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Neuroradiology Case of the Week

Case 88

Ravinder Sidhu MD, Leena Ketonen MD, PhD, Henry Wang MD,
and P-L Westesson MD, PhD, DDS

Clinical Presentation: A two-month-old male presented with a history of neck stiffness and increased tone.

Radiological Findings:  Non-contrast enhanced head CT showed subdural hemorrhage along the posterior falx and frontal regions (Fig. 1A). A few small cortical contusions were also seen in the bilateral frontal lobes and left parietal lobe (Fig. 1B). Coronal FLAIR MR image revealed high-signal left and low-signal right subdural hematoma (Fig 2). Axial T2-weighted image showed increased signal intensity parenchymal contusions in left parieto-occipital sulcus due to intracellular methemoglobin (Fig 3).

Diagnosis: Non-accidental head injury (child abuse)

Discussion: Head trauma from child abuse is a major cause of morbidity and mortality. Subdural hematoma is one of the most common manifestations of head trauma in abused children. In the absence of any other documented trauma, the presence of subdural hematoma serves as an important indicator of non-accidental head injury. Interhemispheric bleeding is accepted as an early and specific finding in intracranial bleeds caused by shaking. The purpose of cranial imaging is to, 1) diagnose the presence of intracranial injury, 2) establish the need for therapeutic intervention, and 3) provide documentary evidence for any potential social or forensic investigation [1,2].
     Radiologically, CT is the imaging tool in the evaluation of craniocerebral non-accidental trauma. It can be performed quickly and has a high sensitivity in detecting acute intracranial bleed, bone trauma, cerebral edema and hypoxic-ischemic injury. CT has high sensitivity in detecting acute hemorrhage because of the intrinsic density differences between brain and clotted, extravasated blood. The CT attenuation of subdural hematoma varies being high-density in acute hematomas, isodense in subacute and low-density in chronic hematomas. However, various factors such as active bleed into the collection, low hematocrit at the time of injury, and fresh hemorrhage into pre-existing older subdural collections may affect the density of a subdural hematoma [2].
     MR imaging is an essential second investigation; best performed 5-10 days after the insult, when it can reliably differentiate between acute and chronic subdural hematoma. MR scanning is the most sensitive modality for detecting early ischemic changes particularly with diffusion-weighted imaging. Anatomical locations that are difficult to image with CT (posterior fossa, anterior part of the middle cranial fossa and close to the inner table of the skull) are clearly shown on MR imaging. Sagittal T1, axial T2-weighted and coronal proton density sequences are three important sequences, which increase the sensitivity of the examination. Sagittal T1-weighted sequences sensitively detect the fresh subtentorial subdural hematoma whereas axial T2-weighted sequences are best for parenchymal damage and parafalcine hematoma. Coronal proton density images are more sensitive for detection of subdural bleeds along the cerebral convexities [2,3].

References:

1. Hoskote A, Richards P, Anslow P, McShane T. Subdural haematoma and non-accidental head injury in children. Childs Nerv Syst. 2002; 18: 311-317.
2. Jaspan T, Griffiths PD, McConachie NS, Punt JA. Neuroimaging for non-accidental head injury in childhood: a proposed protocol. Clin Radiol. 2003; 58: 44-53.
3. Barlow KM, Gibson RJ, McPhillips M, Minns RA. Magnetic resonance imaging in acute non-accidental head injury. Acta Paediatr.1999; 88: 734-740.