- Occipital lobe epilepsy
Occipital lobe epilepsy (OLE) approximately 5% of all epilepsies It constitutes 10
The type that generally develops in the presence of neurological deficit and is closely related to structural lesions is considered symptomatic OLE, while those with normal neurological examination and brain imaging are considered OLE. Patients with >OLEare classified as idiopathic OLE. It is also known as idiopathic OLE, benign OLE (BOLE). Although idiopathic OLE usually begins in childhood, symptomatic occipital seizures can start at any age
Idiopathic occipital lobe epilepsies can be classified as early (Panayiotopoulos type)and late according to their clinical characteristics. It is divided into three-onset (Gastaut type) types. The early-onset type usually begins between the ages of 1 and 12, with misalignment of the eyes and vomiting as the main ictal symptom. Hemi- or generalized seizures or partial status epilepticus are rare in this type. On the other hand, the late-onset type is completely different from the early-onset type. It often begins between the ages of 3-16 and the main ictal symptom is visual seizures.
Occipital lobe epilepsy is not very common among epilepsy types. For this reason, data on clinical features and follow-up are limited in the literature. Additionally, the diagnosis of OLE is difficult due to temporal or frontal motor seizures seen in 50% of cases as a result of rapid ictal spread to different brain areas. Visual and oculomotor ictal symptoms are the most common symptoms in OLE.
Visual auras and/or simple visual hallucinations, ictal amaurosis, contralateral eye or head deviation, eye movement oscillations, eye Blinking, eyelid twitching, blurred vision, and diplopia have been reported in patients withOLE, but none are pathognomonic. In a study, the auras of 276 patients with lesional partial epilepsy were examined and it was reported that visual auras were more common in partial lobe or occipital lobe epilepsies.
Interictal spikes and sharp discharges are common in OLE patients. On the other hand, OLE patients Regional rather than focal involvement can be seen in the ictal EEGs of as many as 50% of the population. In EEG evaluation, spike wave paroxysms during eye closure are a feature of the early-onset idiopathic form, but multifocal discharges and generalized spike waves are also common in occipital lobe epilepsies.
According to the literature, idiopathic OLEchildhood is benign. It constitutes 20-25% of partial epilepsies. For the diagnosis of idiopathic OLE, neurological examination and brain imaging must be normal. There are two main types distinguished according to ictal symptoms; early-onset Panayiotopoulos and late-onset gastaut types. While vomiting and tonic deviations of the eyes are the main features of the early-onset type; Visual seizures are more characteristic of the late-onset type. It is important to distinguish the idiopathic form, especially
Gastaut subtype, from migraine in terms of clinical outcomes and rapid treatment. Both types, especially the early-onset type, have a benign process. Alves-Leon et al. examined 12 children with benign occipital epilepsy and found that 4 had early onset (33.3%), 6 had late onset and two had late onset (16.7%). reported that early and late onset forms are intertwined. In this study, the most common ictal symptoms were vomiting, headache and visual hallucinations, and the prognosis was good in all patients using a single anti-epileptic drug. Since these syndromes are seen in early childhood, they are thought to be a result of the maturation process. In fact, both focal and generalized features have been shown in family studies. These findings support that these types of epilepsy are not very different from idiopathic epilepsies. There is probably genetic similarity. Genetic studies are needed, especially to classify this subgroup of epilepsy types and to elucidate their etiology.
In their study where Aksoy et al. examined 35 patients diagnosed with idiopathic OLE, 15 of these patients were Panayiotopoulos, 11 of them were considered to be in the Gastaut subgroup, and 9 of them were classified as a mixed group due to the atypical findings of the patients. In this study, the Panayiotopoulos subtype was found to be more frequent and more benign. Similarly, in recent studies, it is emphasized that not only the Panayiotopoulos and Gastautalt types, but also the necessity of performing a mixed subgroup in which patients carry some characteristics of both groups.
In a study conducted by İncecik et al. in our country, idiopathic Of 42 patients with occipital lobe epilepsy, 81% were successfully treated with a single drug, while the remaining 19% of patients required two or more drugs. No relationship was found between the number of AEDs and gender, family history, or EEGfindings. However, it was reported that statistically significantly more patients with Gastaut subtype required 2 or more AEDs compared to Panayiotopoulos. In a study conducted by Değerliyurt et al. in our country, 38 patients diagnosed with Panayiotopoulos syndrome with an average seizure onset age of 4.6 years were evaluated, and the most common symptoms in this patient group were reported to be ictal vomiting, head-eye deviation, and confusion. While eye findings were reported in 5% of patients, the rate of patients requiring two or more AEDs was reported as 13%. Interestingly, in this study, a large proportion of the patients had a personal or family history of migraine or febrile convulsion.
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