# Spinocerebellar ataxia with mixed tremor and hippocampal atrophy: case report and literature review

## TL;DR

This paper reports a case of spinocerebellar ataxia 12 (SCA12) with mixed tremor and hippocampal atrophy, highlighting its clinical features and genetic confirmation.

## Contribution

The study provides a detailed clinical and genetic analysis of SCA12 with mixed tremor and hippocampal atrophy, expanding its known presentation.

## Key findings

- The patient had 69 CAG repeats in the PPP2R2B gene, confirming SCA12 diagnosis.
- SCA12 can present with mixed tremor and hippocampal atrophy.
- Hippocampal atrophy may be related to age or vascular changes rather than SCA12 pathology alone.

## Abstract

This study aimed to investigate the clinical features of spinocerebellar ataxia 12 (SCA12).

Sanger sequencing-based genetic testing was performed on a patient initially diagnosed with essential tremor.

The patient exhibited an abnormal expansion of 69 cytosine-adenine-guanine (CAG) repeats, confirming the diagnosis of SCA12.

SCA12 may present with mixed tremor, predominantly postural/kinetic tremor with a superimposed resting component and hippocampal atrophy. However, the direct association between hippocampal atrophy and SCA12 pathology remains unclear and may reflect concomitant age-related or vascular changes. Furthermore, PPP2R2B gene abnormalities may also affect the synergistic function of the basal ganglia-thalamocortical and cerebello-thalamocortical circuits.