DrVarsha Dr Sajith Kesavan/ Dr Greeshma Isaac(Paed pulmonologist ,Intensivists)
DrC Jayakumar
Department Of Pediatrics, AIMS Kochi
Three years old female child developmentally normal, fully immunized according to NIS with no significant past history presented with c/o fever with myalgia of 4 days duration followed paraxysmal event with stiffening of both limbs of 2minutes duration which was self aborted.At admission child was febrile with post ictal drowsiness. Vitals were stable with neurological examination showing internuclear ophthalmoplegia and spasticity with brisk reflexes and truncal weakness.
Labs done showed neutrophilic leucocytosis with negative CRP.
RFT, LFT, SE done were normal.
At this point an infection triggered encephalopathy syndrome was suspected. MRI brain showed T2 FLAIR hyperintense homogeneous signal with diffusion restriction seen involving the pontine and midbrain tegmentum, suggestive of a probable infectious brainstem encephalitis.
Bedside VEEG testing showed generalized non-specific disturbances of electrical function.
Respiratory viral panel testing was positive for H1N1, Rhino and enterovirus.
CSF analysis was within normal limits, culture was sterile and CSF Meningo encephalitis panel was negative for viral and bacterial etiologies.
CSF H1N1 PCR testing was negative. She was initiated on IVMP at 30mg/kg/day over 5 days and IVIG at 2g/kg over 4 days. Oral steroids were continued at 1 mg/kg/day.
Empirical antibiotics were continued and oseltamivir was given for 5 days. Ophthalmology evaluation showed primary gaze Left eye Exo deviation and right gaze palsy with right limited adduction, suggestive of Right one and half syndrome.
Blurring of nasal margin of right eye retina but macula was normal.
Mild temporal pallor was noted in bilateral eyes.
During the course of PICU stay, she improved gradually and her encephalopathy resolved, overall activity improved, and was taking oral feeds well.
She was shifted to ward and observed. During ward stay, her overall clinical condition improved. No further events were noted.
Early rehabilitation measures were initiated including gait therapy the physiatrist
Her eyes showed mild improvement in inter-nuclear ophthalmoplegia. Family is explained in detail about the nature of the child’s condition and the need for the regular follow up.
Over all clinical evaluations suggestive of infection triggered encephalopathy, probably post H1N1.
Discussion:
Influenza A (H1N1) virus usually involves respiratory system with self-limiting flu like illness including fever, cough, rhinorrhea, and sore throat. Multiorgan involvement can occur in patients with influenza, leading to unusual presentations and severe complications causing significant morbidity and mortality. H1N1 can rarely have severe neurological complications including seizure, encephalitis, encephalopathy, raised intracranial pressure (ICP), acute disseminated encephalomyelitis (ADEM), acute necrotizing encephalopathy of childhood (ANEC), Guillain-Barre syndrome, and transverse myelitis. The incidence of seasonal influenza-related neurologic complications has been estimated at 4 cases per 100,000 children per year
Definitive Investigation is MRI Brain with CSF examination. MRI brain can show bilateral symmetrical basal ganglia and deep nuclei abnormalities, and widespread white matter abnormalities along with T2 hyperintensity and restricted diffusion in the thalami, cerebellar hemispheres and brain stem. CSF pleocytosis is usually noted.
Treatment of Influenza A (H1N1)-infected patients with neuraminidase inhibitors (Oseltamivir or Zanamivir) leads to reduction in duration of illness and reduction in rate of complications. There are no randomized, controlled studies examining the efficacy of antiviral treatment on influenza-related neurologic complications and it is not clear whether the prognosis is better following treatment. Pulse dose of steroids were found to be effective with supportive management. Mortality and sequelae risk is high in Reye’s syndrome and acute necrotizing encephalopathy.