The role of computed tomography in acute head injury

‘Thomas

Depar;menl Maryland

6.

Seul,

H.D.

of Neurosurgery, Hospital, Baltimore.

University Maryland

of

The manilgemrnt of acute head injury offers diagnostic and therapatic challenges to neurosurgeons. The !rearment of these patients should consist of lonical. lhwntgh proccdur& that are organized and ex&di: tmusly executed (I). The procedures should be fkxible enough to allow sound clinical decision-making, especially if other organ FYS~I~E are involved. It is well accepted that the prmary cbjettives in treating a:ure head injury include imnedlste resuscitation and smbilizatmn of the patient and early recognition and surgical ttwtment of expandina intracranial mass lesions a-4). Computed tomogr&hy (CT) of the hea,l assists in achieving these objectives. It has become obvious over the past 5 years that CT scanning provides px ompt diagnoses of intracra. nial pathology (!i-IO), but. as with any innovation in medicine, the availability of CT raises questions regarding its use. Are there Jefitdte indications for CT? What are the advantages of CT over alternative farms of diagnosis? How is CT really beine; used in the managentenr of head traumaV Does it fulfill any needs other than immediate diagnosis? Is it changing the treatment of head?njured patients? This paper discusses, from the neurcwri~eon’s viwpoint, the role uf CT in Ihe treatment oi acute head injury. More apccifically, we describe the various ways we employ CT scanning nt the Maryland Institute for Emergency hiedical Services System (MIEMSS)

MIEMSS is a 54.bed trauma facility established witiIv for the detinitlve manaeement of crilicaltv iniurcd Over l200 are adr&te> per year to this hstitrtior The majority of patienr; are delivered from the sceuc by the State Pcdi~;~Me&%x Helicopter Program. Head injury is a common feature. occurring ‘m approximately 403 patients per year. In 1979-19aO.279 were head injuries were admitted. Of those, 115 patients had Glasgow Coma scores less than 8 and underwent intracranial pressure monitoring and intensive treatment. Fifty& perctmt of these patients had at least one other sody system injured. Twenty-four ptrant had two other systems injured. Twenty&x percent of the patients underwent emergency intracrrnial surgery for mass lesiilns. Our head-injured paput&m. therefore. is a large ad diverse group with P high lncidcnce of multiple trauma. Upon arrival in the admitting area. the patient undergoes immediate rwscitation, stabiliition, and triage. Life-threatening problems are given apriority. Theneurosur~~lobiativrpinthiaorocess r&e cl&: to determine tie severity of the neur&gictd injury and to rule out B surgically wnectable intracranial lesion. It is at this point that the indications, limb% and value of the CT are addressed.

,rms.

tmm. patknts

In order to properly discuss these wpstsofCT, some very important clinical facts must bc known. Patients who sustain B head injury and luvc a clinical atalus of not following commands, or war%. bave I 25% or greater incidence of * major intracmnial mam leaion (3. 4. It. 12). This means that the burden is on the neurosurgeon to ruk aout these lesions. Furthermore. the ruling-out should be done PI rapidly as pwrible. since, if a ma811lesion is prcscnr. the patknt hu the potential for sudden cdinlctd deterlorati~n. In our settin& there is no question that CT ia the diagnostic test of choia far identifying these lesions. The reasons fiIr this are presented later. Our indications fw obtaining a Cf arc aimP@ any patient who

ha surtiacd m~uncet” dysfunction

had

,rzuma and wb., pr l~er,,s up”” ad-

“or hospital wilh soy sizn 3f ncurologicat aill undergo IX.

Ne~arol qiwl

dysfunc-

lion includes any awratiou in mental ~,+vus (dirorien,a,i”n, drowsinus. etc.). as well USlocalizing or latera’ifiw rigm fiemiparesis, pupillay ctili,ation. cm.). Every patient who will “M speak. follow commands. open eyes 1” v”i6r. or move purporfully 1” pain “oderaoa CI without qwsti”“. timing of CT &cods on tic patieor’r ,,a-

log~al death m a rho,, fxriod of time. The value ad csamplaofthi~anpiopr~phicl~hnique~eprnentcd in more de,oil lafer. vnce w have mastered the proccdure ,” a point that we CM gain a c”osidcrab:c ao~oun, of information

rhis way.

The

bility in regard to other body system njwia,

as well

a~ on his neurologic condition. If chc puien, has no other associaled injuria axl is mma,ox or has tareralizing neurzdogic signs coosistc”; rrith a unila,eral mass Won. the patient should be scanned immcdintcly after Iwage,

initial

br.wlion

resusci,ation.

lines. e,c.. may be Jeferrd the prtimr

Rot tins pcri,onerd

of loop in,ravrsakr

moniloring

until after ,hc CT, so that

should be studied within 33 min of admir-

Go”. If the paGent has no “,hcr asszwaled injuries lrM his neuiolo~ic condition is aLso s,ablc (ix.. ,he palien, is awake bu, with altered men al s,s,us). ,here is KSS u-y

for emergency :~a”. The patient may

under80 comde,e evnluntion in the a imiuinn

aifrea&

area a3

Our reasons for p:eierrmg CT over any “we/ auilablediagn”r,ic wt\, areaughlforwrrd. andale probably similar 1” t.x”se of other neorosurgcons Y:I” handt ncuw head inlury on a regular basis. The) arc: I) C.!‘ is rapid, non-invnsiw. and safe 1” perform; 2) CT aivcs ar .auaI

“ictur~ of ,he in,rcrPnial

“ar~bolow.

;h”s avoiding

romc of fhc “guorwork”

ncc&;y

with other diagnostrc 1~1s: 3) CT differentiates beruern mlraparenchymnl blood and brain swelling or edema. These are fundamema, facts ,har rnos, ‘xx.s”ns in this field are au’s Ihe porpaw

of and acknoulcdqc,

of this arliclc is no, IO emphxdx

vious. The rcnaindcr

and

,he ob-

of this discussion deals with

long kvm, IS ml”) oeurclogic chkks fire done. CT Bhoutd be obruoed within I-l’/2 hr of addmissioo. This wneplu, applies 1” paricn,~ who hew other body s:%em injuries and arc neurologiually stsbte. In Ibc polytrauma ti~:,im. i, ma> be ne~ewry 1” contrd any assocta~cd Iproblems bohm ,hc patient is rraosported to the rsdidogy departmmt. The bipgcst

more rpecilic bu, perhaps more subtle advantages of Cf. We emphasize the various ways that CT is used and ways in which I, has ~~rually changed rhe barm
dii is thv patlcat who has both life-threatening usocilted i”.urles (Le.. hem”- r,d,“r poeurn”. ,h”rpx: rlald. dincoded ~,bdomen: IIC., m well as a sw‘ls vnilateral dccmbratioo; d Lted, fried pupil 01 cupils; e,c.t. The idmt solutlor~ ,s to have f IC CT scan LCI in Ibc admittiru area, whc~e s,abiliz:l&on of lb: patient can be conlirwd tiile d!c on&n, is beiu scanned. How-

n&d. The succc~ful rerowd of an acute subdural hcmwoma, hi11 with no dinicel improvemen,. or, even worse, p~r,“pcrs,wc deleriaration due 1” a hidden inrracercbral clot cm beadisasrcr for the patlcn~. Similarly. B routine dcpresxd skull franurc may be complicated by more scrne in,rxrsninl pnlhobgy. Kgurc I is an example of this ,ypc of situaion. The CT clmrly shows ,be type of p,hd”r,y and 1,s Cwe”,.

ours. tave this luxury. ““c of two thin)c EP” be done. Flrsl. one

thu! ensuring thst the paticrd wil! undergo ,be Correc, nor&l procedure and ,bu surgery will no, be tcrov-

~11 rrdt unltt the homed a10 threat of urdiovwulsr or ardtowtmonuy Ruth La under :on,rol and then obuin a fX. Tbis b usually no, dairabte nor in the

n~ld before all Ihe pntholo~y is treated. Figure 2 shows the skull x-ray of wbar appeared 1” bc a” u”comohared low-rckxln bulln wound 1” ,he skull. How&r. the CT (Fig& 3) showed rhe concomilanc lu8e UC”,: rubdulal hemaroma, oassitntiw d Idwe crti~ltomy facilir@te evacualial of lhc bcma,“m,. A hus,y surpicpl procedure based on the skull filmr alone n&h, hwc missed this palhoiogy,

Crkk‘i“eiloJJlicd

tc*“s61ost:

ever. fewCC"WS. includbu ThCref”fe,

“rrhagc can have grwe convqucnca

nap 10

if ,r is nor rccog-

F+zre 4 is rbe xco of a young man who fell and sustaineda head injury. CT clearly demonstratedthe cpidurcl hematoma. and it also showed the extent of the lesion aboveand b:low the tentorium. As a result, the proper skin and bone flaps were turned to give adequate~XPOSWC of the entire clot and all possible somcesof bleeding. Theseexamplesdemonstratethat CT cco aid in planning a more precisesurgical treatment and increasesth: likelihood that the patient receivesthe correct operation. There crc occasion,when CT can be usedalmost cs ,a” intra-ooerative tcchniouc to asseu the comequenceof a s&gical procedor~.The prime exampleof Ihis is the patient who is admitted and immediately exptriences transtwtorial hernialion and undergoes emergencyburr hoks. Sometimes.the patient can be mken for immediate CT scanningto make c full cssessmmt before the formal craniotomy is performed. Figure 5 shows such a case. The patient sustaineda head injury in a motor vehicle accident. Dn admission, he was nonresponsiveto verbal stimuli and eyuaily purposeful with all four extremities. The CT Vigure 5A) demonstratcdbilarerai extra-axial masses with someleft cerebral hemisphereswelling. Upon his

return to the admitting crcp. the patient’s left pupil becamedilated and nonreactive. An emergencysmall left temporal craniotomy was performed. and an acutesubdural hcmstcma was removcL lmmcdiatclv after the procedure. the patient wad k&t under me;the& and taken back for a CT. Follow-UP Cm Wigurc 58) demonstrated that the right &dural hid become large end that the brain shift was now from right to I&. 1 be patient WI immedlgIcly returned to the operaling room and a right crlniotomy was performed. with evacuation of the expanding epidural clot, and the patient subsequentlyrecovered. Not infrequently. patients arc admitted with an ambiguoushistory. and it ir not clear whether trauma is the primary problem or whether someother intracranial pmcnr causedthe trsuma. Figure 6 is the CT of a young adult mak who had P minor head injury several weeks prior to admission. Incrcwing head. achesand intermittent lossof consclousnesr orouressing to coma rc~nltcdin his admissionto our~un~. An immediate CT dcmonrtratcd wutc hydroccphatus secondarytoa colloidcystobstrwtingthe foramen of Monro. Figure 1 showsthe CT of a man who was involved in a motorcycle accident. He WBScomgtosc

Flgun 7.

of ICP and aggressivetreatment of even mild ekvations in ICP are the mainstaysof our supportivetherapy of thesepatients. Consequently,knowing the COTrect ICP is important. Although somecorrelation has been shown, we do not employ CT as an indicaror of ICP o, the needto manitar ICI’. Tbc need for a ICP monitor is basedstrictly on the patimt’s clinical murologic evaluation. Widespread ux of CT has dcmonrtratrd that certain Cl tindi!w can be of twognosticvalue. Dif-

FUM cerebral swelling manifested by obliteration of the vetwicles and the perimcsencephaliccisterns is characte%tic of a severebrain injury (IS). However, recent wports have shown that aggressivemedical therapy :an alter the courseof suchinjuries and can have a beneficial effect on the otherwise poor outcome (Z-4). Multiple hemorrhagiccontusionsare frequently ieenon CT (Figure IO) when there has beena severeimpact resulting in sheering injuries to intraparenchymalblood vesselsand fiber tracts (16). These injuries have a very pow prognosis with respectto neurolo3le recovery. The CT findings enable us to commu!dcatc realistically with families early in the patient’s cotuse,end we can givethem a very guarded oroeoo:.isfor survival and functlonat neuroloeic reSo&y. Figure 1 illustrates a similar type of Lion. which was solitery and located in the internal cavsule. FromtheCT, we wreableto tell thepalient and family that her profotmd left arm weaknessmay be permanent or persist for a very long time. Brseo on our experience using CT in head trewns , beginning to realize that not every extra-axial mass necessarilyrequires surgery. Thus, the CC’T assumesthe role of a monitoring technique

I

WC arc

by which we follow the progressionof small extraaxial messes not essocis&d with brain shift (17). Figure I2 showssuchawe. Thep:dient, ayounggirl, sustained a head injury with loss Jf conxiousnas. Motor examination show:d equal purposeful movement in all extremities. Ws decidednot to operateon the left frontal extra-axial collection. Sequentia!CT (Figure 12) over the next 4 weeks demonstratedresolution of the lesions.The 3latientleft the hospital neurologically intact without 41craniotomy. Accor,%ngly. the informarion froa c’f end the av.xilebility of repeated non-invasivesrudirs are actually chana,ngthe treatment of certain patients. If thesepatientshad initially receivedangiograms,they may well haveundergone surgery bawd oo tbs radiologic appcerenceof the lesion. Recentlv. invesdaators have documented that significant d? abnormalities CR”developlater in the patient’s course(18-20). Thesedelayedabnormalities may change the progncnis and/or require surgery. How often a severelyhead-injured patient should be scannedduring his hospibdization is a question that may have as many anew s as there are head-injury centers.At MIEMSS. we r,lutinely repeat scansin pa-

dents who have persistent coma or who have modrrare to severe necrologic deficit after 3 Lo 5 days. This is done specifically to rule out P delayed hemorrhage. infarction,

or recurrence of an extra-axial

collection.

We also repeat Ihe CT after 2 10 4 weeks in order to assess the ventricular size. Figure 13 demonrw.tes a case of post-traumatic hydrocephalus that developed 4 weeks post-injury. Obviously, a repeat CT is obtained at any other lime in the patient’s course if there is clinical deterioradon or if ICP increases significantly without a reasonable explanation.

As stated earlier. there are a small number of multiple injured palicnls who are too eriticrdly ill 10 be moved out of the rCsuscilation area or who must go immediately to the operating room for a life-saving wrgical procedure. If the patient also has a were neurologic status from a head injury, one faces a diagnostic dilemma. To miss the inlracraniul mass lesion may result in the patient’s neurologic death. To move the patient out of the resuscitation area or to defer the non-neurosurgical operation ma) also result in the patient’s death. In a situation >u:h as this. we perform a percutaneous common carotid arterial puncture and a “one-shot” mid-arterial phase angiogram lo determine the presence or absence of an extra-axial

or massivelocalircd intraparenchymal mass. This is performed wader sterile technique using parable x-ray eqoipmenl. One lateral and one AP film are taken. The films obtained by this technique are of adequarcqtiality to make the appropriate diagnoses. If the resti:! i* negative (Figure 14), an intracranial prwuw monitor is inserted immediately or while the necwary surgeryis being performed. Al the lirsr pasible opportunity, a CT is obtained to confirm thr wgiographic findings. If the results ore positiw for ao extra-axial mass(Figure ISA). an immediate craoi-

Flgun 15B.

ofomy is paformed simultaocourly with any other necessary surgery. Postoperatively, the patient is taken for a CT (Figure 158) to ascertainif any additional pathology ha; been missed. The “one-shot” angiogramcan be completedin IS-20 min while other proceduresarc being done. Our feeling is that this is a satisfactory techniqre in critical situations.

In our trauma center, CT is th: diag.mstictest of choice in patimtr with acute head injury. Our protocol is desirned so that a CT is oerformed as soon a: is mcdically~onsible nturolonic

on every p&t

dysfunction.

who presents with

We prefer CT becaose it is

rapid, non-invasive. and safe, and it actually giver a picture of the type and extent of various le.&m. In addition to these advantages, CT offers other benefits: 1) It identifies coexisting path&zic lesions and their localization. This aids in planning a “tore precise surgical intervention. diately

2) It can bt used imme-

after or even during

operative

procedures.

This allows one to assess the car sequences of therapeutic maneuvers and to detect evolving patbalogy.

3)

CT can identify pathologic processes other than trauma that may be the fietiology of the patient’s clinical condition (subarachnaid hemorrhage. “cute hydrocephalus, etc.). 4) Certain findings on CT can be of prognostic value in determining the patient. monitor

5) Sequential

intracranial

the outcome for

scanning can be used to

lesions that may not need sur-

gery and to identify delayed abnormalities that may affect outcome. There is no doubt thm CT provides remarkable advantages in treating acute head injuries-advantages that go beyond the obvious rapid diagnosis of mass lesions.

Management

Saul TG, Ducker TO: of swerc head injuries. M~rylandSt~t~M~dieal)ournal. J~nunry. 1981 Becker DP. Miller JD. Ward I”. ct al.: The outcome from ~cvershead injury with early disgnosisand intenIiVe ma”tigemmt. J t4eurosurg 47:w. ,917 Br”EC DA. tirnnsrct,i TA. t_B”gfilt TW: fterurci,o. don from coma due to head injury. Cdl Care Mcd 6.914, 1’128 Marsha” Lf.. Smith RW. Shapiro HM: The oureomc with aweswe treamcnt in were head injuries. Part t: 7%~ rignitieaner of intracmni~l pressure mmitoring. J Neurosurs IO:u)-25. 1979 Zimmerman RA, B,,.n,uk LT, Bruce “.\. et ill.: Com-

1.

The increased use of CT in acute head injury has demonstrated a. Subdural hematomas are less common than IO yean ago. b. c. d.

that:

Not every extra-axial tmus lesion necessarily requires surgery. All depressed skull fractures require surgery. None of the above.