Acute bilateral thalamic necrosis in a child with Mycoplasma pneumoniae

Abstract

A previously neurodevelopmentally intact 5-year-old male was admitted to hospital with a right lower lobe pneumonia with pleural effusion, subsequently confirmed to be a Mycoplasma pneumoniae infection. On the seventh day of the illness he had a prolonged generalized tonic or tonic-clonic convulsion, requiring intubation and ventilation. He was slow to regain consciousness (Child's Glasgow Coma Score 7-10 over 6 days) and brain imaging with CT and then MRI demonstrated bilateral thalamic lesions with oedema and central haemorrhage suggestive of acute bilateral thalamic necrosis, without striatal or white-matter involvement. He was treated with a 2-week course of erythromycin, and as an autoimmune process was considered possible, 5 days of intravenous methylprednisolone (20 mg/kg/day) followed by a 4-week oral prednisolone taper. He made a slow recovery over the next few weeks with almost complete neurological recovery by 2 months but with significant dysarthria, drooling, and a mild left hemiparesis. At 9 months, significant dystonia continued to affect his speech and, together with tremor, his upper-limb fine motor function bilaterally. His gait, personality, and higher cognitive functions appeared to have recovered fully. Although acute striatal necrosis, acute disseminated encephalomyelitis, and encephalitis have been reported with Mycoplasma pneumoniae and a similar picture of acute bilateral thalamic necrosis with influenza-A ('acute necrotizing encephalopathy'), this is the first reported case of Mycoplasma pneumoniae-associated isolated acute bilateral thalamic necrosis.

Influenza A virus-associated acute necrotizing encephalopathy in the United States

“…7 The hallmark of this type of encephalopathy is multifocal, symmetric brain lesions affecting the thalamus bilaterally, brainstem tegumentum, cerebral periventricular white matter and cerebellar medulla, which can be visualized best by MRI. 3,8 Our patient had MRI findings consistent with those described in ANE, and influenza A virus was isolated from the upper respiratory tract; therefore this patient appears to be the first patient described in the United States with ANE related to documented influenza A infection.…”

Mycoplasma pneumoniae as an Under- Recognized Agent of Vasculitic Disorders

“…Concerning its etiology, it has been reported that no patients with M. pneumoniae-associated striatal necrosis have also exhibited systemic hypercoagulative state. A similar disease called acute necrotizing encephalopathy affecting the bilateral thalami is believed to stem from vascular injury in the absence of a thrombotic mechanism [Mizuguchi et al, 1995], and a few cases of bilateral thalamic necrosis strongly resembling acute necrotizing encephalopathy have been reported in association with M. pneumoniae infection [Ashtekar et al, 2003;Perez et al, 2002]. It can reasonably be postulated that the pathomechanism underlying striatal necrosis must be local vasculitis induced by M. pneumoniae through the operation of cytokines and chemokines and leading eventually to vascular occlusion.…”

Central nervous system manifestations of Mycoplasma pneumoniae infections

“…Encephalitis with or without meningeal involvement, aseptic meningitis, transverse myelitis and acute disseminated encephalomyelitis (ADEM), thromboembolic stroke, Guillain-Barre syndrome and radiculitis have all been reported (Table 1). [67][68][69][70][71][72] Acute bilateral thalamic necrosis 151 Haemorrhagic leukoencephalitis (Hurst) 9 Bickerstaff's brainstem encephalitis 74 Postinfectious leukoencephalopathy-ADEM 3 …”