Lesional epilepsy

Dr. M.Manoranjitha kumariProf V.G.Ramesh‘s unit

Madras Institute Of NeurologyChennai

Case

14 yr old male, 8 th std, namakkalc/o seizures- 5 yrs durationHOPI: apparently normal till 5 yrs ago, one day he

developed staring look, not responding to his mother call, lasting for 1 -2mnts without any clonic tonic movement, regained his activities after few minutes without any post ictal confusion , head ache, or weakness not preceeded aura. 1 episode in a month- 3 yrs. Started on CBZ and Levitiracetam, frequency of seizures increased to once in 10 days- 2 yrs.

• For the past one month 2-3 times a day, starts as a starring look followed by turning of head towards left side with deviation of eye towards left side,with tonic posturing of left hand followed by right hand, some times with clonic movements, with loss of consciousness lasting for 1-2 mnts, without any post ictal confusion or weakness, with or without preceeding aura

• no head ache /vomiting/behavioural disturbances/limb weakness/cranial nerve disturbances/trauma

• Past history: evaluated for epilepsy in 2004

ct plain was reported as calcified glioma, started on AED, 2008 AED dose increased and ct was repeated and was reported as calcified granuloma

Antenatal natal post natal history, family history nil relevant

• O/E : pt conscious, oriented

thin bult, no neurocutaneous marker

HMF: normal

Lobar functions: normal

Cranial nerves: normal

Sms : normal

Cerebellar function: normal

Spine and cranium: normal

CT brain

2004 2008

MRI3.5*2.5*2.5*cm sized T1 &T2 hetero intense lesion noted in the right superior middle temporal gyrus with cortical expansion. Calvarial remodelling noted in the adjacent right temporal lobe. No evidence of diffusion restriction in the cortical lesion, minimal heterogenous enhancement noted in the lesion. Evidence of blooming in GRE

D/D

DNET

Oligidendroglioma

Ganglioglioma

• EEG- normal study• Other investigations- normal

Differential diagnosis

• Oligodendroglioma• Ganglioglioma• DNET

Surgery

• Right temporal craniotomy, trans cortical approach and total excision of tumor done, the tumor was soft, with areas of old hemorrhages and calcification.

Biopsy

• Squash : tuberculoma• HPE– suggestive of vascular tumor - angioma

Post opertative

• No fits after surgery• On AED – dose is being taperd

Post op scan

Post op EEG

• Background shows well formed alpha waves in posterior head regions, responding normally to eye opening. Bilateral sharp waves and spikes seen more during hyperventilation and after hyperventilation. No slow waves seen.

• Imp : abnormal record suggestive of bilateral epileptiform avtivity

What is lesional epilepsy?

• In some patients with longstanding epilepsy the cause of the seizure may be a slow growing tumors , vascular malformations, infections or congenital anomalies. These lesions are picked up in the MRI.

• Removal of the lesion may cure a patients with epilepsy

Classification

• Temporal lobe epilepsy• Extra temporal lobe lesional epilepsy• Subcortical lesional epilepsy• Catastrophic epilepsy

Temporal lobe and extra temporal lobe lesional epilepsy

• Neoplastic- eg. Astrocytoma, ganglioglioma,pleomorphic xanthoastrocytoma, DNET

• Vascular-eg. Cavernous hemangioma, arteriovenous malformation, angioma

• Dysgenetic -eg. Focal or diffuse cortical dysplasia, sturge weber syndrome, tuberous sclerosis

• Traumatic • Ischemic

Subcortical epilepsy

• Hypothalamic hamartoma• Cerebellar seizures

Catastrophic epilepsy

• Hemimegalencephaly• Diffuse cortical dysplasias• Rasmussens• Porencephalic cyst

Long term seizure control after lesionectomy

9 years follow up of 53 patients operated for supra tentorial cavernomas:

45 (84.9%)pts- free from disabling seizure- Engels class1

37(69.8%)pts –completely free of post op seizure Engels class 1A

International league against epilesyJNS nov 2008- volume 63

• 22 out of 26 cases -84.6% of seizure control after surgery for temporal lobe ganglioglima

• Complete seizure relief in12 of16 patients(75%) operated for DNET

(Morris et al)

Raymond et al

Predictors of seizure control after surgery

• Lower pre op frequency of partial seizure associated with better outcome

• Presence of CPS – supportive predictive parameters for satisfactory seizure relief

• Secondary seizure generalization- negative predictor for seizure control

• Because of very low rate of patients with discordant EEG patterns , information derived from EEG recordings is not suitable to discriminate patients with a lower expectation of seizure control.

• Other studies found a significant contribution of EEG data in predicting outcome after surgery especially in patients with mesial temporal sclerosis.