Case Diagnosis: Non-Polio Enteroviruses (NPEVs) including Coxsackievirus, Echovirus and newly discovered Enteroviruses (EVs), which are implicated causes of acute flaccid paralysis (AFP), are emerging public health concerns after the Poliovirus has experienced significant stepwise reduction over the past few decades. Lately, the Department of Health in the Philippines announced an outbreak of Poliomyelitis nineteen (19) years after it was declared Polio-free. AFP-associated cases of human parechovirus (HPeV) infection in young children have been reported in literature since 2004. Confirmatory tests include stool analysis and neuroimaging of the central nervous system. While clinical and radiological features are identified in literature, descriptions of electrophysiological abnormalities are limited.
Case Description: This is a case of a 1-year old Filipino boy who presented with initial focal flaccid limb weakness following a prodromal illness, which progressed asymmetrically with respiratory paralysis. Lumbar puncture results were normal, nasopharyngeal swab showed enteroviral antigens, and HPeV was isolated in stool samples. Cervical spine MRI initially demonstrated inflammatory changes in the C4 to C6 cord levels, but was normal on repeat testing after five months. Following the case definition of EV-D68 related AFM, these findings altogether led to diagnosis of AFP.
Discussions: Nerve conduction study (NCS) of the upper limbs revealed normal sensory nerve action potential parameters, but the motor nerves exhibited reduced compound muscle action potential amplitudes with normal latencies and conduction velocities, indicating a pure motor axonal loss. Electromyography (EMG) was consistent with active partial denervation with patchy evidence of reinnervation process on all limbs. These findings of a diffuse axonal motor polyneuropathy are compatible with neurophysiological changes seen in limited published studies on enterovirus-associated AFP (specifically Enterovirus-D68).
Conclusions: Electrophysiological studies are clinically useful as part of the multidisciplinary approach in diagnosing enterovirus-associated AFP. To our knowledge, this is the first electrophysiological description of parechovirus-associated AFP in Asia.
Abigail Mendoza– Resident Physician, Department of Physical Medicine and Rehabilitation
Ephraim Gambito– Affiliate Consultant, Department of Physical Medicine and Rehabilitation
Reynaldo Rey-Matias– Associate Professor and Head, Department of Physical Medicine and Rehabilitation
Lyde Alday-Magpantay– Active Consultant, Department of Physical Medicine and Rehabilitation