Dados do Trabalho

Título

Corticobasal Degeneration Diagnostic Challenges in a Patient with Wernicke-Mann's Position

RESUMO

Case Report
A 52 year-old male with a prior history of hypertension and well controlled epilepsy was admitted to the outpatient neurology department with severe pain and rigidity in the right upper limb. The symptoms had an insidious onset and gradual progression over the course of 2 years, assuming a Wernicke-Mann position. The patient reported depressive mood, irritability and self-injurious behavior mainly against his right arm. On neurological examination, hemiplegic gait, allodynia in the right upper limb, weakness and hypertonia in the right side were observed. Evaluation of the affected limb was limited by the patient's pain. Brain MRI was normal without noticeable vascular lesions that could explain the motor symptoms. He was started on citalopram and was referred to psychiatry that suspected of conversion disorder. Over the next years, he presented with worsening of the cognitive symptoms with memory impairment, ideomotor apraxia and mild dysarthria and developed loss of balance and bradykinesia in the four limbs, unresponsive to Levodopa. A new MRI showed mild corpus callosum atrophy, leading to the hypothesis of corticobasal degeneration (CBD).

Discussion
CBD is a rare neurodegenerative disease characterized by intracellular accumulation of misfolded tau proteins which presents as an asymmetric rigid-akinetic parkinsonism with dystonia and cortical deficits. Frontal behavioral-spatial syndrome, nonfluent/agrammatic variant of primary progressive aphasia and progressive supranuclear palsy (PSP) syndrome are also possible phenotypes of this disorder. Similarly, multiple etiologies may mimic its symptoms, namely PSP, Alzheimer disease, Pick disease and dementia with Lewy bodies.

This overlap represents a challenge to the diagnosis of CBD with an antemortem prediction in only 25 to 56% of cases. Also, as seen in this case, symptoms like dystonia and pain may hinder the assessment of apraxia and bradykinesia. In this context, new biomarkers are important to distinguish similar etiologies. Unfortunately, their high cost is impracticable for use in the general population, especially in developing countries.

Conclusion
Misdiagnosing CBD is frequent and can lead to harmful and unnecessary interventions. Even without a specific treatment, the prognostic perspective to the patient and its family is invaluable. Also, it is important for neurologists to be able to distinguish CBD from its mimics because of potential future treatments.

Palavras Chave

Corticobasal Degeneration; Corticobasal Syndrome; Hemiplegic Gait; Wernicke-Mann Position; Pain; Dystonia;