Severe post-influenza (H1N1) encephalitis involving pulvinar nuclei in an adult patient.
Neurological complications of H1N1 infections are mostly found in children, but rare cases of acute encephalopathy and post-infectious encephalitis such as acute disseminated encephalomyelitis (ADEM) have been described in adults. We report a case of an adult presenting with a progressive and severe encephalopathy that developed after H1N1 respiratory infection resolution. Cerebrospinal fluid (CSF) analysis was normal, including negative PCR for herpes simplex virus, H1N1, influenza B and JC virus, and absent oligoclonal IgG bands in CSF and serum. Initial CT scan was normal, but later MRI showed posterior multifocal leucoencephalopathy with pulvinar sign. The delayed neurological findings together with the ancillary investigation, namely the MRI pattern with both grey and white matter involvement, raised the possibility of a post-infectious process, rather than an acute encephalitis. Despite aggressive immunotherapy, the patient experienced severe neurological sequelae. Early recognition of ADEM manifestations by those dealing with H1N1 infection is important as early immunotherapy may improve the prognosis.
Neurology Department, Coimbra Hospital and University Centre, Coimbra, Portugal.
José
http://orcid.org/0000-0002-5667-2055
J
Tomás
Neurology Department, Coimbra Hospital and University Centre, Coimbra, Portugal.
Maria Carmo
MC
Macário
Department of Internal Medicine, Coimbra Hospital and University Centre, Coimbra, Portugal.
Elsa
E
Gaspar
Neurology Department, Coimbra Hospital and University Centre, Coimbra, Portugal.
Isabel
I
Santana
D001766:Blindness / Q000209:etiology; D004673:Encephalomyelitis, Acute Disseminated / Q000209:etiology*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications* / Q000276:immunology*; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology; D012640:Seizures / Q000209:etiology