Biomedical subjects

Zelko Matkovic

Publications and source records attributed to Zelko Matkovic.

4 recordsLinked to original sources

PubMed2005

Tiagabine-induced generalised non convulsive status epilepticus in patients with lesional focal epilepsy.

PURPOSE: To report 3 cases with focal lesional epilepsy that had non-convulsive status epilepticus (NCSE) induced by treatment with tiagabine (TGB) and review the previously published cases. Drugs that enhance GABAnergic transmission are recognised to promote absence seizures in patients with generalised epilepsy syndromes and may on occasions even induce NCSE. However, that TGB can also induce NCSE in focal lesional epilepsy is not widely recognised in clinical practice. METHOD: The clinical history, EEG and MRI findings were reviewed in 3 patients with lesional focal epilepsy who presented to our epilepsy programs over a 12 month period with TGB-induced NCSE. All previously reported cases in the English medical literature were reviewed. RESULTS: The three patients had longstanding complex partial and secondarily generalised seizures refractory to multiple different anti-epileptic drugs. In two cases, MRI demonstrated a focal malformation of cortical development in the left parieto-occipital region and in the third left mesial temporal sclerosis. Following commencement of TGB in one patient and dose escalation in two, prolonged episodes of confusion and poor responsiveness were noted. Prolonged EEG monitoring demonstrated continuous high amplitude, generalised, 2-4 Hz delta activity with intermingled spikes during the episodes of unresponsiveness, consistent with NCSE. The clinical and EEG activity normalised following the administration of IV clonazepam followed by dose reduction or withdrawal of the TGB. Eleven previously reported cases of patients with partial epilepsy and a focal underlying lesion on MRI were identified, all of whom had similar features to that seen in our cases. CONCLUSIONS: These cases illustrate that TGB may induce generalised NCSE in patients with focal lesional epilepsy, in addition to those with generalised syndromes. We hypothesise that patients may have developed an acquired alteration in the sensitivity of their thalamocortical circuitry that renders them more sensitive to the effects of drugs that enhance GABAnergic activity.

Adolescent↗

PubMed2004

"Convulsive" nonepileptic seizures have a characteristic pattern of rhythmic artifact distinguishing them from convulsive epileptic seizures.

PURPOSE: Approximately 30% of patients admitted for video-EEG monitoring have psychogenic nonepileptic seizures (PNES). Differentiation of "convulsive" PNES from convulsive seizures can be difficult. The EEG often displays rhythmic movement artifact that may resemble seizure activity and confound the interpretation. We sought to determine whether time-frequency mapping of the rhythmic EEG artifact during "convulsive" PNES reveals a pattern that differs from that of epileptic seizures. METHODS: EEGs from 15 consecutive patients with "convulsive" PNESs were studied with time-frequency mapping by using NEUROSCAN and compared with 15 patients with convulsive epileptic seizures. Fast Fourier transforms (FFTs) were performed to determine the dominant frequency for 1- to 2-s windows every 2 s through the seizures. RESULTS: The dominant frequency remained stable within a narrow range for the duration of the PNES, whereas in the epileptic seizures, it evolved through a wide range. The coefficient of variation of the frequency during the seizures was considerably less for patients without epilepsy (median, 15.0%; range, 7.2-23.7% vs. median, 58.0%; range, 34.8-92.1%; p < 0.001). The median frequency did not differ significantly between groups (4.2 vs. 4.6 Hz; p = 0.290). CONCLUSIONS: "Convulsive" PNES display a characteristic pattern on time-frequency mapping of the EEG artifact, with a stable, nonevolving frequency that is different from the evolving pattern seen during an epileptic seizure.

Adult↗

PubMed2004

Epilepsy surgery for pathologically proven hippocampal sclerosis provides long-term seizure control and improved quality of life.

PURPOSE: To examine long-term seizure and quality-of-life outcome in a homogeneous group of patients after temporal lobectomy with pathologically proven hippocampal sclerosis (HS). Previous research has had limited follow-up (generally <2 years) and has grouped patients across multiple pathologies. METHODS: Fifty consecutive patients were identified as having had a temporal lobectomy for the treatment of temporal lobe epilepsy at Royal Melbourne Hospital with pathologically proven HS and >or=2 years' follow-up. All patients were sent a postal survey concerning seizure activity, quality of life (QOLIE-89), and antiepileptic drug (AED) use. The mean follow-up was 5.8 years (range, 2-9.2). RESULTS: The rate of complete postoperative seizure freedom was 82% at 12 months, 76% at 24 months, and 64% at 63 months (no further seizure recurrences observed after this time). A class I seizure outcome was achieved by 83.3% of patients. Patients with better seizure outcome had significantly better quality of life (Kendall's tau =-234, p < 0.01). Seizure recurrence was associated with a reduction in AED intake or absorption in five (29%) of 17 cases, including three of the five patients with a first seizure recurrence after 24 months after surgery. CONCLUSIONS: Temporal lobectomy provides continued long-term seizure control in the majority of patients with HS. However, patients remain at risk of seizure recurrence >or=2 years after surgery. Long-term quality of life is dependent on seizure outcome.

Adolescent↗

PubMed2003

Preoperative evaluation for temporal lobe surgery.

Temporal lobe epilepsy (TLE), the most common form of partial epilepsy in adults is often refractory to medical treatment and in these patients epilepsy surgery is considered. Successful surgery is dependent on accurate localisation and lateralisation of the epileptogenic zone. The preoperative evaluation involves a series of assessments and investigations including detailed clinical history, interictal EEG, video-EEG monitoring, MRI, PET, SPECT, and neuropsychology and neuropsychiatric assessment. The role of each of these investigations and assessments in the preoperative evaluation is discussed. Advanced MR techniques including magnetic resonance spectroscopy, MR diffusion and MR perfusion have recently been assessed and are likely to enhance the pre-surgical evaluation of patients with TLE.The surgical outcome and preoperative investigations performed of 80 consecutive patients who underwent temporal lobe surgery between 1993 and 2002 at Royal Melbourne Hospital were reviewed. All patients had MRI, video-EEG monitoring and neuropsychology assessment and 56% a PET scan. During a mean follow-up of 5.9 years 75% had Class 1 outcome, 22% non-Class 1 outcome and 3% were lost to follow-up. The results of preoperative investigations were correlated with outcome. For interictal EEG, seizure semiology, ictal EEG, PET and neuropsychology assessment the surgical outcome of patients in whom results were concordant to side of surgery was compared with those discordant or non-lateralising. There was no significant difference. In 78 of 80 patients MRI revealed mesial temporal sclerosis or a foreign tissue lesion. The outcome was no different between these two groups. Results suggest that in patients with unilateral temporal lobe lesion on MRI and where ictal EEG is either concordant or non-lateralising, other investigations including PET, provide little additional prognostic information.

Electroencephalography↗