Rapidly Progressive Corticobasal Degeneration Mimicking Brainstem Encephalitis

Abstract

Background Corticobasal degeneration (CBD) may have a rapidly progressive (RP) clinical course, mimicking other neurological conditions. Objectives To describe a neuropathologically proven case of RP‐CBD in a patient initially diagnosed with immune‐mediated brainstem encephalitis. Methods Retrospective data collection from electronic records and authorized video material. Results A 51‐year‐old man presented with bilateral ptosis, diplopia, and dysphagia. The diagnostic workup was negative for myasthenic syndromes. He progressively developed cognitive dysfunction with frontal release signs and asymmetric parkinsonism. Cerebrospinal fluid evaluation revealed 4 leukocytes/uL, 0.32 g/L proteins, 0.85 g/L glucose, and absent oligoclonal bands. Weakly positive anti‐PNMA2 (Ma2/Ta) antibodies were present, and magnetic resonance imaging showed a T2 hyperintensity involving the midbrain and pons. Based on these features, the diagnosis of immune‐mediated brainstem encephalitis was considered. The patient did not improve after several cycles of methylprednisolone, intravenous immunoglobulin, and plasma exchange. At 1 year after onset, he developed horizontal and vertical gaze limitation and worsening of the parkinsonism and cognitive dysfunction. By age 53, he was severely disabled, requiring percutaneous gastrostomy for feeding. Anti‐IgLON5 was negative. He fulfilled the clinical criteria for probable progressive supranuclear palsy. He died from pneumonia at age 54. The neuropathological examination revealed a 4‐repeat tauopathy with features of CBD with extensive involvement of the brainstem. Conclusions RP‐CBD may resemble brainstem encephalitis. The severity of brainstem and upper spinal cord pathology in the postmortem examination correlated with the clinical and imaging features.

Diplopia in Movement Disorders: A Systematic Review of the Literature

“…The rest of the articles were manually screened by the authors in order to meet the eligibility criteria. In the end, a total of 26 articles remained: five were retrospective studies [ 21 , 22 , 23 , 24 , 25 ], three were prospective studies [ 26 , 27 , 28 ], nine were case reports [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ], six were case series [ 38 , 39 , 40 , 41 , 42 , 43 ], and three were observational cross-sectional studies [ 44 , 45 , 46 ]. Table 2 shows detailed information about the included studies on diplopia in other movement disorders (besides Parkinson’s disease).…”

“…He presented with diplopia, bilateral ptosis, and dysphagia and rapidly developed cognitive dysfunction, asymmetrical parkinsonism, and gaze limitation. The differential diagnosis included PSP and immune-mediated brainstem encephalitis due to the clinical and paraclinical findings [ 33 ].…”