Flaccid quadriplegia from tonsillar herniation in pneumococcal meningitis

Brain death and the cervical spinal cord: a confounding factor for the clinical examination

STUDY DESIGN

This study is a systematic review.

OBJECTIVES

Brain death (BD) is a clinical diagnosis, made by documenting absent brainstem functions, including unresponsive coma and apnea. Cervical spinal cord dysfunction would confound clinical diagnosis of BD. Our objective was to determine whether cervical spinal cord dysfunction is common in BD.

METHODS

A case of BD showing cervical cord compression on magnetic resonance imaging prompted a literature review from 1965 to 2008 for any reports of cervical spinal cord injury associated with brain herniation or BD.

RESULTS

A total of 12 cases of brain herniation in meningitis occurred shortly after a lumbar puncture with acute respiratory arrest and quadriplegia. In total, nine cases of acute brain herniation from various non-meningitis causes resulted in acute quadriplegia. The cases suggest that direct compression of the cervical spinal cord, or the anterior spinal arteries during cerebellar tonsillar herniation cause ischemic injury to the cord. No case series of brain herniation specifically mentioned spinal cord injury, but many survivors had severe disability including spastic limbs. Only two pathological series of BD examined the spinal cord; 56-100% of cases had upper cervical spinal cord damage, suggesting infarction from direct compression of the cord or its arterial blood supply.

CONCLUSIONS

Upper cervical spinal cord injury may be common after brain herniation. Cervical spinal cord injury must either be ruled out before clinical testing for BD, or an ancillary test to document lack of brainstem blood flow is required in all cases of suspected BD. BD may not be a purely clinical diagnosis.

Lumbar puncture and brain herniation in acute bacterial meningitis: a review

There has been controversy regarding the risk of cerebral herniation caused by a lumbar puncture (LP) in acute bacterial meningitis (ABM). This review discusses in detail the issues involved in this controversy. Cerebral herniation occurs in about 5% of patients with ABM, accounting for about 30% of the mortality. In many reports, LP is temporally strongly associated with this event of herniation and is most likely causative based on pathophysiologic arguments. Although a computed tomography (CT) scan of the head is useful to find contraindications to an LP, a normal CT scan in ABM does not mean that an LP is safe. Clinical signs of "impending" herniation are the best predictors of when to delay an LP because of the risk of precipitating herniation, even with a normal CT scan. Some of these clinical signs to be considered are deteriorating level of consciousness (particularly to a Glasgow Coma Scale of <or= 11), brainstem signs (including pupillary changes, posturing, or irregular respirations), and a very recent seizure. The risk of not doing an LP when it is contraindicated because of concern of the risk of herniation is extremely small. In those considered high risk for herniation, interventions to control intracranial pressure, such as attention to airway, breathing, and circulation, with a mannitol infusion and antibiotics started, should be the priorities, followed by an urgent CT scan and not an LP.

Spinal cord infarction complicating acute hydrocephalus secondary to a colloid cyst of the third ventricle. Case report

Occipital lobe infarction secondary to tentorial herniation is a rare but well-recognized complication of posterior cerebral artery interruption during acute hydrocephalus; however, a similar event in which tonsillar herniation leads to symptomatic occlusion of the anterior spinal arteries (ASAs) has not been reported. The authors present the case of a third ventricular colloid cyst in a previously healthy 24-year-old man who presented with symptoms and signs of critically raised intracranial pressure. He subsequently survived the ictus of insults following emergency external cerebrospinal fluid drainage and definitive resection of the colloid cyst, but he sustained occipital lobe and spinal cord infarction despite the absence of systematic hypotension. The presence of watershed cervicothoracic cord infarction on magnetic resonance imaging suggested that the most likely causes were compromise of ASAs during the period of acute hydrocephalus and the accompanying downward brain herniation. To the authors' knowledge, this is the first report to provide evidence that acute hydrocephalus may lead to ASA syndrome.

Spinal cord infarction in meningitis: polygenic risk factors

We report a male with spinal cord infarction and tetraplegia after Streptococcus pneumoniae meningitis. He was subsequently found to have both a Chiari I malformation and factor V Leiden mutation. A literature search was conducted to identify previously reported cases of pediatric spinal cord infarction associated with acute bacterial meningitis, anatomic brain anomalies, and hypercoagulability disorders. This article is the first report of spinal cord infarction in a child with hypercoagulability disorder and structural brain anomaly in the setting of acute bacterial meningitis. The confluence of infection, inflammation, localized pressure, and predisposition to hypercoagulability produced unique conditions resulting in infarction of the cervical spine. This report emphasizes the polygenic nature of the expression of spinal cord infarction.

Diffusion-weighted imaging in acute bacterial meningitis in infancy

Bacterial meningitis is frequently fatal or leads to severe neurological impairment. Complications such as vasculitis, resulting in infarcts, should be anticipated and dealt with promptly. Our aim was to demonstrate the complications of meningitis by diffusion weighted imaging (DWI) in patients who deteriorated despite therapy. We studied 13 infants between the ages of 1 day and 32 months who presented with symptoms ranging from fever and vomiting to seizures, encephalopathy and coma due to bacterial meningitis, performing MRI, including DWI, 2-5 days after presentation. Multiple infarcts were found on DWI in 12 of the 13, most commonly in the frontal lobes (in 10). Global involvement was seen in four children, three of whom died; the fourth had a very poor outcome. In one case abnormalities on DWI were due to subdural empyemas. We diagnosed vasculitis in three of five patients studied with MRA. We think DWI an important part of an MRI study in infants with meningitis. Small cortical or deep white-matter infarcts due to septic vasculitis can lead to tissue damage not easily recognized on routine imaging and DWI can be used to confirm that extra-axial collections represent empyemas.