Mri in seizure disorder a pictorial essay

In focal transmantle dysplasia, abnormal signal is seen to extend from the cortex to, or almost to, the ventricle [14] [Figure - 8].

Delayed - onset seizures after an acute stroke carry much greater risk of developing into chronic epilepsy [22]. Beyond age 50, stroke is the most frequent cause of seizures [30]. White matter fibres from the alveus then gather medially into thickened bundles as the fimbria, which are continuous posteriorly with the fornix [ 1 ]. The anterior hippocampal artery supplies the hippocampal head, whereas the middle and posterior hippocampal arteries vascularize the hippocampal body and tail. Normal cortical thickness is 4mm [4]. Accurate diagnosis of the cause of seizure in a patient is crucial for finding an effective treatment. In the inflammatory stage provoked by the dying parasite, the cerebral lesions of cysticercus appear as small enhancing rings on CT and MR with variable degree of oedema in surrounding brain [25] [Figure - 20]. Alternatively, they maybe "open" in which there is wide communication between the subarachnoid space and ventricle through a broad hemispheric cleft [Figure - 14]. The relationship with epilepsy is unclear. Its usefulness for the distinction of AD from other dementia syndromes is limited however, as MTA not only occurs in AD, but can be seen in other dementia syndromes as well Fig. Indications that require tailored sequences for optimal visualization of the hippocampus are medically refractory epilepsy and dementia [ 4 , 5 ]. The left collateral sulcus asterisk has a more vertical orientation and is found lateral of the hippocampal body Open image in new window Fig. The head 1 is located in front of the mesencephalon, the body 2 can be found at the level of the mesencephalon and the tail 3 is posterior to the mesencephalon. Studies of women with eclampsia disclose multiple foci of cortical and subcortical white matter edema, primarily in the occipital lobes. A variety of etiologic factors has been linked to polymicrogyria including prenatal cytomegalovirus infection, cerebral ischaemia and genetic disorders [17] , [18].

For an optimal evaluation of the hippocampi in patients with dementia, a 3D T1W sequence with coronal reconstructions perpendicular to the plane of the hippocampi is recommended. This syndrome consists of a facial port-wine nevus in the trigeminal nerve distribution, leptomeningeal angiomatosis, epilepsy, mental retardation, and other neurologic deficits.

Intracranial tuberculomas are characterized by a spectral pattern that primarily involves long chain lipids, with a 0.

MTS is characterized pathologically by hippocampal gliosis and neuronal loss. Patients developing acute central nervous infection before four years of age have a higher propensity to develop hippocampal sclerosis [4]. Tuberous sclerosis is an inherited systemic disease with prominent cutaneous and CNS manifestations with the classic triad of adenoma sebaceum, epilepsy, and mental handicap. Other secondary signs can be present such as: 1 loss of the internal architecture of the hippocampus; 2 loss of hippocampal head digitations; and 3 dilatation of the ipsilateral temporal horn. At the level of the hippocampal tail, the fimbriae continue posteriorly as the crux of the fornix 11 that slants upwards towards the splenium of the corpus callosum 9 and the hippocampal tail continues as the subsplenial gyri Beyond age 50, stroke is the most frequent cause of seizures [30]. Coronal FLAIR b and axial T2-weighted c images show a space-occupying cystic lesion, iso-intense to cerebrospinal fluid, at the level of the right choroid fissure Function The hippocampus plays an important role in spatial and episodic memory. Arterial supply of the hippocampus Usually, three arteries or groups of arteries arising from the main or branches of the posterior cerebral artery vascularize the hippocampus: the anterior, middle and posterior hippocampal arteries. On follow-up MRI performed 3 years later, there is clear bilateral hippocampal sclerosis with atrophy and increased T2 signal intensity of both hippocampi b.

MR Spectroscopy has been found to be specific for intra-cranial tuberculomas when combined with imaging. On MR, polymicrogyria is seen as thickened cortex with poorly developed sulci and irregular margin of the cortical white matter junction [Figure - 12].

In certain developing regions of the world, neurocysticercosis has been reported to be the most common cause of new onset partial seizures.

Gliosis usually appears as a region of increased signal change on T2W images, often associated with volume loss [Figure - 24]. Very rarely can choroid fissure cysts become symptomatic due to mass effect on the surrounding structures [ 9 ]. The aetiology of choroid fissure cysts is less clear. If acquisition time is limited, at least coronal IRT1W 1. In the axial and sagittal plane, it can be divided into three parts: 1 the head or anterior segment; 2 the body or intermediate segment; and 3 the tail or posterior segment. Symptoms are often limited to seizures and correlates of intra-cranial pressure. MRI may determine patient selection for surgery and directly affects the presurgical evaluation and operative strategy. Over the past decades, the role of imaging in dementia has shifted from merely excluding possible treatable causes of dementia e. Its usefulness for the distinction of AD from other dementia syndromes is limited however, as MTA not only occurs in AD, but can be seen in other dementia syndromes as well Fig. Polymicrogyria: - This refers to an abnormal appearance of the cortex with multiple abnormally small convolutions and too few sulci. They are isointense with grey matter on all imaging - Subcortical heterotopia may occur at any location from the periventricular - white matter to the grey-white matter junction. It maybe unilateral or bilateral, symptomatic or asymptomatic and associated with other anomalies or isolated.

Tuberous sclerosis is an inherited systemic disease with prominent cutaneous and CNS manifestations with the classic triad of adenoma sebaceum, epilepsy, and mental handicap. The cornu ammonis continues inferomedially in the parahippocampal gyrus, a gray matter structure that forms the transition area between the basal and mesial areas of the temporal lobe.

These clefts are lined by grey matter.

Mri in seizure disorder a pictorial essay

The hippocampus consists of two interlocking gray matter folds, the cornu ammonis or hippocampus proper and the dentate gyrus. The left side the hippocampal volume looks normal, but T2 signal intensity is slightly increased in the CA1 and CA2 sectors and there is blurring of the internal structure a.

High flow vascular lesions appear as curvilinear signal voids [Figure - 18]. The hippocampal head is the only portion of the hippocampus not covered by the choroid plexus 7.

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MRI in seizure disorder