Laminar subdural hematoma

Abstract

We report the case of a 10-month-old female infant who presented with localized swelling over the parietal region after a minor head trauma. Neuroimaging revealed a laminar subdural hematoma associated with non-displaced parietal fractures and a small extracranial bone fragment. This case highlights the conservative management of laminar subdural hematomas and the importance of clinical-radiological correlation in pediatric head trauma.

Introduction Subdural hematomas (SDHs) in infants can range from minor, self-limited collections to life-threatening compressive lesions. The term laminar subdural hematoma is used descriptively to indicate a thin, sheet-like collection of subdural blood, typically without mass effect. Their detection, especially in the context of minor trauma, requires careful evaluation, as such findings can also raise concern for non-accidental injury (NAI).

Case Presentation

Patient: A previously healthy 10-month-old female infant

Chief complaint: Soft swelling over the left side of the head

History of Present Illness:

The patient was brought to the emergency department by her parents, who noted swelling in the left parietal region. Five days earlier, the child had reportedly fallen from standing height while under the supervision of her maternal aunt. There were no associated symptoms such as vomiting, seizures, or altered behavior. The infant had been exclusively in the care of her parents for the previous days and did not attend daycare.

Clinical Examination:

Alert and interactive

Glasgow Coma Scale: 15

No focal neurological deficits

Negative meningeal signs

Palpable, fluctuant swelling over the left parietal area with crepitus

Neuroimaging (CT scan):

Two non-displaced linear fractures in the left parietal bone

Small extracranial bone fragment measuring 6 x 5 mm

Laminar subdural hematoma up to 2 mm in thickness along the left parietal convexity

No mass effect, midline shift, or signs of herniation

Soft tissue hematoma of up to 4 mm in the same region

Basal cisterns were preserved, and no other intracranial abnormalities were seen

Diagnosis

Laminar subdural hematoma, left convexity

Non-displaced parietal skull fractures with associated extracranial bone fragment

Soft tissue hematoma, parietal region

Management and Outcome

The patient was admitted for clinical observation with close neurological monitoring. No seizures, vomiting, or neurological deterioration were observed during a 48-hour inpatient stay. Given the absence of mass effect and stable neurological status, no surgical intervention was deemed necessary. The patient was discharged with scheduled outpatient follow-up in the pediatric neurosurgery clinic. Given the age and the mechanism, the case was discussed with the child protection team; no further work-up for non-accidental trauma was indicated based on available information and consistent history.

Discussion

Laminar subdural hematomas are thin, linear collections of blood that lie in the subdural space, often along the convexity. These hematomas, typically <3 mm in thickness and without mass effect, are frequently seen in minor pediatric head trauma and may not require surgical intervention.

Key considerations in pediatric SDH:

Surgical evacuation is generally reserved for cases with midline shift >5 mm, hematoma >10 mm, or neurological deterioration.

In infants, the absence of signs like bulging fontanelle, seizures, or altered consciousness supports conservative management.

When the mechanism of injury is unclear or inconsistent with the severity of imaging findings, non-accidental trauma must be excluded.

In this case, the presence of a small extracranial bone fragment and laminar SDH required differentiation from more significant hematomas. The absence of neurological signs and normal cisternal anatomy further supported a non-operative course.

Conclusion

Laminar subdural hematomas are frequently benign and self-limiting in infants following minor trauma. Thorough clinical evaluation, appropriate imaging, and careful observation are the cornerstones of management. A high index of suspicion for non-accidental trauma should be maintained in all pediatric head injuries.

Keywords: Pediatric head trauma, laminar subdural hematoma, skull fracture, non-accidental injury, neuroimaging, conservative management

Definition: A *laminar subdural hematoma* refers to a thin, sheet-like (≤2–3 mm) extraaxial collection of blood, typically without mass effect or midline shift. It is usually seen along the convexities in infants and may result from minor trauma.

Differential considerations:

• Can be difficult to distinguish from normal venous blood in infants
• Often resolves spontaneously
• Important to consider non-accidental trauma in infants with subdural blood, especially if bilateral or without a witnessed fall

When to consider surgery in pediatric SDH:

• Midline shift >5 mm
• Hematoma thickness >10 mm
• Neurological deterioration (↓GCS, seizures, vomiting)
• Refractory raised ICP
• Depressed fracture with dural tear or open injury

Management of laminar SDH:

• Usually conservative
• Observation with serial neurological exams
• Repeat imaging only if clinical status worsens
• Follow-up in neurosurgery or pediatric neurology