Conclusions: We present the first case of neuropathologically confirmed multiple system atrophy with the eyeof-the-tiger sign on brain MRI. The presence of supranuclear vertical gaze palsy further complicated a correct clinical diagnosis. A pathological postmortem study remains essential to establish a definite diagnosis in atypical parkinsonisms.

Automated summary

This study presents a case of neuropathologically confirmed multiple system atrophy with the eye-of-the-tiger sign on brain MRI, emphasizing the role of pathology in establishing a definitive diagnosis in atypical parkinsonisms. It highlights how clinical syndromes and neuroimaging can sometimes lead to misunderstandings, as well as the complexities involved in making a correct clinical diagnosis.