Extradural hematoma in an infant of 8 months.

Dear sir,

Extradural hematoma (EDH) in an infant is a very rare entity. The presentation, the site, and the course of EDH in infants are quite different from that in adults. In about 85% of EDH in infants, there is no loss of consciousness, and hence a high degree of suspicion is required not to miss the diagnosis in infants harboring life-threatening EDH. Because the developing brain in infants is more compactly fitted to the skull, a small increase of volume in intracranial compartment raises the intracranial pressure (ICP) more alarmingly. Again the EDH and scalp hematoma are sufficient enough to produce anemia and shock as the total blood volume is less in infants. So they need early surgical intervention for EDH and blood volume replacement.

An 8-month-old infant slipped from his mother's lap as she fell down from motor cycle near a hump while traveling as a pillion rider. Commonly, the ladies in this part of the country sit on the bike as a pillion rider facing to one side so that they are more vulnerable to fall on slight acceleration or deceleration. The child cried immediately after fall and after a while slept calmly. Later he vomited twice after taking mother's milk. So, the child was taken to a local hospital where he was prescribed with antiemetic syrup and discharged. In the next 2 days parents noticed that the child had become more irritable although his feeding was normal. They also noticed gradual increase in the size of scalp swelling. So, the apprehensive parents brought the infant to neurosurgery outdoor. On examination, the baby was conscious, taking mother's milk normally without vomiting. No neurological deficit was detected. A computerized tomographic (CT) scan of head was done which showed right parietal EDH with midline shift of 3 mm [Figure 1]. The blood hemoglobin was 9 gm%. There was no associated skull fracture.

Figure 1

CT scan plain: Right parietal EDH with mass effect

The child was operated under general anesthesia in supine position with head turned to left. A curved right parietal skin incision with the base of the flap laterally was given. Osteoplastic craniotomy was done after making four burr holes by Hudson's brace. The EDH was evacuated, dural hitch was given, the bone flap was reposed and skin stitched. The postoperative period was uneventful.

EDH is quite uncommon in infants.[12] The lower incidence is presumed to be due to various factors such as:

The pliable nature of infant skull that resists fracturing.[34]

The unfused sutures and presence of fontanelles make the infant skull more elastic.

The middle meningeal artery that is the most common source of bleeding in EDH in adults is not indented into temporal bone in infants, so it is less vulnerable to injury.[5]

The dura is tightly adherent to the skull.[67]

The skull is formed by membranous ossification. The ossification centers appear at the prominences of frontal, parietal, squamous occipital, and squamous temporal bones, whereas the intervening areas form fibrous sutures and fontanelles. There develops bony spicules surrounding the primary center of ossification which gradually spreads radially. The sutures generally fuse at the end of the second year of life. Till then the skull is more pliable and deformability persists naturally.[8]

However, EDH has been documented in infants. This is probably due to:

The diploec space of skull bone and dura are highly vascular in infants and may be a source of bleeding in EDH.[12467]

Instrumentation during difficult delivery may cause injury leading to incidences of EDH in newborn.[9]

The most common anatomical site of traumatic supratentorial EDH in infants is parietal and temporoparietal area, contrary to adults where temporal area is the most common site.[5] As the parietal eminence is the most prominent part of infant's head, it is the most likely part to get hurt and develop EDH when the infant falls down. Fall is the most common mode of injury leading to EDH.[49-12]

Changes in the level of consciousness are absent in about 50% cases even at the time of injury. In such cases, EDH is detected only after doing a CT scan which is done due to the presence of subgaleal hematoma or cephalohematoma.[13] Choux and colleagues reported that 85% infants with EDH have no loss of consciousness at the time of impact and 7% have no alteration in consciousness at any time following injury.[1] Unconsciousness is conspicuously absent because of the absence of diffuse axonal component. Clinically significant life-threatening intracranial mass lesion can exist in children with no significant initial clinical manifestation.[14] Irritability is the most common presenting symptom as the infant cannot complain anything.[5] The cause might be due to headache as a result of raised ICP.

Pallor and anemia are reported in 88%, 90%, and 96% cases by Yusuf and colleagues,[3] Pasagalu and colleagues[13] and Ceurea AV,[5] respectively.

Subgaleal hematoma is a collection of blood between galea and periosteum which is more diffuse, whereas cephalohematoma is a collection below periosteum and its spread is restricted by suture lines and it is associated with fractures.[1415] Cephalohematoma is seen commonly and reported in 68% by Ciurea AV et al. in their series. Large subgaleal hematoma are associated with anemia, hypotension, and shock.[1617]

Convulsion and bulging fontanel may be seen in 34% cases. Presence of anemia and bradycardia may be diagnostic of EDH in the absence of other source of bleeding.[8] Fracture of skull bone associated with EDH is seen rarely as (i) the deformability and pliable nature of skull bone in infants resists fracture[1518] and (ii) fractures may not be recognizable by conventional radiography because of the thinness of skull.[1518]

The radiological indication for surgical intervention is (i) hematoma volume larger than 30 ml, (ii) thickness of >15 mm, and (iii) midline shift >5 mm. Surgical intervention is also indicated in symptomatic patients with altered sensorium, focal neurological deficit, presence of temporal or posterior fossa EDH or with associated intracranial lesions.[19-22] Smaller EDH in sites other than temporal or posterior fossa may be managed conservatively with careful observation.[23-26] In these cases, the time interval between initial CT scan and time of injury is very important. The reported mortality rate of EDH in infants is 0% to 17%[12627] and 6.5% by AV Ciurea in their series.

Most of the extadural hematoma in infants are asymptomatic although there may be a large extadural hematoma endangering life of the infant. Hence, any head injury in infants needs special attention and a high level of suspicion, especially when the infant is having a scalp hematoma or pallor. Early detection and proper management can reduce the mortality rate of extadural hematoma in infants with good results.

Considering the risk of radiation in infants, difficulty in taking the history, varied symptomatology than the adults, and the risk of early coning, the clinician is always in a dilemma whether to advice CT scan in all infants with head injury.