Intercaudate distance to inner table width ratio

Dr Rohit Sharma and A.Prof Frank Gaillard ◉ ◈ et al.

Intercaudate distance to inner table width ratio (CC/IT) is used in assessing patients with neurodegenerative diseases that affect the caudate nuclei. It is best known for assessing individuals with suspected Huntington disease but is in no way specific for the diagnosis, also seen in other less common diseases (e.g. Nasu Hakola disease).

On the same axial plane obtained on the ACPC (anterior commissure and posterior commissure) line, the ratio between the distance between the caudate heads (where they are closest) and the distance between inner table of the skull (measured along the same line as the intercaudate distance) is obtained.

The normal CC/IT ratio range 0.09 to 0.12. As the caudate heads reduce in size, the CC distance will increase and as such the CC/IT ratio will increase.

An alternative measurement is the frontal horn width to intercaudate distance ratio (FH/CC).

References

Neurodegenerative diseases

Neurodegenerative diseases are legion and their classification just as protean. A useful approach is to divide them according to underlying pathological process, although even using this schema, there is much overlap and thus resulting confusion.

neurodegenerative MRI brain (an approach)
- measurements and ratios
  - midbrain to pons area ratio (for PSP)
  - Magnetic Resonance Parkinsonism Index (MRPI) (for PSP)
  - frontal horn width to intercaudate distance ratio (FH/CC) (for Huntington disease)
  - intercaudate distance to inner table width ratio (CC/IT) (for Huntington disease)
- signs
  - hummingbird sign (of PSP)
  - Mickey Mouse sign (of PSP)
  - morning glory sign (of PSP)
  - hot cross bun sign (of MSA-C)
  - hockey stick sign (of Creutzfeldt-Jakob disease)
  - pulvinar sign (of Creutzfeldt-Jakob disease)
- scoring systems
  - Fazekas scale for white matter lesions
  - posterior atrophy score of parietal atrophy (PA/PCA) (Koedam score)
  - medial temporal lobe atrophy score (MTA score)
  - global cortical atrophy scale (GCA scale)
neurodegenerative diseases
- synucleinopathies
  - diseases with Lewy bodies
    - Parkinson disease
      - Parkinson-plus syndrome
    - Lewy body disease
  - multiple systemic atrophy (MSA)
    - Shy-Drager syndrome
    - MSA-P (striatonigral degeneration)
      - putaminal rim sign
    - olivopontocerebellar atrophy (MSA-C)
- tauopathies
  - Alzheimer disease
    - typical/classical Alzheimer disease
    - variant (e.g. posterior cortical atrophy)
  - chronic traumatic encephalopathy (CTE)
  - corticobasal degeneration
  - frontotemporal lobar degeneration (FTLD) (not all are tau)
    - behavioral variant frontotemporal dementia (bvFTLD)
    - language variant frontotemporal dementia (lvFTLD) (primary progressive aphasia (PPA))
    - right temporal variant frontotemporal dementia
  - Pick disease
  - progressive supranuclear palsy (PSP)
- amyloidoses
- TDP-43 proteinopathies
  - limbic-predominant age-related TDP-43 encephalopathy
  - frontotemporal lobar degeneration (FTLD) (not all are TDP-43)
  - amyotrophic lateral sclerosis (ALS)
- spinocerebellar ataxias
- Huntington disease
- hereditary spastic paraplegia
- clinically unclassifiable parkinsonism (CUP)
- Unverricht-Lundborg disease
- prion diseases (not always included as neurodegenerative)
  - Creutzfeldt-Jakob disease (sporadic, variant, familial, and iatrogenic)
  - fatal familial insomnia
  - Gerstmann-Straussler-Scheinker disease
  - kuru
  - variably protease sensitive prionopathy

Article information

rID: 28843

System: Central Nervous System

Section: Approach

Tag: measurement

Synonyms or Alternate Spellings:

Intercaudate distance to inner table width ratio (CC/IT)
CC/IT

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Cases and figures

Figure 1: FH:CC ratioFigure 1: FH:CC ratio

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