Temporal lobe hypogenesis associated with arachnoid cyst in patients with epilepsy

Abstract

-Objective: To determine the frequency of temporal lobe hypogenesis (TLH) associated with arachnoid cysts (AC) in patients with epilepsy. Method: We retrospectively revised 655 consecutive MRI scans from patients followed in our epilepsy clinic. We identified patients with temporal AC and then performed careful visual analysis in a workstation. Patients with evident expansive or destructive lesions were excluded. Results: Only 4 (0.6%) patients had AC in the left temporal lobe, all associated with TLH. In addition, there were also ipsilateral dysgenetic characteristics in the ipsilateral hippocampus including abnormal shape and axis, and hyperintense T2 signal. In one patient this hippocampal abnormality was bilateral. Conclusion: AC with TLH was rarely found in our patients with epilepsy and it was always associated with hippocampal dysgenesis. Although volumetric reduction of the temporal lobe can be observed in patients with epilepsy and hippocampal abnormalities, the presence of adjacent AC points to a malformative etiology.KEY WORDS: hippocampal dysgenesis, cortical development malformation, partial epilepsy, seizures, magnetic resonance imaging.Hipogenesia de lobo temporal associada a cisto aracnóide em pacientes com epilepsia Hipogenesia de lobo temporal associada a cisto aracnóide em pacientes com epilepsia Hipogenesia de lobo temporal associada a cisto aracnóide em pacientes com epilepsia Hipogenesia de lobo temporal associada a cisto aracnóide em pacientes com epilepsia Hipogenesia de lobo temporal associada a cisto aracnóide em pacientes com epilepsia RESUMO -Objetivo: Determinar a freqüência de hipogenesia de lobo temporal (HLT) associada a cistos de aracnóide (CA) em pacientes com epilepsia. Método: Revisamos retrospectivamente 655 exames consecutivos de ressonância magnética de pacientes do ambulatório de epilepsia da UNICAMP. Identificamos os pacientes com CA na região temporal e então realizamos análise visual em uma estação de trabalho. Pacientes com lesões expansivas ou destrutivas evidentes foram excluídos. Resultados: Apenas 4 (0,6%) pacientes tinham CA na região temporal esquerda, todos associados a HLT. Além destas alterações, observamos características disgenéticas no hipocampo ipsilateral incluindo anormalidades no formato e eixo e hipersinal em T2. Em um paciente estas alterações hipocampais eram bilaterais. Conclusão: CAs associados a HLT foram raramente encontrados, e quando presentes, estavam sempre acompanhados de disgenesia hipocampal. Apesar da redução volumétrica do lobo temporal poder ser observada em pacientes com epilepsia e alterações hipocampais, a presença de um CA adjacente indica uma etiologia de malformação. PALAVRAS-CHAVE: disgenesia hipocampal, epilepsia parcial, convulsões, cistos de aracnóide, ressonância magnética. Arachnoid cysts are considered frequent and incidental findings in neuroimaging studies 1 . The most frequent localization is in the middle fossa, corresponding to more than half the cases reported in the literature 2 . The origin of middle fossa ...

Bilateral Temporal Arachnoid Cysts Associated With Tuberous Sclerosis Complex

“…20,21 However, some authors consider that, in many cases, arachnoid cysts may be the cause of seizures and have a relationship with epilepsy in childhood and adolescence. 22,23 In our case, coexistence of cortical developmental anomalies and bitemporal arachnoid cysts was detected. In addition, electroencephalogram revealed focal epileptic focus predominating over the right temporal region.…”

Clinical and radiological outcomes of surgical treatment for symptomatic arachnoid cysts in adults

“…While intracranial hypertension and neurological deficits are more definite surgical indications for AC, patients presenting with headaches or seizures as the only symptom can also benefit from surgery, as has been shown in earlier studies [1,12,13]. Headaches may indicate a chronic or intermittent rise of intracranial pressure while seizures are related to cyst compression and may therefore resolve after surgery.…”

“…Surgery is advised in symptomatic patients presenting with hydrocephalus, raised intracranial pressure or focal neurological symptoms [6,11,12]. In some patients, however, for symptoms such as a headache or seizures, medical treatment has been recommended and is generally accepted [5,6,13]. Unfortunately, it was not always efficacious to control these nonspecific symptoms with conservative measures alone.…”

“…Early authors advocated for excision of the cyst wall, either partially or entirely, in patients with cyst regrowth and recurrence [1,2,8,20]. However, this is rarely achieved because of the close anatomical relationship between the medial wall of the cyst and the adjacent neurovascular structures [13,19,21]. Therefore, more recent authors have suggested that selective fenestration of the cyst into the normal cerebrospinal fluid cisterns is sufficient for reduction of the cyst volume and will avoid postoperative morbidity [11,18,22,23].…”

Clinical and Neuroimaging Outcomes of Surgically Treated Intracranial Cysts in 110 Children

“…Headache remain a controversial indication for cyst surgery47) and there is even skepticism about the effectiveness of cyst treatments48). Epilepsy is frequently associated with intracranial cysts15,25,33), but the seizure etiology remains unknown, and the coexistence of seizures and cysts may be incidental15,27,33,47). Thus, careful preoperative selections are mandatory.…”