Intractable reflex audiogenic epilepsy successfully treated by peri-insular hemispherotomy

Abstract

We report a case of an infantile hemiplegia seizure syndrome (IHSS) that presented with intractable reflex audiogenic startle epilepsy which in itself is an uncommon form of seizure disorder. Peri-insular hemispherotomy provided complete seizure control. Also of particular interest was that this syndrome resulted from an iatrogenic brain injury sustained during the course of a caesarian section. We review the different mechanisms of birth injury reported in the literature and, discuss the physiopathogenesis of the hemispheric damage in this patient. We also review the literature on "reflex epilepsy" as it applies to this case. Intractable reflex audiogenic (startle) epilepsy in IHSS submitted to hemispherotomy has not previously been reported.

A hemispherotomy for intractable startle epilepsy characterized by infantile hemiplegia and drop attacks

“…There are two major hypotheses regarding the origin of ectopic craniopharyngiomas: (i) it is possible that ectopic squamous epithelial remnants may migrate into the posterior fossa; and (ii) such ectopic squamous cells may subsequently develop into an ectopic craniopharyngioma in the cerebellopontine angle. 6 Conversely, the…”

“…1,2 Previous studies have documented that most patients with startle epilepsy have mental retardation, hemiplegia, or tetraparesis and uni-/bilateral hemispheric lesions due to congenital or infantile brain damage. [1][2][3][4][5][6] The patients do not always exhibit neurological deficits or abnormal neuroimaging. 1 The pathophysiology of startle epilepsy is yet to be explained.…”

“…Such epileptogenesis may be triggered by the primary sensory cortex, such as the auditory cortex, through the direct projection of sensory afferents or by the proprioceptive input of the startle reaction to various sensory stimuli. 3,6 Some reports have also shown the effectiveness of antiepileptic drugs, especially clonazepam, 8-10 but most have shown such seizures to be refractory to medical treatment. 1,5,11 Some surgical procedures for intractable startle epilepsy have been documented.…”

“…1,5,11 Some surgical procedures for intractable startle epilepsy have been documented. 3,4,6,11,12 The surgical techniques were selected according to the extent of epileptogenic lesions and neurological deficits. We performed a hemispherotomy because the patient had a unilateral dysfunctional hemisphere due to widespread atrophic lesions and because the epiletogenic area was likely to be larger than the area revealed by ictal SPECT.…”

“…To date, only 5 surgically treated patients have been reported (Table 1). [3][4][5][6][7] We describe a patient with an isolated cerebellopontine angle craniopharyngioma infiltrating into the brainstem and discuss the clinical, radiological, and surgical findings.…”