A case of brainstem encephalitis with CT scan abnormality mimicking Fisher syndrome

Pediatric Bickerstaff brainstem encephalitis: a systematic review of literature and case series

OBJECTIVE

To characterize the phenotype of pediatric Bickerstaff's brainstem encephalitis (BBE) and evaluate prognostic features in the clinical course, diagnostic studies, and treatment exposures.

METHODS

We systematically reviewed PubMed, Web of Science, and SCOPUS databases as well as medical records at the Lucile Packard Children's Hospital to identify cases of pediatric BBE. Inclusion required all of the following criteria: age ≤ 20 years, presence of somnolence or alterations in mental status at the time of presentation or developed within 7 days of presentation, ataxia, and ophthalmoplegia.

RESULTS

We reviewed 682 manuscripts, identifying a total of 47 pediatric BBE cases. We also describe five previously unreported cases. The phenotype of these pediatric patients was similar to previously published literature. Sixty-eight percent of patients demonstrated positive anti-GQ1b antibody titers, yet the presence of these antibodies was not associated with longer times to recovery. Patients with neuroimaging abnormalities featured a longer median time to recovery, but this was not statistically significant (p = 0.124). Overall, patients treated with any form of immunotherapy (intravenous immunoglobulin, steroids, or plasmapheresis) demonstrated shorter median time to resolution of symptoms compared to supportive therapy, although this trend was not statistically significant (p = 0.277). Post-hoc t tests revealed a trend towards use of immunotherapy against supportive care alone (p = 0.174).

CONCLUSION

Our study identified clinical, radiologic, and treatment features that may hold prognostic value for children with BBE. The role of immunotherapy remains under investigation but may prove of utility with further, randomized controlled studies in this rare disease.

Rhomb- and bickerstaff encephalitis: two clinical phenotypes?

We report unusual cases of brainstem encephalitis in two young boys. Both presented with acute febrile illness, progressive encephalopathy, and marked cerebrospinal fluid pleocytosis. Case one shared some of the clinical features that have been seen in previously reported cases of brainstem encephalitis, such as ophthalmoplegia, ataxia, and progressive encephalopathy. Case two presented with similar clinical features, although without ophthalmoplegia and ataxia. A review of magnetic resonance imaging revealed mild differences with respect to anatomic lesion localization and confirmed a neuroanatomic basis for the variance in each patient's symptoms. The features of these cases deviate from the classical symptoms described in the Miller-Fisher syndrome/Bickerstaff brainstem encephalitis/Guillain-Barré syndrome spectrum, although the cause for variability in clinical phenotypes is unknown.

Neuro-ophthalmic manifestations of the syndrome of ophthalmoplegia, ataxia and areflexia: a review

Controversy regarding the nosological position of the syndrome of ophthalmoplegia, ataxia and areflexia (Miller Fisher syndrome) exists. The oculomotor dysfunction was presumed to represent an unusually symmetrical peripheral cranial nerve dysfunction. To investigate the neuro-ophthalmic manifestations in this rare syndrome we reviewed 109 reports describing 243 cases. The ophthalmoplegia was remarkable in its constant association with a cerebellar type ataxia. It was described to be remarkably symmetrical at all stages of development and recovery. From the early description of the syndrome by Fisher the ophthalmoplegia was observed to evolve as a symmetrical failure of upgaze followed by loss of lateral gaze and last by downgaze, recovery develops in the opposite pattern. Despite the severe nature of the ophthalmoplegia, 58 patients were reported to have sparing of downgaze and 192 (79%) had relative sparing of the eye lids. Active lid retraction and preserved Bell's phenomenon, despite upgaze paralysis, were described in 22 and 15 patients respectively. Upper lid jerks were described in 2, Parinaud's syndrome in 2, convergence spasm in 6, internuclear ophthalmoplegia in 15 and horizontal dissociated nystagmus in 11. Interestingly 23 were reported to present with paralysis of abduction progressing to lateral gaze paralysis and 5 had paralysis of abduction and contralateral gaze paralysis. Four had defective vestibulo-ocular reflex despite recovery of upgaze, 10 had central type nystagmus including rotatory, retractory and rebound nystagmus. Relative preservation of optokinetic nystagmus and preservation of vestibulo-ocular reflex despite an otherwise complete ophthalmoplegia were reported in 6 and 2 patients respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Ataxia and areflexia in SOAA

Fifteen patients with the classical syndrome of ophthalmoplegia, ataxia, and tendon areflexia (SOAA) were studied in an attempt to clarify the mechanisms of ataxia and myotatic hyporeflexia. All showed features of cerebellar rather than sensory ataxia. Peripheral nerve conduction studies, including F-waves, were normal in a majority of the patients, as was needle EMG. Low-amplitude compound sensory nerve potentials were seen in four patients only, and mild slowing of sensory conduction velocity in two. Three had abnormal blink reflex studies, suggestive of a central lesion in two, and another two showed a transient delay of N5 peak of brainstem auditory evoked potentials. Somatosensory evoked potentials were normal. Despite clinically depressed or absent tendon jerks, T-waves were elicited at normal latencies. These findings do not support the prevailing view that the neurological abnormalities in SOAA are due to involvement of sensory fibres in the peripheral nerves and dorsal roots. We suggest that lesions scattered in the brainstem tegmentum and in the cerebellar peduncles are responsible for the ataxia and the depressed tendon jerks.

Acute disseminated encephalomyelitis probably related to a Mycoplasma pneumoniae infection

A 36-year-old woman was suffering from acute disseminated encephalomyelitis, which had been preceded by a febrile illness. Brain CT showed diffuse white matter hypo-attenuation. Electroencephalography initially revealed altered non-REM sleep followed by diffuse slowing. Brain stem auditory evoked potentials showed interwave delay, while pattern visual evoked potentials were normal. The patient made a full recovery and the CT scan and EEG normalized. Serological evidence of Mycoplasma pneumoniae was present.

Dorsal midbrain encephalitis caused by Propionibacterium acnes. Report of two cases

A syndrome of dorsal midbrain dysfunction in association with a central nervous system anaerobic diphtheroid infection is described. Two cases of infection with Propionibacterium acnes manifested as shunt malfunctions with a clinical dorsal midbrain syndrome. Magnetic resonance images showed increased signal in the midbrain tectum which has decreased slowly over time. The evidence suggesting that this syndrome represents bacterial midbrain encephalitis is discussed.