Abstract
BACKGROUND AND PURPOSE: Low brain tissue perfusion due to abnormal venous drainage is thought to be a central mechanism of brain damage in SWS. Here, HR-PWI was used to quantify WM perfusion abnormalities and to correlate these with brain atrophy and clinical variables.
MATERIALS AND METHODS: Fourteen children (age range, 0.8–10.0 years) with unilateral SWS underwent MR imaging examinations, including HR-PWI. rCBV, rCBF, and MTT in the affected WM and in contralateral homotopic WM were measured. AI for each perfusion parameter was correlated with age, brain atrophy, and motor and seizure variables as well as IQ.
RESULTS: Increased perfusion was seen in the affected hemisphere in 5 children and decreased perfusion in 9 children. Brain atrophy was more severe in the low-perfusion group (P = .01) and was related to both CBF-AI and CBV-AI (r = −0.69, P = .007; r = −0.64, P = .014, respectively). Older children had lower CBV values on the affected side (r = −0.62, P = .02). Longer duration of epilepsy was related to lower CBF (more negative CBF-AI, r = −0.58, P = .03) and low CBV (r = −0.55, P = .04) on the affected side. Lower perfusion was associated with more frequent seizures (rCBF-AI: r = −0.56, P = .04; rCBV-AI: r = −0.63, P = .02).
CONCLUSIONS: Increased perfusion in the affected cerebral WM may indicate an early stage of SWS without severe brain atrophy. Decreased perfusion is associated with frequent seizures, long duration of epilepsy, and brain atrophy.
Abbreviations
- AI
- asymmetry index
- AIc
- calculated asymmetry index
- AIs
- hemispheric perfusion parameter
- Amr
- age at MR examination
- Asz
- age at first seizure
- BA
- brain atrophy
- CBF
- cerebral blood flow
- CBV
- cerebral blood volume
- Cont
- contralateral (to angioma)
- HR-PWI
- high-resolution perfusion-weighted imaging
- Ipsi
- ipsilateral
- IQ
- intelligence quotient
- MTT
- mean transit time
- PET
- positron-emission tomography
- PHT
- phenytoin
- PWI
- perfusion-weighted imaging
- rCBF
- relative cerebral blood flow
- rCBV
- relative cerebral blood volume
- rHP
- relative high perfusion
- rLP
- relative low perfusion
- rMTT
- relative mean transit time
- ROI
- region of interest
- SPECT
- single-photon emission CT
- SPIN
- Signal intensity Process in Neuroimaging
- SWS
- Sturge-Weber syndrome
- T1WI
- T1-weighted imaging
- T2WI
- T2-weighted imaging
- WM
- white matter
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