Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS)

Last revised by Assoc Prof Craig Hacking on 18 Aug 2021

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an uncommon and only recently described disorder characterized by infiltration of the brain by inflammatory cells. It has a predilection for the pons, with fairly characteristic curvilinear regions of enhancement best seen on MRI. The disorder usually readily responds to immunosuppression with glucocorticosteroids. 

CLIPPERS has been reported in a wide range of ages (13 to 86 years) but generally is seen in middle age 1. There may be a slight male predilection 1

Patients typically present subacutely with a wide variety of signs and symptoms dominated by 1:

  • cranial nerve dysfunction (e.g. dysarthria, altered facial sensation, diplopia) 
  • cerebellar signs (e.g. ataxia)
  • long tract signs (e.g. spasticity, altered sensation) 

Generally, patients remain cognitively intact and do not suffer from other signs of inflammation (e.g. fevers or sweats or meningism) 1

These lesions histologically demonstrate a lymphocytic perivascular inflammatory pattern 4. However, the condition is still poorly understood and, based on its natural history, an (auto)immune-mediated or other inflammatory pathogenesis of unknown etiology is proposed 1,4

MRI is the imaging modality of choice for the assessment of patients with suspected brainstem pathology. The protocol should include contrast. 

The appearance of CLIPPERS on MRI is fairly unique, characterized by multiple punctate, patchy and linear regions of contrast enhancement relatively confined to the pons 1. Similar changes may also be visible caudal and rostral to the pons, in the cerebellar peduncles, cerebellar hemispheres, and involving the cervical spinal cord 1,6

Despite striking post contrast appearances, there is relatively little edema or positive mass effect. No vasculitic angiographic changes (i.e. no beading) are reported 1

Susceptibility weighted imaging can reveal prominent veins and punctate regions of signal loss 5

Patients typically respond rapidly to the administration of glucocorticosteroids but have a tendency to relapse if immunosuppression is ceased. As such long-term immunosuppression is recommended 1

Although the features of CLIPPERS are striking a relatively wide differential should be considered including 1:

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Cases and figures

  • Case 1
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  • Case 2
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  • Case 3: with extensive spinal cord involvement
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  • Case 4
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