ACADEMIC EMERGENCY MEDICINE • September 1999, Volume 6, Number 9 957

Delayed Presentation after Head Injury:Is a Computed Tomography Scan Necessary?

More than 2 million people a yearcome to medical attention as a resultof head trauma in the UnitedStates.1 To date, a large number ofpublished studies relate to the di-agnosis and treatment of acute mi-nor head trauma.2–17 The conclu-sions of these studies often conflictand generally do not address the ap-proach to certain subsets of head-in-jured patients such as those with aminor head injury who present forevaluation after a delay. Most emer-gency physicians agree on the con-cerning signs and symptoms in themoderately or severely head-injuredpatient presenting acutely. However,there is less consensus on the eval-uation and treatment of patientswith ‘‘mild’’ injury, defined as a Glas-gow Coma Score (GCS) of 13–15with or without a history of loss ofconsciousness or posttraumatic am-nesia.2,3 Some physicians advocateearly CT evaluation for nearly allmild head injury cases,4–8 whereasothers would take a more liberal ap-proach.10–12 Recent work has begunto make it clear that clustering allpatients with a GCS of 13–15 intoone population may be inappropri-ate because a significant number ofpatients with scores of 13 and 14have brain injury.2,4,5,9 This leavesthose patients with a GCS of 15 andhistory of head injury as a poten-tially low-risk population. However,even here, there is debate as to thebest approach and disposition.13–17

Given this controversy in the man-agement of acute head trauma, it isdifficult to know how to treat a pa-tient with minor head trauma whopresents after a delay.

While some reports describe de-layed head injury, there is little use-ful information in regard to evalua-tion and management.18–24 In thisera of managed care, it would behelpful to determine whether a de-layed presentation of at least 12hours constitutes an adequate pe-riod of ‘‘observation,’’ or whetherthese patients warrant further eval-uation. The objective of this studywas to determine the incidence ofsignificant injury despite havingsurvived a period of at least 12

hours since head trauma. Addition-ally, specific risk factors for predict-ing injury were sought.

METHODS

Study Design. This was a retro-spective chart review performed atthe EDs of two academic Level 1trauma centers in the same city witha combined volume of approximately85,000. As a chart review, this studywas considered exempt from in-formed consent.

Study Setting and Popula-

tion. All ED charts from Januarythrough December 1996 were re-viewed for chief complaint or symp-toms relating to head injury. Pa-tients were included if the initialinjury occurred at least 12 hoursprior to presentation and the patienthad a GCS of 15 at the time of thefirst ED evaluation. While an exactdefinition of ‘‘delayed presentation’’does not exist, those patients withsignificant head injury commonlydecompensate before 12 hours havepassed. Therefore, patients who pre-sented 12 hours or more after theirhead injuries were considered de-layed for the purposes of this study.Patients evaluated by a physicianimmediately after head injury witha GCS of 15, but who returned later,were included even if a CT had beenperformed at the initial evaluation.These patients were included be-cause neither a negative evaluationnor a negative CT scan immediatelyfollowing head trauma excludes thepossibility that pathology was pres-ent or may develop.24,25 The charts ofpatients who had received a priorED evaluation were reviewed to en-sure that the initial GCS was 15 andthat the initial neurologic examina-tion was listed as normal. Trans-ferred patients were excluded.

Measurements. Charts were re-viewed for the following data: age,time of injury, type of injury, symp-toms both at time of injury and atpresentation (including headache,dizziness, nausea, vomiting, vision

changes, neck pain), associated in-juries (facial injury, multipletrauma), historical features (loss ofconsciousness, amnesia, alcohol ordrug intoxication, posttraumatic sei-zure), and physical findings (basilarskull fracture, suspected childabuse, depressed level of conscious-ness, and focal neurologic findings).Additionally, any progression of theabove symptoms was noted.

Significant delayed injury wasdefined as abnormal CT results suchas: intracerebral bleeding, skullfracture, or subdural or epidural he-matoma. Because not all patients re-ceived a head CT during the EDvisit, it is possible that small inju-ries were missed that may havecome to attention at a later date dueto evaluation by a provider outsideof the ED. Patients in the militarysetting most commonly come back tothis system for their health care.Therefore, we searched the radio-graphic computer and hospital ad-mission records for all patients whodid not receive a CT during the EDvisit to determine whether they mayhave received a CT at a later date.As well, since a normal CT does notguarantee that no pathology will de-velop later, records were also re-viewed for those patients who had aCT during an ED evaluation.

Data Analysis. The incidence ofdisease was determined with 95%confidence intervals (95% CIs). Thepopulations from the two hospitalswere compared using chi-square andt-test. Comparisons between pa-tients with and without positivefindings were made using multiplelogistic regression.

RESULTS

A total of approximately 85,000charts were reviewed. Of these, ap-proximately 2,900 patients withhead injury as a chief complaint ordischarge diagnosis were located. Ofthese, 194 patients met the criteriafor delayed presentation. Of the 194patients, 101 had CT scans per-formed at delayed presentation (in-dex visit). The rest were dischargedbased on historical and clinical dem-onstration of a normal exam.Twenty-one (10.8%) patients hadbeen seen at the time of their origi-

958 BRIEF REPORTS BRIEF REPORTS

TABLE 1. Patients with Delayed Presentation Following Head Injury

Patient Latency* History†Initial

Symptoms‡PresentingSymptoms

PhysicalFindings

CTFindings

21-month-oldfemale

24 hours MVC Sleepy; lethargic None Hematoma, lefttemple

Basilar skullfracture

74-year-oldmale

25 hours Fall No LOC; nosymptoms

GCS§ = 3 Hematoma, lefttemple; coma

Initial CT(2);repeat CT:large sub-dural he-matoma

29-year-oldfemale

23 hours MVP HA; vomiting;hematoma; noLOC

HA; nausea;decreasedLOC

Scalp hema-toma

Frontal in-traparen-chymal he-matoma

46-year-oldfemale

48 and96hours

Fall HA HA, worsening Normal exam Frontal sub-dural he-matoma;skull frac-ture

60-year-oldmale

48 hours Fall; historyof drink-ing

HA; nausea;slurredspeech; armweakness

HA; dizziness;nausea

Normal exam Subdural andepiduralhematomaswith fron-tal contu-sion

5-month-oldfemale

20 hours Hit by toytruck

Decreased appe-tite; no LOC

Increasedsleepiness

Bruise on tem-poral area

Left frontaland ante-rior hema-toma

*Latency = time to ED presentation following head injury.†MVC = motor vehicle crash; MVP = motor vehicle vs pedestrian crash.‡LOC = loss of consciousness; HA = headache.§GCS = Glasgow Coma Scale score.

nal trauma and returned to the EDwith progressive or continued com-plaints. Nine of the 21 patients hadreceived a CT scan during the initialvisit.

There were 112 women and 82men. The mean age was 34 years(SD 6 24 years). One hundredeleven cases came from one hospital.There was no difference in the vari-ables studied between the two insti-tutions.

Of the 194 patients, six had anabnormality noted on CT. This rep-resents 3.1% incidence of significanthead trauma after delayed presen-tation (95% CI = 1% to 7%). PositiveCT findings included one intracere-bral bleed, three subdural hemato-mas, one subdural and epidural he-matoma, and one skull fracture. Onepatient with a normal CT scan 24hours prior returned with a GCS of3 from a large subdural hematoma,and subsequently died. He was onchronic salicylate therapy but was

not taking any other anticoagulants.This was the only patient who de-compensated after a normal CT scanon initial presentation. Table 1 illus-trates the pertinent findings of thepatients. The mean time to presen-tation or representation after the in-itial head injury was 73 hours(6105) for the entire population. Forthose found to have pathology, themean time to presentation was 29.3hours (610.7).

Upon review of radiographic andinpatient admissions for those pa-tients who did not receive a CT dur-ing an ED visit, 14 were found whoreceived a CT scan at some point af-ter their ED evaluation for symp-toms that appeared to relate to theirhead injury. One patient received ahead CT for abrupt onset of head-ache three months after her originalED visit. At that time she was foundto have a chronic subdural hema-toma, and it is likely that this injurywas present at the time of her initial

ED visit. Her original ED complaintwas of neck pain related to a fall.She struck her head, but had no lossof consciousness and no other spe-cific complaint related to this andshe did not receive a head CT. Nomedical or surgical intervention wasneeded for this patient. If this pa-tient was considered to have a sig-nificant delayed injury, the incidenceof disease was 3.6% (95% CI = 1% to7%).

Five of the seven patients withabnormal CT scans had no reportedloss of consciousness at the time oftrauma. With the exception of thewoman who was found to have asubdural hematoma months later,most of the patients had concerninghistorical or physical features thatled the physician to get a CT scan.Two of the patients were young chil-dren for whom the parents reportedchanges in mental status, one was a60-year-old male with history of al-coholism and report by the family

ACADEMIC EMERGENCY MEDICINE • September 1999, Volume 6, Number 9 959

suggestive of focal neurologic deficit(although at the time of the evalua-tion his neurologic examination wasnormal), one patient was having in-creasingly severe and unusual head-aches, one patient was markedlyconfused, and one patient presentedcomatose. Only the last patient, whowas taken emergently to surgery, re-quired neurosurgical intervention.Three patients were admitted for abrief period of observation but nomedical or surgical therapy wasneeded. The two children were al-lowed to go home in the care of theirparents with daily neurosurgical fol-low-up. There was no significant dif-ference between the patients withpathology and those without; how-ever, the numbers were small. Dueto the limited number of patientswith disease, predictors of pathologycould not be determined.

DISCUSSION

At the end of the last century, de-layed posttraumatic hemorrhagewas identified in four patients twoweeks after initial presentation andcriteria were proposed for its diag-nosis.18 There have been reportssince then of delayed posttraumaticintracranial hemorrhage.19,20,22,23,25,26

Snoey and Levitt described three pa-tients who developed delayed sub-dural hematomas, all of whom hadpreviously had normal CT scans.24

Other recent reports have identifiedcases with a significantly prolongedinterval of minimal symptoms priorto deterioration from intracranialhemorrhage.5,21,22

To the best of our knowledge,only one study has addressed de-layed presentation in detail. In thisstudy patients were included if 1)they had previous evaluation byskull film and observation in the EDand 2) they returned to the ED. Sev-enteen percent of patients had anabnormality other than skull frac-ture on CT scan.25 It is difficult toknow whether the 17% rate of pa-thology found applies to a popula-tion with delayed presentation orapplies only to those who receive aninitial evaluation (without a CT) andthen return due to worsening symp-toms. It is possible that the groupwho waited to be seen had milder in-itial trauma, which is why they didnot think it was worthwhile to come

for medical evaluation immediately.This may be a very different popu-lation from the group presenting im-mediately after head injury, only toreturn again due to continued orworsening symptoms. However, bothpopulations represent delayed pre-sentation patients.

In our study, seven of 194 pa-tients (3.6%) with delayed presen-tation of head injury had significantfindings on CT. Five of the seven pa-tients had no reported loss of con-sciousness. Fortunately, most of thepatients had some historical orphysical findings that would haveled most prudent physicians to get aCT scan. Only one of the group pre-viously had a CT scan that was readas normal. He returned 23 hourslater comatose and subsequentlydied. This patient serves to remindus that an initially negative CT is noguarantee that pathology will notdevelop in the future. In those pa-tients with increasingly severesymptoms, even with a previouslynormal CT scan, it may be prudentto repeat a CT scan.27

One study, a case series of pa-tients presenting to the ED morethan 24 hours after suffering blunthead trauma, found an 6.3% inci-dence of disease.28 None of these pa-tients required neurosurgical inter-vention and, unlike our study, theseinvestigations found that a historyof loss of consciousness was helpfulin predicting CT abnormalities.

Our study and that of Stein andRoss8 suggest an incidence of CT ab-normality between 3% and 6% in pa-tients with delayed presentation fol-lowing head injury. However, thesignificance of some of the more mi-nor CT findings in both studies couldbe questioned since only one patientin both studies needed neurosur-gery. Indeed, some of the ‘‘positive’’findings may have gone undetectedin the era prior to CT scans, with lit-tle symptomatology or long-termmorbidity. Certainly this raises thequestion of the need to use the CTscanner to find what may amount toinsignificant pathology. One study,however, would suggest that up to5% of patients with these late find-ings will eventually need urgentneurosurgical intervention.25 Withthese conflicting study results, anargument can be made that there issome merit in finding pathology inthe patient with a delayed presen-

tation following head trauma. Pa-tients found to have an abnormalityon CT may need hospitalization todetect early mental status declineshould complications develop. Yetexactly which head-injured patientwith a delayed presentation shouldbe hospitalized for observation hasnot been determined. At a minimum,all patients with CT abnormalityshould have close follow-up ar-ranged. Another reason to diagnosepathology in these patients is thatthose with injury may have a delayin returning to baseline function.Identification of injury can allow ap-propriate counseling, time off fromwork, and follow-up to maximize re-covery.

LIMITATIONS AND FUTUREQUESTIONS

The nature of the retrospective re-view makes it difficult to ensure thatall of the desired data points arepresent on each patient chart, andthus, some important data may bemissing. In addition, physicians maydocument more details for patientsin whom injury was found.

Not all patients in this study re-ceived a head CT when they pre-sented. As suggested by the singlepatient found to have a chronic sub-dural on the CT scan done monthslater, it is possible that other pa-tients may have had pathology thatwas never detected. Since patientsmay harbor pathology that never ne-cessitates intervention, it remainslikely that this study underesti-mated the incidence of disease.

The clinical significance of thesefindings is uncertain. We considered‘‘significant pathology’’ to be anyfinding that, at our institution,would change the disposition ormanagement of the patient. Thismay differ at other institutions, andbetween consulting neurosurgeonsand emergency physicians.

We believe that the potential forsignificant CT findings suggested bythis and other studies warrants fur-ther study with greater statisticalpower. A prospective multicenterstudy may identify both the inci-dence and predictive criteria for sig-nificant findings in delayed-presen-tation head-injury patients. Furtherstudy might also determine the out-come of those patients found to have

960 BRIEF REPORTS BRIEF REPORTS

pathology to further determine thenecessity of finding this disease.

CONCLUSIONS

We found a 3.6% incidence of pa-thology on CT scan in patients pre-senting more than 12 hours afteracute head injury. Most patients didnot require acute surgical or medicalintervention. We suggest that pa-thology does exist in patients pre-senting to the ED in a delayed fash-ion after head injury; however, theneed for urgent medical or neuro-surgical intervention is low. We rec-ommend that clinicians approachthis population cautiously untillarger studies better define the clin-ical significance and outcomes ofthose patients who have pathologydetected at delayed ED presenta-tions following head trauma.—ROBIN R. HEMPHILL, MD, San An-tonio Uniformed Services Health Ed-ucation Consortium, EmergencyMedicine Residency, Brooke ArmyMedical Center, San Antonio, TX,and Department of Emergency Med-icine, Vanderbilt University MedicalCenter, Nashville, TN; SALLY A.SANTEN, MD, Department of Emer-gency Medicine, Vanderbilt Univer-sity Medical Center, Nashville, TN;and PAUL E. KLEINSCHMIDT, MD,San Antonio Uniformed ServicesHealth Education Consortium,Emergency Medicine Residency,Brooke Army Medical Center, SanAntonio, TX

Presented in abstract form at the ACEPResearch Forum, San Francisco, CA, Oc-tober 1997.

Key words. head injury; closed; de-layed; brain injury; skull fracture;emergency department; computedtomography.

References

1. Collins JG. Types of injuries by se-lected characteristics: United States,1985–1987. Vital Health Stat 10. 1990;Dec:1–68.2. Shackford SR, Wald SL, Ross SE. Theclinical utility of computed tomographicscanning and neurologic examination inthe management of patients with minorhead injuries. J Trauma. 1993; 33:385–94.3. Borczuk P. Mild head trauma. EmergMed Clin North Am. 1997; 15:563–79.4. Harad FT, Kerstein MD. Inadequacy

of bedside clinical indicators in identify-ing significant intracranial injury intrauma patients. J Trauma. 1992; 32:359–63.5. Stein SC, Ross SE. Mild head injury:a plea for routine early CT scanning. JTrauma. 1992; 33:11–3.6. Teasdale GM, Murray G, Anderson E,et al. Risks of acute traumatic intracra-nial hematoma in children and adults:implications for managing head injuries.BMJ. 1990; 300:363–7.7. Klauber MR, Marshall LF, LuerssenTG, et al. Determinants of head injurymortality: importance of the low risk pa-tient. Neurosurgery. 1989; 24:31–6.8. Stein SC, Ross S. The value of com-puted tomographic scans in patientswith low-risk head injuries. Neurosur-gery. 1990; 26:638–40.9. Madden C, Witzke DB, Sanders AB,et al. High-yield selection criteria for cra-nial computed tomography after acutetrauma. Acad Emerg Med. 1995; 2:248–53.10. Masters SJ, McClean PM, ArcareseJS, et al. Skull x-ray examinations afterhead trauma. N Engl J Med. 1987; 316:84–91.11. Mohonty SK, Thompson W, RakowerS. Are CT scans for head injury patientsalways necessary? J Trauma. 1991; 31:801–5.12. Borczuk P. Predictors of intracranialinjury in patients with mild head injury.Ann Emerg Med. 1995; 25:731–6.13. Rockswald GL, Pheley PJ. Patientswho talk and deteriorate. Ann EmergMed. 1993; 22:1004–7.14. Stein SC, Ross SE. Minor head in-jury: a proposed strategy for emergencymanagement [editorial]. Ann EmergMed. 1993; 22:1193–5.15. Miller EC, Derlet RW, Kinser D. Mi-nor head trauma: is computed tomogra-phy always necessary? Ann Emerg Med.1996; 27:290–2.16. Miller EC, Holmes JF, Derlet RW.Utilizing clinical factors to reduce headCT scan ordering for minor head traumapatients. J Emerg Med. 1997; 15:453–7.

17. Jeret JS, Mandell M, Anziska B, etal. Clinical predictors of abnormality dis-closed by computed tomography aftermild head trauma. Neurosurgery. 1993;32:9–16.18. Alvarez-Sabin J, Turon A, Lozano-Sanchez M, Vazquez J, Codina A. De-layed posttraumatic hemorrhage ‘‘spatapoplexie.’’ Stroke. 1995; 26:1531–5.19. Dietch D, Kirshner HS. Subduralhematoma after normal CT. Neurology.1989; 39:985–7.20. Ashkenazi E, Constantini S, Pom-eranz S, Rivkind AI, Rappaport ZH. De-layed epidural hematoma without neu-rologic deficit. J Trauma. 1990; 30:613–5.21. Elsner H, Rigamonti D, CorradinoG, Schlegel R, Joslyn J. Delayed trau-matic intracerebral hematomas: ‘‘spat-apoplexie.’’ Report of two cases [com-ment]. J Neurosurg. 1990; 72:813–5.22. Miller JD, Murray LS, Teasdale GM.Development of a traumatic intracranialhematoma after a ‘‘minor’’ head injury.Neurosurgery. 1990; 27:669–73.23. Poon WS, Rehman SU, Poon CY, LiAK. Traumatic extradural hematoma ofdelayed onset is not a rarity. Neurosur-gery. 1992; 30:681–6.24. Snoey ER, Levitt MA. Delayed di-agnosis of subdural hematoma followingnormal computed tomography scan. AnnEmerg Med. 1994; 23:1127–31.25. Voss M, Knottenbelt JD, Peden MM.Patients who reattend after head injury;a high risk group. BMJ. 1995; 311:1395–8.26. Sainsbury CP, Sibert JR. How longdo we need to observe head injuries inhospital? Arch Dis Child. 1984; 59:856–9.27. Di Rocco A, Ellis SJ. Delayed epi-dural hematoma. Neuroradiology. 1991;33:253–4.28. Borczuk P, Ostrander J, Dienstag J.Cranial computed tomography scans inpatients presenting 24 hours after blunthead trauma [abstract]. Acad EmergMed. 1997; 4:410.

Iatrogenic Worsening of Hypokalemia andNeuromuscular Paralysis Associated with the

Use of Glucose Solutions for PotassiumReplacement in a Young Woman with

Licorice Intoxication and Furosemide Abuse

Chronic licorice intoxication is awell-recognized cause of hypokale-mia. The active ingredient, glycyr-rhizic acid, is a competitive inhibitorof the enzyme 11b-hydroxysteroiddehydrogenase.1 This enzyme cata-lyzes the conversion of cortisol,which has considerable mineralocor-ticoid activity, to its inactive metab-olite cortisone.2

Licorice withdrawal and potas-sium replacement are the mainstayof therapy, though caution is advisedin the use of IV potassium and rec-ommendations are made about therate of infusion. It is clear that theoral administration is the safestroute for potassium supplementa-tion, since potassium enters the cir-culation more slowly with a reduced