Teaching NeuroImages: The zigzag edging sign of adult-onset neuronal intranuclear inclusion disease

  • 66yo F
  • c/c
    • dementia
    • urinary incontinece
    • episodic coma
  • Ex
    • T1 / T2
      • leukocencephalopathy
    • DWI
      • zigzag edging sign
    • skin biopsy
      • intranuclear inclusion body(++) in sweat glands / perivascular cells
  • Dx
    • neuronal intranuclear inclusion disease (NIID)

A 66-year-old woman presented with dementia, urinary incontinence, and episodic coma for 3 years without remarkable family history. Brain MRI showed leukoencephalopathy and a high signal intensity along the corticomedullary junction on diffusion-weighted imaging (DWI) (zigzag edging sign) (figure 1). Skin biopsy revealed intranuclear inclusion bodies in sweat glands and perivascular cells (figure 2). FMRI CGG permutation was not present. Finally, the diagnosis of neuronal intranuclear inclusion disease (NIID) was confirmed.

Figure 1

Brain MRI
Brain MRI shows bilateral cerebral white matter lesions, hypointensity on T1 (A), hyperintensity on the T2 (B) and fluid-attenuated inversion recovery (C), and high signal intensity along the corticomedullary junction on diffusion-weighted imaging (D).

Figure.1

Figure 2

Skin biopsy
Electron microscope shows intranuclear inclusion bodies in sweat gland (A, B) and perivascular cells (C, D) (arrows).

Fiugre.2

Adult-onset NIID

  • heterogenous neurodegenerative disorder
  • defnite Dx
    • skin biopsy: intranuclear inclusions
    • r/o fragile X sund

Adult-onset NIID is a clinically heterogeneous neurodegenerative disorder. The zigzag edging sign on DWI is a strong diagnostic clue.1 A definite diagnosis requires skin biopsy revealing intranuclear inclusions and genetic evaluation ruling out fragile X syndrome.1,2

References

  1. Sone J, Mori K, Inagaki T, et al. Clinicopathological features of adult-onset neuronal intranuclear inclusion disease. Brain 2016;139:3170–3186.
  2. Sone J, Tanaka F, Koike H, et al. Skin biopsy is useful for the antemortem diagnosis of neuronal intranuclear inclusion disease. Neurology 2011;76:1372–1376.