Skull X-ray in trauma To do or not to do? Dr Pauline Louw Who has done a Skull Xray on a trauma patient this past year? What was the indications? The uncertainty that exists about the likely outcome after traumatic brain injury (TBI) is encapsulated in the Hippocratic aphorism “No head injury is so serious that it should be despaired of nor so trivial that it can be ignored.” “No head injury is so serious that it should be despaired of nor so trivial that it can be ignored.”

Introduction Head injury common presentation to EC Most mild TBI (70-90% worldwide) 8% of Mild TBI has intracranial pathology (95% CI 3-13%) 1% of these will require neurosurgical intervention Does plain Scull X-ray have a place in the assessment of mild TBI in the EC?? Most mild head injury don’t require admission or further work-up. In evaluation of 13 studies with 12 750 patients mean prevalence of intracranial head injury was 8%

Does this patient need a CT head? Depressed skull fracture

Does this patient need a CT head?

Does this patient need a CT head? Leptomeningeal cyst Traumatic meningocele Cerebrocranial erosion Cephalhydrocele Meningocele Spuria infant linear fracture, baseline skull x-ray needed for comparison on return visit to exclude growing fracture or evaluate growing fracture Growing skull fractures: In children, most skull fractures heal rapidly, with no long-term sequelae. However, in a small minority of children, a fracture may remain un-united and enlarge to form a growing skull fracture First case described in 1816, John Hopkins described an infant with growing skull fracture after a head injury. Since then, cases of growing skull fracture continue to appear in the literature, with various names such as a leptomeningeal cyst, traumatic meningocele, cerebrocranial erosion, cephalhydrocele, meningocele, and spuria. Growing skull fracture is rare and affects 1.2-1.6% of patients with severe head injury, with a vast majority occurring in children younger than 3 years. The exact pathophysiology remains elusive. Serial conventional radiographs of the skull show evolution of the initial diastatic fracture into a larger defect. Although plain radiographs are sufficient for diagnosis, brain CT better defines the exact pathology. Growing skull fracture are treated surgically to reduce the herniated cerebral tissue and repair the dural laceration or to perform cranioplasty. Early recognition is crucial to prevent long-term neurologic sequelae. Hence, radiologic and clinical follow-up is essential in cases of head trauma in children. Growing fracture Linear skull fracture

Does this patient need a CT head? Right parietal fracture Right parietal fracture

Does this patient need a CT head? Pneumocephalus

Does this patient need a CT head? Maybe, depend on clinical picture of patient Normal X-ray

Does this patient need a CT head? B A A: Penetrating brain injury resulting from nail-gun use is a well-characterized entity, one that is increasing in frequency as nail guns become more powerful and more readily available to the public. 50-year-old male present with two intracranial penetrating nail gun injuries. Nail gun brain injuries are commonly intentionally self-inflicted. Suicide should be considered when straight nails cause wounds to the chest, head, or abdomen. The primary preoperative concern is formation of a traumatic pseudoaneurism, which prompts both preoperative and follow-up cerebral angiography. B: A 44 year old man was referred to the accident and emergency department by the psychiatric services, having claimed to have hammered several nails through his skull over a three month period. The patient had a long history of depression, personality disorder, and previous deliberate self-harm. He had remained well throughout this period and had been cleaning the wounds with weak antiseptic on a regular basis. He had concealed the injuries by wearing a hat. Two days prior to admission he had inserted a much larger 12.7 cm (5 inch) masonry nail and had developed left sided weakness and unsteadiness of gait. Examination showed that the patient remained well with no evidence of infection in the central nervous system. Neurological examination revealed a mild left sided weakness affecting both the arm and leg. The patient was fully alert and orientated and conversed normally. Inspection of the scalp revealed a large masonry nail protruding from the scalp with several other healed puncture wounds. Plain skull X-rays revealed a total of ten 5 cm nails and a larger, 12.7 cm masonry nail penetrating the skull. A computed tomography (CT) scan was performed, which despite considerable artefact confirmed that the nails had penetrated the brain substance. The patient was later transferred to the local neurosurgical unit for further management where, after angiography, all the nails were removed under general anaesthetic. He subsequently made an uneventful recovery.

Guidelines Different guidelines available: North America – No SXR, CT choice ACEP – No SXR, CT choice Europe (EBIC) – CT choice NICE – CT choice, SXR for NAI and per discussion SIGN – CT but pro SXR where risk factors present Australia – No SXR, Use Canadian CT rule SA – WC guidelines Consensus in most guidelines = CT choice, No SXR ?MRI emerging modality to use in future NICE: New amended guidelines 2007: Plain X-rays of the skull should not be used to diagnose significant brain injury without prior discussion with a neuroscience unit. However, they are useful as part of the skeletal survey in children presenting with suspected non-accidental injury. Scottish Intercollegiate Guideline Network (SIGN) guidelines place more emphasis on skull x rays where there are risk factors for fracture or intracranial injury, although they acknowledge that skull fractures in children are less commonly associated with intracranial injury, and therefore their detection is less helpful than in the adult population.

Canadian CT rule Validated rule 100% Sensitive 2 risk groups High risk: At risk for neurosurgical intervention CT mandatory Medium risk May have clinically important injury on CT, but not at risk for neurosurgery intervention CT/observation depending on resources Prospective validation was carried out in Canada and reported a sensitivity of 100% and a specificity of 52.1% for clinically important brain injury 100% sensitive for need for neurosurgical intervention Don’t cover whole spectrum including coagulopathy, seizures, focal neurology ect..

Canadian CT rule Inclusion: Exclusion Minor head injury, GCS 13-15 Witnessed LOC, confusion or amnesia Exclusion No trauma experienced Younger than 16 GCS <13 On warfarin or coagulopathy Has obvious open skull fracture

Canadian CT rule High risk: Medium risk Failure to reach GCS of 15 within 2 hours Suspected open or depressed skull fracture Sign of basal skull fracture Vomiting more than once Age over 65 Medium risk Retrograde amnesia >30 min Dangerous mechanism Dangerous mechanism: PVA, ejected from vehicle, fall from height >3feet or 5 stairs Dangerous mechanism form part of Level B recommendations

New Orleans Criteria Recommend CT after minor TBI if: GCS=15 and one of the following Headache Vomiting Age >60 years Drug or alcohol intoxication Deficits in short term memory Seizure Evidence of injury above clavicle 100% Sensitive All of above are level A evidence together with GCS <15, focal neurology deficit and coagolopathy

Western Cape What are the Western Cape guidelines? What are the WC indications for CT scan? What are the place of SXR in WC EC’s?

SXR Studies Multitude of studies looked at abolishing SXR From as early as 1977 and early 1980’s Included adult and paediatric population Still ongoing studies - 2008 Consensus in most countries other still debating especially in areas with limited CT access Most concluded that SXR is not needed

Cost effectiveness of CT Less than 10% of CT scans in Mild TBI positive findings, thus > 90% CT’s normal Are we wasting money with all these normal CT’s? Compare CT vs. admission for observation Discharge safely vs. lack of supervision at home CT alone vs. CT and SXR + extra radiation Guidelines vs. CT all CT scan vs need for admission in hospital for neuro-observations, care from nursing staff including regular neuro-observations, food/catering, bed, lined, bed occupancy in overfull hospitals ect Discharge safely after CT normal vs discharge home without CT but no supervision at home, no transport, delay return to hospital with resultant longer hospital stay or increase morbidity and mortality Guidelines help to identify high risk cases needing CT vs CT scan for all. Guidelines decrease need for CT and saving money and radiation exposure. Remember 1 CT in a child = 100 CXR’s

MRI in TBI Emerging modality to use – Controversial 10-20% missed injuries from CT MRI 30% more sensitive than CT in picking up intracranial injury in acute mild TBI Not shown yet if picking up additional injuries would change acute management of TBI Currently need more studies in EC timeframe No current EBM recommendations EBM=Evidence based medicine recommendations. Need more studies, ACEP currently no level A/b/c recommendations Forty-eight to 72 h after injury, MRI is generally considered to be superior to CT. Although CT is better at detecting bony pathology and certain types of early bleeds, the ability of MRI to detect hematomas improves over time as the composition of the blood changes. The overwhelming majority of patients with mild brain injury show no abnormality on MRI Studies have shown that CT missed approximately 10–20% of abnormalities seen on MRI New MRI technology and acquisition sequences have improved the sensitivity of MRI

MRI in TBI Advantages Useful in sub-acute/chronic and limited acute setting Better soft tissue definition Better at Detecting DAI Small areas of contusion Subtle neuronal damage Posterior fossa: Cerebellum and brainstem CT posterior fossa – bone artifacts

MRI in TBI Disadvantages Not widely available and accessible Patient monitoring problem Long imaging time Foreign bodies Patient safety (pacemakers, previous ferromagnetic foreign bodies) Cost constraints Insensitive to acute SAH, parenchymal haemorrhage and fracture compared to CT Patient motion artefacts Patient motion artefacts more of an issue with MRI than with CT

MRI images MRI of brain stem injury. This patient presented with a Glasgow Coma Score of 4 after a road traffic accident and failed to improve, despite maximal medical therapy, and therefore underwent MRI to assess the extent of injury. The T1 weighted images are displayed in axial (A) and coronal (B) section. These demonstrate a high signal abnormality within the pons (arrow) which extended from the basal ganglia through the midbrain and into the pons

MRI images FLAIR images from two levels in a patient who sustained a severe head injury after a road traffic accident. The left image appears unremarkable except for a thin collection of subdural fluid and loss of volume within the underlying right temporo-parietal cortex. The right image demonstrates high signal within the right internal carotid (arrow) consistent with dissection and thrombosis secondary to basal skull fracture

Positron Emission Tomography (PET) Fig 7 Assessment of the efficacy of acute hyperventilation using PET imaging. Gray scale PET CBF images obtained from a headinjury patient at relative normocapnia (A) and hypocapnia (B). Voxels with a CBF less than 20 ml 100 ml21 min21 are picked out in red. Baseline ICP was 21 mm Hg and supports the use of hyperventilation to lower PaCO2 and improve ICP control. Hyperventilation did result in a reduction in ICP to 17 mm Hg but, in this individual, led to a substantial increase in the volume of hypoperfused brain.

Important Points on SXR Not all skull fractures have intracranial injury Not all intracranial injuries have a skull fracture Objective not to diagnose skull fracture but risk for intracranial injury SXR low diagnostic yield Fractures easily missed or over diagnosed SXR give false sense of reassurance if normal Low sensitivity to use as screening test

Summary CT modality of choice in whole spectrum of TBI No place for EC Skull X-ray in trauma MRI starting to gain favour, but limitations issue

So when do we use Skull X-ray? Trauma Foreign body Penetrating injuries (slot fracture and compound) Growing fracture in child less than 1 year Medical Multiple myeloma Paeds NAI as part of skeletal survey

Multiple Myeloma

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References Reed MJ, Browning JG, Wilkinson AG. Can we abolish skull xrays for head injury? Arch Dis Child 2005;90:859–864 Glauser J. Head injury: Which patients need imaging? Which test is best? Clevelend Clin J Med 2004;71(4):353-357 Coles JP. Imaging after brain injury. Br J Anaesth 2007; 99: 49–60 Lee B, Newberg A. Neuroimaging in traumatic brain injury. NeuroRx 2005;2(2): 372-382 ACEP/CDC. Clinical Policy: Neuroimaging and decision making in adult mild traumatic brain injury in the acute setting. Ann Emerg Med 2008;52:714-748 NICE clinical guideline 56: Head injury: Triage, assessment, investigation and early management of head injury in infants, children and adults. NICE update 2007 Stiell IG, Wells G et al. Canadian CT head rule for patients with minor head injury. Lancet 2001;357:1391-6