Chikungunya Encephalomyeloradiculitis: Report of 2 Cases with Neuroimaging and 1 Case with Autopsy Findings

Abstract

SUMMARY:Chikungunya, an alphavirus presenting with fever, rash, and polyarthritis, is derived from the Makonde word that means "that which bends up," in reference to the crippling manifestations of the disease. Most often it is a self-limiting febrile illness. Neurologic complications of Chikungunya infection have been reported. We are reporting the clinical and neuroimaging data in 2 patients with Chikungunya encephalomyeloradiculitis and brain autopsy findings in 1 patient. Chikungunya virus was first isolated in Calcutta, India, in 1963, 1 with several reported outbreaks in India since then. The first isolation of the disease worldwide was in 1952, following an outbreak on the Makonde Plateau. The symptoms include fever, headache, rash, and severe arthralgia. Many of these symptoms are indistinguishable from dengue fever, and simultaneous isolation of both dengue and Chikungunya from sera of patients has been reported.2 Chikungunya virus, an Old World alphavirus, is related antigenically to O'nyongnyong virus and is not known to be neurotropic. However, meningoencephalitis has been reported in outbreaks in India and the Reunion Islands. 3,4 We present the clinical, neuroimaging, and brain autopsy findings of Chikungunya encephalomyeloradiculitis, a relatively unknown and rare complication of the infection. Case Reports Case 1A 65-year-old man had low-grade fever and joint pain, which were treated with analgesics. A few days later he became drowsy. Findings of a complete blood analysis were normal. However, the patient's condition deteriorated clinically. On examination, he was semiconscious with neck rigidity, no limb movements, and an extensor plantar response. CSF analysis revealed elevated proteins, low sugars, and a few cells with lymphocyte predominance. CSF and serum were positive for immunoglobulin M (IgM) antibodies to Chikungunya virus. Intravenous methylprednisolone was administered for 5 days with 5 cycles of plasmapheresis. The patient was shifted to our hospital 45 days after the onset of symptoms. Electromyography (EMG) and nerve-conduction studies revealed acute generalized motor axonal neuropathy with no sensory component. Brain MR imaging revealed bilateral frontoparietal white matter lesions with restricted diffusion (Fig 1A), which enhanced on postcontrast T1-weighted (T1WI) fatsaturated images (Fig 1B). Spinal MR imaging revealed enhancement of the ventral cauda equina nerve roots (Fig 1C). He was administered IV dexamethasone and given supportive treatment; however, he did not improve clinically and was lost to further follow-up. Case 2A 73-year-old man had fever and joint pain, which were treated with analgesics. A few days later, he became drowsy and unresponsive with reduced limb movements. He was admitted 1 week after initial onset of symptoms. Examination revealed absent deep tendon reflexes with an extensor plantar response. CSF studies revealed increased cells (predominantly lymphocytes), elevated proteins, and low sugar. CSF and serum were positive for IgM antibodies to the Chikun...

Case Reports of Neuro-Chikungunya in Southern Thailand

“…Such findings were rather unique and were also reported in patients with CHIK in India. 21,22 A pathologic correlation with autopsy specimens suggested that these findings were caused by the subcortical demyelination process. 22 Although such findings have been described in Nipah virus encephalopathy, they were quite distinct from Japanese encephalitis or herpes virus encephalitis, which affect only the gray matter, 23 are patchy lesions, and are usually involve the thalamus.…”

“…21,22 A pathologic correlation with autopsy specimens suggested that these findings were caused by the subcortical demyelination process. 22 Although such findings have been described in Nipah virus encephalopathy, they were quite distinct from Japanese encephalitis or herpes virus encephalitis, which affect only the gray matter, 23 are patchy lesions, and are usually involve the thalamus. 24 Patient 3 had acute progressive quadriparesis and myeloneuropathy confirmed by MRI and electromyography, which showed acute sensorimotor peripheral neuropathy typical for demyelinating disease.…”

“…7,20 There have been few reports of detailed neuroimaging findings for neuro-chikungunya. 21,22 For patient 2, brain MRI abnormalities were exclusively located in the subcortical white matter, and multiple tiny hyperintense dots were observed in T2-weighted and fluid-attenuated inversion recovery images ( Figure 2 ). Such findings were rather unique and were also reported in patients with CHIK in India.…”

“…8 The pathologic changes were more those of non-specific encephalitis, and no definite viral inclusions were seen. 9,22 However, direct invasion of the central nervous system by the virus probably accounts for the encephalitic form because neurologic manifestations arise at the acute viremic stage of infection 6 and CHIKV has been isolated from brain 9 and CSF of patients. 4,21 In addition, the presence of IgM against CHIKV in the CSF, such as that found in patient 1, also supports the theory of neuroinvasion.…”

Encephalitic Arboviruses: Emergence, Clinical Presentation, and Neuropathogenesis

“…CHIKV is a re-emerging alphavirus that can cause severe and fatal disease with CNS involvement of both adults and neonates [11][12][13][14]. Prior to its re-emergence in the Indian Ocean in 2004 and ensuing worldwide spread, CHIKV infections rarely involved the CNS.…”