CEREBELLITIS
A.K.A.
acute cerebellar ataxia,
Inflammatory
process characterized by an acute or subacute onset of cerebellar ataxia
following an infection (usually viral; usually GI or respiratory)
- Most
frequently seen in children 1-6 y.o. and young adults, but may occur in elderly
- 0.05-0.1%
of children with varicella infection develop cerebellar ataxia
- In young
adults, male:female 2:1 to 4:1
Symptoms / Signs
- Ataxia
may develop over several hours, days or slowly over a period of 1-4 weeks after
infection
- May
present as a pure cerebellar syndrome or as part of a more diffuse inflammatory
process (brain stem, cerebrum)
Cerebellar symptoms/signs
-
Dysarthria (45%)
- Ataxia
(limb (55%), truncal / gait (42%))
-
Oculomotor disturbances (75%)
Impaired smooth pursuit (60%), dysmetria of saccades (55%),
impaired suppression of VOR (55%), nystagmus (40%), macro square wave jerks,
ocular flutter, opsoclonus (12%)
Extracerebellar symptoms/signs
- Cranial
nerve palsies
-
Uni-/bilateral sensory disturbance
-
Hyperreflexia, upgoing plantar responses, increased tone
- Nausea /
Vertigo
- Seizures,
drowsiness (diffuse inflammation)
Etiology of Cerebellitis
***Causative
agent not identified in 35% of cases
Children
- VZV,
Measles, Mumps, EBV, Hepatitis A, Parvovirus B19
- Rubella
- Pertussis
- Q fever (C.
burnetti)
-
Vaccinations (DTP, MMR, Varicella, Influenza, HepB)
Adults
- EBV,
influenza, parainfluenza, enterovirus (polio, coxsackie, echo), HSV, VZV, CMV,
adenovirus, HIV, mumps
- Lyme (B.
burgdorferi)
- Mycoplasma
-
Legionella
-
Salmonella typhi
- P.
falciparum
(malaria)
-
Rickettsia
Differential diagnosis
Infectious
Listeria
TB
Demyelinating
MS, ADEM
Neoplastic
Cerebellar / Posterior fossa tumor
(primary or secondary)
Neuroblastoma
Paraneoplastic cerebellar
degeneration (PCD)
Lymphoma
Inflammatory
Sarcoid
GBS
/ Miller Fisher variant (ataxia, ophthalmoplegia, areflexia)
Drugs
Thallium, lead, barbiturates,
dilantin, piperazine, alcohol, solvents, antineoplastic drugs
Hydrocephalus
Foramen
magnum compression
Investigations
- Serology,
acute and convalescent
- Blood
films (malaria)
- CSF
Pleocytosis (WBC up to 250/mcl),
60-99% lymphocytes
Elevated protein; Glucose normal or
slightly reduced
IgG/albumin ratio: normal in 40%
Oligoclonal banding: usually absent
Viral culture / PCR
- EEG /
Evoked potentials (Degree of CNS involvement)
- CT / MRI
Inflammation (bright on T2,
gadolinium enhancement)
Edema / swelling (10-15%)
Obstructive hydrocephalus
Treatment
- IV
acyclovir 10mg/kg q8h x 10-14 days
Reduces duration and severity if
given early for VZV or HSV infection
- Lyme disease
IV ceftriaxone 2g BID x 2 weeks
- Q fever (C.
burnetti)
Minocycline 4mg/kg OD
-
Corticosteroids
Controversial, disease self-limiting
Depends on severity
IV methylprednisolone 1g/day x 5
days followed by oral taper
Prognosis
- Complete
recovery in majority in 1-30 weeks
- Mild to
moderate cerebellar deficits in 10% to 40%
- Bad
prognostic signs during acute phase: Yawning, hiccoughs, >40 y.o.
- Patients
with long term sequelae usually demonstrate moderate to severe cerebellar
atrophy
References:
The
cerebellum and its disorders. Mario Ubaldo Manto and Massimo Pandalfo (ed.),
Cambridge University Press,
Last
update: August 2003
Reviewed
by: pending review
Neurological
Medicine Pocketbook
© 2003-2004
UWO Neurology Residents
http://www.uwo.ca/cns/resident
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