Developmental Diseases of the Nervous System Flashcards
failure of evagination in the brain
schizencephaly
huge brain defects with apposition of ventricular and pial surfaces
porencephaly
This term refers to a marked enlargement of one cerebral hemisphere as a result of a developmental abnormality
hemimegalencephaly
in hemimegalencephaly, clearly embryogenesis has been deranged at the stage of
neuroblast formation
craniostenoses
when the lambdoid and coronal sutures are both affected, the thrust of the growing brain enlarges the head in a ________ direction
vertical
tower skull
oxycephaly or turricephaly or acrocephaly
Craniostenoses
When only the sagittal suture is involved, the head is ____________ or ____________ and the closed suture projects, keel-like, in the midline
long and narrow
or scahpocephalic
Craniostenoses
With premature closure of the coronal suture, the head is excessively _____________ or __________
wide and short or brachycephalic
The so-called ___________ skull is the most severe and lethal of the craniostenoses because of the associated developmental anomalies of the brain
clover-shaped
True or False
The most recently “born” neurons in the development of the cortex are those that are in the outermost part of the cortex
true
p1007
refers to an excessive number of abnormally small gyri
polymicrogyria
cortex may fail to become sulcated
lissencephaly
cerebral defect in holoprosencephaly is reflected physically as
having a single eye and absence of nose
An eventration of brain tissue and its coverings through an unfused midline defect in the skull is called an
encephalocoele
A failure of development of the midline portion of the cerebellum
Dandy-Walker syndrome
a bony spicule or fibrous band protrudes into the spinal canal from the body of one of the thoracic or upper lumbar vertebrae and divides the spinal cord into halves for a variable vertical extent
Diastematomyelia
developmental cavity within the cervical cord, extending a variable distance caudally or rostrally, and usually associated with an Arnold-Chiari malformation
Syringomyelia
types of Chiari Malformation
Chiari’s Type I - cerebellomedullary descent without a meningomyelocele
Type II - cerebellomedullary descent with a meningomyelocele
Type III Chiari malformation with a high cervical or occipitocervical meningomyelocele with cerebellar herniation,
Type IV cerebellar hypoplasia
triad of adenoma sebaceum, epilepsy, and developmental delay
tuberous sclerosis
abnormal genes in Tuberous Sclerosis
long arm of chromosome 9, designated as TSC 1 (hamartin) short arm of chromosome 16, TSC 2 (tuberin)
characterized by the triad of adenoma sebaceum,
epilepsy, and developmental delay
Tuberous sclerosis
abnormal genes in Tuberous Sclerosis
TSC 1, chromosome 9, hamartin
TSC2, chromosome 16, tuberin
function as tumor suppressor proteins and interact to suppress cell growth
surgically resected tubers show activation of a cell-size control pathway
mTOR
mammalian target of rapamycin
The facial cutaneous abnormality, adenoma sebaceum in TS, appearslater in childhood, usually between
4-10 yrs
True or False
As the years pass, the pattern of seizures remain constant.
False
p1022
In the first year or two they take the form of massive flexion spasms with hypsarrhythmia (irregular dysrhythmic
bursts of high-voltage spikes and slow waves in the
EEG). Later, the seizures change to more typical generalized motor and psychomotor attacks or atypical petit mal.
True or False
As a general rule in TS, early onset of seizures is predictive of developmental delay.
True
p1022
congenital hypomelanotic macules in TS
“ash-green” lesions
The hypomelanotic areas are arranged in linear fashion over the trunk or limbs and range in size from a few millimeters to several centimeters; their configuration is oval, with one end round and the other pointed, in the shape of an ash leaf
A Wood lamp, which transmits only ultraviolet rays, facilitates the demonstration of the ash-leaf lesions because of the absence of__________ which normally absorb light in the ultraviolet range (360-nm wavelength).
melanoblasts
facial lesions pathognomonic in TS
adenomas of Pringle
called adenoma sebaceum but are angiofibromas
Typically they are red to pink nodules with a smooth, glistening surface, and they tend to be limited to the nasolabial folds, cheeks, and chin
True or False
in TS
The earliest manifestation of facial angiofibromatosis
may be a mild erythema over the cheeks and forehead
that is intensified by crying.
True
p1022
shagreen patch in TS is mostly found in
lumbosacral region
preferred imaging for detecting tuber lesions
CT
tuber lesions tend to be located in the periventricular area
preferred imaging for detecting hamartomatous giant cell subependymal and subcortical lesions
MRI
It is usually pointless to attempt the excision of
tumors in TS, especially in severely affected individuals with the exception of ___________
renal hamartomas that impair kidney function
in TS
___________ suppresses the
mTOR signaling pathway and causes slight regression of
the bodily angiolipomas
sirolimus
mTOR inhibitor which has been found to be useful in suppressing the status epilepticus associated with some cases of TS
everolimus
enumerate genes affected in NF 1 and 2
NF1 neurofibromin
NF2 merlin, also called schwannomin
both involved in tumor suppression
75% of patients with Tuberous sclerosis or bourneville disease present with
seizure or by slowed psychomotor development
mor eprominent within 2-3 years
when does facial abnormality, adenoma sebaceum in Tuberous sclerosis appear
childhood 4-10th year
T/F
Pattern of seizures in TS remain the same.
False
change in pattern, massive flexion spasma with hypsarrhtyhmia then generalized motor and psychomotor attacks or atypical petit mal
p1022
Tuberous sclerosis
plaque of subepidermal fibrosis
most often found in lumbosacral region
“pigskin”, “elephant hide”
shagreen patch
overgrowth of subcutaneous tissue
occur most often in scalp, face, neck, and chest
on palpation: like bag of worms
plexiform neuromas
T/F
NF is associated with peroneal muscular atrophy, congenital deafness, and partial albinism.
True
p1027
features of schwannomas and neurofibromas
palisading of nuclei and sometimes encircling arrangements of cells (Verocay) bodies
child with sensorimotor seizures contralateral to a facial “port-wine mark”
Sturge-Weber Syndrome
T/F
In Sturge-Weber, the involvement of the upper eyelid is not of any importance.
False
p1029
involvement of upper eyelid is associated with cerebral lesions
other name for Herediatry Hemorrhagic Telangiectasia
Osler-Rendu-Weber Disease
Autosomal Dominant
genes identified with Osler-Rendu-Weber Disease
endoglin and novel kinase
genetic disease of multiple neoplasms specifically by the presence of hemangioblastoma, sometimes multiple
von Hippel-Lindau Disease
also referred to as Louis-Bar syndrome
progressive ataxia with humoral immune deficiency and
telangiectasia
autosomal recessive
Ataxia-Telangiectasia
attributed cause in Ataxia-Telangiectasia
defective DNA repair
features of Ataxia-Telangiectasia
onset coincides with walking, awkward and usteady
by age 4-5 yrs, ataxic, choreoathetosis, grimacing, dysarthric speech,
eye movements are jerky, apraxia for voluntary gaze
patient turns head but not the eyes on attempting to look to the side
optokinetic nystagmus is lost, severe cognitive developmental dely is infrequent
seizures are not part of the syndrome
T/F
Seizures are part of Ataxia-Telangiectasia.
False
p1031
location of telangiectatic lesions in Ataxia-Telangiectasia
these are transversely oriented subpapillary venous plexuses that appear at 3-5 years of age or later
seen in the outer parts of bulbar conjunctivae
over the ears
exposed parts of the neck
on the bridge of the nose and cheeks in a butterfly pattern
flexor creases of forearms
the absence or decreased in several immunoglobulins in patients with Ataxia-Telangiectasia has been attributed to
decrease in synthesis from hypoplasia of thymus, loss of follicles in lymph nodes, failure of delayed hypersensitivity and lymphophenia
significant abnormalities in the CNS in Ataxia-Telangiectasia
severe degeneration in the cerebellar cortex
loss of myelinated fibers in the posterior columns, spinocerebellar tracts, peripheral nerves
degenerative changes in the posterior roots and cells of sympathetic ganglia
loss of anterior horn cells in the spinal cord
defective gene in Ataxia-Telangiectasia
ATM gene
kinase transducer in the pathway for DNA repair that halts the cell cycle after DNA damage
great risk for lymphomas, leukemias, other tumors
Congenital lack of Lateral Gaze
Cogan Oculomotor Apraxia
unable to turn their eyes volitionally or on command
attempting to look to the right the child turns the head to the right but the eyes lag and turn to the left
Cause of matrix hemorrhage in preterm neonates
related to greatly increased pressure in the thin-walled veins of the germinal matrix coupled with a lack of adequate supporting tissue in these zones
prognosis of Hypoxic-ischemic damage and neonatal encephalopathy in neonates
mortality rate 20%
neurodevelopmental disability in survivors 25%
now a rare cause of extrapyramidal motor disorder in children and adults
neurologic sequelae of erythroblastosis fetalis secondary to Rh and ABO blood incompatibilities
Kernicterus
what should be considered in patients with progressive muscular atrophy associated with enlargement of tongue, heart, liver or spleen
Glycogen storage disease (usually Pompe form)
TORCH/LATCH
cerebral calcifications
CMV - periventricular distribution
toxoplasmosis - widely disseminated
TORCH/LATCH
cardiac lesions
rubella
TORCH/LATCH
deafness
CMV
rubella
diagnosis of congenital rubella
Immunoglobulin IgM antibodies to the virus or by the isolation of the virus from the throat, urine, stool, CSF
tetrad of cataracts, deafness, congenital heart disease and developmental delay
Congenital Rubella
HIV infection from vertical transmission may be acquired
in utero
during delivery
breast-feeding
onset first days and weeks of postnatal life
seizures, impaired alertness, hypotonia, weakness of the extremities, progressive HCP, chorioretinitis
Congenital Toxoplasmosis
In congenital neurosyphilis, a negative VDRL reaction in umbilical cord does not exclude congenital syphilis.
True
p1045
At birth the spirochetemia may not have had time to cause syphilitic antibodies to appear
If the syphilitic mother is treated before the ____ month of pregnancy, the fetus will not be affected
a. second
b. third
c. fourth
d. fifth
C fourth
before the fourth
dysmorphic features
large ears, broad forehead
elongated face
enlarged testes
Fragile X
defective gene in Fragile X
FMR1 gene
hereditary form of developmental delay affects girls
defect at chromosomal site Xq28
fatal outcome in boys because of severe neonatal encephalopathy,
in girls mosaics for the mutation
Rett syndrome
involved gene in Rett syndrome
MECP2
alteration in synaptogenesis and neural connectivity
clinical features of Rett syndrome
withdrawan behavior simulates autism, dementia, ataxia, loss of purposeful hand movements, respiratory irregularities
characteristic: period of 6-18 months of normal development followed by rapid appearance and progression of all the signs
X-linked
prominent dystonia of hands, sometimes of feet or ataxia
mutated gene: Aristaless-related homeobox (ARX)
involved with regulation of protein-DNA interactions
Partington Syndrome
male-sex-linked developmental delay
small stature, slightly microcephalic
mutated gene: PQBP1
Renpenning Syndrome
mild and variable developmental delay
striking retention and even precocity or superiority of musical aptitude and social amiability
wide mouth, almond-shaped eyes, short upturned nose, flat nasal bridge, long philtrum,, delicate chin, small pointed ears
elfin appearance
Williams Syndrome
Williams-Beuren Syndrome
Williams Syndrome
deletion in chromosome in what gene
ELN gene
asocial, lacking in communicative skills both verbal and non-verbal, committed to repetitive ritualistic behaviors
Autism
Kanner-Asperger Syndrome
Autistic Spectrum Disorders
Approximately one-quarter of affected children with craniostenoses will be found to have a single gene or chromosomal abnormality most commonly in
FGFR3
maximum length of skull is in the diagonal plane
plagiocephaly
wry head
chorioretinopathy retinal lacunae staphyloma coloboma of optic nerve microphthalmos, MR inafantile spasms and other forms of epilepsy agenesis of corpus callosum batwing deformity of third and lateral ventricles on MR images females
Aicardi syndrome with ocular abnormality
microcephaly with no craniostenosis
small and symmetrically receded chin
glossoptosis (tingue falls back into pharynx)
cleft palate, flat bridge of nose, low-set ears, mental deificency, CHD
Camptomelia (bent bones) diastrophic dwarfism
Pierre Robin syndrome
autosomal recessive
skin lesions appear in infancy
taking the form of erythema, blistering, scaling, scarring, and pigmentation on exposure to sunlight
old lesions are telangiectatic and parchment like
covered with fine scales, skin cancer may develop later
Xeroderma pigmentosum
Folic acid given before the ___day of pregnancy is protective
28th
