| Abstract|| |
A 2½-year-old male child with a prior history of a left anatomic hemispherectomy to treat refractory epilepsy fell down two steps, striking his head on the ipsilateral side of the hemispherectomy. He presented with non-consolable crying and emesis. CT scan of the head demonstrated a left frontal epidural hematoma beneath the site of his prior craniectomy. The patient was initially treated by close observation. However, due to an increase in the hematoma from 29.5 to 49.3 ml over a 12-hour period along with the patient's lack of clinical improvement, surgical evacuation was performed. Intraoperatively, the source of the hemorrhage was found to be the skull fracture. Postoperatively, he returned to his neurologic baseline and was discharged home on postoperative day 3.
Keywords: Epidural hematoma, head trauma, hemispherectomy
|How to cite this article:|
Mesfin FB, Riccio AR, Kuo YH. Low pressure traumatic epidural hematoma in a child with a prior hemispherectomy: Case report. J Emerg Trauma Shock 2015;8:112-4
|How to cite this URL:|
Mesfin FB, Riccio AR, Kuo YH. Low pressure traumatic epidural hematoma in a child with a prior hemispherectomy: Case report. J Emerg Trauma Shock [serial online] 2015 [cited 2019 Aug 17];8:112-4. Available from: http://www.onlinejets.org/text.asp?2015/8/2/112/155514
| Introduction|| |
Cerebral hemispherectomy is a surgical option for refractory epilepsy when the seizure focus is diffusely localized to one hemisphere. An anatomic hemispherectomy removes the cerebral hemisphere, but spares the basal ganglia.  Anatomic cerebral hemispherectomy is associated with a number of postoperative complications, including a high rate of communicating hydrocephalus and cerebral hemosiderosis.  Other complications include intracranial hemorrhage, global infraction, and postoperative infections.  There is one case report of an epidural hematoma in the immediate postoperative period.  Here, we report on the development of an epidural hematoma after minor head injury in a child who had a prior anatomic hemispherectomy over one year prior. To our knowledge, this is the first report of a traumatic epidural hematoma in a patient with a hemispherectomy. Intraoperatively, the source of hemorrhage was found to be from fracture site. The low pressure, venous source of hemorrhage suggests that a different mechanism of epidural hematoma formation can occur after hemispherectomy.
| Case Report|| |
History and examination
A 2½-year-old male child who had undergone a prior left-sided anatomic hemispherectomy to treat refractory epilepsy fell down two steps, striking the left side of his head. There was no loss of consciousness or any immediate behavior changes. However, over the next four hours, he became increasingly irritable and vomited after eating, prompting the parents to bring the child for evaluation. On presentation to the emergency room, the patient was awake and alert, but irritable. His pupils were bilaterally equal and reactive, and his extraocular motions were intact. His right-sided hemiparesis from his hemispherectomy was unchanged from baseline per his parents. A CT scan of the head demonstrated a left frontal epidural hematoma beneath the site of his prior craniectomy. This measured 4.6 × 1.8 cm in size [Figure 1]a. A linear nondisplaced skull fracture was seen overlying the hematoma. He was admitted to pediatric intensive care unit for further observation. His irritability did not improve and the patient was unable to tolerate food without vomiting. A repeat CT scan done approximately 12 hours after initial presentation showed an increase in the size of the epidural hematoma from 29.5 to 49.3 ml. Due to the increase in the size of the hematoma and the patient's lack of clinical improvement, he was taken for surgical evacuation of the epidural hematoma.
|Figure 1: (a) A CT scan at presentation that demonstrates an acute left frontal hematoma. (b) An intraoperative photograph shows a linear nondisplaced skull fracture. (c) An intraoperative photograph shows the epidural hematoma with mass effect on the dura. (d) A postoperative CT scan shows resolution of the epidural hematoma|
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The patient's prior left frontal incision was reopened revealing a linear nondisplaced skull fracture measuring greater than 4 cm in length [Figure 1]b. Venous bleeding was observed from the cancellous bone of the fracture line. His prior craniotomy flap was identified and encompassed the de novo fracture. The bone flap was elevated to reveal a solid epidural hematoma with mass effect on the dura [Figure 1]c. The epidural hematoma was evacuated by aspiration. There were no dural tears of or any evidence of arterial bleeding identified during the srugery. The bony edges of the craniotomy flap were waxed and tacking sutures placed both circumferentially as well as centrally to obliterate the epidural space. The bone plate was secured and the incision was closed. The patient was able to be extubated in the operating room prior to return to the pediatric intensive care unit.
By postoperative day one, the patient was able to take solid food without emesis. His neurologic examination returned to baseline. A postoperative CT scan showed complete resolution of the epidural hematoma [Figure 1]d. He was subsequently discharged home with his parents in stable condition on postoperative day 3. At his one-year follow-up, his hemiparesis continues to show improvement and he is in the process of being weaned off phenobarbital.
| Discussion|| |
Cerebral hemispherectomy is a treatment option for lateralized epilepsy that is refractory to pharmacologic treatment. Vining et al. (1997) reported that in 54 of 58 surviving patients who underwent a hemispherectomy, 54% were cured of seizures, 24% had non-debilitating seizures, whereas 23% had seizures that to some extent interrupted normal function.  They also found that performing a hemispherectomy when the patient is young can lead to a dramatic quality of life improvement.  The most common long-term complications of hemispherectomy are hemiplegia, cognitive impairments, and visual field deficits.  The reported incidence of hydrocephalus after anatomic hemispherectomy ranges from 2 to 33%.  Kalkanis et al. (2005) suggest that superficial cerebral hemosiderosis is associated with hydrocephalus.  There are also reports that hemispherectomy is associated with an increased incidence of normal pressure hydrocephalus in adulthood. 
There has been one report of an immediate postoperative epidural hematoma in patient who had undergone a hemispherectomy.  To our knowledge, this is the first case report of a traumatic epidural hematoma in a patient who has had a hemispherectomy. A literature search of PubMed using a combinations of the terms "epidural hematoma AND hemispherectomy," "trauma after hemispherectomy," and "trauma AND hemispherectomy" did not yield any articles. The "classical" epidural hematoma associated with traumatic skull fractures are due to avulsion of the middle meningeal artery. Patients often have a lucid interval after the injury, followed by a rapid deterioration in neurologic status as the hematoma expands under arterial pressure. Haselsberger et al. (1988) observed a mortality rate of 25% for patients with acute epidural hematomas.  After evacuation, a full neurologic recovery was achieved by 58% of the patients.
The patient presented here demonstrated a different clinical course than typically observed for traumatic epidural hematomas. The patient did not have a rapid deterioration of his neurologic examination, but presented with subtle behavioral changes and persistent emesis. The epidural increased in size approximately 60% over a 12-hour interval, a rate slower than typically seen in traumatic epidurals.  We theorize that the low pressure source of hemorrhage resulted in a slower rate of hematoma growth. Significant epidural hematomas from skull fractures are rare events unless avulsion of an artery or sinus occurs, as tamponade of the diploic bleeding occurs at low pressure. There are a few mechanisms that we hypothesize contributed to the growth of the hematoma in patient in this case. First, the loss of cerebral parenchyma with the hemispherectomy removed a source of physical tamponade for the hemorrhage. Second, dissection of the dura from the inner table of the skull during the prior craniotomy may have created space for epidural collection. The epidural hematoma in this child did not expand into the epidural space beyond the prior craniotomy, further supporting this hypothesis.
Although this patient was initially managed conservatively, he eventually underwent evacuation due to his continuous irritability, emesis, and increase in the size of the hematoma on imaging. It is possible that with continued observation, the hematoma would have ceased expansion. Growth of the hematoma largely occurred orthogonal to the inner table of the skull. It is possible that with further enlargement of the hematoma, the dura may have provided enough resistance to tamponade the hemorrhage as tension on the dura increased. Furthermore, this patient could tolerate a significantly larger hematoma without neurologic deficit than a patient without a hemispherectomy as there is no mass effect on cerebral parenchyma. The hematoma expands into cerebral spinal fluid space and compressive forces are diffused through the fluid space minimizing potential mass effect of structural brain tissues. The contralateral hemisphere was not shifted by the hematoma [Figure 1]a. The patient's continued irritability and emesis may not have been due to increased intracranial pressure, and may have improved with time. In retrospect, the decision to proceed to surgical evacuation may have been overly aggressive. Further reports of traumatic epidural hemorrhages in patients who have had a hemispherectomy will help to better understand the natural history of this process and develop algorithms for treatment.
| Conclusion|| |
Patients who have had a hemispherectomy may have a different mechanism for traumatic epidural hematoma formation. This may result in a different progression of disease than the "classic" epidural hematoma from arterial avulsion. These patients may have a slower progression of their hematoma and the role of surgical evacuation is unclear.
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Prof. Yu-Hung Kuo
Division of Neurosurgery, Albany Medical Center, New York
Source of Support: None, Conflict of Interest: None