Craniocervical cerebellar contusion in a child with Chiari malformation.

Dear Sir,

Hans Chiari, an Austrian pathologist, first described three hindbrain anomalies characterized by varying degrees of cerebellar ectopia.[1] With the advent of magnetic resonance imaging (MRI), cerebellar tonsillar ectopia is often identified in asymptomatic subjects, or those with nonspecific symptoms. The significance of such findings or the need for surgery in the context of nebulous symptoms is unclear. Little guidance exists on management of patients with incidental Chiari malformations following head injury.

We report a case of a newly diagnosed type I Chiari malformation with a traumatic head injury. Our experience adds to anecdotal evidence on management.

A 3-year-old girl presented to her local hospital emergency department after sustaining a head injury. Her head and neck had collided with a suspended truck jack. On admission, she had a fluctuating conscious level, nausea, and vomiting. A minor scalp laceration was noted in her right parietal region. A computerized tomographic (CT) scan of her head showed subarachnoid hemorrhage in the right sylvian fissure, parietal region and prepontine cistern. She had some layering of blood within her lateral ventricles and a base of skull fracture through the left mastoid process extending to the posterior margin of the left jugular foramen. There was no demonstrable fracture of her cervical spine. A CT scan of her chest, abdomen, and pelvis revealed a hepatic laceration and contusions.

The child was intubated, sedated, ventilated and transferred to a level 1-trauma center pediatric intensive care unit with neurosurgical care on site. She was noted to be persistently hypotensive with warm peripheries, inexplicable by her liver injuries alone. An MRI of her head and spine were expedited to exclude spinal shock. The MRI revealed a type I Chiari malformation with moderate cerebellar ectopia, contusions and hemorrhagic changes in the right flocculus and right cerebellar tonsil with obliteration of the cerebrospinal fluid spaces around the foramen magnum [Figure 1a].

Figure 1

T2-weighted magnetic resonance imaging sagittal view of head and neck (a) at time of injury showing type 1 Chiari malformation with cerebellar tonsillar contusion and obliteration of cerebrospinal fluid spaces surrounding foramen magnum and (b) after 10 weeks’ conservative management showing contusion resolution, cerebrospinal fluid flow restoration and subtle improvement of the persisting Chiari malformation

The patient's sedation was weaned and her neurological status assessed. About 3 h after starting to wean from sedation, she self extubated. She had been ventilated for 10 h. She recovered conscious level to a Glasgow Coma Score (GCS) of 14 with confused speech. The following day her GCS improved to 15. She was an inpatient for 9 days in total.

At clinic follow-up 10 weeks after the accident she remained neurologically intact and asymptomatic with radiological improvement in her cerebellar contusions and craniocervical junction cerebrospinal fluid flow. There was concomitant subtle improvement in her persistent Chiari malformation [Figure 1b].

The case reported raises questions about managing patients with incidental Chiari malformations with a traumatic brain injury. True prevalence of incidental Chiari type I malformations in children is unknown.[2] However, retrospective studies report an incidence of 1% in pediatric populations subject to cranial and spinal MRI scans.[3] Published literature on management of head injury patients with incidental Chiari type I malformation is limited.

We elected to observe the patient's neurological status after weaning them from sedation, rather than proceed with a foramen magnum decompression as we could not be certain of the significance of the imaging findings without assessing the child clinically. The few analogous cases reported in the literature are discussed below.

Couldwell et al. reported a case of an 11-year-old boy with an open depressed right temporo-parietal skull fracture following a tobogganing accident.[4] CT head demonstrated a cerebellar contusion and subarachnoid blood at the craniocervical junction. An MRI scan revealed a type I Chiari malformation. The cerebellar tonsils extended beyond the first cervical vertebrae. The authors demonstrated slowing of conduction between the upper cervical spinal cord and the medulla with somatosensory evoked potentials. The wound was debrided with irrigation and elevation of the depressed skull fracture. The Chiari malformation was managed conservatively. They reported a slow resolution of neurological deficits and improvement of conduction across the cervicomedullary junction.

Murano and Rella reported the case of a 36-year-old woman, involved in a road traffic accident.[5] She was fully conscious and alert, with no neurological deficits, but brisk reflexes in all four limbs. She had experienced headaches for several years, and MRI showed obstructive hydrocephalus with compression of the fourth ventricle and a Chiari type I malformation with 20 mm of tonsillar descent. Her headaches worsened in the emergency department with nausea and vomiting, but were relieved by dexamethasone and she was discharged following 24 h observation, receiving a ventriculoperitoneal shunt 6 weeks later. Both cases were managed conservatively.

The clinical course of children with Chiari malformation following head trauma is not well understood. Evidence favoring conservative versus surgical management is anecdotal. Close observation is required during in-patient stay, with careful clinical and radiological follow-up to assess for emergence or progression of neurological symptoms.

BAPJ and EACP wrote the paper and produced the figures. SM and PGR managed the patient clinically and edited the paper. PGR is its guarantor.