Bickerstaff's Brainstem Encephalitis
Bickerstaff's brainstem encephalitis is an immune disorder of unknown aetiology with acute, progressive cranial nerve dysfunction, associated with cerebellar ataxia and coma. Bickerstaff brainstem encephalitis is associated with the presence of anti-GQ1b antibodies.
It may result in apnoea and a reversible brain death picture.
No structural brain damage has been demonstrated.
Bickerstaff reported eight patients who, in addition to acute ophthalmoplegia (diplopia) and ataxia, showed drowsiness, extensor plantar responses or hemisensory loss.
Clinical deterioration in Bickerstaff's brainstem encephalitis is caused by overlapping Guillain-Barré syndrome. There is a clinical continuum between Bickerstaff brainstem encephalitis and Fisher syndrome.
Epidemiology
Very rare. Mostly reported in adults but cases affecting children have also been reported.4
Very often follows preceding illness and an association with certain infections, including cytomegalovirus, Campylobacter jejuni, typhoid fever and Mycoplasma pneumoniae, has been documented.
Presentation
Acute diplopia
Ataxia
Pyramidal tract paralysis
Disturbance of consciousness
Headache is common
Progressive, symmetrical ophthalmoplegia, ataxia and either disturbance of consciousness or hyperreflexia
Facial palsy, extensor plantar reflex, pupillary abnormality, nystagmus and bulbar palsy
Differential diagnosis
MRI scan abnormalities; multiple sclerosis, Behcet's disease , Lyme Disease, progressive multifocal leukoencephalopathy, sarcoidosis, Whipple's disease, listeria rhombencephalitis, vasculitis due to systemic lupus erythematosus (SLE), and acute disseminated encephalomyelitis all produce similar inflammatory lesions in the brainstem and cerebellum.7
Investigations
One review of 62 patients found positive serum anti-GQ1b IgG antibody in 66%, and brain abnormality on MRI scan in 30% of patients.8
The presence of anti- GQ1b antibodies and an abnormal brain MRI can help to support its diagnosis but absence of anti-GQ1b antibodies and a normal MRI do not exclude the diagnosis, which remains based on clinical criteria and exclusion of other aetiologies.9
Electrodiagnostic study results suggested peripheral motor axonal degeneration.
Associated diseases
A large number of patients have associated Guillain-Barre syndrome, suggesting that the two disorders are closely related.10
Miller Fisher syndrome:11 syndrome of ophthalmoplegia, ataxia and absent reflexes.
Management
Success has been achieved with treatment with steroids plus double filtration plasmapheresis12 and also with immunoglobulin therapy.13
However there are no randomised controlled trials of immunomodulatory therapy.
Prognosis
Although the initial presentation is severe, there is usually a good outcome with complete resolution.
Cases of recurrent Bickerstaff's brainstem encephalitis have been reported.
divisions of the nervous system explained in simple language
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment