CLIPPERS


KEY FACTS

Terminology

  • C hronic l ymphocytic i nflammation with p ontine p erivascular e nhancement r esponsive to s teroids (CLIPPERS)

    • Predominantly involving brainstem, adjacent rhombencephalic structures

    • Shows clinical, imaging response to glucocorticosteroids

Imaging

  • Location: Predominately pons

    • May extend into cerebellar peduncles, hemispheres

    • Caudally into medulla, spinal cord

    • Rostrally into midbrain

  • MR

    • Classic: Enhancing punctate/curvilinear lesions; pons often appears “peppered”; may exhibit subtle radiating pattern

    • ± faint, patchy or “speckled” punctate hyperintensities on T2/FLAIR

    • Beware: May begin as isolated, enhancing mass in pons/cerebellar peduncle before exhibiting typical pattern of multifocal punctate pontine lesions

Top Differential Diagnoses

  • Angiocentric (intravascular) lymphoma

  • Neurosarcoidosis

  • Demyelinating disease (multiple sclerosis, neuromyelitis optica spectrum)

  • Vasculitis (primary, secondary, Behçet)

  • Lymphomatoid granulomatosis

  • CNS histiocytosis (Langerhans cell histiocytosis, Erdheim-Chester, hemophagocytic)

Clinical Issues

  • Brainstem symptoms, gait ataxia, diplopia

    • Often relapsing-remitting course (without treatment)

    • Mean age at onset 40-50 years (range 13-86 years)

  • Keep in mind: CLIPPERS is diagnosis of exclusion

Sagittal FLAIR MR in a 56-year-old woman with weight loss and 3-week history of diplopia and disequilibrium shows confluent and punctate hyperintensities in the pons
and medulla
.

Axial T1 C+ scan in the same patient shows multiple punctate and curvilinear enhancing foci “peppering” the pons
. Additional lesions are present in both cerebellar peduncles, vermis, and the left cerebellar hemisphere.

More cephalad T1 C+ scan in the same patient shows the punctate
and curvilinear
lesions involving the upper pons.

Coronal T1 C+ FS scan in the same patient shows the lesions “peppering” the pons. Note cephalad extension into the cerebral peduncles
and inferior extension into the medulla
and upper cervical cord
. DSA (not shown) was negative. The lesions resolved with corticosteroids, so this is a presumed case of CLIPPERS.

TERMINOLOGY

Abbreviations

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

Definitions

  • Recently described inflammatory CNS disorder

  • Predominantly involving brainstem, adjacent rhombencephalic structures

  • Clinical, imaging response to glucocorticosteroids

IMAGING

General Features

  • Best diagnostic clue

    • Enhancing punctate/curvilinear lesions “peppering” the pons

      • May exhibit subtle radiating pattern

  • Location

    • Predominately pons

    • May extend laterally into cerebellar peduncles or hemispheres

    • Caudally into medulla, spinal cord

    • Rostrally into midbrain

    • Sometimes involves basal ganglia, cerebral WM

    • May begin as isolated, enhancing mass in pons/cerebellar peduncle before exhibiting typical pattern of multifocal punctate pontine lesions

  • Morphology

    • Typically small, punctate or curvilinear

CT Findings

  • Usually normal

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here