Developmental abnormalities Flashcards
(258 cards)
1
Q
What is an arachnoid cyst?
A
A congenital fluid-containing abnormality of the arachnoid membrane that displaces brain and typically remodels bone
Arachnoid cysts are filled with cerebrospinal fluid (CSF) and can occur in various regions of the brain.
2
Q
Where are arachnoid cysts most commonly located?
A
Middle fossa, cerebellopontine angle (CPA), suprasellar region, and posterior fossa
They may also occur in the spine.
3
Q
Are most arachnoid cysts symptomatic or asymptomatic?
A
Most are asymptomatic (i.e., an incidental finding) except in the suprasellar region
Asymptomatic cysts are often discovered during imaging for unrelated reasons.
4
Q
What do imaging studies typically show for arachnoid cysts?
A
Imaging characteristics exactly mimic CSF on CT or MRI in most cases
Imaging often shows remodeling of bone.
5
Q
What is the recommendation for incidentally discovered arachnoid cysts in adults?
A
A single follow-up imaging study in 6–8 months is usually adequate to rule out any increase in size
Subsequent studies are only recommended if concerning symptoms develop.
6
Q
Fill in the blank: Arachnoid cysts typically _______ brain and remodel bone.
A
displace
This displacement can lead to various neurological symptoms if the cyst is large enough.
7
Q
True or False: Arachnoid cysts can only occur in the brain.
A
False
Arachnoid cysts can also occur in the spine.
8
Q
What are Sylvian fissure arachnoid cysts?
A
Cysts located in the Sylvian fissure area of the brain
9
Q
Who proposed the classification scheme for middle fossa cysts?
A
Galassi et al
10
Q
Fill in the blank: The classification scheme of Galassi et al is used for _______.
A
[middle fossa cysts]
11
Q
What is the significance of Fig. 15.1 in relation to Sylvian fissure arachnoid cysts?
A
It illustrates the classification scheme for middle fossa cysts
12
Q
What is the Galassi classification used for?
A
It is used to classify types of lesions associated with the Sylvian fissure.
13
Q
What characterizes Type I lesions in the Galassi classification?
A
Small, biconvex, located in anterior temporal tip, no mass effect, communicates with subarachnoid space on WS-CTC.
14
Q
What are the features of Type II lesions in the Galassi classification?
A
Involves proximal and intermediate segments of Sylvian fissure, completely open insula gives rectangular shape, partial communication on WS-CTC.
15
Q
Describe the characteristics of Type III lesions in the Galassi classification.
A
Involves entire Sylvian fissure, marked midline shift, bony expansion of middle fossa, minimal communication on WS-CTC.
16
Q
What happens during surgical treatment of Type III lesions?
A
Surgical treatment usually does not result in total reexpansion of brain and may approach type II lesion.
17
Q
Fill in the blank: Type I lesions have _______ effect.
A
no mass
18
Q
True or False: Type II lesions have a completely open insula.
A
True
19
Q
What is the shape of Type II lesions due to the completely open insula?
A
Rectangular
20
Q
Fill in the blank: Type III lesions involve _______ of the Sylvian fissure.
A
entire
21
Q
What type of communication is observed in Type I lesions on WS-CTC?
A
Complete communication
22
Q
What type of communication is observed in Type III lesions on WS-CTC?
A
Minimal communication
23
Q
What is cyst shunting?
A
A surgical procedure to redirect fluid from a cyst to prevent complications.
Cyst shunting is often performed to manage symptoms associated with cysts.
24
Q
What should be avoided during cyst shunting to prevent injury?
A
Tunneling in front of the ear.
This area is close to the facial nerve, and injury can lead to facial paralysis.
25
What is recommended if the anterior route during cyst shunting is unavoidable?
Solicit the services of a plastic surgeon.
## Footnote
A plastic surgeon can help navigate the procedure safely to avoid damaging the facial nerve.
26
What is the anterior fontanelle?
The largest fontanelle, diamond shaped, measuring 4 cm (AP) × 2.5 cm (transverse) at birth.
## Footnote
Normally closes by age 2.5 years.
27
What is the normal closure age for the anterior fontanelle?
By age 2.5 years.
## Footnote
This is when the anterior fontanelle typically closes.
28
What is the shape of the posterior fontanelle?
Triangular.
## Footnote
This distinguishes it from the anterior fontanelle.
29
At what age does the posterior fontanelle normally close?
By age 2–3 months.
## Footnote
This is significantly earlier than the anterior fontanelle.
30
What is craniosynostosis?
A condition where one or more of the sutures in an infant's skull fuse prematurely.
31
What happens to skull growth when a suture ossifies in craniosynostosis?
Normal growth of the skull perpendicular to the suture terminates and growth proceeds parallel to the suture.
32
What condition can coronal synostosis cause?
Amblyopia
## Footnote
Amblyopia, also known as lazy eye, is a vision development disorder where an eye fails to achieve normal visual acuity.
33
What is dolichocephaly?
An elongated skull with high forehead/frontal bossing
## Footnote
Dolichocephaly is characterized by a long and narrow head shape.
34
What is scaphocephaly?
A 'boat-shaped skull' with prominent occiput
## Footnote
Scaphocephaly results from the premature fusion of the sagittal suture.
35
What closes early in trigonucephaly?
Abnormal closure of the frontal or metopic suture
## Footnote
This condition can lead to various cranial deformities.
36
What condition results from the abnormal closure of the frontal or metopic suture?
Trigonocephaly
## Footnote
Trigonocephaly is characterized by a pointed or triangular shaped forehead.
37
What are the physical characteristics of trigonocephaly?
Pointed or triangular shaped forehead with a midline ridge and hypotelorism
## Footnote
Hypotelorism refers to decreased distance between the eyes.
38
Fill in the blank: Abnormal closure of the frontal or metopic suture produces _______.
trigonocephaly
39
True or False: Trigonocephaly can result in a normally shaped forehead.
False
## Footnote
The forehead in trigonocephaly is typically pointed or triangular.
40
What is hypotelorism?
Decreased distance between the eyes
## Footnote
This condition is often associated with cranial deformities.
41
What is bilateral coronal CSO commonly associated with?
Craniofacial dysmorphism with multiple suture CSO, e.g., Apert’s
## Footnote
Apert's syndrome is a genetic disorder characterized by the premature fusion of certain skull bones, affecting head shape and facial features.
42
What are the characteristics of brachycephaly associated with bilateral coronal CSO?
Broad, flattened forehead (acrocephaly)
## Footnote
Brachycephaly refers to a condition where the head is short and broad, often due to craniosynostosis.
43
Is bilateral coronal CSO more common than unilateral coronal CSO?
Yes
## Footnote
Bilateral coronal craniosynostosis is more frequently observed in clinical cases than the unilateral form.
44
What is positional flattening also known as?
Lazy lamboid
## Footnote
This term refers to a specific type of flattening of the occiput.
45
What must lambdoid synostosis be distinguished from?
Positional flattening
## Footnote
Lambdoid synostosis is a condition that affects skull shape and needs differentiation from positional flattening.
46
What is associated with flattening of the occiput in positional flattening?
Anterior displacement of the ipsilateral ear
## Footnote
This means that the ear on the same side as the flattening is positioned more forward.
47
What does 'beaten copper cranium' (BCC) refer to?
Indentations in the bone from underlying gyri due to locally increased intracranial pressure (ICP)
## Footnote
BCC is a clinical sign that may be observed in certain neurological conditions.
48
What causes the indentations seen in a beaten copper cranium?
Locally increased intracranial pressure (ICP)
## Footnote
Increased ICP can result from various medical conditions, leading to deformation of the skull.
49
What is oxycephaly?
Fusion of many or all cranial sutures
## Footnote
Oxycephaly is a type of craniosynostosis characterized by a high, tower-like head shape due to abnormal skull growth.
50
What are craniosynostosis syndromes caused by?
Mutations in the FGFR
## Footnote
FGFR stands for Fibroblast Growth Factor Receptor, which plays a crucial role in bone development.
51
What should a nasal polypoid mass in a newborn be considered until proven otherwise?
An encephalocele
## Footnote
An encephalocele is a condition where brain tissue protrudes through an opening in the skull.
52
What are the components of the classic triad of Dandy Walker malformation?
1. Complete or near complete absence of the cerebellar vermis
2. Cystic dilation of the 4th ventricle projecting posteriorly
3. Hydrocephalus, present in 75-95%
## Footnote
Hydrocephalus is the accumulation of cerebrospinal fluid within the ventricles of the brain.
53
What happens to the posterior fossa in Dandy Walker malformation?
It is often enlarged, leading to elevated tentorium & torcula-lambdoid inversion
## Footnote
This anatomical change can affect brain function and development.
54
What other abnormalities are frequent in Dandy Walker malformation?
Other CNS and systemic abnormalities are frequent, including cardiovascular anomalies
## Footnote
Such anomalies should be considered when planning surgical interventions.
55
What is the treatment for seizures in Dandy Walker malformation?
Antiepileptic medications
## Footnote
Seizures occur in approximately 15% of cases.
56
When is surgery indicated in Dandy Walker malformation?
For symptoms of brainstem compression by the cyst or hydrocephalus
## Footnote
Surgical intervention is necessary to alleviate pressure on critical brain structures.
57
What are the surgical options available for Dandy Walker malformation?
1. Shunting (the cyst and/or the ventricles)
2. Cyst fenestration (open or endoscopic)
3. ETV (occasionally used if aqueduct is open)
## Footnote
These procedures aim to relieve pressure and manage symptoms.
58
What is the expected cognitive outcome for individuals with Dandy Walker malformation?
50% are cognitively impaired
## Footnote
Cognitive outcomes can vary significantly among individuals.
59
What common physical impairments are associated with Dandy Walker malformation?
Ataxia, spasticity, and poor fine motor control
## Footnote
These motor deficits can affect daily activities and quality of life.
60
What is aqueductal stenosis?
A congenital malformation that may be associated with Chiari malformation or neurofibromatosis
## Footnote
Aqueductal stenosis refers to the narrowing of the cerebral aqueduct, which can impede cerebrospinal fluid flow.
61
What are some acquired causes of aqueductal stenosis?
Inflammation following hemorrhage or infection, such as:
* Syphilis
* Tuberculosis
## Footnote
These acquired causes can lead to the narrowing of the aqueduct due to scarring or obstruction.
62
Which type of neoplasm is associated with aqueductal stenosis?
Brainstem astrocytomas, including:
* Tectal gliomas
* Lipomas
## Footnote
Neoplasms can cause obstruction of the aqueduct, leading to increased intracranial pressure and various symptoms.
63
What type of cysts can lead to aqueductal stenosis?
Quadrigeminal plate arachnoid cysts
## Footnote
These cysts can cause compression of the aqueduct, contributing to the development of stenosis.
64
What happens to the aqueduct proximal to the obstruction?
It is dilated and demonstrates 'funneling'.
## Footnote
'Funneling' refers to the gradual narrowing of the channel as it approaches the obstruction.
65
What is a Torkildsen shunt?
A procedure that shunts a lateral ventricle to the cisterna magna
## Footnote
This technique is used to manage conditions such as hydrocephalus.
66
What is agenesis of the corpus callosum?
A failure of commissuration occurring ≈ 2 weeks after conception
67
What are the results of agenesis of the corpus callosum?
Expansion of the third ventricle and separation of the lateral ventricles
## Footnote
This includes dilated occipital horns and atria, and concave medial borders.
68
How does the corpus callosum (CC) develop?
Forms from rostrum (genu) to splenium
69
What does the absence of the anterior corpus callosum with some posterior corpus callosum indicate?
Some form of holoprosencephaly
70
What is another name for Septo-optic dysplasia?
de Morsier syndrome
71
What causes the symptoms of Septo-optic dysplasia?
Incomplete early morphogenesis of anterior midline structures
72
What are the primary features of Septo-optic dysplasia?
* Hypoplasia of the optic nerves
* Possibly optic chiasm hypoplasia
* Pituitary infundibulum abnormalities
73
What is a common consequence for affected patients with Septo-optic dysplasia?
Patients are blind
74
In what percentage of cases is the septum pellucidum absent in Septo-optic dysplasia?
About half
75
What additional condition is present in about half of the cases of Septo-optic dysplasia?
Schizencephaly
76
Where are intracranial lipomas usually found?
In or near the midsagittal plane, particularly over the corpus callosum.
77
What condition is frequently associated with lipomas located over the corpus callosum?
Agenesis of the corpus callosum.
78
What is a hypothalamic hamartoma?
A rare, non-neoplastic congenital malformation, usually occurring in the tuber cinereum.
79
What are the two types of hypothalamic hamartomas based on location?
* Parahypothalamic (pedunculated)
* Intrahypothalamic (sessile)
80
What is a common presentation of hypothalamic hamartomas?
* Precocious puberty due to gonadotropin-releasing hormone (GnRH)
* Seizures (usually starting with gelastic seizures)
* Developmental delay
81
What type of seizures are commonly associated with hypothalamic hamartomas?
Gelastic seizures (brief unprovoked laughter).
82
What is the treatment for precocious puberty caused by hypothalamic hamartomas?
GnRH analogs.
83
What surgical options are available for pedunculated lesions of hypothalamic hamartomas?
Latero-basal craniotomy.
84
What approach is used for intrahypothalamic lesions?
Transcallosal interforniceal approach.
85
What is an option for treating lesions that are 1.5 cm in diameter or smaller?
Endoscopic approach.
86
What alternative treatment may be considered for hypothalamic hamartomas?
Stereotactic radiosurgery.
87
What is the characteristic feature of a pedunculated or parahypothalamic tumor?
Narrower base attached to the floor of the hypothalamus, not arising within the hypothalamus
88
What is the effect of a pedunculated or parahypothalamic tumor on the 3rd ventricle?
No distortion of the 3rd ventricle
89
Which condition is generally associated with pedunculated or parahypothalamic tumors?
Precocious puberty more than seizures
90
What defines an intrathalamic or sessile tumor?
Within hypothalamus or broad attachment to hypothalamus, distorting the 3rd ventricle
91
What is the common association with intrathalamic or sessile tumors?
More often associated with seizures
92
What percentage of patients with intrathalamic or sessile tumors have developmental delay?
66%
93
What percentage of patients with intrathalamic or sessile tumors experience precocious puberty?
50%
94
What is spinal dysraphism?
Spinal dysraphism is a term that refers to a group of congenital malformations of the spine, including spina bifida.
95
What is spina bifida?
Spina bifida is a type of spinal dysraphism where there is an incomplete closing of the backbone and membranes around the spinal cord.
96
What are the main types of spina bifida?
* Spina bifida occulta
* Meningocele
* Myelomeningocele
97
True or False: Spina bifida only affects the lower back.
False
98
Fill in the blank: Spina bifida is caused by the _______ of the neural tube.
[failure to close]
99
What are common symptoms of spina bifida?
* Physical disabilities
* Neurological issues
* Bladder and bowel dysfunction
100
What is the significance of folic acid in relation to spina bifida?
Folic acid supplementation is known to reduce the risk of neural tube defects, including spina bifida.
101
What are potential complications associated with spina bifida?
* Hydrocephalus
* Chiari malformation
* Latex allergy
102
True or False: Spina bifida can be diagnosed before birth.
True
103
What imaging techniques are used to diagnose spina bifida?
* Ultrasound
* MRI
* CT scan
104
Fill in the blank: Treatment for spina bifida may include _______ and surgery.
[therapies]
105
What is the role of surgery in managing spina bifida?
Surgery is often performed to close the defect and prevent further complications.
106
What is the relationship between spina bifida and mobility?
Individuals with spina bifida may experience varying degrees of mobility issues depending on the severity of the condition.
107
What conditions may SBO be associated with?
Diastematomyelia, tethered cord, lipoma, dermoid tumor
## Footnote
SBO stands for small bowel obstruction, and these associations may indicate underlying congenital or structural abnormalities.
108
What percentage of myelomeningocele patients who develop hydrocephalus do so before age 6 months?
Over 80%
## Footnote
This statistic highlights the early onset of hydrocephalus in myelomeningocele patients.
109
What type of malformation is commonly associated with myelomeningocele patients?
Chiari type 2 malformation
## Footnote
Chiari type 2 malformation is a common neurological condition in myelomeningocele.
110
What effect can the closure of the myelomeningocele defect have on hydrocephalus?
It may convert a latent HCP to active HCP
## Footnote
This occurs by eliminating a route of egress of cerebrospinal fluid (CSF).
111
What percentage of myelomeningocele patients are allergic to latex?
Up to 73%
## Footnote
Latex allergy in these patients is due to proteins found in naturally occurring rubber products.
112
Fill in the blank: Closure of the MM defect may convert a latent _______ to active HCP.
HCP
## Footnote
HCP stands for hydrocephalus.
113
What are the critical goals of myelomeningocele repair?
1) Free placode from dura (to avoid tethering)
2) Water-tight dural closure
3) Skin closure (can be accomplished in essentially all cases)
## Footnote
Closure does not restore any neurologic function.
114
What is the ideal timing for surgical closure of myelomeningocele?
≤ 36 hours after birth
## Footnote
A latex-free setup is preferred.
115
What should be done to avoid trapping skin during myelomeningocele repair?
Undermine skin to achieve closure
## Footnote
Trapping skin can lead to a dermoid tumor.
116
What does a post-operative CSF leak usually indicate?
A shunt is required
## Footnote
CSF leaks can complicate recovery.
117
Fill in the blank: The first critical goal of myelomeningocele repair is to free the _______ from dura to avoid tethering.
[placode]
118
What is a helpful tip for myelomeningocele repair regarding the dura?
Start at normal dura, open as wide as the defect
## Footnote
Trim placode if necessary to close dura.
119
What condition may mimic various symptoms and requires ruling out shunt malfunction?
Hydrocephalus
## Footnote
Hydrocephalus is a condition characterized by an accumulation of cerebrospinal fluid (CSF) in the brain's ventricles, which can present symptoms similar to numerous other disorders.
120
Late problems post MM repair
- Hydrocephalus
- Tethered cord syndrome
- Dermoïd tumor
- Syringomyelia
- Medullaire compression (Chiari II)
- Short stature
121
What is a lipomyelomeningocoele?
A subcutaneous lipoma that passes through a midline defect in the lumbodorsal fascia, vertebral neural arch, and dura, and merges with an abnormally low tethered cord.
122
What are the common cutaneous stigmata associated with spina bifida in patients with lipomeningomyelocoele?
Fatty subcutaneous pads, dimples, port-wine stains, abnormal hair, dermal sinus opening, skin appendages
## Footnote
These stigmata are usually located over the midline and may extend asymmetrically to one side.
123
What foot condition may occur in patients with lipomeningomyelocoele?
Clubbing of the feet (talipes equinovarus)
## Footnote
This condition affects the positioning and movement of the feet.
124
What percentage of patients may have a normal neurologic exam?
Up to 50%
## Footnote
Many of these patients present with skin lesions only.
125
What is the most common neurologic abnormality in patients with lipomeningomyelocoele?
Sensory loss in the sacral dermatomes
## Footnote
This finding is significant as it may indicate underlying neurological involvement.
126
Fill in the blank: Almost all patients with lipomeningomyelocoele have cutaneous stigmata of the associated _______.
spina bifida
127
What is Filum terminale lipoma (FTL)?
A lumbosacral lipoma with the fat limited to the filum terminale and not involving the conus medullaris.
128
What are the alternative names for Filum terminale lipoma?
* Fibrolipoma of the filum terminale
* Fatty filum
129
What is a dermal sinus?
A tract beginning at the skin surface, lined with epithelium.
130
Where is a dermal sinus usually located?
At either end of the neural tube: cephalic or caudal.
131
What is the most common location for a dermal sinus?
Lumbosacral.
132
What is a potential complication of dermal sinus?
A potential pathway for intradural infection
## Footnote
Dermal sinuses can lead to complications such as meningitis and intrathecal abscess.
133
What complications can arise from a dermal sinus?
Meningitis and intrathecal abscess
## Footnote
Meningitis may sometimes be recurrent.
134
True or False: Dermal sinuses are always symptomatic.
False
## Footnote
Dermal sinuses may appear innocuous.
135
What should be done with sinuses above the lumbosacral region?
They should be surgically removed.
## Footnote
This is a standard recommendation for managing these sinuses.
136
What is the controversy regarding sinuses located more caudally?
Their management is slightly controversial.
## Footnote
The approach to these sinuses may vary among medical professionals.
137
What percentage of presumed sacral sinuses seen at birth will regress to a deep dimple?
Approximately 25%.
## Footnote
Follow-up time for this regression is not specified.
138
What is recommended for all dermal sinuses?
They should be surgically explored and fully excised prior to the development of neurologic deficit or signs of infection.
## Footnote
Early intervention is crucial to prevent complications.
139
How do the results of surgery following intradural infection compare to surgery prior to infection?
The results following intradural infection are never as good as when undertaken prior to infection.
## Footnote
This emphasizes the importance of timely surgical intervention.
140
When is surgery appropriate after diagnosis of a sinus?
Surgery within the week of diagnosis is appropriate.
## Footnote
Prompt surgical action is advised to minimize risks.
141
What is a hemivertebra?
A type of vertebral formation failure
## Footnote
Hemivertebra is characterized by the incomplete formation of a vertebra, leading to potential complications such as scoliosis.
142
What does fully segmented mean in vertebral formation?
Fully formed disc space above and below with no attachment to adjacent vertebrae
## Footnote
This form has the highest risk for scoliosis progression, with a reported 100% progression rate in one study.
143
Define semi-segmented vertebra.
Incomplete vertebral body fused without a disc to either adjacent vertebra
## Footnote
This type of formation may have implications for spinal stability.
144
What characterizes a non-segmented vertebra?
Connected to the adjacent vertebrae above and below with no disc
## Footnote
Non-segmented vertebrae do not have potential for scoliosis progression.
145
What does incarcerated mean in the context of vertebral formation?
Vertebrae above and below compensate for the abnormal level, neutralizing scoliosis
## Footnote
This is referred to as a “balanced hemivertebra.”
146
What is unilateral failure of segmentation?
Osseous bridging of one side between adjacent vertebrae or posterior elements
## Footnote
This condition produces scoliosis that is concave on the side of the bridging bar.
147
Describe bilateral failure of segmentation.
Characterized by block vertebra, as seen in Klippel-Feil syndrome
## Footnote
This condition involves the fusion of two or more vertebrae.
148
Fill in the blank: Fully segmented vertebrae have the highest risk for _______.
scoliosis progression
149
True or False: A non-segmented vertebra has the potential for scoliosis progression.
False
## Footnote
Non-segmented vertebrae are connected and do not allow for progression.
150
What is Klippel-Feil syndrome?
Congenital fusion of two or more cervical vertebrae.
## Footnote
The fusion can range from only the bodies being fused (congenital block vertebrae) to the entire vertebrae, including posterior elements.
151
What does Klippel-Feil syndrome involve?
Fusion of cervical vertebrae.
## Footnote
This condition can vary in severity and extent.
152
In Klippel-Feil syndrome, what is a congenital block vertebra?
Fusion of only the bodies of cervical vertebrae.
## Footnote
This represents one end of the spectrum of Klippel-Feil syndrome.
153
What can the extent of fusion in Klippel-Feil syndrome include?
Fusion of the entire vertebrae including posterior elements.
## Footnote
This indicates a more severe form of the condition.
154
What is Klippel Feil syndrome characterized by?
Classic clinical triad:
* low posterior hairline
* shortened neck (brevicollis)
* limitation of neck motion
## Footnote
All three features are present in less than 50% of cases.
155
What is the prevalence of low posterior hairline in Klippel Feil syndrome?
Less than 50%
## Footnote
It is part of the classic clinical triad.
156
What are the symptoms associated with Klippel Feil syndrome?
Limitation of neck motion, facial asymmetry, torticollis, webbing of the neck
## Footnote
Limitation of movement is more common in rotation than in flexion–extension or lateral bending.
157
In Klippel Feil syndrome, what percentage of patients have scoliosis?
60%
## Footnote
Scoliosis is one of the clinical associations.
158
What factors can affect the visibility of limitation of neck motion in Klippel Feil syndrome?
If less than 3 vertebrae are fused, fusion is limited to lower cervical levels, or hypermobility of nonfused segments compensates
## Footnote
Limitation of movement may not be evident under these conditions.
159
True or False: Limitation of neck motion in Klippel Feil syndrome is more commonly observed in flexion–extension than in rotation.
False
## Footnote
Limitation of movement is more common in rotation.
160
Fill in the blank: A characteristic feature of Klippel Feil syndrome is _______.
shortened neck (brevicollis)
## Footnote
This is part of the classic clinical triad.
161
What is Tethered Cord Syndrome?
A condition characterized by an abnormally low conus medullaris.
162
What soinal cord deformity is typically associated with Tethered Cord Syndrome?
A short, thickened filum terminale or an intradural lipoma.
163
Which other lesions are considered separate entities from Tethered Cord Syndrome?
Lipoma extending through dura or diastematomyelia.
164
In which condition is Tethered Cord Syndrome most commonly found?
Myelomeningocele (MM).
165
Fill in the blank: Tethered Cord Syndrome is usually associated with a _______.
short, thickened filum terminale.
166
True or False: An intradural lipoma is a common association with Tethered Cord Syndrome.
True.
167
What are the cutaneous findings associated with tethered cord?
Hypertrichosis and sub-Q lipoma (no intraspinal extension)
## Footnote
Hypertrichosis refers to excessive hair growth, while sub-Q lipoma are benign tumors of fatty tissue.
168
What is a common gait issue related to tethered cord?
Gait difficulty with lower extremity weakness
## Footnote
Lower extremity weakness can significantly affect walking and balance.
169
What visible signs may indicate tethered cord?
Visible muscle atrophy, short limb, or ankle deformity
## Footnote
These physical manifestations can be critical in diagnosing tethered cord syndrome.
170
Name a sensory symptom associated with tethered cord.
Sensory deficit
## Footnote
Sensory deficits may affect the ability to perceive touch, pain, or temperature.
171
What type of dysfunction may occur in patients with tethered cord?
Bladder dysfunction
## Footnote
Bladder dysfunction can include issues such as incontinence or retention.
172
What spinal deformities are associated with tethered cord?
Scoliosis or kyphosis
## Footnote
Scoliosis is a lateral curvature of the spine, while kyphosis is an excessive outward curvature.
173
What type of spina bifida is associated with tethered cord?
Posterior spina bifida (lumbar or sacral)
## Footnote
This condition involves incomplete closure of the neural tube, affecting the lower spine.
174
What is the definition of low conus medullaris?
Conus medullaris located below L2
## Footnote
The conus medullaris is the terminal end of the spinal cord.
175
What is considered a normal diameter for the filum terminale?
Normal diameter is < 1 mm
## Footnote
The filum terminale is a fibrous extension of the spinal cord.
176
What diameter is considered pathological for the filum terminale?
Diameters > 2 mm are pathological
## Footnote
A thickened filum terminale can indicate underlying pathology.
177
Fill in the blank: A thickened filum terminale is defined as having a diameter greater than _______.
2 mm
178
True or False: A conus medullaris located at L1 is considered low conus medullaris.
False
## Footnote
Low conus medullaris is defined as being below L2.
179
What is the term used for all double spinal cords?
Split cord malformation (SCM)
## Footnote
SCM refers to a specific type of spinal cord abnormality characterized by the presence of two spinal cords.
180
What is Type I SCM?
Defined as two hemicords, each with its own central canal and surrounding pia, each within a separate dural tube separated by a dural-sheathed rigid osseocartilaginous (bony) median septum
## Footnote
This condition has often (but not consistently) been referred to as diastematomyelia.
181
What does Type II SCM consist of?
Two hemicords within a single dural tube, separated by a nonrigid fibrous median septum.
182
What is another term sometimes used for Type II SCM?
Diplomyelia.
183
What arises from each hemicord in Type II SCM?
Nerve roots.
184
What is Type 1 Chiari malformation?
A heterogeneous entity with impaired CSF circulation through the foramen magnum
## Footnote
It may be congenital or acquired.
185
What is the most common symptom of Type 1 Chiari malformation?
Occipital headache, exacerbated by coughing (tussive headache)
## Footnote
This symptom is a key indicator of the condition.
186
What is the primary evaluation method for Type 1 Chiari malformation?
MRI of the brain and cervical spine
## Footnote
This assesses compression at the foramen magnum and rules out syringomyelia.
187
What does cine MRI evaluate in uncertain cases of Type 1 Chiari malformation?
CSF flow through the foramen magnum
## Footnote
This helps determine the impact of the malformation on cerebrospinal fluid circulation.
188
What is the significance of cerebellar tonsillar herniation on MRI for Type 1 Chiari malformation?
Criteria vary, > 5 mm below the foramen magnum is often cited
## Footnote
However, this measurement is neither essential nor diagnostic of the condition.
189
What is the typical treatment for Type 1 Chiari malformation when indicated?
Surgical intervention, often involving enlargement of the foramen magnum
## Footnote
The specifics of the surgery can be controversial.
190
What percentage of Type 1 Chiari malformation cases are associated with syringomyelia?
30–70%
## Footnote
Syringomyelia almost always improves with treatment of the Chiari malformation.
191
What is considered acquired Chiari 1 malformation?
Following lumboperitoneal shunt or multiple (traumatic) LPs
## Footnote
This condition arises as a consequence of specific medical procedures or trauma.
192
What is the causal relationship established with acquired Chiari 1 malformation?
It is established with following lumboperitoneal shunt or multiple (traumatic) LPs
## Footnote
These procedures can lead to changes in the brain structure associated with Chiari malformation.
193
Can acquired Chiari 1 malformation be symptomatic?
May be asymptomatic
## Footnote
Some individuals may not exhibit any symptoms despite having the condition.
194
What is the most common symptom of Chiari 1 malformation?
Pain (69%)
## Footnote
Pain is often experienced as headaches, particularly in the suboccipital region.
195
Where is headache pain typically located in Chiari 1 malformation?
Suboccipital region
## Footnote
This region is located at the back of the head, just above the neck.
196
What activities can exacerbate headaches in Chiari 1 malformation?
Neck extension or Valsalva maneuver
## Footnote
The Valsalva maneuver includes actions such as coughing, which can trigger tussive headaches.
197
What type of weakness is prominent in Chiari 1 malformation?
Unilateral grasp weakness
## Footnote
This refers to weakness affecting one side of the body, particularly in the ability to grasp objects.
198
What neurological sign may occur in patients with Chiari 1 malformation?
Lhermitte’s sign
## Footnote
Lhermitte’s sign is characterized by a sensation of electric shock that runs down the spine when the neck is flexed.
199
What is a common lower extremity symptom associated with Chiari 1 malformation?
Bilateral spasticity
## Footnote
Bilateral spasticity refers to stiffness or tightness in the muscles of both legs.
200
What is a characteristic of Chiari 1 malformation?
Downbeat nystagmus
## Footnote
Downbeat nystagmus is an eye movement disorder often seen in patients with Chiari 1 malformation.
201
What percentage of patients with Chiari 1 malformation may have a normal neurologic exam?
10%
## Footnote
These patients may present with occipital headaches as their only complaint.
202
What is a possible presentation of some patients with Chiari 1 malformation?
Spasticity
## Footnote
This can be a primary symptom in some cases.
203
List the three main patterns of clustering of signs in Chiari 1 malformation.
* Foramen magnum compression syndrome
* Central cord syndrome
* Cerebellar syndrome
## Footnote
Each pattern presents with specific neurological signs and symptoms.
204
What symptoms are associated with foramen magnum compression syndrome?
* Ataxia
* Corticospinal and sensory deficits
* Cerebellar signs
* Lower cranial nerve palsies
## Footnote
This syndrome is characterized by compression at the foramen magnum.
205
What are the symptoms associated with central cord syndrome?
* Dissociated sensory loss
* Occasional segmental weakness
* Long tract signs
## Footnote
Dissociated sensory loss includes loss of pain and temperature sensation with preserved touch and joint position sense.
206
What symptoms are associated with cerebellar syndrome in Chiari 1 malformation?
* Truncal ataxia
* Limb ataxia
* Nystagmus
* Dysarthria
## Footnote
These symptoms result from cerebellar dysfunction.
207
What is Type 2 (Arnold)–Chiari malformation almost always associated with?
myelomeningocele
## Footnote
Often accompanied by hydrocephalus.
208
What are the key pathological features of Type 2 (Arnold)–Chiari malformation?
caudally displaced cervicomedullary junction, small posterior fossa, tectal beaking
209
Is Type 2 (Arnold)–Chiari malformation solely due to tethering?
No
210
What are the major clinical findings in Type 2 (Arnold)–Chiari malformation?
swallowing difficulties, apnea, stridor, opisthotonos, downbeat nystagmus
211
When a patient with Type 2 (Arnold)–Chiari malformation is symptomatic, what should always be checked first?
the shunt
212
What is the recommended surgical intervention for symptomatic Type 2 (Arnold)–Chiari malformation?
surgical decompression
213
Can surgical decompression correct intrinsic brainstem abnormalities in Type 2 (Arnold)–Chiari malformation?
No
214
What is the diagnostic test of choice for Type 2 (Arnold)–Chiari malformation?
cranial and cervical MRI
215
What is craniolacunia?
Round defects in the skull with sharp borders, separated by irregularly branching bands of bone
## Footnote
Craniolacunia occurs in 85% of cases and is not due to increased intracranial pressure (ICP)
216
What percentage of cases does craniolacunia occur?
85%
## Footnote
This statistic highlights the prevalence of the condition in affected populations.
217
True or False: Craniolacunia is due to increased intracranial pressure.
False
## Footnote
Craniolacunia is characterized by its distinct bone structure and is not associated with increased ICP.
218
What are neural tube defects?
Congenital abnormalities resulting from the failure of the neural tube to close properly during embryonic development.
## Footnote
Common examples include spina bifida and anencephaly.
219
What is the Lemire classification?
A system used to classify neural tube defects based on their characteristics and severity.
## Footnote
This classification helps in understanding different types of neural tube defects.
220
What are migration abnormalities in the context of neural tube defects?
Errors in the normal migration of neural crest cells during development, leading to defects.
## Footnote
These abnormalities can affect the formation of various structures in the central nervous system.
221
What is lissencephaly?
The most severe neuronal migration abnormality, characterized by maldevelopment of cerebral convolutions and severe mental retardation, typically resulting in a lifespan of less than 2 years.
## Footnote
Lissencephaly indicates an arrest of cortical development at an early fetal age.
222
Define agyria.
Completely smooth surface of the brain.
## Footnote
Agyria is a type of lissencephaly.
223
What characterizes pachygyria?
Few broad and flat gyri with shallow sulci.
## Footnote
Pachygyria can be confused with polymicrogyria on imaging studies.
224
Describe polymicrogyria.
Small gyri with shallow sulci, which may be difficult to diagnose by CT/MRI.
## Footnote
Polymicrogyria may be confused with pachygyria.
225
What is heterotopia?
Abnormal foci of gray matter located from subcortical white matter to subependymal lining of the ventricles, often presenting as nodules or a band of cortex.
## Footnote
Heterotopia is an early migration defect that almost always presents with seizures.
226
What is cortical dysplasia?
A cleft that does not communicate with the ventricle, often associated with heterotopias.
## Footnote
It is a migration abnormality not as severe as schizencephaly.
227
Define schizencephaly.
A cleft that communicates with the ventricle, lined with cortical gray matter and may have polymicrogyria.
## Footnote
Schizencephaly can be confirmed with a CT cisternogram.
228
What are the two forms of schizencephaly?
* Open lipped: large cleft to ventricle
* Close lipped: walls fused, with a dimple in the lateral wall of the lateral ventricle under the cortical cleft
## Footnote
The open lipped form may mimic hydranencephaly.
229
What is the difference between porencephaly and schizencephaly?
Porencephaly is a cystic lesion lined with glial tissue or connective tissue, while schizencephaly has a cleft lined with cortical gray matter.
## Footnote
Schizencephaly may involve abnormal cortical tissue.
230
What is porencephaly?
A condition characterized by the presence of cysts or cavities in the brain
## Footnote
Usually arises from in-utero insult, not a migration or neurulation defect, and is contrasted with schizencephaly.
231
Is porencephaly a migration defect?
No
## Footnote
It is not classified as a migration or neurulation defect.
232
What typically causes porencephaly?
In-utero insult
## Footnote
This can include factors like maternal infections, trauma, or vascular issues.
233
What is hydranencephaly?
A post-neurulation defect characterized by total or near-total absence of the cerebrum.
234
What remains intact in hydranencephaly?
Cranial vault and meninges.
235
What fills the intracranial cavity in hydranencephaly?
Cerebrospinal fluid (CSF).
236
What may be consistent with the diagnosis of hydranencephaly?
Small bands of cerebrum.
237
What is Holoprosencephaly?
Failure of the telencephalic vesicle to cleave into two cerebral hemispheres.
## Footnote
Holoprosencephaly is a congenital brain malformation that results in varying degrees of developmental defects.
238
What is the definition of microcephaly?
Head circumference more than 2 standard deviations below the mean for sex and gestational age.
239
What is macroencephaly?
An enlarged brain which may be due to hypertrophy of gray matter alone, gray and white matter, presence of additional structures
## Footnote
Macroencephaly can be a result of various conditions and may require further medical evaluation.
240
What does MCAP stand for?
Megalencephaly-capillary malformation syndrome
## Footnote
MCAP is a rare genetic disorder characterized by brain and skin abnormalities.
241
What is one of the key features of MCAP?
Megalencephaly
## Footnote
Megalencephaly refers to an abnormal enlargement of the brain.
242
What type of malformation is associated with MCAP?
Capillary malformation
## Footnote
Capillary malformations are abnormal blood vessel formations in the skin.
243
True or False: MCAP is a common genetic disorder.
False
## Footnote
MCAP is considered a rare genetic disorder.
244
In addition to megalencephaly, name another possible feature of MCAP.
Possible features include:
* Capillary malformations
* Developmental delays
* Other neurological issues
## Footnote
Developmental delays can vary in severity among affected individuals.
245
Fill in the blank: MCAP is caused by mutations in the _______.
PIK3CA gene
## Footnote
Mutations in the PIK3CA gene can lead to abnormal cell growth and development.
246
What type of inheritance pattern is associated with MCAP?
Somatic mosaicism
## Footnote
Somatic mosaicism means that the mutation is not present in every cell of the body, leading to varied symptoms.
247
What is a common neurological symptom of MCAP?
Developmental delays
## Footnote
Developmental delays can affect motor skills, speech, and cognitive functions.
248
Name one diagnostic method for MCAP.
Genetic testing
## Footnote
Genetic testing can confirm the presence of mutations in the PIK3CA gene.
249
What is the recommended daily dosage of folic acid for mothers with no history of neural tube defects?
0.4 mg/d
## Footnote
Early administration of folic acid is crucial for reducing the risk of neural tube defects.
250
What daily dosage of folic acid is recommended for mothers who are carriers or have had a previous child with neural tube defects?
4 mg/d
## Footnote
This dosage is associated with a 71% reduction in the recurrence of neural tube defects.
251
What is the effect of folate antagonists like carbamazepine on the incidence of neural tube defects?
Doubles the incidence of neural tube defects
## Footnote
This highlights the importance of careful medication management during pregnancy.
252
What genetic polymorphism is associated with reduced levels of tissue folate and increased levels of homocysteine?
5, 10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism
## Footnote
The common variant C677T substitutes an alanine residue for valine at position 222 in the MTHFR enzyme.
253
What are the genotype distributions for the MTHFR polymorphism C677T in the population?
10% homozygous (TT genotype), 38% heterozygous (CT genotype)
## Footnote
This polymorphism is linked to an increased risk of neural tube defects.
254
What is the risk of neural tube defects associated with the use of valproic acid (Depakene®) during pregnancy?
1–2% risk
## Footnote
Valproic acid is known to have teratogenic effects.
255
What maternal condition increases the risk of neural tube defects before and during pregnancy?
Obesity
## Footnote
Obesity is a significant risk factor for various adverse pregnancy outcomes.
256
What maternal activity during the first trimester is associated with an increased risk of neural tube defects?
Heat exposure from hot-tubs, saunas, or fever
## Footnote
Electric blankets do not appear to increase this risk.
257
What potential effects does maternal cocaine abuse have on fetal development?
Increases the risk of microcephaly, disorders of neuronal migration, neuronal differentiation, and myelination
## Footnote
Substance abuse during pregnancy poses serious risks to fetal health.
258
True or False: The effects of the TT genotype of the MTHFR polymorphism are more pronounced than those of the CT genotype.
True
## Footnote
The TT genotype is linked to a greater risk of neural tube defects and cardiovascular diseases.
