Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an extremely rare treatable condition with only around 100 cases reported since it was first characterised in 2010. CLIPPERS is a type of encephalomyelitis, which is a general term describing inflammation of the brain and spinal cord. CLIPPERS has been reported in mostly young and middled-aged patients and occasionally in children with slightly more males than females being affected.

What are the symptoms?

The symptoms of CLIPPERS usually develop over weeks or months, with very few patients reporting that symptoms occur over a matter of days. Whilst the symptoms of CLIPPERS are varied, the most common symptoms include difficulty with speech (dysarthria), abnormal or uncoordinated movements (ataxia), double vision (diplopia), cognitive impairments and abnormal facial sensations such as numbness and tingling. Other symptoms may include bouts of sudden uncontrollable and inappropriate laughing or crying (pseudobulbar affect), ringing in the ears (tinnitus), a shaking or tremor in the muscles, uncontrolled eye movements (nystagmus), distortion of taste or smell, nausea, or the partial loss of the function of the legs (paraparesis)

What are the causes?

CLIPPERS is likely an inflammatory condition, although the underlying cause is unknown.

How is it diagnosed?

There is currently there is no unified diagnostic standard for diagnosing CLIPPERS and no single laboratory or imaging test that can confirm a CLIPPERS diagnosis. Instead, diagnosis is based on the symptoms and various laboratory and imaging tests which are needed to support the diagnosis and to rule out many other conditions with overlapping symptoms. These can include:

  • Blood tests
  • Tests of the fluids around the brain and spine (via a lumbar puncture)
  • Magnetic resonance imaging (MRI) brain
  • A small sample of the brain is taken (biopsy)

How is it treated?

Most patients with CLIPPERS recover significantly within weeks of starting steroids, an anti-inflammatory medicine. These can be taken either intravenously (through the vein) or orally. However, depending on the severity of the symptoms and the length of these symptoms before treatment, some people may not completely recover. Prolonged treatment with steroids (for at least one year) is usually necessary to prevent symptoms from recurring or worsening again.



By Rhys Inward, Research Assistant in Genomic Epidemiology and Data Science, University of Oxford, and peer-reviewed by Dr Yun Huang, University of Liverpool


Page created: December 2021/ Next Review: December 2024

Disclaimer: We try to ensure that the information is easy to understand, accurate and up-to-date as possible. If you would like more information on the source material and references the author used to write this document please contact the Encephalitis International. None of the authors of the above document has declared any conflict of interest, which may arise from being named as an author of this document.

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Page Created: 15 November 2023
Last Modified: 8 February 2024
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