Epilepsy in Down Syndrome without videos or pictures

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Epilepsy in Down’s Syndrome
Dr Sameer Zuberi
Paediatric Neurologist
Fraser of Allander Neurosciences Unit
Royal Hospital for Sick Children
What is epilepsy ?
• An epileptic seizure is the
behavioural manifestation of
an abnormal
hypersynchronous electrical
discharge from cortical
• Epilepsy is recurrent epileptic
seizures not provoked by
everyday stimuli
Almost every condition affecting the cerebral cortex can result in epilepsy
Chromosome disorders & Epilepsy
6% of (172) patients with learning difficulties and
epilepsy have a chromosome abnormality (Ieshima
A et al 1998)
Rises to 50% in patients with seizures and >3
dysmorphic features
> 400 chromosomal disorders are associated with
epilepsy and many (≈ 40) have epilepsy as a
common feature. Smaller number have epilepsy as a
consistent feature
Chromosome studies rarely ordered when faced with
a child who develops cognitive problems after the
onset of epilepsy
Chromosomal disorders strongly
associated with epilepsy
Wolf-Hirschhorn Syndrome (4p-)
Miller-Dieker Syndrome (del 17p13.3)
Angelman Syndrome
Inversion duplication 15 Syndrome
Duplication syndromes
– additional segment of material
Terminal deletion chromosome 1q
Terminal deletion chromosome 1p
Deletion syndromes
– Segment genetic material missing
Ring 14 syndrome
Breakpoint disruptions
– Only one or very few genes affected
Ring 20 syndrome
?Phenotype related to gene dosage- haploinsufficiency or “triplo-excess”
How common is epilepsy in Down’s
• Figures depend on size of series, definition of epilepsy,
age of cases, source of population
• Prevalence figures vary from 1 to 9%, compares to
<0.5% in general population
• Are some seizure types such as febrile seizures (0.9%)
less common in Down’s Syndrome?
Postal Survey of 1000 families with a child
with Down’s Syndrome
Mary King and John Stephenson (Fits & Faints 1990)
• Most children do not have epileptic or nonepileptic seizures
• Infantile spasms occurred in 2%
• Syncope appeared to be common including
reflex anoxic seizures and convulsive
Goldberg-Stern et al. Brain Dev 2001; 23:375-8
• 350 children & adolescents
• 8% had epilepsy (prevalence)
• 47% partial seizures
• 32% infantile spasms
• 21% generalised tonic clonic seizures
Epilepsy Phenotypes in Down Syndrome
• Infantile spasms
• Focal epileptic seizures secondary to acquired
brain lesions
• Reflex / startle epilepsy
• Late onset myoclonic epilepsy in Down’s
Syndrome (LOMEDS)
A bi-modal distribution
Infantile spasms
• 8-10 x more common than in general
• 2 groups
– Those symptomatic of perinatal hypoxic brain
injury who have a poor prognosis
– No acquired brain injury. A relatively good
Infantile Spasms
• West Syndrome
An electroclinical triad of:
spasms, hypsarrythmia, and
regression or stagnation of
mental abilities
West Syndrome is not synonymous
with Infantile spasms
Classified as symptomatic or
Video of behaviour pre-treatment
EEG prior to treatment
EEG during spasm
Treatment options
• Hormonal treatments
• Steroids
– 2mg/kg of prednisolone for 2 weeks
• Vigabatrin
• Pyridoxine
• Sodium valproate
Important to repeat the EEG
Behaviour post treatment in EEG department
EEG post treatment
Eisermann et al. Infantile Spasms in Down Syndrome –
effects of delayed anticonvulsive treatment.
Epilepsy Research 2003; 55:21-7
• 18 patients with spasms
• Correlation between treatment lag
– cessation spasms
– developmental quotient
– autistic features
Video of Sleep Start
EEG during sleep start
Non-epileptic Paroxysmal Disorders
in Down Syndrome
• Syncope
– Associated with congenital heart disease
– Reflex anoxic seizures / reflex asystolic
• Sleep starts
• Tics / Tourette Syndrome
Focal epileptic seizures
• Can have benign focal epilepsies such as
rolandic epilepsy
• More common are lesional focal epilepsies
– Cyanotic heart disease and abscess
– Stroke related to cardiac disease or to cardiac
Startle Epileptic Seizures
Guerrini R, Genton P, Bureau M, Dravet C,
Roger J Reflex seizures are frequent in patients
with Down syndrome and epilepsy.
Epilepsia. 1990 Jul-Aug;31(4):406-17.
Seizures with variety of aetiologies but triggered by
sound and touch. Is there reduced cortical
inhibition in Down’s Syndrome?
Late onset myoclonic epilepsy
• Incidence of epilepsy in Alzheimer’s
disease without Down’s Syndrome is 10%
• Incidence of epilepsy in Down’s Syndrome
with Alzheimer’s like dementia is 75%
Late onset progressive myoclonus
Most common after age 50
Associated with dementia
May respond to valproate or
Occasional generalised
generalised tonic clonic seizures
Also called senile myoclonic