Peripheral nervous system involvement in SSPE as a parainfectious manifestation - A case report

Abstract

Abstract Background Rapidly progressive encephalopathy in a young adult has a range of differentials requiring an exhaustive workup. We present a man with a history of encephalopathy with neuropathy and a rare diagnosis. Case presentation A 40 year-old man presented with a 6-month history of cognitive dysfunction and an asymmetric gradually progressing ascending quadriparesis with the involvement progressing in the order of motor, sensory, autonomic and bulbar. MRI of the brain showed diffuse atrophy. Nerve conduction studies revealed sensorimotor neuropathy affecting all four limbs. CSF showed a negative autoimmune panel and no signs of an infectious etiology. The patient was started on plasma exchange with a provisional diagnosis of an immune mediated disorder. A nerve biopsy showed axonolysis and demyelination. EEG showed delta wave slowing and periodic discharges. A possibility of SSPE was considered, although peripheral neuropathy is an atypical presenting feature, following which the measles IgG antibodies titers in CSF and serum were found to be raised at 377.2 U/mL and 197 U/mL respectively. He had persistent sepsis and several episodes of respiratory distress requiring invasive mechanical ventilation. He was started on intrathecal interferon with a period of objective stability after which the sensorium gradually deteriorated and the outcome was fatal. Conclusions Subacute sclerosing panencephalitis (SSPE) is a progressive disorder caused by a persistent defective measles virus and causes death several years after the measles infection. It is suspected based on characteristic clinical features, EEG findings and demonstration of measles antibodies in CSF. The diagnosis is made based on Dyken's criteria. SSPE can present in an atypical fashion with peripheral nerve involvement. Neuropathy may occur due to para-infectious demyelination with no cellular infiltration seen on the nerve biopsy. A high index of suspicion aids diagnosis in rarer presentations.