Trismus caused by paraneoplastic brainstem encephalitis

Trismus as the Initial Presentation of Anti-Hu Paraneoplastic Neurological Syndrome

A 73-year-old man presented with subacute trismus and pancerebellar dysfunction. Brain imaging and routine blood test results were unremarkable. Chest computed tomography revealed an indistinctly enhancing 4.7 × 2.5 × 1.8-cm3 pulmonary mass in the right upper lung, with enlarged right paratracheal and hilar lymph nodes. Biopsy of the right supraclavicular lymph node confirmed metastatic carcinoma, with differential diagnoses of small cell carcinoma and poorly differentiated carcinoma, indicating lung cancer as the primary source. Paraneoplastic immunohistochemistry screening revealed anti-Hu antibodies in the serum at a titer of 1:7680 (normal range <1:240) and in the cerebrospinal fluid (CSF) at a titer of 1:256 (normal range <1:2). The line blot method yielded positive results for anti-Zic4 antibodies in serum, with a titer of >1:10 (normal range <1:10), whereas CSF anti-Zic4 was negative (normal range <1:2). The patient developed non-responsive hospital-acquired pneumonia and respiratory failure, and discharged himself against medical advice. This rare case indicates that trismus can be an initial manifestation of anti-Hu paraneoplastic neurological syndrome, and emphasizes the importance of clinical awareness.

Brainstem Encephalitis. The Role of Imaging in Diagnosis

Encephalitis is a relatively challenging rare condition caused by a diverse group of etiologies. Brainstem encephalitis/Rhombencephalitis (BE), which affects the cerebellum, pons, and medulla, is even less common and more challenging for diagnosis and treatment. At this time, there is scattered data about BE in the literature, mainly in the form of case reports and case series. In this manuscript, the imaging presentation of BE is reviewed with the help of case examples. Many imaging presentations are not pathognomonic for BE; however, in many cases, clinical presentation, the spatial distribution of lesions, and other associated radiological lesions can provide the radiologists and clinician the clues to an accurate diagnosis.

[Recurrent ataxia and respiratory failure with probable paraneoplastic syndrome responsive to plasma exchange therapy]

An 80-year-old male with prostatic adenocarcinoma who was treated with orchiectomy presented dysarthria and difficulty in walking. His symptoms subacutely progressed. Seven days later, he was non-ambulatory and was admitted to our hospital. He had poor vision and cerebellar ataxia of the lower extremities; however, his muscle strength, tendon reflexes, and sensory functions were preserved. Paraneoplastic retinopathy was diagnosed based on electroretinographic and visual field defect. Further, brain and spinal MRI, cerebral spinal fluid, and nerve conduction assessments were normal. These symptoms were followed by consciousness disturbance and respiratory failure; consequently, he required non-invasive positive pressure ventilation (NPPV) and tube feeding. Steroid pulse therapy and plasma exchange (PE) were performed. In response to the therapy, all these symptoms were relieved, and NPPV and tube feeding were withdrawn. However, the same symptoms occurred additional three times throughout the course of approximately 1 year. Each time, PE was the most effective treatment. Although paraneoplastic neurological syndrome associated with prostatic cancer is rare, immunotherapy could be a therapeutic choice to relive symptoms.