Spontaneous subdural haematoma in a neonate requiring urgent surgical evacuation

The incidence of clinically apparent subdural haematomas in infants is estimated to be 24.1/100,000 [5]. Whilst subdural haematomas may occur due to peripartum trauma, occurrence after elective caesarean section (CS) and requirement for surgical intervention is extremely rare.

Subdural haematomas occurring in the peripartum period are almost always caused by the trauma of birth and are usually asymptomatic. Indeed, MRI immediately post-partum demonstrates that 8–46% of infants have asymptomatic subdural collections [12, 20, 25]. Symptomatic subdural haematomas are much more rare, occurring in 16.5/100,000 infants under the age of 1 year [6]. Whilst such cases have been described following emergency/complicated CS, incidence following uncomplicated elective CS is extremely rare [2, 12]. The available evidence is summarized in Table 1.

Presenting symptoms are due to focal neurological deficit or raised ICP. The skull’s elasticity allows some tolerability to increased pressure; therefore, clinical signs may be subtle, such as poor feeding, irritability and frequent vomiting. On examination, scalp veins may be distended and the anterior fontanelle full. Focal neurological deficits may manifest with weakness or cranial nerve deficits. Papilloedema does not usually develop in neonates, but retinal venous engorgement may be noted [19]. If compression of the brainstem occurs, bradycardia and apnoeic spells may manifest.

Ultrasound provides a rapid non-invasive method for diagnosis and can be done at the bedside. CT is also rapid and usually readily available. However, a significant dose of radiation poses long-term implications. MRI does not deliver radiation and provides exquisite images of the brain but can be time-consuming and not as readily available.

It is imperative to assess for potential underlying causes, such as trauma, coagulopathy, meningitis, cerebral venous thrombosis, metabolic diseases or structural lesions (including tumours or vascular malformations) [7‐11, 21]. If time permits, MRI is the most helpful imaging tool in ruling out structural causes. Additional sequences that afford an assessment of the cerebral vasculature are vital. This informs best management and likely prognosis, guiding shared decision-making with the patient’s parents/guardians. In this case, a multidisciplinary decision was made to pursue MRI rather than CT in view of these benefits (without significant time penalty), but we emphasize that in most situations, CT remains the imaging of choice for acute intracranial haemorrhage due to its rapidity.

Management of these cases is based upon the patient’s clinical state, the size of the collection and the preference of the surgeon/parents/guardians [15]. A conservative approach could have been considered given her clinical state, but this could have led to sudden rising ICP and deterioration. Subdural transcutaneous puncture or external subdural drainage allows relief of pressure, if the viscosity of the collection permits; however, there is a risk of infection. Neither of these procedures tends to achieve haematoma resolution but can be useful temporizing methods. In a study of 184 children with subdural haematomata in children under 2 years old, Melo et al. [15] found that despite these procedures, 82% and 50% of children, respectively, required further surgery due to recurrent/residual collection. Shunts provide an option to divert the haematoma but again may be ineffective if the clot is thick. Shunting to the subgaleal space may be employed in children under 3 months old as it negates opening the abdomen. Shunting to the peritoneum may be employed in older infants, typically with a valveless system to encourage drainage. The complication rate for shunting in such cases is around 25%, including the risk of recurrent subdural haematoma upon removal, due to tethering of the proximal catheter [15]. Craniotomy achieves immediate access to the subdural space and evacuation of the clot in order to relive associated mass effect. It also allows evaluation of the brain surface to assess for and control any bleeding source. Given the small circulating blood volume in neonates, the risk of blood loss and death are significant.

If an underlying cause for the haemorrhage is demonstrated on imaging, immediate surgical intervention could lead to catastrophic bleeding and prove fatal. The underlying cause may require treatment prior to surgical management, for example, correction of an underlying coagulopathy or aneurysm [7]. Once we had ruled out any underlying cause and decided to perform a craniotomy, the plan was to perform as small a craniotomy as possible and remove the convexity haematoma. We aimed to leave the presumed clot in the posterior inter-hemispheric fissure alone in order not to provoke further bleeding but draped and planned to extend the unicoronal incision posteriorly along the midline in case of uncontrollable bleeding. Fortunately, this was not required; nevertheless, having bailout strategies is vital when operating on neonates.

Long-term outcomes for infants following non-traumatic subdural haematoma are difficult to predict due to a paucity of reported cases with robust follow-up. In cases of non-accidental injury with subdural haematoma, the reported rate of neurological disability is approximately two-thirds [8]. This may be due to the diffuse nature of the brain injury. For subdural haematomas related to accidental trauma, good outcomes are observed in 45–56% of patients [9‐11]. Vinchon et al. reported sixteen cases of symptomatic spontaneous/atraumatic subdural haematomata, noting that twelve of these had idiopathic macrocrania and seven arachnoidomegaly [24]. They suggest idiopathic macrocephaly/arachnoidomegaly, and dehydration may underlie some cases of spontaneous subdural haematomata. Although not the case in our patient, this study provides a useful comparison in terms of outcome. Over a mean follow-up of 21.2 months, they reported a Glasgow outcome score (GOS) of 1 (normal life) in 87.5%. Outcomes were significantly better compared with a matched cohort of infants sustaining traumatic injuries [24].

In conclusion, clinically apparent subdural haematoma is an unusual condition in the neonatal period. The vast majority of these are due to birth-related trauma, or non-accidental injury, which must be readily suspected and its possibility evaluated on a case-by-case basis. However, spontaneous subdural haematomas exist, and a thorough search for an underlying cause is imperative. These cases are difficult due to uncertainty regarding optimal management strategy. Moreover, there is limited evidence to guide prognosis, and so in these rare cases, close collaboration between the multidisciplinary teams involved, and the patient’s caregivers, is mandatory to guide best treatment for the individual child.