Genetics, Epilepsy and Behavioral Manifestations in Children with Lissencephaly and Subcortical Band

1
Genetics, Epilepsy and Behavioral Manifestations
in Children with Lissencephaly and Subcortical
Band Heterotopia

• Joseph G. Gleeson, MD
• Neurogenetics Laboratory
• Dept. Neurosciences
• University of California, San Diego

2
Acknowledgements
Gleeson Lab Teruyuki Tanaka, MD Finley
Serneo Stephanie Bielas Holden Higgenbotham Magda
Chechlacz, Ph.D. Hiroyuki Koizumi, Ph.D. Carrie
Louis Sarah Marsh, MS Tracy Salazar-Dixon Jennifer
Silhavey Organizations Joubert Syndrome
Foundation Lissencephaly Network NHLBI Mammalian
Genotyping Service (J. Weber, Marshfield
WI) Funding NINDS, March of Dimes, EFA
Collaborators Dr. B. Ben-Zeev Dr. Geoff Woods Dr.
Richard Leventer Dr. Terry Sanger Dr. Steven
Leber Dr. William Weiss Dr. Clem Donahue Dr.
Brian Tsemg Dr. Jin Hahn Dr. Saevar
Halldórsson Dr. Petúr Ludvigsson Dr. Darryl De
Vivo Dr. Kathryn Swoboda
Dr. Laszlo Sztriha Dr. Lihadh Al-Gazali Dr.
William Dobyns Dr. Bernard Maria Dr. Eva
Andermann Dr. Melissa Parisi Dr. A. James
Barkovich Dr. Alvaro Pasqual-Leone Dr. Enza Maria
Valenti Dr. Gururaj Aithala Dr. Asma A.
Al-Tawari Dr. Hulya Kayserili
3
Approximately 40-60 of pediatric drug-resistant
epilepsies are caused by malformations of the
cerebral cortex
Dowd et al. Epilepsia 1991 Jay et al. J
Neurosurg 1993 Prayson et al. Ann Diagn Pathol
2003 Porter et al. Neurol 2003
4
Many patients with dysplasia can become
seizure-free on AEDs
Seizure tractability on par with other seizure
etiologies
Stephen LJ, Kwan P, and Brodie MJ. Does the cause
of localization-related epilepsy influence the
response to antiepileptic drug treatment?
Epilepsia (2001) 42, 357.
5
Neuronal Migration Disorders
Generalized -Cortical -Lissencephaly
(Agyria/Pachygyria) -Polymicrogyria -Subcortica
l -Double cortex (Subcortical band heterotopia)
-Periventricular heterotopia Focal -Cortical
-Focal cortical dysplasia -Cortical
tuber -Focal or regionalized polymicrogyria -Su
bcortical -Subcortical heterotopia -Subependym
al nodules
6
Normal Cerebral Cortex Development
7
Long distance neuronal migration
22 week normal human cortex, courtesy J. Golden,
U. Penn
8
Classical Lissencephaly
Normal MRI
Lissencephaly MRI
9
LissencephalySmooth Brain

• Clinical Features
• Acquired microcephaly
• Severe mental retardation
• Hypotonia
• Intractable epilepsy
• Infantile spasms
• Atonic/myoclonic
• GTC seizures
• AED Treatment
• ACTH, valproate, clonazepam, lamotrigine,
  vigabitrin, etc.

10
Classical lissencephaly is characterized by a
4-layered cortex
2 y.o. normal
2 y.o. lissencephaly
11
Double Cortex
12
Double Cortex Subcortical Band Heterotopia

• Clinical Features
• Normocephaly
• Mild-moderate mental retardation
• Gross fine motor delay
• Seizures starting around 4 years often with
  Lennox-Gastaut syndrome
• Seizure onset correlated with ictal discharges
  from heterotopia and outer cortex (Mai et al.
  Neurology 2002)

13
Activation of overlying cortex and band with
volitional movement
L R
L R
Finger tapping left Finger tapping right
Draganski, Neuroreport 2004
14
Genetic etiology of classical lissencephaly and
double cortex syndrome
doublecortin (DCX)
lissencephaly-1 (LIS1)
Xq22.3-23
17p13.3
15
DC/X-LIS
Pinard et al. 1994
16
X-inactivation
17
X-chromosome mosaicism underlies DC pathogenesis
Normal
Lissencephaly
Double cortex
18
(No Transcript)
19
Somatic mutations can lead to double cortex in
males
(Gleeson 2000)
20
Mutation predicts severity in DC/XLIS
Type of mutation
Degree of Cognitive Impairment
Reproductive Fitness
Thickness of Heterotopic Band
21
Lissencephaly with Ambiguous Genitalia
Aristaless Related Homeobox (ARX)
Xp22
Bonneau et al. 2002 Ann Neuro.
22
Aristaless Related Homeobox (ARX)

• Several distinct syndromes
• Lissencephaly and ambiguous genitalia
• Hydrancephaly with ambiguous genitalia
• West syndrome with subsequent severe MR/SZ
• Moderate MR w/ dystonic hand movements
• Infantile myoclonic seizures and subsequent
  cerebral palsy
• Non-syndromic XLMR

23
Genotype-Phenotype correlations in ARX Protein
termination mutations -gt malformationsPolyAla
expansions -gt epilepsy/MR
Malformations include hydrancephaly, XLAG,
ACC Non-malformations include West syndrome,
epilepsy, autism, MR
(Kato et al. Hum Mut, 2003)
24
Etiology of Seizures in XLAGInsufficient
GABAergic interneurons?
Wild-type
Arx -/y
Kitamura et al. 2002 Nat Genet.
25
Surgical resection for intractable epilepsy in
double cortex syndrome yields inadequate results

• Eight patients received full pre-surgical
  evaluation
• All had regional or focal seizure onset, although
  most with multilobar epileptic abnormalities
• Surgeries Multiple subpial transections(2),
  Frontal lesionectomy(1), Temp lobectomy (5)
  callosotomy(1)
• Five patients had no significant improvement, two
  had some improvement, and one was greatly improved

Bernasconi et al. Epilepsia 2001
26
Patients with lissencephaly may benefit from VNS
27
Joubert syndrome and cortical polymicrogyria
28
Joubert Syndrome Agenesis of the cerebellar
midline (vermis)
Normal
Vermis Agenesis
29
Joubert Syndrome Molar tooth malformation
Normal
Vermis Agenesis
30
Joubert Syndrome

• Clinical Hallmarks
• Hypotonia (100)
• Developmental Delay (100)
• Ataxia (75)
• Hyperpnea/Apnea (50-75)
• Oculomotor apraxia (50-75)
• Autism
• Seizures

31
Three consanguineous JS families map to Chr. 6
Dixon-Salazar et al. 2004 A J Hum Genet
32
Chr. 6-linked Joubert syndrome Polymicrogyria and
Corpus Callosum Abnormalities
MTI10 MTI115
MTI144
Dixon-Salazar et al. 2004 A J Hum Genet
33
Mutations in the AHI1 gene, encoding Jouberin,
leads to Joubert syndrome with PMG
MTI10 MTI115
MTI144
Dixon-Salazar et al. 2004 A J Hum Genet, Ferland
et al. 2004 Nat Genet
34
Polymicrogyria/Epilepsy/Spasticity in
Chr.6-linked Joubert syndrome
Sp spasticity Sz seizures CCA corpus
callosal abnormalities PMG diffuse
polymicrogyria u unknown
Lagier-Tourenne 2004, Ferland 2004, Dixon-Salazar
2004.
35
Mutations in AHI, encoding Jouberin, lead
to Joubert syndrome and PMG
Dixon-Salazar et al. 2004 A J Hum Genet
36
Summary
Neuronal Migration Disorders
Subcortical
Cortical
Focal
Generalized
Focal
Generalized
37
Genetics, Behavioral Manifestations, and Epilepsy
in Children with Polymicrogyria
andPeriventricular Nodular Heterotopia

• Bernard S. Chang, M.D.
• Assistant Professor of Neurology
• Harvard Medical School
• Comprehensive Epilepsy Center
• Beth Israel Deaconess Medical Center
• American Epilepsy Society
• Annual Meeting 2004
• New Orleans, LA

38
Outline

• The behavioral and functional study of
  malformations of cortical development
• Polymicrogyria Bilateral symmetric syndromes
• Periventricular nodular heterotopia Imaging and
  cognitive findings
• Lessons and conclusions

39
Malformations of cortical development area
common cause of childhood epilepsy

• Cortical malformations are diagnosed in
• 13.1 of partial epilepsy cases
• 16.8 of intractable partial epilepsy cases
• 6.7 of symptomatic generalized epilepsy cases
• Fujiwara and Shigematsu, 2004
• 64 of refractory temporal lobe epilepsy cases
  had cortical dysplasia histologically, including
  those with other risk factors
• Porter et al., 2003

40
Genetics of MCDs are increasingly well-known,but
behavioral consequences less so
Mochida and Walsh, 2004
41
Polymicrogyria (PMG) is characterized byan
excessive number of small gyri
Courtesy C. Giannini, Mayo Clinic
42
Etiologies of PMG include bothenvironmental and
genetic factors

• Intrauterine ischemia
• Twin-twin tranfusion
• Intrauterine infection
• CMV
• Toxoplasmosis
• Syphilis
• VZV
• Metabolic disorders
• Pelizaeus-Merzbacher disease
• Glutaric acidemia type II
• Maple syrup urine disease
• Histidinemia
• Leigh syndrome
• Zellwegers syndrome
• Neonatal ALD

• Mitochondrial disorders
• Leigh syndrome
• Peroxisomal disorders
• Zellwegers syndrome
• Neonatal ALD
• Chromosomal/genetic disorders
• Chromosome 22q11 deletions
• GPR56 gene mutations
• Aicardi syndrome

Greenfields Neuropathology, 2002
43
PMG most likely arises from a defect inmigration
or post-migrational organization

• Each developing cerebral hemisphere has a
  ventricular zone that consists of neuronal
  progenitors
• Neurons migrate radially outward to form the
  external ribbon of gray matter, the cerebral
  cortex

Rakic and Lombroso, 1998
Olson and Walsh, 2002
44
There are a number of bilateralsymmetric PMG
syndromes
Piao et al., 2004
45
BFPP (bilateral frontoparietal polymicrogyria)has
a severe phenotype

• Clinical features
• Severe cognitive and motor delay
• Dysconjugate gaze
• Some with cerebellar dysfunction
• 15/16 patients have epilepsy, most refractory
• Most have generalized tonic-clonic, tonic,
  atonic, and/or myoclonic seizures
• Complex partial seizures are rare
• EEG shows multifocal and generalized epileptiform
  discharges

Chang et al., 2003
46
The gene responsible for BFPP encodes
aG-protein-coupled receptor of unknown function

• GPR56 (16q12)
• An orphan G protein-coupled receptor
• Expressed in neuronal progenitor areas but not
  cerebral cortex
• As-yet-unknown function in human brain
  development
• Evolutionary lineage suggests an important role
  in frontal lobe size of primates

Piao et al., 2004
47
BFP (bilateral frontal polymicrogyria)is less
clinically severe than BFPP

• Clinical features
• Developmental delay and mild spastic
  quadriparesis
• 12/13 with impaired language 11/13 with mental
  retardation
• No gaze or cerebellar abnormalities
• 5/13 have epilepsy
• Partial, atypical absence, clonic, and
  generalized tonic-clonic seizures
• EEGs show bifrontal slowing with superimposed
  sharp waves and spike-and-wave activity

Guerrini et al., 2000
48
BFP genetics are unknown, but theremay be
multiple subtypes

• Original BFP description included all sporadic
  cases, though 2/3 from consanguineous parents
• Guerrini et al., 2000
• More recently, a number of cases have been seen
  consistent with autosomal recessive inheritance
• Some affect only specific subregions of the
  frontal lobes bilaterally and symmetrically

49
BPP (bilateral perisylvian polymicrogyria) is
characterized by pseudobulbar dysfunction

• Clinical features
• Pseudobulbar palsy and cognitive deficits
• Dysarthria and/or limitation of tongue movement
• 85 mental retardation (mild to severe)
• 27/31 (87) with epilepsy
• Mostly atypical absence, atonic/tonic,
  tonic-clonic, less frequently partial
• EEG in some shows background slowing,
  intermittent bilateral slowing, and multifocal or
  generalized sharps, spikes, and
  polyspike-and-wave activity

Kuzniecky et al., 1993
50
BPP appears to be genetically heterogeneous

• X-linked
• Autosomal dominant, recessive

Villard et al, 2002
Guerreiro et al., 2000
51
BGP (bilateral generalized polymicrogyria)is a
more widespread malformation

• Clinical features
• Cognitive and motor delay of variable severity
• No pseudobulbar signs
• No gaze or cerebellar abnormalities
• 10/12 have epilepsy
• Myoclonic, tonic/atonic, and generalized
  tonic-clonic seizures
• EEGs show multifocal or generalized epileptiform
  activity

Chang et al., 2004
52
Polymicrogyria Lessons

• PMG is a very epileptogenic malformation
• Bilateral PMG syndromes typically lead to
  symptomatic generalized epilepsy rather than
  focal epilepsy
• There are some distinctive clinical features to
  each bilateral PMG syndrome
• The identification of genes responsible for such
  syndromes may shed light on mechanisms for
  regional patterning of the cerebral cortex

53
Periventricular nodular heterotopia is
characterized by gray matter nodules lining the
ventricles
54
PNH is associated with seizures butgrossly
normal intellectual function

• 8 patients with simple PNH
• All had normal early developmental milestones
• All had normal FSIQ

dOrsi et al., 2004
55
The gene responsible for PNH encodesa protein
necessary for neuronal migration

• Early pedigrees suggested X-linked dominant
  inheritance
• FLNA (Xq28) is an intracellular
  actin-crosslinking protein essential for cell
  locomotion
• X-inactivation in heterozygous females leads to
  heterotopic nodules normal overlying cerebral
  cortex

Fox and Walsh, 1999
56
Anatomy, biochemistry, and functional imagingof
cortex in PNH are normal
57
However, the cortex in PNH is focally thinand
has cytoarchitectural abnormalities
Kakita et al., 2002
58
Nodules in PNH have normal signal and
biochemistry and may be physiologically active
Janszky et al., 2003
59
PNH subjects have a specific disability in
reading
60
There is a discrepancy betweenreading ability
and measured IQ
61
Affected subjects show variability in the number,
size, and location of heterotopia
62
but lower reading scores and IQ are seen in
those with diffusely distributed heterotopia
63
Periventricular nodular heterotopia Lessons

• Widespread malformations may lead to surprisingly
  specific behavioral deficits
• Learning disabilities should be considered even
  in MCD patients with grossly normal intellectual
  function
• The study of such patients may expand our
  understanding of dyslexia and other learning
  disabilities

64
Conclusions

• As MCDs are diagnosed with increasing frequency
  using neuroimaging, detailed clinical study is
  needed for complete characterization
• Genotype-phenotype correlations can help to
  elucidate molecular mechanisms involved in
  cortical development
• Behavioral manifestations can be surprising and
  can help to answer questions about cognitive
  processing in the brain

65
Acknowledgments

• Genetics
• Christopher A. Walsh, M.D., Ph.D.
• Ganesh Mochida, M.D., M.M.Sc.
• Volney Sheen, M.D., Ph.D.
• Sophie Currier, B.A.
• Xianhua Piao, M.D., Ph.D.
• Neuroimaging
• Susanne Knake, M.D.
• Bruce Fischl, Ph.D.
• Gottfried Schlaug, M.D., Ph.D.
• Barbara Appignani, M.D.
• David B. Hackney, M.D.
• Neuropsychology
• Jenny Ly, B.A.
• Margaret OConnor, Ph.D.
• Michael Doherty, M.D.
• Hillary Shurtleff, Ph.D.

• Neuropathology
• Jeffrey Joseph, M.D., Ph.D.
• Caterina Giannini, M.D.
• Subject recruitment
• Adria Bodell, M.S.
• Kira Apse, Sc.M.
• Support
• National Institute of Neurological Disorders and
  Stroke (K23 NS 049159-01)
• Clinical Investigator Training Program (Beth
  Israel Deaconess Medical Center, Harvard-MIT,
  Pfizer Inc.)

66
Unilateral Hemispheric MalformationsClinical,
Neuroimaging Spectrum And Surgical
TreatmentPediatric Epilepsy SymposiumAmerican
Epilepsy Society MeetingDecember 6, 2004

• Ajay Gupta, M.D.
• Cleveland Clinic Foundation
• Cleveland Ohio

67
Hemispheric Brain MalformationsOutline

• Discuss phenotypic spectrum of hemispheric
  malformations (Project)
• Clinical diagnosis of associated genetic
  disorders
• Possible Patho-genetic mechanisms
• Surgical treatment

68
Background Pre MRI Era

• Unilateral brain hypertrophy (Sims JM, 1835)
• Hemimegalencephaly A prototype of hemispheric
  malformation
• Dysplasia, disorganization, and overgrowth of one
  entire hemisphere (Hamartomatous)
• A disorder of abnormal proliferation or lack of
  apoptosis
• Histopathology
• Blurred gray-white junction, dysplastic cortex,
  neuronal heterotopia, cytomegaly

Laurence KM Dev Med Child Neurol 1964 Manz MJ et
al. Acta Neuropathol 1979 Robain O et al.
Neuropathol Appl Neurobiol, 1988
69
Hemimegalencephaly

• Sporadic, no known cause
• May be an isolated condition
• Associated syndromes (Entities in Limbo)
• Epidermal nevus syndrome
• Hypomelanosis of Ito
• Klippel-Trenaunay-Weber syndrome
• Proteus syndrome
• Neurofibromatosis type 1
• ? Tuberous Sclerosis

Several case reports 1970s onwards
70
Brain MRI Expanded Phenotypic Spectrum of
Hemispheric Malformations

• Limited to series of case reports
• Hemimegalencephaly Umbrella term
• Subtle or no overgrowth or even small size
• Substantial vs. complete hemisphere
• Large vs. small ventricles
• white matter vs gray matter hyperplasia
• Variety of pathological findings
• Immunohistochemical, ultrastructural studies

Gupta A et al., Neurology, 2004
71
Brain MRI Expanded Phenotypic Spectrum of
Hemispheric Malformations

• Hemimegalencephaly
• 3 clinical types (Sener RN, Comput Med Imaging,
  1997)
• Isolated Syndromic Total (Brain stem,
  cerebellum)
• 3 grades of severity (N10) (Battaglia D,
  Neuropediatr, 1999)
• Grade 1 (Mild) to 3 (Marked) enlargement
• Non specific terms in surgical series
• Hemispheric Syndromes
• Hemispheric cortical dysplasia

Gupta A et al., Neurology, 2004
72
Aim I

• To systematically classify (phenotype) the
  unilateral hemispheric malformations based on the
  brain MRI from the database of two institutions
• Hypothesis Hemispheric malformations are a
  heterogeneous group of conditions with more than
  one distinct MRI phenotype that are currently
  lumped under the umbrella of Hemimegalencephaly
  or hemispheric dysplasias

73
Aim - II

• In a possible scenario that distinct brain MRI
  phenotypes of hemispheric malformations are
  identifiable, then each phenotype may help
• In Clinical and Pathological correlation for
  management decisions
• Motor deficits, Neuro-cutaneous, DQ, seizure
  outcome
• In study of underlying Patho-Genetic mechanisms
  

74
Methods - 1

• Cleveland Clinic and Univ. of Chicago database
• Include patients (after 1996) with predominantly
  unilateral hemispheric involvement
• Estimate 45-52 patients
• Blind review of brain MRI by Pediatric
  Neuro-radiologist (P.R.) on a standardized
  pre-defined matrix

75
Brain MRI Data
76
Methods - 2

• Clinical Evaluation
• Hemiparesis and Neuro-cutaneous stigmata
• Neuropsychological Evaluation
• Developmental Quotient
• Those who had hemispherectomy
• Seizure outcome
• Pathological correlation

77
Summary Of Preliminary Findings

• Brain MRI (N 26)
• Largest single series ever
• We intend to continue

Gupta A et al., unpublished data
78
Hemispheric Malformations May Occur With Normal
or Decreased Size (N26)

• Size of cerebral hemisphere
• Increased 17 (65)
• 1 7
• 2 5
• 3 5
• No change 6 (23)
• Decreased 3 (11)

Gupta A et al., unpublished data
79
Hemispheric malformations commonly have a gradient

• Gradient
• Anterior gt Posterior 9 (35)
• Posterior gt Anterior 9 (35)
• Whole hemisphere (no gradient) 8 (31)

Gupta A et al., unpublished data
80
I - Typical Hemimegalencephaly
81
II - Posterior Predominance
82
6 months old with seizures
Parental consent for educational activities
83
Interictal EEG
84
Interictal EEG Higher gain
85
Seizure Onset
86
Modified Anatomic Hemispherectomy
87
Epidermal Nevus Syndrome

• Defining Feature
• Face and/or scalp sebaceous nevus
• Hyperpigmented and hyperkeratotic, linear,
  midline
• Asymmetric overgrowth of tissue
• CNS Seizures, MR, plagiocephaly or macro or
  microcephaly
• Eyes and dental abnormalities
• 15 skin basal cell epitheliomas with Vitamin D
  resistant rickets (with AEDs)

Rogers M et al., J Am Acad Dermatol 1989
88
II - Posterior Predominance
89
7 Months Old With Seizures
Parental consent for educational activities
90
Posterior dominance

• N 19
• Hemi-hemi megalencephaly 14/19
• Posterior Quadrantic Dysplsia 5/19
• Partial resections with variable results
• 6 class I outcome

• DAgostino et al.,
• Neurology, 2004

91
Outcome after HemispherectomyComplete vs.
Partial Hemispheric MCD
Courtesy Elaine Wyllie, MD Carreno et al,
Neurology 2001
92
III - Frontal Predominance
93
III - Frontal (Para-central) Predominance And
White Matter Hyperplasia
94
III Frontal (Para-central) Predominance
Right
Left
95
17 years old with rare seizures - 2
Patients assent for educational activities
96
Klippel-Trenaunay-Weber Syndrome - 2
97
III - Frontal Predominance and White Matter
Hyperplasia / Abnormal Signal
98
5 Y-O With Infrequent Seizures Klippel-Trenaunay-W
eber Syndrome
Parental consent for educational activities
99
Klippel-Trenaunay-Weber Syndrome

• Defining Feature Hemangiomatous hypertrophy of 1
  limb, 75 1 leg
• Uncommonly other body, rarely bilateral
• Hemangiomata Cavernous Capillary,
  Phelbectasia, Varicosities
• CNS involvement lt 25
• Seizures usually respond to treatment
• Sporadic, 814 translocation, 8q locus gene
  affecting angiogenesis

Wang Q et al., 1999 Torregrosa et al.,
Neuroradiol 2000
100
III - Para-Central Predominance and White Matter
Hyperplasia
101
2 years-old With No SeizuresProteus Syndrome
Parental consent for educational activities
102
Turner JT et al., Am J Med Genet 2004
103
IV - Hemispheric Malformation with Small Size
(Hemi-micrencephaly)
104
IV - Hemispheric Malformation with Small Size
(Hemi-micrencephaly)
105
More Preliminary Findings
106
Polymicrogyria (PMG) Is The Most Common Gray
Matter Abnormality (N26)

• Gray Matter Abnormalities
• Polymicrogyria 15 (57)
• Others 9 (35)
• Gray-white blurring, thick cortex, anomalous
  sulcation
• Pachygyria 2 (8)
• PMG is commonly misread or missed on cursory
  review
• PMG may suggest a different (?environmental)
  mechanism of injury

Gupta A et al., unpublished data
107
Involvement Of Contralateral Hemisphere Is Common
On Brain MRI (N26)

• Contralateral hemisphere
• Abnormal 18 (65)
• Minor 16
• Dysmorphic or abnormal sulci, White matter signal
  abnormalities
• Major 2
• Normal 8 (35)
• Abnormal findings in the contralateral are easily
  missed on cursory review

Gupta A et al., unpublished data
108
Patho-Genetic Mechanisms

• We do not have a clue
• Sporadic (no families)
• Phenotypic spectrum of cases reported as
  hemimegalencephaly is wide
• Histological features overlap with dysplasias
• Possible genetic disorder of genes of asymmetry
• Pitx2, Lefty-1 and 2, Zic3, Fog
• Flores-Sarnet L, Peds Neurol, 2002
• First step - systematic multi-center study should
  pool the cases for phenotyping

109
Hemispheric Brain MalformationsSurgical Treatment

• Redefining phenotypic spectrum of hemispheric
  malformations
• Clinical recognition of associated genetic
  disorders
• Possible Patho-genetic mechanisms
• Surgical treatment

110
Hemispherectomy Is An Effective Treatment

• Seizure freedom (3mon-22yr)
• Overall (for any indication) 50-70
• Congenital malformations 30-55
• Hemimegalencephaly LOWEST
• Significant improvement (gt75 seizure reduction)
  20-25

Kossoff EH et al. Neurology 2003 Jonas R et al.
Neurology 2004 Devlin AM et al. Brain 2003
Boongird A et al. J Neurosurg 2005 (abstract)
111
HemispherectomyCognitive outcome

• DQ (Development Quotient) or IQ
• 80-90 show moderate improvement or no change
• Higher post-surgery DQ correlates with
• Shorter preoperative duration of seizures
• Higher pre-operative score (acquired cause)
• Seizure free outcome
• Improved behavior in most

Pulsifier MB et al. 2004 Jonas et al. 2004
Maehara et al. Brain and Development 2002 Devlin
AM et al. Brain 2003
112
Hemispherectomy Motor Function Outcome

• Children who walk Before - walk After
• Children (walkable age) but too impaired to walk
  before do not walk after (2 yrs follow-up)
• Exception did not walk due to seizures or EPC
• Motor function improve to pre operative level
• Exception - Hand
• Recovery of function in arm and leg follows
  different course

van Empelen R et al. Brain 2004 Holthausen
Strobl, Adv Neurol 1997
113
Hemispherectomy Motor Function Outcome
van Empelen R et al. Brain 2004
114
Hemispherectomy Surgical Mortality

• Perioperative deaths 1-2
• Blood loss during surgery
• Acute intracranial hematomas
• Shunt failure
• Perioperative morbidity up to 25-33
• VS.
• Medically Refractory children
• Risk of death high (15/1000 person-years)
• More in grand mal seizures
• Comorbid neurological and cognitive deficits

Callenbach PM et al. Pediatrics 2001 Camfield et
al. Lancet 2002
115
Other Indications For Hemispherectomy A Classic
from Cecil's storehouse of human knowledge
Dear Cecil Is it true that ducks can have one
side of their brain sleep while the other side
remains awake? And how can I, as a struggling
graduate student, learn to do the same thing?
--Olivia, via AOL
Dear Olivia One might try slicing one's brain
down the middle, thereby permitting the left and
right hemispheres to operate independently, which
has been done experimentally.  But I cannot in
good conscience recommend this. So you're stuck
with No-Doz for now. --Cecil
116
Conclusions

• Hemispheric malformations are heterogeneous group
  of conditions
• We claim.. that we know how to treat them
• But we do not know their Etio-pathogenesis
• A multi-center effort and pooling of cases for
  systematic study may help clarify distinct
  phenotypes based on brain MRI findings
• There by help study causative patho-genetic
  factors and less drastic treatments

117
Study Collaborators

• Cleveland Clinic Foundation

• Neuroradiology
• Paul Ruggieri
• Mike Lauber

• Pediatric Epilepsy
• Elaine Wyllie
• Deepak Lachhwani
• Prakash Kotagal
• William Bingaman

• Neuropathology
• Rick Prayson

• University of Chicago
• Bill Dobyns (group)

• . If interested, please contact guptaa1_at_ccf.org

118
American Epilepsy Society 2004Catastrophic
Epilepsy In Infants and Children with Brain
Malformations Cellular Mechanisms of Genes That
Cause Human Brain Malformations
Volney L. Sheen, MD PhD Assistant Professor of
Neurology

• Department of Neurology, Beth Israel Deaconess
  Medical Center

119
Cerebral Cortical Development
1. Proliferation 2. Exit from the VZ 3.
Migration 4. Arrest
120
Developmental disorders of the cerebral cortex
121
Developmental disorders of the cerebral cortex

• 1. Disorders of proliferation
• Microcephalin
• ASPM
• 2. Disorders of exit from the ventricular zone
• 3. Disorders of migration
• 4. Disorders of arrest

Microcephaly vera
(C. G. Woods, P. E. Grant, K.S. Krishnamoorthy
and G. H. Mochida)
122
Asp protein is associated with the centrosome
Asp (red)
asp mutant
Wild-type Drosophila neuroblast
from do Carmo Avides and Glover (1999)
123
Aspm is expressed in neuronal progenitors

• Expressed throughout telencephalic ventricular
  zones during neurogenesis

• Rapidly down-regulated after neurogenesis

During active neurogenesis
After neurogenesis
124
ASPM protein increases in size with increased
brain size
IQ domains
of IQ repeats
2
C. elegans
22
Drosophila
62
Mouse
70
70 identity
69
African green monkey
97 identity
71
Human
primate insert
CH (Calponin homology) domain
125
Developmental disorders of the cerebral cortex

• Disorders of proliferation
• Disorders of exit from the ventricular zone
• FilaminA (X-linked dominant)
• ARFGEF2 (autosomal recessive)
• Disorders of migration
• Disorders of arrest

Filamin A
ARFGEF2
Sheen and Walsh
Fox and Walsh
126
Filamin A

• Large (280kD) cytoplasmic phosphoprotein
• Actin cross-linker (Hartwig and Stossel)
• Required for
• Cell migration
• Vascular development
• Neuroependyma
• Function in cortex not known
• Migration initiation
• Radial glial adhesion

127
Structure of Filamin A dimer
SEK1 Trio Presenilin-1 ß1, ß2 Integrin Rho GTPases
Over 30 proteins bind to FLNA
Signal transduction
Extended rod domain (Ig-like repeat units)
Actin binding domain
(Fox et al, 1998)
128
ARFGEF2

• BIG2 202kDA, BIG1 209kDA
• Intracellular trafficking
• Human brain
• Chromosome 20, chromosome 8
• BFA (fungal metabolite blocks protein secretion
  and causes disintegration of Golgi structure -gt
  inhibits BIG1 and BIG2)
• Roles in neurite extension

129
ARFGEF2 mutations disrupt transport of adhesion
proteins from the Golgi
130
Case 2 month old female with PH and filamin
mutation
Sheen, unpublished observations
131
PH nodules are composed of neurons
Sheen, unpublished observations
132
PH nodules are composed of later generated neurons
Sheen, unpublished observations
133
Impairment of the neuroependyma along the lateral
ventricles
Sheen, unpublished observations
134
Developmental disorders of the cerebral cortex

• 1. Disorders of proliferation
• 2. Disorders of exit from the ventricular zone
• 3. Disorders of migration
• Doublecortin (X-linked lissencephaly)
• LIS-1 (Miller Dieker syndrome)
• ARX
• 4. Disorders of arrest

Doublecortin
LIS1
135
X-linked lissencephaly in males and double cortex
in females are due to a single X-linked gene, DCX
(doublecortin)
DC females band of heterotopic neurons in
white matter
XLIS males smooth four- layered cortex
XLIS male
136
DCX is a microtubule-associated protein

• Overlapping subcellular localization
• Recombinant DCX polymerizes microtubules
• Patient mutations affect the microtubule effects
  of DCX

Partners?
microtubules
(J. Gleeson, P. Lin, J. Corbo)
137
Case33 gestational week female with Miller
Dieker syndrome
Sheen, unpublished observations
138
Human LIS1 neural precursors
Sheen, unpublished observations
139
Impaired proliferation in human neural precursors
Sheen, unpublished observations
140
Developmental disorders of the cerebral cortex

• 1. Disorders of proliferation
• 2. Disorders of exit from the ventricular zone
• 3. Disorders of migration
• 4. Disorders of arrest
• Reelin (Lissecephaly with cerebellar hypoplasia)
• Fukutin (Fukuyama congenital muscular dystrophy)
• POMGnT1 (Muscle eye brain syndrome)
• POMT1 (Walker Warburg syndrome)

Lissencephaly with cerebellar hypoplasia Cobblesto
ne Lissencephaly
141
Cobblestone dysplasia (Type II lissencephaly)

• Usually associated with congenital muscular
  dystrophy and/or retinal dysplasia
• Three major autosomal recessive syndromes
• Fukuyama-type congenital muscular dystrophy
• Almost unique to Japan
• Muscle-eye-brain disease
• Almost unique to Finland
• Walker-Warburg sydrome
• Relatively equal world-wide distribution
• Gyral pattern (gross pathology or imaging)
  lissencephaly or polymicrogyria

142
Neurons migrate beyond the pial surface in type
II lissencephaly (e.g., Walker-Warburg syndrome)
WWS
Normal
WWS
(Courtesy of Dr. J. Joseph)
143
Type II/cobblestone lissencephaly genes encode
glycosyltransferases
FCMD Fukutin (Kobayashi et al) MEB POMGnT1 (Yo
shida et al) WWS POMT1 (Beltran-Valero De
Bernabe, Currier et al.) Protein O-mannose
beta-1,2-N-acetylglucosaminyltransferase
Protein O-mannosyltransferase 1 (Only some cases
of WWS have been shown to have POMT1 mutations)
Pial surface
Cell membrane
(Olson and Walsh, Curr Opin Genet Dev 2002)
144
ConclusionDifferent disorders affect different
aspects of cortical development
Cobblestone lissencephaly Lissencephaly with
cerebellar hypoplasia
Classical (type I) lissencephaly (Miller-Dieker
syndrome, X-linked lissencephaly, XLAG)
Periventricular heterotopia (X-linked dominant,
autosomal recessive with microcephaly)
Microcephaly
145
Acknowledgements

• Collaborators
• Saad Al Shahwan
• Eva Andermann
• Jim Barkovich
• Urs Berger
• Sam Berkovic
• Daniel Beltran-Valero De Bernabe
• Jacquie Bond
• Han Brunner
• Bill Dobyns
• Ellen Grant

• Walsh lab
• Chris Walsh
• Kira Apse
• Adria Bodell
• Joe Corbo
• Sophie Currier
• Yuanyi Feng
• Jeremy Fox
• Joe Gleeson
• Sean Hill
• Susan Hong

Jonathan Hourihane Peter Huttenlocher Jeff
Joseph Neil Martin Anna Rajab Betsy Ross Ingrid
Scheffer Yin Yao Shugart Geoff Woods
Peter Lin Eric Olson Volney Sheen
146
The Impact of Early Catastrophic Epilepsy on
Cognitive Development Lessons from Animal Models
Gregory L. Holmes
147
Epileptic Encephalopathy

• Neurological deterioration resulting from
  epileptiform activity.
• While the underlying etiology is clearly
  important in cognitive outcome, the concept is
  that the seizures, EEG abnormalities, or both,
  contribute to the encephalopathy.
• Epilepsy is catastrophic.

148
EEG Characteristics of Epileptic Encephalopathy

• Frequent seizures/myoclonus
• Abundant (almost continuous) interictal
  epileptiform activity, e.g. ESES
• Epileptiform activity usually widespread
• Often accompanied by background abnormalities

149
Electrical Status Epilepticus Of Sleep
150
Epileptic Encephalopathies Issues Regarding
Mechanisms

• Lack of definition/classification
• Lack of biological marker
• Lack of etiology
• Lack of animal models that mimic epileptic
  encephalopathies

151
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155
Time Course of Biochemical, Anatomic and
Functional Changes After Seizures
Susceptibility to Recurrent Seizures
Neurogenesis
Behavioral Deficits
Neuronal Cell Loss
Glial Activation
Protein Expression
Kinase Activation
Early Gene Activation
Ca Ion Influx
10-3
10-1
1010
10-2
1
10
102
104
106
107
103
105
108
109
1 min
1 hour
1 day
1 week
Time (seconds)
Cole et al, 2002
156
Bengzon et al, 2002
157
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158
Whole-cell 1 (ipsi-)
Field 2 (ipsi-)
Kainate (250 nM)
Field 1
1 mV
ACSFKA
40 mV
Whole-cell 1
ACSF
40 mV
Whole-cell 2
ACSF
Field 2
1 mV
Whole-cell 2 (contra-)
Field 2 (contra-)
1 min
Interictal
Tonic
Clonic
Field 1
C-clamp 1 (-63 mV)
C-clamp 2 (-65 mV)
Field 2
1 s
500 ms
2 s
Khalilov et al., 2003
159

Field 1 (ipsi-)
1 mV
Field 2 (contra-)
1 mV
5 min
500 µV
500 µV
1 s
Field 1 (ipsi-)
1 mV
TTX
1 mV
Field 2 (contra-)
10 min
700 µV
500 ms
Khalilov et al., 2003
160
Developmental Aspects of Receptor Development
161
GABA Friend or Foe?
Köhling, 2002
162
Major Intrinsic Connections ofHippocampal
Formation
Cohen and Eichenbaum, 1993
163
Neuronal Circuitry Between Entorhinal Cortex And
Hippocampus
Johnston, 1993
164
Seizure-Induced Cell Loss
165
Flurothyl-Induced Seizure
166
EEG During Flurothyl Seizures
167
Water Maze Training
168
Water Maze Training
169
Water Maze Training
170

171
Water Maze Performance Following Neonatal Seizures
de Rogalski Landrot, 2001
172
Mossy Fiber Sprouting Following Neonatal Seizures
173
Mossy Fiber Sprouting Following Neonatal Seizures
174
Enriched Living Enviornment Increases Neurogenesis
Kempermann and Gage, 1999
175
Reduced Neurogenesis Following Neonatal Seizures
McCabe et al. 2000
176
NeuN-BrdU Double Labeling
177
BrdULABELED CELLS (DGC 36 HRS)
McCabe et al, 2000
178
BrdU-Labeled Cells in Adult Animals
McCabe et al, 2000
179
Seizures in the Developing Brain

• Seizures can cause damage without cell loss
• Recurrent seizures result in cognitive impairment
• Reduced seizure threshold
• Recurrent seizures result in
• Altered synaptogenesis (sprouting)
• Decreased in dendritic spines
• Reduced neurogenesis
• Changes in receptor physiology/distribution
• Alterations in hyperpolarization-activated
  cyclic-nucleotide cation channels (HCN)
• Whether all or any of these changes are
  maladaptive
• is unclear!

180
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181
Rodrigues et al., 2004
182
Cortical Afferent and Efferent Connections of
Parahippocampal Gyrus
Cohen and Eichenbaum, 1993
183
Wiltgen et al., 2004
184
Wiltgen et al., 2004
185
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186
Diagram of the Setup for Place Cell Recordings
Rotenberg et al, 1996
187
Place Cell Firing Fields
188
Place Cell Stability (Controls)
189
Place Cell Stability (Experimentals)
190
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191
Post-seizure
Baseline
192
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193
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194
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195
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196
Collaborators Yehezkel Ben-Ari Rustem
Kazhipov Robert Muller Alexander
Rotenberg Fellows Cigdem Akman Li-Tung
Huang Zianzeng Liu Qian Zhou
Students Bridget McCabe Ivan de Rogalski
Landrot Stephanie Faverjon Marian
Albada Anne-Marieke Rutten
Funding NIH AES
197
Newer AEDs in Infants with Catastrophic Epilepsy

• John M. Pellock, MD
• Professor and Chairman, Division of Child
  Neurology
• Vice Chairman, Department of Neurology
• Medical College of Virginia/Virginia Commonwealth
  University
• Richmond, Virginia

198
Treatment Options
Partial
Simple
Generalized
Complex
Secondarygeneralized
Tonic- clonic
Tonic
Myoclonic
Atonic
Infantile Spasms
Absence
PHT, CBZ, PB GBP, TGB, LVT, OCBZ
ESX
ACTH TPM TGB VGB ZNS
VPA, LTG, TPM, ZNS, LVT, FBM
199
Phenobarbital vs. Phenytoin

• Painter M et al. N Engl J Med 341485-9, 1999
• PB and PHT are equally, but incompletely,
  effective in neonates
• With either drug given alone, seizures were
  controlled in lt 50 of the neonates
• Response rate increased from 43-45 to nearly
  60 when the two were combined

200
Na Channel Antagonists and GABAergic AEDs Injure
the Immature Brain
Bittigau et al. Proc Natl Acad Sci USA 2002
201
Ikonomidou C et al Science 28370-74, 1999.
Blockade of NMDA Receptors and Apoptotic
Neurodegeneration in the Developing Brain
Vehicle (A) vs. MK-801 (B) in 8-day-old pups
E After PCP Rx
202
Practice Dilemma

• AED with most likelihood for both efficacy and
  safety in the immature brain with demonstrated
  ability antagonize AMPA/KA-evoked Na currents to
  produce neuroprotection is topiramate.
• No parenteral formulation available, and none is
  likely
• Most commonly used AEDs in the NICU are of
  limited efficacy and animal models suggest
  neurotoxicity
• No clinical trial on the horizon involving a AED
  with the pharmacology akin to topiramate

Sankar, Neurology (suppl), 2004
203
What is the Potential for Levetiracetam in this
Setting

• Shown to be NOT an antagonist of voltage- gated
  Na channels, direct or allosteric modifier of
  GABAA currents or NMDA receptors thus not
  likely to be neurotoxic
• Some preclinical data suggests effect on
  synchronization Niespodziany et al Neuroreport,
  141273-6, 2003
• Other data suggests an ability to block
  seizure-induced gene expression Gu et al
  Eur J Neurosci 19334-45, 2004

204
Infantile SpasmsAAN/CNS Practice Parameter

• ACTH probably effective short term- optimal
  dosage/therapy duration not determined
• Vigabatrin possibly effective short term
  retinal toxicity/visual field testing
  difficulties
• VPA, ZNS, TPM, NT, B6, others not supported
• Mackay et al, Neurology, 2004

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207
Encephalopathic Epilepsy in Childhood Tiagabine
Treatment of IS

• Initial therapy for IS
• 5 children, 6-10 mos, symptomatic
• Dose 0.2 mg/kg/d (max 5 mg/kg)
• 3/5 hypsarrhythmia resolution and spasm cessation
• 2/3 developed other seizure types
• Morton, et al, Epilepsia, 2004

208
Infantile Spasms/West SyndromeWest Delphia Group
Proposal

• Clinical spasms epileptiform EEG
• Age at onset lt 2 years
• Interictal EEG consistent with IS

?
lt
IS
Single spasm variant Clusters
?
Hypsarrhythmia
?
Symptomatic (specific) Idiopathic Cryptogenic
lt
West Syndrome
Lux, Osborne, Epilepsia, 2004
209
Infantile Spasms/West SyndromeWest Delphia Group
Proposal
Hypsarrhythmic EEG
?
?
No
Hypsarrhythmia without infantile spasms (HWIS)
(may be subclassified according to clinical
features
Spasms
?
Yes
?
Infantile spasms single-spasm variant with
hypsarrhythmia
No
Clusters
?
West syndrome
If spasms of clusters are not observed
clinically, we recommend performing video-EEG for
a period of ?24 h to rule out their occurrence
reliably.
Lux, Osborne, Epilepsia, 2004
210
New AEDs for Refractory Epilepsy (AAN/AES)
French, et al, 2004
211
Monotherapy for Lennox-Gastaut Syndrome Evidence
of Efficacy
212
Lennox-Gastaut Syndrome Treatment Drop Attacks
P .002
P .01
P .04
FBM Placebo1
LTG Placebo2
TPM Placebo3
(n37)
(n36)
(n75)
(n89)
(n46)
(n49)
1. Felbamate Study Group. N Engl J Med. 1993
32829-33. 2. Motte J. N Engl J Med.
19973371807-1812. 3. Sachdeo RC et al.
Neurology. 1999521982-1987.
213
Lennox Gastaut Syndrome
Prospective and Retrospective, Open-label, Add-on
therapy

• 5 children with LGS (1 -9 years old)
• LEV dose 25 60 mg/kg/day
• 3 (60) gt50 Reduction
• 3 (60) Continue on LEV
• Lagae et al.,2003

• 11 children with LGS (mean age 10 years)
• LEV dose 15 52 mg/kg/day
• 6 (54.5) gt50 Reduction
• Barron et al.,2001

• 6 children with LGS (3 -17 years old)
• LEV dose 10 115 mg/kg/day (mean 48)
• 1 (16.7) Seizure-Free
• De los Reyes et al., 2004

Tonic did not respond to treatment
214
Myoclonic SeizuresTreatment

• Useful AEDs
• VPA, BZDP
• ZNS, TPM, LEV
• FBM
• Others may exacerbate (CBZ, PHT, GBP, TGB, OXC,
  VGB)
• Syndrome dependent

215
ZNS in Progressive Myoclonic Epilepsy

• Reports by Kyllerman and Ben-Menachem 1998
• 7 patients with Unverricht-Lundborg type
• 1 patient with Lafora Body
• Intractable seizures with VPA/benzodiazepine
• After ZNS therapy added
• Amount of myoclonias and generalized seizures
  were dramatically reduced
• Patient marked decrease in seizure frequency
• Significant improvement in functioning

216
Adjunctive levetiracetam for generalized
epilepsies Evidence of efficacy
217
Unverricht-Lundborg Disease
Retrospective, Add-on therapy

• Patient characteristic
• 13 Patients 1452 years old (mean 36.5)
• Disease duration 4-40 years (mean 13.8 months)
• Age of onset 6-17 years
• LEV treatment 2000-4000 mg/day
• Results
• Decrease in average myoclonus score (from 3.1 to
  2.4 p0.01)
• 8/12 measurable improvement
• Correlation between disease duration and LEV
  effect
• LEV more effective within 25 years of onset

Magaudda et al., Epilepsia 2004 45(6)678-681
218
Aggravation of seizures or epilepsy syndromes
Bourgeois, 2004
219
Drug options by seizure type
NICE guideline 20. The epilepsies, 2004
220
AEDs for Epilepsy Syndrome
NICE guideline 20. The epilepsies, 2004.
221
Drug Options by Epilepsy Syndrome
A Hepatic enzyme-inducing AED B should be used as
a first choice under circumstances as outlined in
the NICE technology appraisal of newer AEDs see
page 47 C Should rarely be initiated if a
barbiturate is required, phenobarbital is
preferred D Steroids prednisolone or ACTH
(adrenocorticotrophic hormone) E Not licensed in
the UK, but available by importation NICE
guideline 20. The epilepsies, 2004.
222
Drug Options by Epilepsy Syndrome
A Hepatic enzyme-inducing AED B should be used as
a first choice under circumstances as outlined in
the NICE technology appraisal of newer AEDs see
page 47 C Should rarely be initiated if a
barbiturate is required, phenobarbital is
preferred D Steroids prednisolone or ACTH
(adrenocorticotrophic hormone) E Not licensed in
the UK, but available by importation NICE
guideline 20. The epilepsies, 2004.
223
Drug Options by Epilepsy Syndrome
A Hepatic enzyme-inducing AED B should be used as
a first choice under circumstances as outlined in
the NICE technology appraisal of newer AEDs see
page 47 C Should rarely be initiated if a
barbiturate is required, phenobarbital is
preferred D Steroids prednisolone or ACTH
(adrenocorticotrophic hormone) E Not licensed in
the UK, but available by importation NICE
guideline 20. The epilepsies, 2004.
224
Childhood Encephalopathic Epilepsy AED
Evaluation VCU Model

• Well defined subsets (seizure/syndromes)
• Inclusive with
• Randomized, sequential monotherapy
• Titration/dose defined (to control or tolerance)
• Seizure types counted, prolonged video-EEG
• Outcome variables seizure reduction,
  tolerability, time continued on AED
• Escape criteria
• Rescue therapy

225
Encephalopathic Epilepsy of ChildhoodTreatment

• Refractory to most existing therapies
• Not well studied
• Largely based on case series
• Need studies with
• Well defined patients/syndromes
• Structured observations and endpoints
• Large subject numbers
• Design allowing early randomization to treatment,
  rescue, alternatives
• Multicentered, minor protocol variability

226
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