Aims Acute Disseminated Encephalomyelitis (ADEM) is a non-vasculitic, autoimmune demyelinating condition affecting predominantly cerebral white matter. ADEM commonly presents after a well defined pro-dromal febrile illness, and typically has a monophasic presentation with predominance of cortical signs such as encephalopathy and seizures. There is considerable interest in identifying clinical and radiographic features at initial presentation which might predict future risk of clinical reoccurrence. We reviewed the radiological features of a case series of children presenting with ADEM to determine if spinal inflammatory changes on MRI were related to increased risk of recurrent demyelination.
Methods Review of the case records and MRI imaging of 31 cases with a clinical diagnosis of ADEM from 2002 to 2010 in a tertiary referral centre for paediatric neurology.
Results A total of 4 of the 31 (12.9%) cases re-presented with a second episode of demyelination. These cases presented following a discrete pro-dromal febrile illness, with encephalopathic features including lethargy, and confusion, ‘being off legs,’ and ataxia. Initial brain and cervical spine MRI imaging showed both cerebral white matter and spinal high signal changes, correlating with inflammatory lesions in these two areas. The spinal lesions in these cases predominated in the cervical region, with variance of affected regions from the posterior to lateral cervical cord areas, with some pathology also noted in the thoracic cord in two cases. Clinical reoccurrence occurred in three of these four cases and ranged from limb hemiparesis to cranial nerve palsies. In these three cases, reoccurrence correlated with either persistence or extension of inflammatory lesions seen on initial imaging. However, in three further cases with cerebral and spinal lesions on presentation, there was no documentation of clinical reoccurrence within the follow-up period. Conversely, in the 24 (77%) cases within the series, without spinal pathology (with only cerebral and/or brainstem lesions), there was only one case of recurrent demyelination.
Conclusions We propose that the presence of spinal inflammatory lesions, particularly involving the cervical region of the spine on MRI imaging in the context of initial presentation, may be a risk factor for clinical reoccurrence. Further prospective longitudinal studies are warranted to investigate this hypothesis.