Pediatrics CNS Flashcards
- In mild-moderate hypoxic brain injury in a full term neonate typically spares:
A. Watershed areas
B. Parasagital cortex
C. Deep grey matter structure
D. Subcortical white matter
E. Frontal lobes
C. Deep grey matter structure
The brainstem, cerebellum and deep grey structures are spared in mild-moderate ischemia. Severe hypoxic injury involves the ventral and lateral thalamus, posterior putamen, perirolandic regions and corticospinal tracts.
- A 7-year-old boy with a well mother and father develops a progressive deterioration in vision, loss of hearing, optic disc pallor and ataxia. Mental deterioration is also noted. CT shows symmetric low densities in the occipitoparietal temporal white matter with thin curvilinear enhancing rims. MR shows hypodensity on T1 and bilateral hyperintense confluent areas. Which is the most likely diagnosis?
A. Adrenomyloneuropathy
B. Adrenoleukodystrophy
C. Friedreich’s ataxia
D. Ataxia telangiectasia
E. Spongiform leukodystrophy
B. Adrenoleukodystrophy
Features describe adrenolukodystrophy, an X linked recessive condition. Patients also have adrenal gland insufficiency with increased pigmentation and raised Adrenocorticotropic Hormone (ACTH) levels.
- The absence of which of the following indicates a diagnosis of Dandy-Walker variant rather than Dandy-Walker malformation?
A. Dysgenesis of the corpus callosum
B. Holoprosencephaly
C. Cerebellar heterotopia
D. Enlargement of the posterior fossa
E. Cerebellar gyri malformation
D. Enlargement of the posterior fossa
The other features are common to both.
(CNS) 8. A CT brain of a 25-year-old male with a head injury but no focal neurology shows no acute abnormality. A thin cerebrospinal fluid (CSF) density is noted between the frontal horns of the lateral ventricles in the midline. Which is the diagnosis?
A. Cavum septi pellucidi
B. Cavum vergae
C. Cavum veli interpositii
D. Colloid cyst
E. Arachnoid cyst
A. Cavum septi pellucidi
Occurs in 80% of term infants and 15% of adults. Rarely may dilate and cause obstructive hydrocephalus.
- MRI brain in a neonate shows multiple abnormalities including an anterior interhemispheric fissure adjoining a high riding third ventricle, an enlarged foramen of monro and a sunburst gyral pattern. An interhemispheric cyst is also seen. Which is the diagnosis?
A. Arachnoid cyst
B. Agenesis of the corpus callosum
C. Prominent cavum septum pellucidi and vergae
D. Chiari II malformation
E. Dandy-Walker malformation
B. Agenesis of the corpus callosum
Absence of septum pellucidum, corpus callosum and cavum septum pellucidi, and wide separation of the lateral ventricles, are other features of agenesis of the corpus callosum.
- Ovoid areas of increased echogenicity are seen on US of a neonate. Which of the following favours choroid plexus rather than germinal mature haemorrhage?
A. Tapering toward cardiothalamic grove
B. Inferolateral to floor of frontal horn
C. Bulbous enlargement of cardiothalamic groove
D. Location anterior to foramen of Monro
E. Low birth weight and premature neonate
A. Tapering toward cardiothalamic grove
Prematurity and low birth weight are amongst risk factors for GMH. Chord plexus is attached to inferomedial aspect of ventricular floor, tapering toward cardiothalamic groove and never anterior to the foramen of Monro.
(CNS) 17. Which of the following associations favour Chiari I rather than Chiari II malformation?
A. Klippel-Feil anomaly
B. Myelomyeocele
C. Dysgenesis corpus callosum
D. Absence of septum pellucidi
E. Excessive cortical gyration
A. Klippel-Feil anomaly
Syringohydromyelia, hydrocephalus, malformation of small bones and spine are also associations of Type I Chiari malformation.
(CNS) 25. A combination of subependymal nodules, giant cell astrocytomas, white matter lesion and retinal phakomatoses suggests:
A. Tuberous sclerosis
B. NFI
C. NF2
D. Sturge-Weber syndrome
E. Von Hippel-Lindau
A. Tuberous sclerosis
These are all features of tuberous sclerosis.
(CNS) 31. A patient with a genetic condition and known bilateral renal cysts undergoes MRI brain showing a cystic lesion with mural nodule. This finding is associated with:
A. VHL
B. Tuberous sclerosis
C. Sturge-Weber
D. Heritary Haemorrhagic Telangiectasia (HHT)
E. Neurofibromatosis
A. VHL
1/3 haemangioblastomas are purely solid, 1/3 are cystic with mural nodes and 1/3 are cystic with a more complex solid component.
(CNS) 32. Tram track gyriform calcification is most likely to be seen in:
A. NF I
B. Tuberous sclerosis
C. Von Hippel-Lindau
D. HHT
E. Sturge-Weber
E. Sturge-Weber
Other features include cerebral atrophy with thickening of skull vault and surface enhancement, enlarged choroid plexus and enlarged medullary/subependymal veins. Choroid angiomas may be present.
1) A finding of bilateral meningiomas in a child suggests a diagnosis of which of the following phakomatoses?
a. neurofibromatosis type 1
b. neurofibromatosis type 2
c. von Hippel-Lindau disease
d. Sturge-Weber syndrome
e. tuberous sclerosis
b. neurofibromatosis type 2
The phakomatoses are neuroectodermal disorders with skin and central nervous system manifestations.
Neurofibromatosis type 2 (central neurofibromatosis) accounts for only 10% of cases, type 1 accounting for 90%.
Although the hallmark finding of type 2 is bilateral acoustic schwannomas, multiple meningiomas, particularly in a child, should bring the diagnosis to mind.
A mnemonic for remembering the associations is MISME (multiple inherited schwannomas, meningiomas and ependymomas), and tumours may be seen in the brain or spinal cord.
In the spine, multiple nerve sheath tumours are often located in the cauda equina.
Skin manifestations are seen relatively infrequently, unlike in the more common type 1.
@#e (CNS) 2) A child who undergoes MR of the brain for clinically apparent facial abnormalities is shown to have a defect of midline cleavage of the brain. What structure is abnormal or absent in all forms of holoprosencephaly, and therefore is the most sensitive indicator of a midline cleavage abnormality?
a. falx cerebri
b. third ventricle
c. fourth ventricle
d. corpus callosum
e. septum pellucidum
e. septum pellucidum
Holoprosencephaly is failure of the primitive brain to cleave into two hemispheres, and is commonly associated with midline facial abnormalities (ranging from cyclopia to hypertelorism) and absence of many intracranial midline structures.
There are three types, the most severe being the alobar form, which shows no cleavage at all, with absence of the falx cerebri and third ventricle, fusion of the cerebral hemispheres and thalami, and a single large lateral ventricle.
The semilobar form has variable cleavage with a partially formed falx, rudimentary third ventricle, and variable cleavage of the thalami, lateral ventricles and cerebral hemispheres.
In the lobar type of holoprosencephaly, brain formation may be nearly normal, but the septum pellucidum is always absent, as in all forms. The falx, corpus callosum and ventricular system may be normal in the lobar type.
6) A 6-year-old boy presents with learning disability, seizures and a facial rash. MRI of the brain shows several cortical lesions with low signal on T1W and high signal on T2W images. They show no enhancement with administration of intravenous gadolinium. Low-signal subependymal nodules are identified on all sequences. Subsequent renal ultrasound scan demonstrates multiple, bilateral hyperechogenic lesions. What is the most likely diagnosis?
a. neurofibromatosis type 1
b. Sturge-Weber syndrome
c. von Hippel-Lindau disease
d. tuberous sclerosis
e. metachromatic leukodystrophy
d. tuberous sclerosis
Tuberous sclerosis is a member of the phakomatoses, a group of neuroectodermal disorders characterized by coexistence of skin and central nervous system tumours.
The classic clinical triad of seizures, learning disability and adenoma sebaceum (a facial rash) is seen in approximately half of presenting patients.
Imaging findings seen on MRI and sometimes CT are periventricular nodules, which often calcify, and ‘cortical tubers’, which represent brain parenchymal hamartomas. These lesions are low signal on T1 and high signal on T2W images, and typically do not enhance. Enhancement of a lesion suggests associated giant cell astrocytoma, which is most commonly seen at the foramen ofMonro, where it may obstruct, causing hydrocephalus.
Common associations are renal angiomyolipoma, bone abnormalities and spontaneous pneumothorax.
(CNS) 22) What is the most sensitive sign on non-contrast CT for detecting early hydrocephalus?
a. cortical sulcal effacement
b. uncal herniation
c. enlarged third ventricle
d. enlarged fourth ventricle
e. enlarged temporal horns of the lateral ventricles
e. enlarged temporal horns of the lateral ventricles
In many cases of hydrocephalus due to subarachnoid haemorrhage, the temporal horns of the lateral ventricles become dilated sooner than the frontal horns.
Dilatation of the temporal horn is often particularly conspicuous, as it is frequently not visualized at all on CTof normal brains.
Uncal herniation is herniation of the medial temporal lobe into a subtentorial location, where it may exert pressure on the brain stem and is a late sign of raised intracranial pressure, often presenting with oculomotor nerve palsy resulting in a fixed dilated pupil.
23) MRI of the brain in a premature baby reveals ischaemic lesions adjacent to the trigone of the lateral ventricle. What is the most likely insult to have caused these appearances?
a. prolonged partial asphyxia
b. acute profound asphyxia
c. germinal matrix haemorrhage
d. rupture of a choroid plexus cyst
e. venous sinus thrombosis
a. prolonged partial asphyxia
There are three patterns of hypoxic ischaemic encephalopathy.
Periventricular leukomalacia occurs in watershed areas of arterial distribution. It is caused by prolonged partial asphyxia in preterm or term babies.
Acute profound asphyxia causes lesions in the deep grey matter, hippocampus and dorsal brain stem.
Lastly, there is multicystic encephalomalacia that follows devastating encephalopathy and generalized brain oedema.
(CNS) 27) A 22-year-old man with von Hippel-Lindau syndrome presents with headaches, vomiting and ataxia. CT of the brain demonstrates an abnormality in the posterior fossa. What are the most likely findings?
a. cystic lesion with an enhancing mural nodule
b. multiple ring-enhancing lesions with surrounding oedema
c. gyriform cortical calcifications
d. multiple calcified subependymal nodules
e. hypodense, ill-defined mass with central necrosis and marked surrounding oedema
a. cystic lesion with an enhancing mural nodule
Haemangioblastomas are the most commonly recognized manifestation of von Hippel-Lindau syndrome. They usually occur in the cerebellum and may be multiple in up to 15% of cases.
Patients also commonly develop renal cell carcinoma, and difficulty may occasionally arise in distinguishing metastases from multiple haemangioblastomas.
Typical features are of a cystic mass in the hemisphere or vermis, with an enhancing mural nodule, though entirely solid lesions may also occur. Calcification is not a feature.
Gyriform cortical calcifications are a feature of Sturge-Weber syndrome, and usually occur in the temporoparieto- occipital region.
Calcified subependymal nodules (hamartomas) are a feature of tuberous sclerosis.
A hypodense, ill-defined mass with central necrosis and marked surrounding oedema is a classic appearance of a glioblastoma multiforme.
32) Of the choices below, which best describes the pattern of normal myelination of the brain in the first 9 months of life?
a. cranial to caudal, posterior to anterior, deep to superficial
b. cranial to caudal, anterior to posterior, deep to superficial
c. cranial to caudal, posterior to anterior, superficial to deep
d. caudal to cranial, posterior to anterior, deep to superficial
e. caudal to cranial, anterior to posterior, superficial to deep
d. caudal to cranial, posterior to anterior, deep to superficial
Myelination is an important feature of the maturation of the normal central nervous system. It is a dynamic process that begins in utero and continues after birth in a predetermined manner. It is well demonstrated on MRI, where initially white and grey matter show the reverse signal characteristics to those seen in the adult brain, with the white matter appearing of lower signal on T1 and higher signal on T2 than grey matter.
As myelination occurs, the white matter gains fat content and so becomes of higher signal on T1 and lower signal on T2 than grey matter, with completion at around 9 months. The process progresses caudal to cranial, posterior to anterior, and deep to superficial, beginning with the brain stem and cerebellum, then the basal ganglia, with the final areas to mature being the peripheral cortical white matter.
(CNS) 32) An 18-month-old toddler presents with progressive gait disturbance, motor developmental delay and muscle weakness. Biochemical tests show abnormally low levels of arylsulphatase A enzyme in peripheral blood leukocytes and urine. MRI demonstrates symmetrical, confluent areas of high signal on T2W images affecting the periventricular and cerebellar white matter, corpus callosum and corticospinal tracts with sparing of the subcortical U fibres. The periventricular abnormality shows a striped ‘tigroid’ pattern. There is no enhancement with administration of intravenous gadolinium. What is the most likely condition?
a. Alexander’s disease
b. Canavan’s disease
c. acute disseminated encephalomyelitis
d. mucopolysaccharidosis
e. metachromatic leukodystrophy
e. metachromatic leukodystrophy
Dysmyelinating diseases (leukodystrophies) are a wide spectrum of inherited neurodegenerative disorders affecting myelin in the brain and peripheral nerves.
Most fall into one of three categories: lysosomal storage diseases, peroxisomal disorders and diseases caused by mitochondrial dysfunction.
The most common, metachromatic leukodystrophy, is an autosomal recessive disorder caused by a deficiency of the lysosomal enzyme arylsulphatase A, which leads to accumulation of sulphatides in tissues.
It usually manifests as a late infantile subtype in children at 12–18 months of age, and is characterized by motor signs of peripheral neuropathy followed by deterioration in intellect, speech and coordination, leading to death within a few years.
On T2W MRI, symmetrical confluent areas of high signal intensity are seen in the periventricular white matter with sparing of the subcortical U fibres.
Sparing of the perivascular white matter gives a striped or tigroid appearance to the periventricular area of abnormality, particularly well seen in the centrum semiovale.
Other sites often affected are the corpus callosum, internal capsule and corticospinal tracts.
(CNS) 35) A 9-month-old boy presents to the paediatric neurologist with general developmental delay, left-sided weakness from birth and tonic-clonic seizures. MRI performed under anaesthetic reveals a thin cleft containing CSF extending from the right lateral ventricle to the cortical surface of the right frontal lobe. The margins of the cleft are opposed and lined with heterotopic grey matter that shows polymicrogyria. Which disorder of cortical formation is described?
a. porencephaly
b. schizencephaly
c. holoprosencephaly
d. lissencephaly
e. hemimegalencephaly
b. schizencephaly
The development of the cerebral cortex takes place in three stages: cell proliferation, cell migration and cortical organization.
Schizencephaly is a disorder of the final stage where there is a CSF-containing cleft lined with grey matter (which is often polymicrogyric) connecting the subarachnoid CSF space with the ventricular system.
Differentiation can be made from the cyst or cavity of porencephaly, by the presence in schizencephaly of a lining of heterotopic grey matter, whereas a porencephalic cyst is lined by white matter.
To result in schizencephaly, the insult must involve the entire thickness of the cerebral hemisphere during cortical organization, as in injuries due to prenatal infection, ischaemia or chromosomal abnormalities.
Clinical presentation varies but often includes developmental delay, motor impairment and seizures.
51) A 12-year-old girl presents with altered sensation in the upper and lower limbs. Clinical assessment demonstrates weakness of the lower limbs with reduced pain and temperature sensation. MRI shows syringohydromyelia and tonsillar ectopia of 7 mm with the fourth ventricle in normal position. No myelomeningocele is seen. What is the most likely diagnosis?
a. Chiari I malformation
b. Chiari II (Arnold-Chiari) malformation
c. Chiari III malformation
d. Dandy-Walker syndrome
e. diastematomyelia
a. Chiari I malformation
Chiari I malformation is characterized by tonsillar ectopia. The fourth ventricle is elongated but normal in position. It is associated with syringohydromyelia, hydrocephalus and malformations of the skull base.
Chiari II (Arnold-Chiari) malformation is characterized by hindbrain abnormalities, with caudal displacement of the fourth ventricle. A lumbar myelomeningocele is seen in over 95% of cases.
Chiari III malformation is rare and has a high cervical/low occipital meningomyelo-encephalocele. Survival beyond infancy is unusual.
In Dandy-Walker syndrome, there is enlargement of the posterior fossa with cystic dilatation of the fourth ventricle and abnormalities of the cerebellar vermis.
Diastematomyelia results in sagittal splitting of the spinal cord into two hemi-cords, and is sometimes associated with a myelomeningocele.
(CNS) 63) A 20-year-old male patient has an MR scan of his spine for investigation of back pain. He has low IQ and multiple skin patches. The MR scan shows bilateral branching tubular paraspinal masses, with widening of the intervertebral foramina and posterior scalloping of the vertebral bodies. A sharply angulated kyphosis is present at the thoracolumbar junction. What is the most likely diagnosis?
a. neurofibromatosis type 1
b. neurofibromatosis type 2
c. tuberous sclerosis
d. Marfan’s syndrome
e. Ehlers-Danlos syndrome
a. neurofibromatosis type 1
Neurofibromatosis type 1 (peripheral neurofibromatosis or von Recklinghausen’s disease) is a multisystem disorder affecting the majority of organ systems.
The presence of plexiform neurofibroma is pathognomonic. In the spine, there is abnormal development of the vertebral bodies with hypoplasia of pedicles and posterior elements.
Dural ectasia is seen secondary to weakness of the meninges.
Neurofibromatosis type 2 (central neurofibromatosis) is characterized by bilateral acoustic neuromas, meningiomas and ependymomas.
Tuberous sclerosis produces multiple hamartomas and malformations of several organ systems.
Marfan’s and Ehlers-Danlos syndromes may also cause posterior scalloping of vertebral bodies.
(CNS) 65) A severely hypoplastic cerebellar vermis in an enlarged bony posterior fossa, with associated hydrocephalus and communication of the fourth ventricle with a posterior midline CSF cyst, are features of which of the following posterior fossa malformations?
a. mega cisterna magna
b. Dandy-Walker malformation
c. Dandy-Walker variant
d. Arnold-Chiari malformation
e. Joubert’s syndrome
b. Dandy-Walker malformation
Classically, the Dandy-Walker malformation consists of partial or total absence of the cerebellar vermis, dilatation of the fourth ventricle into a large cystic mass, an enlarged posterior fossa, hydrocephalus (in 75% of cases) and torcular-lambdoid inversion (elevation of the torcular herophili above the lambdoid suture).
The proposed aetiology is obstruction of CSF outflow at the foramina of Magendie and Luschka.
The vermis abnormality is the key component in all forms of the Dandy-Walker complex.
The variant is less severe with a better prognosis.
Chiari malformations have the fundamental abnormality of an underdeveloped, small posterior fossa, in contrast to the Dandy- Walker complex where it is normal or enlarged.
66) During a routine new-baby check, a unilateral, firm, tense, nonpitting, parietal mass is noticed. Ultrasound scan demonstrates a crescent-shaped lesion adjacent to the outer table of the skull. The mass is most likely to be which of the following?
a. caput succedaneum
b. cephalocele
c. cephalhaematoma
d. leptomeningeal cyst
e. fibrous dysplasia
c. cephalhaematoma
Cephalhaematoma is seen with birth trauma, particularly following poor instrumentation and skull fracture during delivery. It is seen in 1-2% of deliveries. It can grow after birth and takes weeks or months to resolve. It does not cross sutural lines because the haematoma is beneath the outer layer of periosteum. The haematoma can calcify.
Caput succedaneum is localized scalp oedema that does cross sutural lines.
A cephalocele is a skull defect through which meninges, brain and cerebrospinal fluid may protrude.
67) Hyperechoic lesions are seen within the brain of a preterm neonate during a cranial ultrasound scan. Of the following, which most strongly suggests that the appearances are due to germinal matrix haemorrhage rather than periventricular leukomalacia?
a. the baby is premature
b. the hyperechoic changes are anterior to the caudothalamic groove
c. the hyperechoic changes are adjacent to the trigone of the lateral ventricle
d. cystic changes follow the acute phase in the affected brain
e. there was no birth trauma
b. the hyperechoic changes are anterior to the caudothalamic groove
Germinal matrix is highly vascular tissue seen at 24-32 weeks’ gestational age, located anterior to the caudothalamic groove and inferior to the lateral ventricles. It is at risk of hypoxaemia and ischaemia. Haemorrhage here can be promoted by trauma at birth or coagulopathy including rhesus incompatibility.
Germinal matrix haemorrhage less than 7 days old is hyperechoic but without shadowing.
Within 2-3 weeks, the abnormal area decreases in size and the echogenicity reduces.
Periventricular leukomalacia is white matter necrosis following hypoxaemia. It is seen in 5-10% of preterm babies. It occurs in arterial watershed areas and may appear acutely as a broad region of periventricular increased echogenicity. Cystic degeneration may follow after 2 weeks or more.
70) A 15-year-old girl with a history of multiple febrile convulsions as an infant presents to the neurologist with complex partial seizures. The episodes start with special and somatosensory aura followed by a wide-eyed stare with behavioural arrest, before finally proceeding to a generalized tonic-clonic seizure. MR imaging is requested. Which sequence is best to evaluate the temporal lobes for signs of mesial temporal sclerosis?
a. axial T1W
b. axial T2W
c. axial FLAIR
d. coronal T1W
e. coronal T2W
e. coronal T2W
Mesial temporal sclerosis is a pattern of hippocampal neuronal loss that can occur with long-standing temporal lobe epilepsy as a result of excessive neuronal depolarization leading to cytotoxic oedema.
Three patterns of loss are described, with relative sparing of the CA2 subfield often a feature.
The typical findings are of asymmetrical atrophy of the hippocampus with abnormally high signal returned on T2W images.
Ipsilateral findings in the limbic system include atrophy of the fornix and maxillary body.
Cortical abnormalities may exist in the temporal cortex, and this is best evaluated on high-resolution T1 sequences.
78) Germinal matrix haemorrhage is identified on a cranial ultrasound scan of a neonate. Which of the following imaging features confers the worst prognosis?
a. subependymal haemorrhage
b. intraventricular haemorrhage
c. intraventricular haemorrhage with ventricular dilatation
d. intraparenchymal haemorrhage
e. choroid plexus pulsation
d. intraparenchymal haemorrhage
Subependymal haemorrhage (grade 1) usually has no long-term consequence. Mortality rates for intraventricular haemorrhage, intraventricular haemorrhage with ventricular dilatation and intraparenchymal haemorrhage are 10%, 20% and more than 50%, respectively. These represent grades 2, 3 and 4 haemorrhage. Normal choroid plexus pulsates while haematoma at the same location is not pulsatile.
82 A term neonate whose birth per vaginum was notably protracted has an MRI of the brain at age 4 days. There are changes in keeping with hypoxic ischaemic encephalopathy. Affected areas are marked by T1 shortening without T2 signal change. Which of the following is the most likely explanation for this pattern of abnormal signal?
a. high T2 signal is masked by a high degree of myelination
b. high T2 signal is masked by a low degree of myelination
c. high T1 signal is accentuated by a high degree of myelination
d. high T1 signal is accentuated by a low degree of myelination
e. low T1 signal is masked by a high degree of myelination
b. high T2 signal is masked by a low degree of myelination
Neonatal hypoxic ischaemic encephalopathy occurs in 1-2/1000 live births. Clinically, it manifests as disturbed neurological function such as difficulty with respiration, abnormal tone, depressed reflexes, altered level of consciousness, feeding difficulties or seizures. Initial MRI findings, particularly in the first week of life, can be T1 shortening (bright) rather than a high T2 signal. This is because the unmyelinated white matter is brighter on T2W images and can disguise pathological lesions. T1 shortening is thought to be due to lipid breakdown products of damaged myelin or to mineralization.
85) Craniosynostosis of the sagittal suture of the skull results in which skull vault shape abnormality?
a. brachycephaly
b. scaphocephaly
c. trigonocephaly
d. oxycephaly
e. plagiocephaly
b. scaphocephaly
Craniosynostosis means premature closure of a suture of the skull, and skull growth is arrested in the direction perpendicular to the affected suture.
Craniosynostosis of the sagittal suture therefore results in a head shape that is abnormally long and narrow and has the appearance of an upturned boat. This is called scaphocephaly (or dolichocephaly) and accounts for 60% of all craniosynostoses.
Closure of the coronal suture accounts for 20% and results in a short, wide head called brachycephaly.
Trigonocephaly is caused by craniosynostosis of the metopic suture and results in a forward-pointing head.
Oxycephaly is the most extreme form, and all sutures may be affected, resulting in a high head.
Plagiocephaly is unilateral craniosynostosis.
Early recognition of all types is important to prevent permanent deformity and allow for surgical correction. Causes may be primary or secondary to dysplasia, a number of genetic syndromes, microcephaly, and metabolic or haematological conditions.
(Ped) 88) From the following renal and adrenal findings, choose that which favours a diagnosis of neurofibromatosis type 1 above von Hippel–Lindau syndrome or tuberous sclerosis.
a. renal cysts
b. renal cell carcinoma
c. phaeochromocytoma
d. renal artery aneurysm
e. angiomyolipoma
d. renal artery aneurysm
Renal artery stenosis and aneurysms plus abdominal coarctation are associated with neurofibromatosis type 1 (NF1).
Renal cysts are found in von Hippel–Lindau syndrome (VHL) and tuberous sclerosis,
while renal cell carcinoma is found in VHL.
NF1 and VHL are associated with phaeochromocytoma.
Angiomyolipomas, usually multiple and bilateral, are found in 50% of cases of tuberous sclerosis.
89) A 12 year old presents with a painless swelling in the right side of his neck, at the angle of the mandible. Ultrasound scan shows a cystic lesion with internal debris. CT confirms a cystic lesion with a beak of tissue pointing between the internal and external carotid arteries. What is the most likely diagnosis?
a. cystic hygroma
b. abscess
c. branchial cleft cyst
d. carotid body tumour
e. lymphadenopathy
c. branchial cleft cyst
The described features are typical of a branchial cleft cyst arising from the second branchial cleft.
The mass displaces the sternocleidomastoid posteriorly, and the carotid and internal jugular vessels posteromedially.
The pointing between the internal and external carotid arteries is pathognomonic.
Cystic hygromas present in infancy as a cystic mass in the posterior cervical space.
Abscesses present with associated symptoms and a painful red swelling, though imaging findings may be similar.
Carotid body tumours are solid, highly vascular masses lying between the internal and external carotid artery origins.
2 A 15 year old boy is under investigation for hypertension. The serum catecholamines and urinary VMAs are raised. CT abdomen confirms a left adrenal phaeochromocytoma and additionally shows multiple cysts within the liver, pancreas and both kidneys. Which of following additional features would you look for?
(a) Bilateral acoustic neuromas
(b) CNS haemangioblastomas
(c) Iris hamartomas
(d) Parathyroid adenomas
(e) Pulmonary lymphangioleiomyomatosis
(b) CNS haemangioblastomas
VHL is associated with CNS haemangioblastomas in 50%, pancreatic/ hepatic/ renal cysts, RCC, and phaeochromocytoma (10%).
Phaeochromocytomas are also associated with MEN types 2A and 2B (also medullary thyroid cancer, parathyroid adenomas), NF-1, & TS.
Bilateral acoustic neuromas are associated with NF-2.
(CNS) 5 A young patient with learning difficulties presents with multiple skin lesions and seizures. On examination there is an erythematous facial rash in a butterfly distribution and subungual fibromas are noted in the hands. A CT head is performed. Which of the following is not typically associated with this condition?
(a) Sclerotic lesions in the skull
(b) Asymptomatic, calcified retinal nodules
(c) Hydrocephalus
(d) Enhancing, calcified cortical tubers
(e) Cerebral arterial ectasia
(d) Enhancing, calcified cortical tubers
The CNS features of tuberous sclerosis include: subependymal nodules which increase in number and calcification with time; parenchymal tubers which are non-enhancing and rarely calcified; hydrocephalus; giant cell astrocytomas; retinal phakomas; arterial ectasia.
(CNS) 6 A newborn child suffers respiratory distress, bradycardia and spasticity. An MRI of the brain is performed. Which of the following features is not associated with a Chiari II malformation?
(a) Small posterior fossa
(b) Towering cerebellum
(c) Small 4th ventricle
(d) Hyperplastic falx
(e) Stenogyria
(d) Hyperplastic falx
A complex of anomalies secondary to a small posterior fossa. The falx is hypoplastic/ fenestrated, with concomitant gyral interdigitation. A summary of the major features: the 4th ventricle and brainstem are caudally displaced, there is tonsillar herniation, a myelomenigiocoele, syringohydromelia, dygenesis of the corpus callosum, obstructive hydrocephalus, absence of the septum pellucidum, and stenogyria.
16 Which of the following types of craniosynostosis is correctly linked to the suture involved?
(a) Anterior plagiocephaly - unilateral lambdoidal suture
(b) Brachycephaly - metoptic suture
(c) Posterior plagiocephaly - unilateral coronal suture
(d) Scaphocephaly - sagittal suture
(e) Trigonocephaly - bilateral coronal suture
(d) Scaphocephaly - sagittal suture
The most common single suture affected is the sagittal suture (scaphocephaly), others include uni-coronal (anterior plagiocephaly), bi-coronal (brachycephaly), metoptic (trigonocephaly) and unilateral lambdoidal (posterior plagiocephaly). Craniosynostosis may be part of a syndrome, with multiple sutures involved, or secondary to drugs, metabolic disease, or other causes of microcephaly.
28 A 3 year old boy presents with a first seizure; he is afebrile. CT scan shows calcification within the right parietal gyri with ipsilateral skull thickening and enlargement of the choroid plexus. What is the likely diagnosis?
(a) Klippel-Trenaunay syndrome
(b) Neurofibromatosis type 2
(c) Sturge-Weber syndrome
(d) Tuberous sclerosis
(e) von Hippel Lindau syndrome
(c) Sturge-Weber syndrome
Sturge-Weber syndrome is associated with a ‘port-wine stain’’ naevus in the distribution of the trigeminal nerve, tram-track gyral calcification (usually parietal lobe), ipsilateral choroid plexus enlargement, leptomeningeal venous angiomas, hemiparesis, seizures, mental retardation, glaucoma (30%) and choidoidal haemangiomas of the orbit.
(CNS) 31 A CT head demonstrates cerebellar vermian hypoplqsia, relatively normal cerebellar hemispheres, and a large CSF space surrounding the cerebellum. The brainstem is not disordered. What is the diagnosis?
(a) Dandy Walker complex
(b) Dandy Walker variant
(c) Mega cisterna magna
(d) Chiari Type II
(e) Spenoidal encephalocoele
(b) Dandy Walker variant
The above is a description of Dandy Walker variant. By contrast, in Dandy Walker complex the cerebellar hemispheres and vermis are both absent or hypoplastic and the brainstem is compressed by a cyst. In mega cisterna magna, the cerebellum is normal and there is a simple dilatation of the CSF space posterior to the cerebellum.
(CNS) 34 An elderly man is found collapsed, and a CT head is performed. The ventricles are noted to be prominent. Which of the following features would support the diagnosis of hydrocephalus over cerebral atrophy?
(a) Concave profile of the third ventricle on axial images
(b) Enlarged choroidal-hippocampal fissures
(c) Normal fornix-corpus callosum distance
(d) Atrophy of the corpus callosum
(e) Mammillo-pontine distance of less than 1 cm
(e) Mammillo-pontine distance of less than 1 cm
Indicators of hydrocephalus include: dilatation of the recesses of the third ventricle, convexity of the third ventricle, expansion of the temporal horns, effacement of sulci, narrowing of the mamillopontine distance, and enlargement of the ventricles out of proportion to the sulcal dilatation. Specific MR findings include: transependymal CSF exudation (seen as high signal on FLAIR imaging), and accentuation of the aqueductal flow void in normal pressure hydrocephalus
38 A 5 year old girl presents with a swelling on the left side of her neck. An MRI examination is subsequently arranged for investigation. Which feature makes branchial cleft cyst more likely than cystic hygroma?
(a) Associated coarctation of the aorta
(b) Extending between ECA/ICA
(c) Extension into mediastinum
(d) High signal on T2W MR imaging
(e) Multi-loculated appearance on US
(b) Extending between ECA/ICA
Branchial cleft cyst is usually in the anterior triangle. The ‘beak sign’, where tissue points between the ICA and ECA is described as pathognomonic. Cystic hygroma is a single or multiloculated lymphangioma and is associated with chromosomal anomalies, including Turner’s syndrome (coarctation in 15%). Both are high signal on T2, cystic hygroma may be low or high signal on T1 (depending on levels of lipid/ protein/ blood products).
40 Which of the following causes of neonatal hydrocephalus is more likely to be communicating rather than noncommunicating?
(a) Aqueduct stenosis
(b) Arnold-Chiari syndrome
(c) Dandy-Walker syndrome
(d) Encephalocoele
(e) Germinal matrix haemorrhage
(e) Germinal matrix haemorrhage
Obstructive (non-communicating) causes are more common and include spina bifida, aqueduct stenosis, Dandy-Walker syndrome, Arnold-Chiari syndrome, meningocoele, and encephalocoele. Nonobstructive causes result from reduced reabsorption within the arachnoid granulation tissue, e.g. infection or haemorrhage, or increased CSF production e.g. choroid plexus papilloma; these can also cause obstructive hydrocephalus also.
41 A request is made for an MRI examination in a neonate. An antenatal US had revealed agenesis of the corpus callosum. The MRI scan shows an abnormal posterior fossa. Which of these features make Dandy-Walker a more likely diagnosis than Chiari II malformation?
(a) Hydrocephalus
(b) Klippel-Feil anomaly
(c) Large posterior fossa
(d) Syringohydromyelia
(e) Towering’ cerebellum
(c) Large posterior fossa
Dandy-Walker malformation results from congenital atresia of the foramina of Magendie and Luschka, leading to an enlarged posterior fossa, a large posterior fossa cyst, hydrocephalus and varying degrees of cerebellar hemisphere and verminian hypoplasia. Both have syringohydromyelia and hydrocephalus; Chiari II has a small posterior fossa; Chiari I is associated with Klippel-Feil.
(CNS) 41 A patient presents with suspected neurofibromatosis type 1. Of the following lists of features, which would not be sufficient to make the diagnosis?
(a) 6 cafe-au-lait macules and two neurofibromas
(b) A Lisch nodule and an optic nerve glioma
(c) Thinning of long bone cortex and axillary freckling
(d) A first-degree relative with NF-1 and inguinal freckling
(e) A plexiform neurofibroma and a sphenoid dysplasia
(b) A Lisch nodule and an optic nerve glioma corrected
At least two of the following seven criteria must be fulfilled for a diagnosis: > 6 cafe-au-lait spots, > 2 neurofibromas of any type (or one plexiform neurofibroma), freckling of the axillary or inguinal region, optic glioma, > 2 Lisch nodules, a distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex, a 1st -degree relative with NF-1.
(GU) 43 A 35 year old man with a history of ataxia presents unconscious after a fall. A previous unenhanced CT abdomen demonstrated multiple solid lesions within the right kidney, an absent left kidney with surgical clips nearby and multiple well-defined cystic lesions within the pancreas. What is the most likely diagnosis?
(a) Tuberous sclerosis
(b) Amyloidosis
(c) Von Hippe! Lindau syndrome
(d) Neurofibromatosis type 1
(e) Lymphoma
(c) Von Hippe! Lindau syndrome
VHL disease is an autosomal dominant neurocutaneous syndrome characterised by renal cell carcinomas, often multiple and bilateral along with cystic renal and pancreatic disease, phaeochromocytomas and spinal, cerebellar and optic nerve haemangioblastomas. The cerebellar lesions can present as ataxia.
(GU) 6 A 34 year old man presents with gradual onset bilateral loin pain. Ultrasound demonstrates multiple bilateral renal cystic masses. Which of the following would not support a diagnosis of VonHippel Lindau?
(a) Contrast enhancement on CT of more than 20 HU
(b) Raised urinary catecholamines
(c) Multiple pancreatic cysts
(d) Cutaneous angiofibromas
(e) Cerebellcir haemangioblastomas on brain MRI
(d) Cutaneous angiofibromas
VHL is associated with CNS, haemangioblastomas, retinal angiomas, pancreatic cysts and carcinomas and phaeochromocytoma. In the kidney it is associated with the presence of RCC and multiple cysts. The renal cell tumours are usually of the clear cell type, and have a variable appearance depending on the degree of soft tissue involvement.
Cutaneous angiofibromas are seen in tuberous sclerosis.
@# (CNS) 9 A plain radiograph is performed on a male child. Unilateral, premature fusion of both the coronal and lambdoid sutures is evident. What is the most appropriate description?
(a) Scaphocephaly
(b) Brachycephaly
(c) Plagiocephaly
(d) Trigonocophaly
(e) Oxycephaly
(c) Plagiocephaly
The common craniosynostoses include:
@# 11 A cranial US is performed in a pre-term neonate. There is hyperechoic material within the ventricles consistent with recent haemorrhage, but the ventricles are not dilated. How would you grade this germinal matrix bleed?
(a) Grade I
(b) Grade II
(c) Grade Ill
(d) Grade IV
(e) Grade V
(b) Grade II
Grade I: subependymal haemorrhage,
Grade II: intraventricular haemorrhage, no ventricular dilation (10% mortality),
Grade Ill: intraventricular hemorrhage with ventricular dilation (20% mortality),
Grade ·IV: intraparenchymal haemorrhage (>50% mortality).
There is no Grade V.
(CNS) 12 A patient develops dissociated anaesthesia of the legs. An MRI brain demonstrates herniation of the cerebellar tonsils. Which of the following is not associated with Chiari type I malformation?
(a) Hydrocephalus
(b) Syringohydromelia
(c) Platyblasia
(d) Incomplete ossification of the C1 ring
(e) Myelomenigocoele
(e) Myelomenigocoele
Chiari I is herniation of the cerebellar tonsils below a line connecting the basion and opisthion. Unlike Chiari II, Ill and IV, Chiari I is not associated with myelomeningocoeles. Indeed, the condition is frequently isolated without supratentorial anomalies. As well as the listed associations, Chiari I occurs with: basiliar impression, craniovertebral fusion, and Klippel-Feil anomaly.
@# 21 Which of the following is not a cause of secondary craniosynostosis?
(a) Crouzon’s syndrome
(b) Hypothyroidism
(c) Previous shunt procedures
(d) Rickets
(e) Thalassaemia
(b) Hypothyroidism
Craniosynostosis is the premature closure of the sutures, which may be primary (idiopathic) or secondary. Secondary causes include: metabolic (rickets, hypercalcaemia, hyperthyroidism, hypervitaminosis D), haematological (thalassaemia, SCD), and bone dysplasias (achondroplasia, metaphyseal dysplasia). It is also associated with syndromes (Crouzon, Apert, Treacher-Collins), and can occur following shunt surgery for hydrocephalus.
(CNS) 40 MR imaging demonstrates bilateral acoustic neuromas. Which of the following is not a recognised association?
(a) Optic pathway gliomas
(b) Parasagittal meningomas
(c) -rarasplnal neurofibromas
(d) Facial nerve schwannomas
(e) Meningiomatosis
(a) Optic pathway gliomas
The patient fulfils the diagnostic criteria for Neurofibromatosis type 2. Unlike NF-1, there is no association with Usch nodules, skeletal dysplasia, optic pathway gliomas or vascular dysplasia.
(CNS) 41 A neonate presents with a soft, painless mass in the posterior triangle of the neck. MR imaging demonstrates a multiloculated, insinuating mass of intermediate signal on T1W and high signal on T2W. What is the most likely diagnosis?
(a) Epidermoid cyst
(b) Dermoid cyst
(c) Lipoma
(d) Cystic hygroma
(e) Laryngocoele
(d) Cystic hygroma
The commonest ‘soft’ neck masses in infants and children are lipomas, haemangiomas and cystic hygromas. The latter have low-tointermediate signal intensity on T1 W and high signal on T2W.
@# 49 A 4 week old ex-premature baby has a witnessed seizure. A cranial US is performed which shows cystic structures bilaterally, adjacent to the trigone of the lateral ventricles. Which of the following favours a diagnosis of chronic periventricular leukomalacia over porencephaly?
(a) Anechoic cysts
(b) Persistenae of cysts on follow-up US
(c) Septated cysts
(d) Symmetrical distribution
(e) Watershed territory distribution
(d) Symmetrical distribution
PVL is more common in preterm children, is secondary to ischaemia and usually occurs in the watershed areas. Initially there will be hyperechoic changes which gradually become cystic (>2 wks); the cysts are never septated and usually resolve over time.
Porencephaly can be developmental or due to a vascular or infectious process which destroys brain tissue; it is almost always asymmetrical, rarely disappears over time and is often seen as an extension of the ventricle or sub-arachnoid space. If secondary to ischaemia it can also be in a watershed distribution.
(CNS) 51 MR imaging of a neonatal brain reveals an absent septum pellucidum, corpus callosum, third ventricle, and interhemispheric fissure. The thalami are fused. Which variant of holoprosencephaly does this most likely represent?
(a) Alobar
(b) Bilobar
(c) Septo-optic dysplasia
(d) Lobar
(e) Semi lobar
(a) Alobar
This is the most profound form of holoprosencephaly, where there is almost no separation of the cerebral hemispheres or ventricles. There is a ‘horseshoe’ configuration of neural tissue with a single crescentshaped ventricle. There is no ‘bilobar’ form of holoprosencephaly. Septo-optic dysplasia can be considered part of the holoprosencephaly spectrum.
@# 53. Regarding rhabdomyosarcoma in the paediatric population. What is the most likely site of origin?
(a) Extremities
(b) Genito-urinary system
(c) Head and neck
(d) Orbits
(e) Retroperitoneal
(c) Head and neck
Rhabdomyosarcoma represents 4-8% of cancers in children and is the 4th commonest after CNS tumours, neuroblastoma and Willl)’s and is the commonest soft tissue sarcoma in children. The sites affected are: head and neck (28%), extremities (24%), genitourinary system, trunk (11%), orbits (7%), and retroperitoneum (6%); other sites in <3%.
57 A 28 week antenatal US scan shows absence of the septum pellucidum and a radial array pattern of the medial cerebral sulci. The ventricles are abnormal, with a dilated, elevated 3rd ventricle, disproportionate enlargement of the occipital horns and small, widely separated frontal horns. Which of the following is not associated with this condition?
(a) Chiari II malformation
(b) Dandy-Walker syndrome
(c) Encephalocoele
(d) lnterhemispheric arachnoid cyst
(e) Lobar holoprosencephaly
(e) Lobar holoprosencephaly
The US features described are those of agenesis of the corpus callosum. Other associations include: alobar and semi-lobar forms of holoprosencephaly, midline intracerebral lipoma, polymicrogyria, grey matter heterotopia and porencephaly.
@# (MSK) 58 A 30 year old patient presents with multiple bilateral renal angiomyolipomas, one of which has bled. She is also found to have a giant cell astrocytoma in her brain and bilateral interstitial lower lobe fibrosis on CXR. Which of the following bone lesions is most commonly associated with this condition?
(a) Bone cysts
(b) Osteochondroma
(c) Giant cell tumour
(d) Fibrous dysplasia
(e) Adamantinoma
(a) Bone cysts
The underlying condition described is tuberous sclerosis. The associated bone cysts most commonly affect the small bones of the hand. Other skeletal features include sclerotic bone islands which most commonly affect the calvarium (in 45% of cases) and also the pelvis and long bones.
59 A neonate has multiple apneic episodes, bradycardia, difficulty in swallowing, and increased tone in the upper limbs. Cranial US shows hydrocephalus and absence of the corpus callosum. An MRI scan is performed which shows a small posterior fossa. Which feature makes Chiari III rather than Chiari II malformation the likely diagnosis?
(a) Agenesis of the corpus callosum
(b) Encephalocoele
(c) Klippel-Feil anomaly
(d) Myelomeningocoele
(e) Syringohydromyelia
(b) Encephalocoele
Chiari II malformation comprises a small posterior fossa, herniation of the tonsils and vermis through the foramen magnum, myelomeningocoele (90%), obstructive hydrocephalus (90%), agenesis of the corpus callosum, syringohydromyelia (50%) and abnormal cortical gyration.
Chiari Ill is rare, has the features of Chiari II, but with an associated encephalocoele.
Chiari I is associated with Klippel-Feil anomaly.
60 A neonate is noted to have an enlarged head. Trans-cranial US confirms symmetrical dilation of the ventricles consistent with hydrocephalus. Which of the following is true regarding congenital hydrocephalus?
(a) Aqueduct stenosis is the commonest cause
(b) It can be readily seen at the 12 week antenatal US
(c) It is more commonly associated with intra- rather than extracranial anomalies
(d) Most germinal matrix haemorrhage-related hydrocephalus requires shunting
(e) US is the most sensitive modality for identifying the cause
(a) Aqueduct stenosis is the commonest cause
Aqueduct stenosis accounts for 43% of congenital hydrocephus.
US assessment is difficult <20 wks because the ventricles normally occupy a large percentage of the cranial vault.
The most sensitive modality for determining the cause (not presence) of hydrocephalus is MRI.
Grade III germinal matrix haemorrhage has hydrocephalus, but in 2/3 this is stable and requires no treatment.
Intracranial anomalies are associated in 37% (e.g. agenesis corpus callosum), extracranial anomalies in 63% (e.g. VSD, spina bifida).
(CNS) 67 A patient presents with a neurocutaneous disorder. Which of the following is not a recognised association?
(a) Neurofibromatosis-1 and plexiform neurofibromas
(b) Osler-Weber-Rendu syndrome and cavernomas
(c) Von Hippel Lindau disease and pheochromocytomas
(d) Tuberous sclerosis and pial enhancement
(e) Sturge-Weber syndrome and cerebral atrophy
(d) Tuberous sclerosis and pial enhancement
Tuberosis sclerosis is associated with, amongst other features: cortical tubers, subependymal nodules, giant cell astrocytomas, white matter lesions, retinal phakomas and vascular abnormalities.
(CNS) 69 A child undergoes MR imaging of their spine. A review of the lower lumbar levels reveals that the dorsal dura is incomplete and the subarachnoid space lies ventral to a neural placode, which is directly continuous with the skin. The ventral subarachnoid space does not appear to be dilated. What would be the most appropriate term to describe this spinal dysraphism?
(a) Myelocoele
(b) Myelomeningocoele
(c) Lipomyelocoele
(d) Lipomyelomeningocoele
(e) Spinal lipoma
(a) Myelocoele
In the case above, if the ventral subarachnoid space were dilated, this would be more appropriately termed a myelomeningocoele. If the dorsal placode were continuous with a lipoma, continuous with the subcutaneous tissues, this would represent a lipomyelocoele.
(CNS) 71 A child presents with a lump in the neck, and a branchial cleft cyst is suspected. Which of the following features would be unusual for this diagnosis?
(a) Attenuation of 10 HU on unenhanced CT
(b) High signal on T2W MR imaging
(c) Located deep to a sternomastoid muscle
(d) Lack of rim enhancement on CT
(e) Present in the posterior triangle of the neck
(e) Present in the posterior triangle of the neck
Branchial cleft cysts are derived from the 1st or (more commonly) the 2nd cervical pouch. These are usually anterior triangle lesions and of water CT attenuation (< 20 HU). Rim enhancement is seen in infected cysts.
(CNS) 72 A 42 year old woman presents with weakness in her hands. On examination she is noted to have wasting of the small muscles of the hand, burns and cuts to her fingers. There are reduced biceps reflexes, increased tone in the legs and upgoing plantars. An MRI brain and spine are requested. What is the 1most likely unifying diagnosis?
(a) Cervical spondylosis
(b) Chiari II malformation
(c) Motor neurone disease
(d) Multiple sclerosis
(e) Rheumatoid arthritis
(b) Chiari II malformation
The patient has lower motor neurone signs in the upper limbs and upper motor neurone signs in the lower limbs. The most likely diagnosis is a syrinx (syringohydromyelia) within the cervical-cord. A Chiari II malformation is usually accompanied by a myelomeningocele, abnormal development of the cerebellar vermis and hydrocephalus. The herniated cerebellum blocks CSF circulation and leads to the formation of a syrinx within the Spinal cord.
(CNS) 8.Routine first-trimester antenatal ultrasound scan reveals a large posterior fossa cyst and ventriculomegaly. Fetal MRI demonstrates dysgenesis of the corpus callosum, a large posterior fossa and hypoplasia of the cerebellar vermis. What is the most likely diagnosis?
a. Dandy-Walker malformation
b. Dandy-Walker variant
c. Megacisterna magna
d. Arachnoid cyst
e. Porencephaly
8.a. Dandy-Walker malformation
Dandy-Walker malformation is characterised by an enlarged posterior fossa (not seen in Dandy-Walker variant) with high-rising tentorium cerebelli, dys/agenesis of the cerebellar vermis (intact in megacisterna magna) and cystic dilatation of the fourth ventricle (normal in arachnoid cyst). Ventriculomegaly is also common.
- The mother of a three week old child notices a mass in her baby’s lower neck. The child is otherwise well. There is a history of normal pregnancy and the child was delivered by forceps. Ultrasound scan reveals homogeneous enlargement of the lower third of the right sternocleidomastoid muscle but no focal lesion is identified. T2-weighted
MRI shows diffuse abnormal high signal intensity over the same area. The most likely diagnosis is:
a. Haematoma
b. Branchial cleft cyst
c. Fibromatosis colli
d. Neuroblastoma
e. Cystic hygroma
- c. Fibromatosis colli
This is a rare form of infantile fibromatosis that occurs solely within the sternocleidomastoid muscle. In the vast majority it is associated with birth trauma (e.g. forceps delivery). This is thought to lead to compartment syndrome, pressure necrosis and secondary fibrosis of the muscle. It usually locates to the lower third of the muscle, between the sternal and clavicular heads, and is usually unilateral.
Ultrasound may reveal a well- or ill-defined mass or may just show homogeneous muscle enlargement. In approximately two-thirds of individuals, the abnormality spontaneously regresses by the age of two. Expected ultrasonographic appearances of a haematoma include a heterogeneous mass of mixed cystic and solid components.
- An 18-month-old girl presents with increasing incoordination and developmental regression. T2WI demonstrates confluent high signal within the periventricular white matter and centrum semiovale, with radiating linear low signal intensity, giving a ‘tigroid’ pattern. Sparing of subcortical U fibres is also noted. What is the most likely diagnosis?
A. Krabbe disease.
B. Metachromatic leucodystrophy.
C. X-linked adrenoleucodystrophy.
D. Alexander disease.
E. Canavan disease.
- B. Metachromatic leucodystrophy.
Leucodystrophies are dysmyelinating inherited white matter diseases, which are secondary to lysosomal, peroxisomal, or mitochondrial dysfunction. Metachromatic leucodystrophy is caused by deficiency of the lysosomal enzyme ayrlsulfatase A. The ‘tigroid’ pattern relates to sparing of perivascular white matter.
Table 5.1 outlines characteristic radiological findings of the major leucodystrophies.
(CNS) 29 A premature baby girl born at 28 weeks’ gestation was intubated for respiratory distress. On day three a cranial USS showed right periventricular flare and hydrocephalus. A month later, on a repeat cranial USS, there was diffuse cystic changes in the right periventricular region with dilatation of the right lateral horn. What is the most likely diagnosis?
a Periventricular leukomalacia
b Porencephalic cyst
c Intraventricular haemorrhage
d Encephalitis
e Meningitis
29 Answer A: Periventricular leukomalacia
Risk factors for germinal matrix haemorrhage are prematurity (less than 3 2 weeks), low birth weight, males, multiple births, prolonged labour and cyanotic heart disease. It typically occurs within the first two days of birth. The germinal matrix lies in the caudothalamic groove and is very metabolically active which makes it sensitive to low levels of oxygen. There are four grades of intraventricular haemorrhage as shown in the table below. A common finding in premature babies is flare within the periventricular white matter. Periventricular leukomalacia is the sequelae of ischaemia in the watershed areas, eventually the cystic areas are reabsorbed and ventriculomegaly occurs.
