Late-onset temporal lobe epilepsy in a patient with juvenile myoclonic epilepsy

We report a patient with longstanding, severe juvenile myoclonic epilepsy who subsequently developed features of temporal lobe epilepsy, which gradually became clinically dominant. Over the years, there was an electrographic evolution from the typical generalised epileptiform patterns, characteristic of juvenile myoclonic epilepsy, to the novel appearance of interictal temporal spikes immediately preceding bisynchronous discharges, and subsequently to temporal intermittent rhythmic delta activity and temporal lobe-onset seizures. In this rare case of coexistent primary generalised epilepsy and focal epilepsy, the epileptic networks of the two forms of epilepsy appear to overlap.     

Dopa-responsive parkinsonism secondary to right temporal lobe haemorrahage.

A 46-year-old man developed a symmetrical parkinsonian syndrome 7 weeks after large right temporal intracerebral haemorrhage resulting from a ruptured arteriovenous malformation. His signs included bradykinesia, rigidity, start hesitation, and poor postural reflexes, without a resting tremor. He also had signs of a Parinaud's syndrome. Computed tomography and magnetic resonance imaging of the brain demonstrated changes in the right temporal lobe associated with the haemorrhage but no abnormality of the basal ganglia or midbrain. Levodopa therapy produced a dramatic improvement within a few days of commencement. We postulate that the parkinsonism resulted from midbrain compression secondary to transtentorial herniation. Although parkinsonism is a rare complication of lobar intracerebral haemorrhage, it is important to recognise as it may be potentially treatable.     

Interstitial radiosurgery in the treatment of gelastic epilepsy due to hypothalamic hamartomas

The authors evaluated a new stereotactic radiosurgical approach in seven patients with gelastic epilepsy due to hypothalamic hamartomas. Stereotactic implantation of 125I-seeds into the hamartoma was feasible in six patients. At follow-up at least 1 year after interstitial radiotherapy, two patients had become seizure-free within 2 months, and two others had only persisting auras. There were no major perioperative or postoperative side effects.     

Late-onset temporal lobe epilepsy with unilateral mesial temporal sclerosis and cognitive decline: A diagnostic dilemma

We present a patient with new onset temporal lobe epilepsy and cognitive decline in his sixth decade with unilateral hippocampal atrophy on structural brain imaging, compatible with mesial temporal sclerosis. This unusual clinical scenario presented a challenging differential diagnosis since it may overlap with primary cognitive disorders, including early-onset Alzheimer's disease and some forms of frontotemporal dementia, and the recently elucidated syndrome of non-paraneoplastic limbic encephalitis associated with voltage-gated potassium channel antibodies.     

Temporal lobe epilepsy caused by choroid plexus papilloma in the temporal horn

Choroid plexus papilloma (CPP) arising in the temporal horn is rare in adult population, and to the best of our knowledge, there has been no report of such a case with temporal lobe epilepsy (TLE). The authors describe a unique case of a 27-year-old woman who was diagnosed as TLE and was found to have a CPP in the temporal horn. Choroid plexus papilloma of the temporal horn, even though rare, can be found in adult population and be causally related to temporal lobe epilepsy.     

Intrinsic epileptogenesis of hypothalamic hamartomas in gelastic epilepsy

Hypothalamic hamartomas and gelastic seizures are often associated with cognitive deterioration, behavioral problems, and poor response to anticonvulsant treatment or cortical resections. The origin and pathophysiology of the epileptic attacks are obscure. We investigated 3 patients with this syndrome and frequent gelastic seizures. Ictal single-photon emission computed tomography performed during typical gelastic seizures demonstrated hyperperfusion in the hamartomas, hypothalamic region, and thalamus without cortical or cerebellar hyperperfusion. Electroencephalographic recordings with depth electrodes implanted in the hamartoma demonstrated focal seizure origin from the hamartoma in 1 patient. Electrical stimulation studies reproduced the typical gelastic events. Stereotactic radiofrequency lesioning of the hamartoma resulted in seizure resulted in seizure remission without complications 20 months after surgery. The functional imaging findings, electrophysiological data, and results of radiofrequency surgery indicate that epileptic seizures in this syndrome originate and propagate from the hypothalamic hamartoma and adjacent structures.     

Transcallosal resection of hypothalamic hamartoma for gelastic epilepsy

Introduction Hypothalamic hamartomas (HHs) are commonly associated with severe epilepsy resistant to anticonvulsant therapy. Historically, surgical resection of HHs resulted in considerable morbidity. Discussion Two series of patients who successfully underwent resection using a transcallosal approach have now been published; we report the first UK experience of this technique in a series of five patients with HHs and gelastic epilepsy resistant to anticonvulsant therapy. Patients were assessed pre- and postoperatively for seizure activity, endocrine function, ophthalmology, and neurocognitive function. Two patients had precocious puberty and all had evidence of developmental delay and behavioral problems. Postoperatively, all children experienced at least a 50% reduction in seizure frequency with abolition of major seizure types; one child remains seizure-free. One child developed a mild postoperative right hemiparesis and one developed transient diabetes insipidus. Conclusion There were no adverse developmental effects of surgery. Transcallosal resection of HHs ameliorates resistant epilepsy syndromes associated with HH.     

Tumors in the temporal horn of the lateral ventricle as a cause of epilepsy

Three neoplastic lesions located in the temporal horn of the lateral ventricle were diagnosed after the onset of seizures. Neither hydrocephalus nor temporal horn entrapment were present. The complete surgical removal of the tumor resulted in the disappearance of the epileptic episodes in 2 cases; the third patient refused surgery, and his lesion appears unmodified after a 3-year follow-up. Histological examination led to a diagnosis of choroid plexus papilloma in 1 case and of neurocytoma in the other; in the third case, the nonextracted lesion was presumed to be a partially calcified choroid plexus papilloma. The mechanism underlying the seizures in the 2 operated children is speculated to be a compression exerted upon the mesial temporal structures that form the medial wall of the temporal horn of the lateral ventricles; this compressive activity was resolved by removal of the tumor, and the epileptic episodes consequently disappeared in the 2 operated children; seizures were controlled by drugs in the third child.     

Bilateral isolated hippocampal malformation in temporal lobe epilepsy

Hippocampal malformations in patients with epilepsy usually are reported in the context of widespread cortical malformations. Isolated hippocampal malformations are more rarely identified in MRI studies with little documentation of their pathologic appearance. Postmortem examination revealed abnormal position and complex convolutional malformations isolated to the hippocampal formation in an adult with temporal lobe epilepsy in whom MRI demonstrated bilateral hippocampal abnormalities.     

Treatment options for gelastic epilepsy due to hypothalamic hamartoma: interstitial radiosurgery

Surgical treatment of hypothalamic hamartomas (HHs) as the underlying etiology of gelastic epilepsy is associated with a high risk of complications because of the close vicinity of adjacent structures such as the optic tracts and mammillary bodies. Treatment with interstitial radiosurgery uses stereotactically implanted (125)I seeds emitting gamma radiation from the center of the lesion, with a steep spatial gradient, over a period of about 3 weeks. This form of HH therapy offers particular advantages regarding the risk for major side effects. In a series of 15 children and adolescents treated in Freiburg, Germany, 53% of patients achieved significant improvement in seizure frequency (Engel class I or II outcome). Transient side effects were related to the development of local edema, resulting in headache and mental slowing. A persistent weight gain was noted in 3 patients, which was severe in 1 (20 kg). There were no other neurologic, neuropsychologic, or neuropsychiatric side effects, which compares favorably with most surgical series.     

Adaptive visual memory reorganization in right medial temporal lobe epilepsy

Purpose: We investigated functional reorganization mechanisms of the human medial temporal lobe (MTL) for episodic memory, in patients suffering from medial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS).
Methods: We used functional magnetic resonance imaging (fMRI) to measure brain activity changes during matched episodic encoding tasks of abstract words (Verbal) and line drawings (Visual), in patients with unilateral right MTLE undergoing presurgical evaluation and healthy controls.
Results: As expected, a significant interaction between material type and the side of MTL activity was present in the control group, with preferential involvement of the left hippocampus in verbal encoding and the right parahippocampal region in visual encoding. When compared with controls, right MTLE patients with intact performance activated a region in the left hippocampus more during visual encoding, which resulted in an interaction between group and hemisphere. Importantly, an effect of memory performance on visual encoding activity was observed in the patients, with greater engagement of the left MTL being associated with higher recognition scores. Interestingly, activity in the left MTL also depended on the epileptic seizure frequency, suggesting a role for this clinical parameter in the recruitment of contralateral regions.
Discussion: Taken together, these results indicate functional reorganization of the MTLs in right HS, through transfer of function from the right to the left hemisphere, and strongly suggest an adaptive role for such reorganization mechanism in supporting preserved visual memory.     

Speech recognition impairments in patients with intractable right temporal lobe epilepsy

PURPOSE: To evaluate speech recognition in patients with focal intractable epilepsy and surgical resections in the nondominant (right) hemisphere. METHODS: Speech recognition was tested prospectively, under different listening conditions, in 22 patients with right temporal lobe (11 patients) or extra-temporal lobe epilepsy. All were left-hemisphere dominant for language on preoperative intracarotid sodium amobarbital testing. RESULTS: All patients demonstrated normal auditory recognition of words and environmental sounds before and after surgery. However, when real-world listening conditions were simulated by using acoustically degraded (filtered) words, patients with temporal lobe epilepsy performed significantly worse than patients with frontal or parietooccipital lobe epilepsy before and after surgery (p<0.0001). CONCLUSIONS: Patients with intractable right temporal lobe epilepsy are at risk for speech recognition impairments in real-world listening environments, independent of surgery. The impact of speech recognition difficulties on verbal communication, coupled with the prevalence of adverse listening environments, underscores the importance of testing speech recognition under different listening conditions in patients with intractable right temporal lobe epilepsy.     

Prognostic implication of contralateral secondary electrographic seizures in temporal lobe epilepsy

PURPOSE: Interhemispheric propagation of seizures in temporal lobe epilepsy is frequently noted during intracranial EEG monitoring. We hypothesized that a distinct secondary electrographic seizure (DSES) in the temporal lobe contralateral to primary seizure onset may be an unfavorable prognostic indicator. METHODS: We reviewed intracranial depth electrode EEG recordings, 1-year outcome, and medical records of 51 patients (M 29, F 22: age 15-64 years) who underwent anterior temporal lobectomy during 1988-96. We defined DSES as a seizure that spread to the contralateral temporal lobe and produced distinct contralateral EEG features. The distinct feature was focal involvement of one or two electrode contacts at onset, which starts and evolves independently from the ipsilateral temporal lobe. We considered DSES as the predominant seizure pattern when it occurred in more than one half of the patients' recorded seizures. RESULTS: Only nine of 19 (47%) patients with predominant DSES had a 1-year seizure-free outcome, whereas 27 of 32 (84%) patients without predominant DSES had a 1-year seizure-free outcome (p < 0.01). Bitemporal independent seizures were more common in patients with predominant DSES (9/19 versus 0/32; p < 0.001). CONCLUSION: Our results suggest that distinct contralateral secondary electrographic seizure is a predictor of unfavorable outcome and is also more likely to be associated with bitemporal seizures.