Preliminary Investigation of Pain-related Changes in Cerebral Blood Volume in Patients with Phantom Limb Pain

Publication date: Available online 6 April 2017
Source:Archives of Physical Medicine and Rehabilitation
Author(s): Cheong Hoon Seo, Chang-hyun Park, Myung Hun Jung, Soyeon Jang, So Young Joo, Yoonkyeong Kang, Suk Hoon Ohn
ObjectiveWe utilized MRI to measure CBV in patients who had undergone unilateral arm amputation following electrical injury to investigate changes in the pain network associated with phantom limb pain.DesignCase-controlled exploratory MRI study of cerebral blood volume (CBV) via magnetic resonance imaging (MRI)SettingUniversity hospitalParticipantsTen patients with phantom limb pain following unilateral arm amputation and 16 healthy, age-matched participants.InterventionsNoneMain Outcome MeasuresThe intensity of phantom limb pain was measured using the Visual Analogue Scale (VAS). Depressive mood was assessed using the Hamilton Depression Rating Scale (HDRS), and cognitive function was assessed using the Korean version of the Mini Mental State Examination (MMSE-K). Voxel-wise comparisons of relative CBV maps were made between amputees and controls over the entire brain volume. The relationship between individual participant CBV (measured in voxels) and VAS score was also examined.ResultsCompared to control participants, amputees exhibited greater degrees of depression; significantly higher CBV in the bilateral medial frontal area (orbitofrontal cortex [OFC] and pregenual anterior cingulate cortex [pACC]); and significantly lower CBV in the right mid-cingulate cortex, posterior cingulate cortex, and primary somatosensory cortex. CBV increased in the contralateral and ipsilateral hemispheres of the amputated arm, regardless of the amputation side. This CBV increase was strongly correlated with pain intensity in the OFC and pACC in all amputees.ConclusionsWe observed increased CBV in regions associated with emotion in the cerebral pain network of patients who had undergone unilateral arm amputation following electrical injury. This study suggests that CBV changes were related to neuroplasticity associated with phantom limb pain.



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