Abstract A 13‐week‐old, male intact Shih Tzu was presented for progressive neurologic deficits prompting advanced imaging. Brain magnetic resonance imaging revealed a heterogeneously contrast‐enhancing lesion, characterised by mixed osseous proliferation and lysis of the right dorsolateral calvarium. The overlying right temporalis muscle was swollen, heterogeneously T2‐weighted and fluid‐attenuated inversion recovery hyperintense and contrast enhancing. The underlying meninges were thickened and strongly contrast enhancing. Cerebrospinal fluid analysis revealed a mild lymphocytic, mixed pleocytosis with a marked elevation in protein. An elevated serum C‐reactive protein was also noted. Skull computed tomography, histopathological analysis and culture of the calvarium supported a diagnosis of calvarial hyperostosis syndrome (CHS) with secondary meningitis. Treatment with a tapering course of prednisone led to marked improvement in neurologic signs and resolution of inflammatory markers. This is the first case report of CHS with secondary aseptic meningitis and the first documented case of CHS in a Shih Tzu.
Connolly et al. (Tue,) studied this question.