Tremors in cats with hepatic encephalopathy-congenital portosystemic shunts or postattenuation neurological syndrome.

Background: Tremors have been reported as a neurological sign in cats with hepatic encephalopathy due to congenital portosystemic shunts (HE-CPSS) or postattenuation neurological syndrome (PANS).

Methods: The clinical records of cats diagnosed with HE-CPSS and manifesting tremors between 2003 and 2023 were retrospectively reviewed to characterise the clinical features of the tremors.

Results: Nineteen cats with HE-CPSS were included, of which 17 manifested tremors at admission and two had PANS. Domestic shorthair was the most common breed (12/19). Tremors were the only neurological sign in six of the 19 cats. Tremor localisation was generalised (10/19) or focal to the head (8/19) or a limb (1/19). Most tremors were episodic and non-intentional (15/19), occurring usually at rest with occasional intentional features (4/19). Of the 14 cats for which 1-month follow-up was available, tremors discontinued in nine after surgical or medical management.

Limitations: The limitations of this study included its retrospective nature and the lack of video recordings, brain magnetic resonance imaging and electrophysiological evaluation of tremors in all cases.

Conclusions: A diagnosis of HE-CPSS or PANS should be considered in cats with generalised or focal tremors.