Post-infectious encephalomyelitis: some aetiological mechanisms

Patient with both lupus anticoagulant and acute disseminated encephalomyelitis

We present the unusual case of 16-year-old girl who developed intractable convulsions five days after the onset of a cold. Meningeal signs, lymphopenia, proteinuria, and lupus anticoagulant were also present. Treatment with anticonvulsants, antituberculous agents, and adenine arabinoside were ineffective. The initiation of methylprednisolone pulse therapy immediately resolved convulsions and fever. The diagnosis, suggested by the clinical course and the marked improvement of the meningoencephalitis by pulse therapy, was an encephalitic form of acute disseminated encephalomyelitis. Clinical and laboratory findings indicated that an immune disorder may have triggered an abnormal response to a viral infection leading to this patient's neurologic disorder.

Acute disseminated encephalomyelitis (ADEM) or ADEM-like inflammatory changes in a heart-lung transplant recipient: a case report

Acute disseminated encephalomyelitis (ADEM) is a white matter inflammatory disease which usually follows a viral infection or pharmaceutical intervention. We describe a case of presumed ADEM in a heart/lung transplant patient, the etiology of which cannot be elucidated. The fascinating aspect is the mode of clinical presentation and the rapid resolution of radiologic abnormalities. Histologic examination of the brain is provided in an attempt to elucidate the radiographic abnormalities.

Disseminated hemorrhagic leukoencephalomyelitis with localized herpes simplex brain stem infection

A case of widespread hemorrhagic and perivenous demyelinative leukoencephalomyelitis complicating a localized herpes simplex virus (HSV) brain stem infection is reported in a 28-year-old man. The presence of the virus is documented immunohistochemically and ultrastructurally. The spinal trigeminal tract at the level of the medulla oblongata contained viral antigen in the neurons, glia and in the vascular walls, including a few endothelial cells. The foci of demyelination showed deposits of gamma globulins and slight inflammatory infiltrations; the virus was absent from these lesions. It is postulated that HSV entered the central nervous system through the trigeminal nerve. Focal expression of the viral antigen on the endothelium in a sensitized host was the likely precipitating factor in the hyperacute autoimmune reaction, resulting in the widespread hemorrhagic and demyelinating lesions in the central nervous system.

Post-infectious leukoencephalopathy as a complication of Mycoplasma pneumoniae infection

We report a 9-year-old girl with leukoencephalopathy who demonstrated serologic evidence of a Mycoplasma pneumoniae infection. She had a mild upper respiratory tract illness 10 days prior to admission and developed walking difficulty and somnolence. The neurologic symptoms progressed to semicoma and spastic paraplegia over a few days but began to improve on the fourth day. Cranial computed tomography on the eleventh day revealed an area of diffuse low density in the white matter. Cerebrospinal fluid examination was normal. The patient recovered with minimal motor deficits. Cranial computed tomography was normal. She was diagnosed as having leukoencephalopathy complicated by a Mycoplasma pneumoniae infection. The pathogenesis of this infection is believed to be an allergic reaction to Mycoplasma pneumonia of the central nervous system as well as an acute disseminated encephalomyelitis.

An autopsied case of acute hemorrhagic leukoencephalitis

This is a clinico-pathological study of one case of acute hemorrhagic leukoencephalitis occurring in a patient with lung cancer. The main changes observed by light microscopy were in the white matter. All of these changes were the result of hemorrhage and demyelination around the venous vessels. Glial mesenchymal reactions were minimal. In view of these findings, this case supports the hypothesis that immune mechanisms play a role in the pathogenesis of neuropsychiatric symptoms during malignant illnesses. Here we will discuss the problem of differential diagnoses of acute hemorrhagic leukoencephalitis and its close morphologic similarities to perivenous encephalitis. Acute hemorrhagic leukoencephalitis and perivenous encephalitis may be a single entity of a demyelinating disease.

Marek's disease virus-induced transient paralysis: a comparison of lesions in susceptible and resistant lines of chickens

A study was conducted to determine the causative lesion of Marek's disease virus-induced transient paralysis. Brain histologic lesions were quantitated and compared in genetically resistant and susceptible inbred chickens. Comparisons were made 11 days post inoculation (PI) of virus when clinical signs were evident in susceptible birds and on day 17 PI when these signs had remitted. Clinically-affected birds from the susceptible line on day 11 PI had consistent evidence of neuropil vacuolation compatible with brain edema; two of these birds also had vasculitis. These lesions were absent in both clinically-recovered birds from this line evaluated on day 17 PI and genetically resistant birds studied on day 11 PI. Our findings suggest that the causative lesion of transient paralysis is vasogenic brain edema.

Neurological complications of swine influenza vaccination

The emphasis upon the remarkably large number of cases of Guillain-Barre syndrome which resulted from the 1976 National Swine Influenza immunization program in the U.S.A. has obscured the fact that other neurological complications, involving the central nervous system also occurred. The anatomical distribution of lesions is almost identical with that seen following other types of vaccination: involvement of the brain, cerebellum, optic nerve, cranial nerves and spinal cord occurred with approximately the same frequency. 5 instances of the very rare subacute or chronic, progressive, post-vaccinal encephalopathy are described, a situation which is identical to the subacute and chronic forms of polyradiculoneuropathy. In a number of cases, in particular the myelopathies, a subclinical involvement of peripheral nerves was demonstrated by means of electrodiagnostic studies, illustrating the often overlooked fact that central nervous system involvement will mask peripheral nerve lesions. The etiological significance of the swine influenza vaccination was overlooked and completely erroneous diagnoses were established in a surprisingly large number of the 26 new cases reported here.

Late onset of Guillain-Barré syndrome

The Guillain-Barré syndrome (GBS) usually occurs within one month of the precipitating cause. It is the purpose of this paper to show that typical cases may, however, appear weeks to months later. We have reviewed the collected data on these cases and suggest that they provide evidence which is in favour of a humoral, rather than a cell-mediated, aetiology for GBS.