What is a cavernoma?
Vascular lesions of the CNS, also known as cerebral cavernous malformations or angiographically-occult arterio-venous malformations
Represent a surgically correctable cause of epilepsy in the paediatric population
Case 1• KM. 9 year old boy• New onset complex partial seizures with right frontal
discharges • Seizure activity well-controlled on sodium valproate,
levetiracetam, and carbamazepine • Imaging suggested cavernoma
Mesh of thick walled vessels
Peri-lesional Haemosiderin
Possible rupture point
Lumen
Craniotomy & Excision
Case 1• MS. 9 year old male• New onset complex partial seizures with right frontal
discharges • Seizure activity well-controlled on sodium valproate,
levetiracetam, and carbamazepine • Imaging suggested cavernoma
• Follow – Up – Seizure frequency ↓– No deficit
Case 2• MK. 10 year old girl• 8 month hx of simple & complex partial seizures
secondary to right tempero-parietal lesion• Failed multiple single & combination anti-convulsants
failed – Side – effects – Fatigue & Poor school performance
• Imaging
Hyalinised Thick Walled Vessels [TWV] – Partly thrombosed [T]
TWV
T
Stealth-guided parietal craniotomy en-bloc resection of lesion + rim of haemosiderin-stained tissue
Case 2• MK. 10 year old female • 8 month hx of simple & complex partial seizures
secondary to right tempero-parietal lesion• Failed multiple single & combination anti-convulsants
failed – Side – effects – Fatigue & Poor school performance
• Uneventful post-operative recovery. • Seizure free in immediate post-operative
period.
Case 3• SC. 20 year old woman• 18 yrs → two episodes of new onset seizures • Imaging demonstrated left frontal 2cm x 2 cm lesion, ??
arterio-venous malformation• Carbamazepine initiated. • Cerebral angiography normal
Case 3• SC. 20 year old woman• 18 yrs → two episodes of new onset seizures • Imaging demonstrated left frontal 2cm x 2 cm lesion, ??
arterio-venous malformation• Carbamazepine initiated. • Cerebral angiography normal
• Uncomplicated recovery and discharged home on post-operative day 4
Natural History• Cavernomas may be multiple, ranging from 1-12 • Size range from 0.1cm - 9cm • Risk of haemorrhage estimated to be 2.5%
annually [cumulative].
• Risk of new onset seizures is 1.51% annually [cumulative]
Aetiology of CavernomasMost are sporadic.
Risk factors include:• previous radiotherapy to brain • more than one first degree relative with
cavernoma.
• 70% of patients with familial cavernomas carry a frameshift mutation for either KRIT1 / CCM1, MGC4607 / CCM2, or PDCD10 / CCM3, mapping, respectively to chromosomes 7q, 7p, and 3q.
Incidence• 0.5% of the population• ~ 25% diagnosed before age 17• ~ 63 - 81% supratentorial • Female preponderance; reason uncertain
PresentationMay present with symptoms secondary
to haemorrhage:
• new onset seizures • Hydrocephalus [superficial haemosiderosis]• neurological deficit
also “Incidentaloma !!!”
RadiologyMRI appearance:• “mulberry” nodules with mixed
signal intensity• peripheral haemosiderin rim is
seen as an area of decreased signal intensity on T2-weighting and as an area of mixed signal intensity on T1-weighting
• no visible feeding vessels, surrounding oedema, or mass effect.
Angiographically occult
Histopathology• Dilated sinuses [DS]• Thin vessel walls [TWV] usually lack
smooth muscle, elastin, and intervening parenchyma
• Electron-microscopy endothelial cells → poorly developed tight junctions, allowing for micro-haemorrhages → characteristic haemosiderin staining.
• Haemosiderin rim surrounded by reactive gliosis.
• Thrombosis [T] may be present Haemosiderin
TWV
DS
T
Why Surgical Excision?
1. Reduces need for long-term anti-convulsants
2. Attainment of intellectual and learning objectives
3. Avoid “labelling” of child as “epileptic”
4. ↓ long-term risk of haemorrhage
Cavernoma Surgery• Stealth-guided Craniotomies• Excision not only of the cavernoma itself
(lesionectomy), but also excision of haemosiderin ring, surrounding gliosis.
• In certain cases, may proceed to hippocampectomy. (Varies centre to centre)
Seizure control appears to be better in patients who had excision of haemosiderin ring. However, a clear correlation between extent of resection and seizure control has yet to be established.
Post-Operative Seizure Control
Post-operative seizure control is dependent on: two factors:
1. Length of time the patient was symptomatic pre-operatively. [The shorter the duration of pre-operative seizures, the more likely it is
the patient will be seizure-free post-operatively].
2. ?? Extent of the surgical procedure
Cavernoma Surgery• Prognosis following surgical excision is usually
good• Overall morbidity in most centres is around 4%. • With complete excision of the lesion, the risk of
haemorrhage is non-existent.
Conclusion• Cavernomas represent an uncommon but
treatable cause of epilepsy and cerebral haemorrhage in the paediatric population.
• Symptomatic children diagnosed and treated early will have a better post-operative result
References
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2. Labauge P, Brunereau L, Lévy C, Laberge S, Houtteville JP. The natural history of familial cerebral cavernomas: a retrospective MRI study of 40 patients. Neuroradiology. 2000 May;42(5):327-32.
3. Raychaudhuri R, Batjer HH, Awad IA. Intracranial cavernous angioma: a practical review of clinical and biological aspects. Surg Neurol. 2005 Apr;63(4):319-28.
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