Electroencephalography findings in patients with acute post coronary artery bypass graft encephalopathy.

OBJECTIVE: To determine the EEG findings associated with acute post coronary artery bypass graft encephalopathy (aPCE), and to study the demographics and neuroimaging findings. METHODS: We reviewed the EEG in all patients with the diagnosis of PCE between February 2006 and December 2011. RESULTS: We identified 21 (20 males, and one female) patients with aPCE. The mean age (+/-SD) was 64 (+/-11.2) years. Thirteen patients had altered level of consciousness, and 8 presented with confusion out of which 3 had acute seizures. The EEG patterns observed were: a) generalized theta plus intermixed diffuse delta in 7 (33%); b) generalized theta with focal epileptiform discharges in 5 (24%); c) generalized triphasic pattern in 3 (14%); d) generalized theta with lateralized delta in 3 (14%); e) generalized theta with periodic lateralized epileptiform discharges (PLEDs), and bilateral synchronous periodic epileptiform discharges (BIPLEDs) in 2 (10%); and f) one patient (5%) with electrographic seizures. On EEG/neuroimaging correlation, the EEGs that showed generalized slowing and generalized triphasic patterns had no acute changes on imaging, while the EEGs that showed lateralized slowing, focal epileptiform discharges, electrographic seizures and PLEDs had fresh infarcts. Patients with BIPLEDs had unremarkable imaging. CONCLUSION: The EEG features such as lateralized slowing, PLEDs, and electrographic seizure were associated with acute cerebral insults. An altered level of consciousness was the most common symptomatology in our cohort, and could possibly be related to hypoxic/toxic-metabolic etiology. Electrographic seizure detected by EEG may clinically present as aPCE.

Tolerability of propofol in Wada testing.

OBJECTIVE: To assess the tolerability of propofol (PF) in Wada test in an Arab population with temporal lobe epilepsy (TLE). METHODS: This observational study with consecutive sampling took place in King Fahad Medical City, Riyadh, Saudi Arabia. Nine consecutive patients with mean (± SD) age of 26 (± 5.8) years, 6 males and 3 females, underwent Wada test between January 2009 and December 2012. Six of them had left TLE, and 3 had right TLE. Each patient received 10 mg of PF in the internal carotid artery (ICA). Right hemispheric injection was followed by left hemisphere injection after 30 minutes. During the procedure, EEG monitoring showed changes within 5-18 seconds of injection as hemispheric delta slowing. Neuropsychological tests were carried out for localization of memory and language. RESULTS: We were able to lateralize speech dominance in 8 patients and memory dominance in 6 patients. Peri-procedural complications included transient euphoria (n=1), transient spasm of ICA (n=1), eye pain (n=1), facial pain (n=1), and generalized tremulousness (n=2). None of the patients exhibited a symptomatic drop in blood pressure. CONCLUSION: We found that PF is well tolerable for the Wada test, with minimally significant complications, although blood pressure should be closely monitored.

Unilateral brain oedema related to focal status epilepticus.

We present a female patient in her late 30s, with baseline vegetative state following prior traumatic brain injury, who presented with prolonged right hemispheric status epilepticus. The neuroimaging revealed a striking right-sided pancortical oedema with left (crossed) cerebellar diaschisis and dilation of right hemispheric arteries. EEG was concordant and showed nearly continuous right hemispheric seizure discharges with suppressed background. Infective and vascular aetiologies were ruled out. The patient showed clinical and electrographic improvement following treatment with antiepileptic drugs. Unilateral cerebral oedema is a rare presentation of focal status epilepticus, and should be considered as a differential diagnosis in the appropriate clinical scenario.

Brake fluid toxicity feigning brain death.

Brake fluid (glycol-based) toxicity is known to have a protean of central and peripheral nervous system manifestations. The principal component of this household poison is ethylene glycol. Toxic effect is generally attributed to peri-vascular deposition of calcium oxalate crystals in various tissues. However, clinical features resembling brain death have rarely been reported. We report a case of brake fluid toxicity simulating brain death in a 21-year-old healthy man who ingested it as a recreational agent.

Long term outcomes in patients with preoperative generalized interictal epileptiform abnormalities following amygdalohippocampectomy.

We evaluated long term surgical outcomes in 21 patients with temporal lobe epilepsy and presurgical generalized interictal epileptiform discharges (IEDs). Following amygdalohippocampectomy, 12 patients (57.1%) were noted to have favorable outcomes (Engel classification of I-II). Favorable outcomes were significantly associated with a history of auras prior to seizure onset (p=0.021), the absence of generalized IEDs on postoperative EEG (p=0.024), and the presence of focal slowing on postoperative EEG (p=0.045).

Definition of intractable epilepsy.

Defining intractable epilepsy is essential not only to identify up to 40% of patients refractory to pharmacological management, but also to facilitate selection and comparison of such patients for research purposes. The ideal definition still eludes us. Multiple factors including number of antiepileptic drug (AED) failures, seizure frequency and duration of unresponsiveness, etiology, and epilepsy syndromes are considered in formulating the definition of pharmaco-resistant epilepsy. Most definitions used in the literature agree on the number of AED failures, which seem to be 2 or 3, however, the seizure frequency and time factor are varied. The International League Against Epilepsy proposed a definition of drug-resistant epilepsy as a failure of adequate trials of 2 tolerated and appropriately chosen and used AED schedules. This for now, could provide an operational definition for clinical and research settings. However, with emergence of new data and novel treatments the criteria for intractability may change.

EEG changes with carotid sinus baroreflex during carotid endarterectomy.

We describe EEG changes in three patients in whom the carotid sinus baroreflex was precipitated during carotid endarterectomy. In all instances, the EEG showed diffuse attenuation and slowing of the baseline anesthetic pattern in association with bradyvcardia. This can help alert the surgeon to the changes occurring as a result of the cardioinhibitory carotid sinus baroreflex and guide appropriate timely intervention.